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Sample records for gemini planet imager

  1. The Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Macintosh, Bruce; Graham, J. R.; Palmer, D.; Doyon, R.; Larkin, J.; Oppenheimer, B.; Saddlemyer, L.; Veran, J.; Wallace, J. K.; Gemini Planet Imager Team

    2007-12-01

    Direct detection of extrasolar planets would be a major step in the study of other solar systems, sensitive to planets beyond the period cutoff of Doppler surveys. Furthermore, such planets can be spectrally characterized to measure temperature, gravity, and perhaps composition, shedding light on planet formation and evolution. Surveys of 50-100 young stars with current generation AO systems have excluded the presence of massive (2-10 MJ), young (? Myr) planets in wide (? AU) orbits, but to probe 5-20 AU scales around a large sample of target stars will require dedicated next-generation instruments. One such facility will be the Gemini Planet Imager (GPI). It combines a 2000-actuator adaptive optics system, an apodized-pupil Lyot coronagraph, a precision infrared interferometer for real-time wavefront calibration at the nanometer level, and a near-infrared integral field spectrograph for detection and characterization of the target planets. GPI will be able to achieve Strehl ratios > 0.9 at 1.65 microns and to observe a broad sample of science targets with I band magnitudes less than 9. In addition to planet detection, GPI will also be capable of polarimetric imaging of circumstellar dust disks, studies of evolved stars, and high-Strehl imaging spectroscopy of bright targets - opening up a new field in the characterization of the environments of nearby stars. I will present an overview of the instrument design and its scientific capabilities. GPI is currently in the design phase, scheduled for deployment as a facility instrument on the Gemini South telescope in early 2011. Portions of this work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership.

  2. The Gemini Planet Imager

    SciTech Connect

    Macintosh, B; al., e

    2006-05-02

    The next major frontier in the study of extrasolar planets is direct imaging detection of the planets themselves. With high-order adaptive optics, careful system design, and advanced coronagraphy, it is possible for an AO system on a 8-m class telescope to achieve contrast levels of 10{sup -7} to 10{sup -8}, sufficient to detect warm self-luminous Jovian planets in the solar neighborhood. Such direct detection is sensitive to planets inaccessible to current radial-velocity surveys and allows spectral characterization of the planets, shedding light on planet formation and the structure of other solar systems. We have begun the construction of such a system for the Gemini Observatory. Dubbed the Gemini Planet Imager (GPI), this instrument should be deployed in 2010 on the Gemini South telescope. It combines a 2000-actuator MEMS-based AO system, an apodized-pupil Lyot coronagraph, a precision infrared interferometer for real-time wavefront calibration at the nanometer level, and a infrared integral field spectrograph for detection and characterization of the target planets. GPI will be able to achieve Strehl ratios > 0.9 at 1.65 microns and to observe a broad sample of science targets with I band magnitudes less than 8. In addition to planet detection, GPI will also be capable of polarimetric imaging of circumstellar dust disks, studies of evolved stars, and high-Strehl imaging spectroscopy of bright targets. We present here an overview of the GPI instrument design, an error budget highlighting key technological challenges, and models of the system performance.

  3. The Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Graham, James R.; Macintosh, Bruce; Perrin, Marshall D.; Ingraham, Patrick; Konopacky, Quinn M.; Marois, Christian; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam Seth; Cardwell, Andrew; Chilcote, Jeffrey K.; De Rosa, Robert John J.; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P.; Gavel, Donald; Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James E.; Maire, Jerome; Marchis, Franck; Marley, Mark S.; McBride, James; Millar-Blanchaer, Max; Morzinski, Kathleen M.; Nielsen, Eric L.; Norton, Andew; Oppenheimer, Rebecca; Palmer, David; Patience, Jenny; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemeyer, Leslie; Savransky, Dmitry; Serio, Andrew W.; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J. Kent; Wang, Jason; Wiktorowicz, Sloane; Wolff, Schulyer; Gpi/Gpies Team

    2015-01-01

    The Gemini Planet Imager (GPI) is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of GPI has been tuned for maximum sensitivity to faint planets near bright stars. GPI has undergone a year of commissioning, verification, and calibration work. We have achieved an estimated H-band contrast (5-sigma) of 106 at 0.75 arcseconds and 105 at 0.35 arcseconds in spectral mode, and suppression of unpolarized starlight by a factor of 800 in imaging polarimetry mode. Early science observations include study of the spectra of ? Pic b and HR 8799, orbital investigations of ? Pic b and PZ Tel, and observations of the debris disk systems associated with ? Pic, AU Mic, and HR 4796A. An 890-hour exoplanet survey with GPI is scheduled to begin in late 2014. A status report for the campaign will be presented.

  4. First light of the Gemini Planet imager.

    PubMed

    Macintosh, Bruce; Graham, James R; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B R; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2014-09-01

    The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-? contrast of 10(6) at 0.75 arcseconds and 10(5) at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of [Formula: see text] near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017. PMID:24821792

  5. First light of the Gemini Planet Imager

    PubMed Central

    Macintosh, Bruce; Graham, James R.; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam S.; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J.; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael P.; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark S.; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, B. R.; Palmer, David; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J. Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2014-01-01

    The Gemini Planet Imager is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of the Gemini Planet Imager has been tuned for maximum sensitivity to faint planets near bright stars. During first-light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-? contrast of 106 at 0.75 arcseconds and 105 at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-s exposure with minimal postprocessing. Beta Pictoris b is observed at a separation of 434 ± 6 milliarcseconds (mas) and position angle 211.8 ± 0.5°. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of 3 improvement in most parameters over previous solutions. The planet orbits at a semimajor axis of 9.0?0.4+0.8?AU near the 3:2 resonance with the previously known 6-AU asteroidal belt and is aligned with the inner warped disk. The observations give a 4% probability of a transit of the planet in late 2017. PMID:24821792

  6. Experimental Design for the Gemini Planet Imager

    E-print Network

    McBride, James; Macintosh, Bruce; Beckwith, Steven V W; Marois, Christian; Poyneer, Lisa A; Wiktorowicz, Sloane J

    2011-01-01

    The Gemini Planet Imager (GPI) is a high performance adaptive optics system being designed and built for the Gemini Observatory. GPI is optimized for high contrast imaging, combining precise and accurate wavefront control, diffraction suppression, and a speckle-suppressing science camera with integral field and polarimetry capabilities. The primary science goal for GPI is the direct detection and characterization of young, Jovian-mass exoplanets. For plausible assumptions about the distribution of gas giant properties at large semi-major axes, GPI will be capable of detecting more than 10% of gas giants more massive than 0.5 M_J around stars younger than 100 Myr and nearer than 75 parsecs. For systems younger than 1 Gyr, gas giants more massive than 8 M_J and with semi-major axes greater than 15 AU are detected with completeness greater than 50%. A survey targeting young stars in the solar neighborhood will help determine the formation mechanism of gas giant planets by studying them at ages where planet brigh...

  7. Vibration suppression for the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Maly, Joseph R.; Erickson, Darren; Pargett, Timothy J.

    2010-07-01

    The Gemini Planet Imager (GPi) is an instrument that will mount to either of two nominally identical Telescopes, Gemini North in Hawaii and Gemini South in Chile, to perform direct imaging and spectroscopy of extra-solar planets. This 2,000-kg instrument has stringent mass, center-of-gravity, flexure, and power constraints. The Flexure Sensitive Structure (FSS) supports the main opto-mechanical sub-systems of the GPi which work in series to process and analyse the telescope optical beam. The opto-mechanical sub-systems within the FSS are sensitive to mechanical vibrations, and passive damping strategies were considered to mitigate image jitter. Based on analysis with the system finite element model (FEM) of the GPi, an array of 1-kg tuned mass dampers (TMDs) was identified as an efficient approach to damp the first two FSS flexural modes which are the main sources of jitter. It is estimated that 5% of critical damping can be added to each of these modes with the addition of 23 kg of TMD mass. This estimate is based on installing TMD units on the FSS structural members. TMD mass can be reduced by nearly 50% if the units can be installed on the opto-mechanical sub-systems within the FSS with the highest modal displacements. This paper describes the structural design and vibration response of the FSS, modal test results, and plans for implementation of the TMDs. Modal measurements of the FSS structure were made to validate the FEM and to assess the viability of TMDs for reducing jitter. The test configuration differed from the operational one because some payloads were not present and the structure was mounted to a flexible base. However, this test was valuable for understanding the primary modes that will be addressed with the TMDs and measuring the effective mass of these modes.

  8. The Gemini Planet Imager: First Light

    E-print Network

    Macintosh, Bruce; Ingraham, Patrick; Konopacky, Quinn; Marois, Christian; Perrin, Marshall; Poyneer, Lisa; Bauman, Brian; Barman, Travis; Burrows, Adam; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J; Dillon, Daren; Doyon, Rene; Dunn, Jennifer; Erikson, Darren; Fitzgerald, Michael; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Kalas, Paul G; Larkin, James; Maire, Jerome; Marchis, Franck; Marley, Mark; McBride, James; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andew; Oppenheimer, B R; Palmer, Dave; Patience, Jennifer; Pueyo, Laurent; Rantakyro, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Soummer, Remi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2014-01-01

    The Gemini Planet Imager (GPI) is a dedicated facility for directly imaging and spectroscopically characterizing extrasolar planets. It combines a very high-order adaptive optics system, a diffraction-suppressing coronagraph, and an integral field spectrograph with low spectral resolution but high spatial resolution. Every aspect of GPI has been tuned for maximum sensitivity to faint planets near bright stars. During first light observations, we achieved an estimated H band Strehl ratio of 0.89 and a 5-sigma contrast of $10^6$ at 0.75 arcseconds and $10^5$ at 0.35 arcseconds. Observations of Beta Pictoris clearly detect the planet, Beta Pictoris b, in a single 60-second exposure with minimal post-processing. Beta Pictoris b is observed at a separation of $434 \\pm 6$ milli-arcseconds and position angle $211.8 \\pm 0.5$ deg. Fitting the Keplerian orbit of Beta Pic b using the new position together with previous astrometry gives a factor of three improvement in most parameters over previous solutions. The planet ...

  9. Gemini Planet Imager coronagraph testbed results

    NASA Astrophysics Data System (ADS)

    Sivaramakrishnan, Anand; Soummer, Rémi; Oppenheimer, Ben R.; Carr, G. Lawrence; Mey, Jacob L.; Brenner, Doug; Mandeville, Charles W.; Zimmerman, Neil; Macintosh, Bruce A.; Graham, James R.; Saddlemyer, Les; Bauman, Brian; Carlotti, Alexis; Pueyo, Laurent; Tuthill, Peter G.; Dorrer, Christophe; Roberts, Robin; Greenbaum, Alexandra

    2010-07-01

    The Gemini Planet Imager (GPI) is an extreme AO coronagraphic integral field unit YJHK spectrograph destined for first light on the 8m Gemini South telescope in 2011. GPI fields a 1500 channel AO system feeding an apodized pupil Lyot coronagraph, and a nIR non-common-path slow wavefront sensor. It targets detection and characterizion of relatively young (<2GYr), self luminous planets up to 10 million times as faint as their primary star. We present the coronagraph subsystem's in-lab performance, and describe the studies required to specify and fabricate the coronagraph. Coronagraphic pupil apodization is implemented with metallic half-tone screens on glass, and the focal plane occulters are deep reactive ion etched holes in optically polished silicon mirrors. Our JH testbed achieves H-band contrast below a million at separations above 5 resolution elements, without using an AO system. We present an overview of the coronagraphic masks and our testbed coronagraphic data. We also demonstrate the performance of an astrometric and photometric grid that enables coronagraphic astrometry relative to the primary star in every exposure, a proven technique that has yielded on-sky precision of the order of a milliarsecond.

  10. Gemini Planet Imager Coronagraph Testbed Results

    SciTech Connect

    Sivaranmakrishnan, A.; Carr, G.; Soummer, R.; Oppenheimer, B.R.; Mey, J.L.; Brenner, D.; Mandeville, C.W.; Zimmerman, N. Macintosh, B.A.; Graham, J.R.; Saddlemyer, L.; Bauman, B.; Carlotti, A.; Pueyo, L.; Tuthill, P.G.; Dorrer, C.; Roberts, R.; Greenbaum, A.

    2010-12-08

    The Gemini Planet Imager (GPI) is an extreme AO coronagraphic integral field unit YJHK spectrograph destined for first light on the 8m Gemini South telescope in 2011. GPI fields a 1500 channel AO system feeding an apodized pupil Lyot coronagraph, and a nIR non-common-path slow wavefront sensor. It targets detection and characterizion of relatively young (<2GYr), self luminous planets up to 10 million times as faint as their primary star. We present the coronagraph subsystem's in-lab performance, and describe the studies required to specify and fabricate the coronagraph. Coronagraphic pupil apodization is implemented with metallic half-tone screens on glass, and the focal plane occulters are deep reactive ion etched holes in optically polished silicon mirrors. Our JH testbed achieves H-band contrast below a million at separations above 5 resolution elements, without using an AO system. We present an overview of the coronagraphic masks and our testbed coronagraphic data. We also demonstrate the performance of an astrometric and photometric grid that enables coronagraphic astrometry relative to the primary star in every exposure, a proven technique that has yielded on-sky precision of the order of a milliarsecond.

  11. Gemini Planet Imager: Preliminary Design Report

    SciTech Connect

    Macintosh, B

    2007-05-10

    For the first time in history, direct and indirect detection techniques have enabled the exploration of the environments of nearby stars on scales comparable to the size of our solar system. Precision Doppler measurements have led to the discovery of the first extrasolar planets, while high-contrast imaging has revealed new classes of objects including dusty circumstellar debris disks and brown dwarfs. The ability to recover spectrophotometry for a handful of transiting exoplanets through secondary-eclipse measurements has allowed us to begin to study exoplanets as individual entities rather than points on a mass/semi-major-axis diagram and led to new models of planetary atmospheres and interiors, even though such measurements are only available at low SNR and for a handful of planets that are automatically those most modified by their parent star. These discoveries have galvanized public interest in science and technology and have led to profound new insights into the formation and evolution of planetary systems, and they have set the stage for the next steps--direct detection and characterization of extrasolar Jovian planets with instruments such as the Gemini Planet Imager (GPI). As discussed in Volume 1, the ability to directly detect Jovian planets opens up new regions of extrasolar planet phase space that in turn will inform our understanding of the processes through which these systems form, while near-IR spectra will advance our understanding of planetary physics. Studies of circumstellar debris disks using GPI's polarimetric mode will trace the presence of otherwise-invisible low-mass planets and measure the build-up and destruction of planetesimals. To accomplish the science mission of GPI will require a dedicated instrument capable of achieving contrast of 10{sup -7} or more. This is vastly better than that delivered by existing astronomical AO systems. Currently achievable contrast, about 10{sup -5} at separations of 1 arc second or larger, is completely limited by quasi-static wave front errors, so that contrast does not improve with integration times longer than about 1 minute. Using the rotation of the Earth to distinguish companions from artifacts or multiwavelength imaging improves this somewhat, but GPI will still need to surpass the performance of existing systems by one to two orders of magnitude--an improvement comparable to the transition from photographic plates to CCDs. This may sound daunting, but other areas of optical science have achieved similar breakthroughs, for example, the transition to nanometer-quality optics for extreme ultraviolet lithography, the development of MEMS wave front control devices, and the ultra-high contrast demonstrated by JPL's High Contrast Imaging Test-bed. In astronomy, the Sloan Digital Sky Survey, long baseline radio interferometry, and multi-object spectrographs have led to improvements of similar or greater order of magnitude. GPI will be the first project to apply these revolutionary techniques to ground-based astronomy, with a systems engineering approach that studies the impact of every design decision on the key metric--final detectable planet contrast.

  12. The Gemini Planet Imager: From Science to Design to Construction

    SciTech Connect

    Macintosh, B; Graham, J R; Palmer, D; Doyon, R; Dunn, J; Gavel, D; Larkin, J; Oppenheimer, B; Saddlemyer, L; Sivaramakrishnan, A; Wallace, J K; Bauman, B; Erickson, D; Marois, C; Poyneer, L; Soummer, R

    2008-07-01

    The Gemini Planet Imager (GPI) is a facility instrument under construction for the 8-m Gemini South telescope. It combines a 1500 subaperture AO system using a MEMS deformable mirror, an apodized-pupil Lyot coronagraph, a high-accuracy IR interferometer calibration system, and a near-infrared integral field spectrograph to allow detection and characterization of self-luminous extrasolar planets at planet/star contrast ratios of 10{sup -7}. I will discuss the evolution from science requirements through modeling to the final detailed design, provide an overview of the subsystems and show models of the instrument's predicted performance.

  13. Gemini planet imager observational calibrations VII: on-sky polarimetric performance of the Gemini planet imager

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane J.; Millar-Blanchaer, Max; Perrin, Marshall D.; Graham, James R.; Fitzgerald, Michael P.; Maire, Jérôme; Ingraham, Patrick; Savransky, Dmitry; Macintosh, Bruce A.; Thomas, Sandrine J.; Chilcote, Jeffrey K.; Draper, Zachary H.; Song, Inseok; Cardwell, Andrew; Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale; Rantakyrö, Fredrik; Sadakuni, Naru

    2014-07-01

    We present on-sky polarimetric observations with the Gemini Planet Imager (GPI) obtained at straight Cassegrain focus on the Gemini South 8-m telescope. Observations of polarimetric calibrator stars, ranging from nearly un- polarized to strongly polarized, enable determination of the combined telescope and instrumental polarization. We find the conversion of Stokes I to linear and circular instrumental polarization in the instrument frame to be I --> (QIP, UIP, PIP, VIP) = (-0.037 +/- 0.010%, +0.4338 +/- 0.0075%, 0.4354 +/- 0.0075%, -6.64 +/- 0.56%). Such precise measurement of instrumental polarization enables ~0.1% absolute accuracy in measurements of linear polarization, which together with GPI's high contrast will allow GPI to explore scattered light from circumstellar disk in unprecedented detail, conduct observations of a range of other astronomical bodies, and potentially even study polarized thermal emission from young exoplanets. Observations of unpolarized standard stars also let us quantify how well GPI's differential polarimetry mode can suppress the stellar PSF halo. We show that GPI polarimetry achieves cancellation of unpolarized starlight by factors of 100-200, reaching the photon noise limit for sensitivity to circumstellar scattered light for all but the smallest separations at which the calibration for instrumental polarization currently sets the limit.

  14. The Integral Field Spectrograph for the Gemini Planet Imager

    E-print Network

    Larkin, James E; Aliado, Theodore; Bauman, Brian J; Brims, George; Canfield, John M; Cardwell, Andrew; Dillon, Daren; Doyon, René; Dunn, Jennifer; Fitzgerald, Michael P; Graham, James R; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Ingraham, Patrick; Johnson, Christopher A; Kress, Evan; Konopacky, Quinn M; Macintosh, Bruce A; Magnone, Kenneth G; Maire, Jérôme; McLean, Ian S; Palmer, David; Perrin, Marshall D; Quiroz, Carlos; Rantakyrö, Fredrik; Sadakuni, Naru; Saddlemyer, Leslie; Serio, Andrew; Thibault, Simon; Thomas, Sandrine J; Vallee, Philippe; Weiss, Jason L

    2014-01-01

    The Gemini Planet Imager (GPI) is a complex optical system designed to directly detect the self-emission of young planets within two arcseconds of their host stars. After suppressing the starlight with an advanced AO system and apodized coronagraph, the dominant residual contamination in the focal plane are speckles from the atmosphere and optical surfaces. Since speckles are diffractive in nature their positions in the field are strongly wavelength dependent, while an actual companion planet will remain at fixed separation. By comparing multiple images at different wavelengths taken simultaneously, we can freeze the speckle pattern and extract the planet light adding an order of magnitude of contrast. To achieve a bandpass of 20%, sufficient to perform speckle suppression, and to observe the entire two arcsecond field of view at diffraction limited sampling, we designed and built an integral field spectrograph with extremely low wavefront error and almost no chromatic aberration. The spectrograph is fully cr...

  15. The Gemini Planet Imager Exoplanet Survey (GPIES) Campaign Initial Results

    NASA Astrophysics Data System (ADS)

    Patience, Jennifer; Macintosh, Bruce; Graham, James R.; Barman, Travis; De Rosa, Robert; Konopacky, Quinn; Marley, Mark; Marois, Christian; Nielsen, Eric Ludwig; Pueyo, Laurent; Rajan, Abhijith; Rameau, Julien; Saumon, Didier; Wang, Jason

    2015-12-01

    The Gemini Planet Imager (GPI) is a next-generation coronagraphic integral field unit with the sensitivity and resolution to detect planetary companions with separations of 0”.2 to 1”.0 around a large set of stars. An 890-hour GPI survey of 600 young, nearby stars commenced in late-2014, and approximately 100 stars have been observed thus far. The central aims of the program are: (1) the discovery of a population of giant planets with orbital radii of 5-50 AU comparable to Solar System gas giant orbits, (2) the characterization of the atmospheric properties of young planetary companions, and (3) the exploration of planet-disk interactions. Initial results from GPI exoplanet observations include the discovery of a new planetary companion to a young F-star; the planet spectrum shows a strong signature of methane absorption, indicating a cooler temperature than previously imaged young planets. An overview of the survey scope, current detection limits, and initial results will be presented.

  16. Resolving the HD 106906 Disk with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Rajan, Abhijith; Kalas, Paul G.; Patience, Jennifer; Wang, Jason; Millar-Blanchaer, Max; Fitzgerald, Michael P.; Chen, Christine H.; Dong, Ruobing; Graham, James R.; Macintosh, Bruce; Murray-Clay, Ruth; Matthews, Brenda; Rameau, Julien; Marois, Christian

    2015-12-01

    We present the first direct detection of the debris disk around the young star HD 106906 using the Integral Field Unit on the Gemini Planet Imager (GPI). In addition to our detection of the inner warm component in the near infrared, we also recovered the cold outer region of the disk in the optical using archival HST/ACS data. The GPI observations show a near edge-on disk with a central cleared region at ~50 AU, and an outer extent >500 AU. The HST data show the outer regions are highly asymmetric, resembling the “needle" morphology seen for the HD 15115 debris disk. The GPI images do not show the strong asymmetry seen in the HST data. The star HD 106906 has an ~11 Mjup planetary mass companion with a projected separation of 650 AU, which poses questions about the formation mechanisms for such a distant companion. We compared the literature photometry measurements of the companion to theoretical models and measure a redder than expected color which might suggest the presence of a disk around the companion as well. The H-band spectroscopy data was used to place constraints on the presence of further Jupiter-mass companions closer in to the star.

  17. GEMINI PLANET IMAGER SPECTROSCOPY OF THE HR 8799 PLANETS c AND d

    SciTech Connect

    Ingraham, Patrick; Macintosh, Bruce; Marley, Mark S.; Saumon, Didier; Marois, Christian; Dunn, Jennifer; Erikson, Darren; Barman, Travis; Bauman, Brian; Burrows, Adam; Chilcote, Jeffrey K.; Fitzgerald, Michael P.; De Rosa, Robert J.; Dillon, Daren; Gavel, Donald; Doyon, René; Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale; Graham, James R.; and others

    2014-10-10

    During the first-light run of the Gemini Planet Imager we obtained K-band spectra of exoplanets HR 8799 c and d. Analysis of the spectra indicates that planet d may be warmer than planet c. Comparisons to recent patchy cloud models and previously obtained observations over multiple wavelengths confirm that thick clouds combined with horizontal variation in the cloud cover generally reproduce the planets' spectral energy distributions. When combined with the 3 to 4 ?m photometric data points, the observations provide strong constraints on the atmospheric methane content for both planets. The data also provide further evidence that future modeling efforts must include cloud opacity, possibly including cloud holes, disequilibrium chemistry, and super-solar metallicity.

  18. Discovery and spectroscopy of the young jovian planet 51 Eri b with the Gemini Planet Imager.

    PubMed

    Macintosh, B; Graham, J R; Barman, T; De Rosa, R J; Konopacky, Q; Marley, M S; Marois, C; Nielsen, E L; Pueyo, L; Rajan, A; Rameau, J; Saumon, D; Wang, J J; Patience, J; Ammons, M; Arriaga, P; Artigau, E; Beckwith, S; Brewster, J; Bruzzone, S; Bulger, J; Burningham, B; Burrows, A S; Chen, C; Chiang, E; Chilcote, J K; Dawson, R I; Dong, R; Doyon, R; Draper, Z H; Duchêne, G; Esposito, T M; Fabrycky, D; Fitzgerald, M P; Follette, K B; Fortney, J J; Gerard, B; Goodsell, S; Greenbaum, A Z; Hibon, P; Hinkley, S; Cotten, T H; Hung, L-W; Ingraham, P; Johnson-Groh, M; Kalas, P; Lafreniere, D; Larkin, J E; Lee, J; Line, M; Long, D; Maire, J; Marchis, F; Matthews, B C; Max, C E; Metchev, S; Millar-Blanchaer, M A; Mittal, T; Morley, C V; Morzinski, K M; Murray-Clay, R; Oppenheimer, R; Palmer, D W; Patel, R; Perrin, M D; Poyneer, L A; Rafikov, R R; Rantakyrö, F T; Rice, E L; Rojo, P; Rudy, A R; Ruffio, J-B; Ruiz, M T; Sadakuni, N; Saddlemyer, L; Salama, M; Savransky, D; Schneider, A C; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vasisht, G; Wallace, J K; Ward-Duong, K; Wiktorowicz, S J; Wolff, S G; Zuckerman, B

    2015-10-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10(-6) and an effective temperature of 600 to 750 kelvin. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold-start" core-accretion process that may have formed Jupiter. PMID:26272904

  19. Discovery and spectroscopy of the young jovian planet 51 Eri b with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Macintosh, B.; Graham, J. R.; Barman, T.; De Rosa, R. J.; Konopacky, Q.; Marley, M. S.; Marois, C.; Nielsen, E. L.; Pueyo, L.; Rajan, A.; Rameau, J.; Saumon, D.; Wang, J. J.; Patience, J.; Ammons, M.; Arriaga, P.; Artigau, E.; Beckwith, S.; Brewster, J.; Bruzzone, S.; Bulger, J.; Burningham, B.; Burrows, A. S.; Chen, C.; Chiang, E.; Chilcote, J. K.; Dawson, R. I.; Dong, R.; Doyon, R.; Draper, Z. H.; Duchêne, G.; Esposito, T. M.; Fabrycky, D.; Fitzgerald, M. P.; Follette, K. B.; Fortney, J. J.; Gerard, B.; Goodsell, S.; Greenbaum, A. Z.; Hibon, P.; Hinkley, S.; Cotten, T. H.; Hung, L.-W.; Ingraham, P.; Johnson-Groh, M.; Kalas, P.; Lafreniere, D.; Larkin, J. E.; Lee, J.; Line, M.; Long, D.; Maire, J.; Marchis, F.; Matthews, B. C.; Max, C. E.; Metchev, S.; Millar-Blanchaer, M. A.; Mittal, T.; Morley, C. V.; Morzinski, K. M.; Murray-Clay, R.; Oppenheimer, R.; Palmer, D. W.; Patel, R.; Perrin, M. D.; Poyneer, L. A.; Rafikov, R. R.; Rantakyrö, F. T.; Rice, E. L.; Rojo, P.; Rudy, A. R.; Ruffio, J.-B.; Ruiz, M. T.; Sadakuni, N.; Saddlemyer, L.; Salama, M.; Savransky, D.; Schneider, A. C.; Sivaramakrishnan, A.; Song, I.; Soummer, R.; Thomas, S.; Vasisht, G.; Wallace, J. K.; Ward-Duong, K.; Wiktorowicz, S. J.; Wolff, S. G.; Zuckerman, B.

    2015-10-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric compositions and luminosities, which are influenced by their formation mechanisms. Using the Gemini Planet Imager, we discovered a planet orbiting the ~20-million-year-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water-vapor absorption. Modeling of the spectra and photometry yields a luminosity (normalized by the luminosity of the Sun) of 1.6 to 4.0 × 10-6 and an effective temperature of 600 to 750 kelvin. For this age and luminosity, “hot-start” formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the “cold-start” core-accretion process that may have formed Jupiter.

  20. Discovery and spectroscopy of the young Jovian planet 51 Eri b with the Gemini Planet Imager

    E-print Network

    Macintosh, B; Barman, T; De Rosa, R J; Konopacky, Q; Marley, M S; Marois, C; Nielsen, E L; Pueyo, L; Rajan, A; Rameau, J; Saumon, D; Wang, J J; Ammons, M; Arriaga, P; Artigau, E; Beckwith, S; Brewster, J; Bruzzone, S; Bulger, J; Burningham, B; Burrows, A S; Chen, C; Chiang, E; Chilcote, J K; Dawson, R I; Dong, R; Doyon, R; Draper, Z H; Duchêne, G; Esposito, T M; Fabrycky, D; Fitzgerald, M P; Follette, K B; Fortney, J J; Gerard, B; Goodsell, S; Greenbaum, A Z; Hibon, P; Hinkley, S; Hufford, T; Hung, L -W; Ingraham, P; Johnson-Groh, M; Kalas, P; Lafreniere, D; Larkin, J E; Lee, J; Line, M; Long, D; Maire, J; Marchis, F; Matthews, B C; Max, C E; Metchev, S; Millar-Blanchaer, M A; Mittal, T; Morley, C V; Morzinski, K M; Murray-Clay, R; Oppenheimer, R; Palmer, D W; Patel, R; Patience, J; Perrin, M D; Poyneer, L A; Rafikov, R R; Rantakyrö, F T; Rice, E; Rojo, P; Rudy, A R; Ruffio, J -B; Ruiz, M T; Sadakuni, N; Saddlemyer, L; Salama, M; Savransky, D; Schneider, A C; Sivaramakrishnan, A; Song, I; Soummer, R; Thomas, S; Vasisht, G; Wallace, J K; Ward-Duong, K; Wiktorowicz, S J; Wolff, S G; Zuckerman, B

    2015-01-01

    Directly detecting thermal emission from young extrasolar planets allows measurement of their atmospheric composition and luminosity, which is influenced by their formation mechanism. Using the Gemini Planet Imager, we discovered a planet orbiting the \\$sim$20 Myr-old star 51 Eridani at a projected separation of 13 astronomical units. Near-infrared observations show a spectrum with strong methane and water vapor absorption. Modeling of the spectra and photometry yields a luminosity of L/LS=1.6-4.0 x 10-6 and an effective temperature of 600-750 K. For this age and luminosity, "hot-start" formation models indicate a mass twice that of Jupiter. This planet also has a sufficiently low luminosity to be consistent with the "cold- start" core accretion process that may have formed Jupiter.

  1. Interpreting Gemini Planet Imager Spectroscopy of the Young Giant Planets HR 8799 c and d

    NASA Astrophysics Data System (ADS)

    Marley, Mark S.; Ingraham, Patrick; Saumon, Didier; Marois, Christian

    2014-11-01

    During the first-light run of the Gemini Telescope’s newest facility instrument, the Gemini Planet Imager (GPI), K-band spectra of exoplanets HR 8799 c and d were obtained. Combined with previous ground based multi-band photometry and spectroscopy, the new datasets place strong constraints on the atmospheric composition, cloud properties, and thermal profile of these two giant planets. Comparison of the data to our newest atmospheric models confirms that thick clouds combined with horizontal variation in the cloud cover is required to best reproduce the planets’ spectral energy distributions. The data also provide further evidence that future modeling efforts must include cloud opacity, possibly including cloud holes, disequilibrium chemistry, and super-solar metallicity. In short there is now little doubt these planets are as complex and dynamic as the giants of our own solar system. In our presentation we will not only discuss the challenges of characterizing these objects but will also look forward to the future of exoplanet direct imaging by both GPI and SPHERE.

  2. Adaptive Optics for Direct Detection of Extrasolar Planets: The Gemini Planet Imager

    SciTech Connect

    Macintosh, B; Graham, J; Palmer, D; Doyon, R; Gavel, D; Larkin, J; Oppenheimer, B; Saddlemyer, L; Wallace, J K; Bauman, B; Erikson, D; Poyneer, L; Sivaramakrishnan, A; Soummer, R; Veran, J

    2007-04-24

    The direct detection of photons emitted or reflected by extrasolar planets, spatially resolved from their parent star, is a major frontier in the study of other solar systems. Direct detection will provide statistical information on planets in 5-50 AU orbits, inaccessible to current Doppler searches, and allow spectral characterization of radius, temperature, surface gravity, and perhaps composition. Achieving this will require new dedicated high-contrast instruments. One such system under construction is the Gemini Planet Imager (GPI.) This combines a high-order/high-speed adaptive optics system to control wavefront errors from the Earth's atmosphere, an advanced coronagraph to block diffraction, ultrasmooth optics, a precision infrared interferometer to measure and correct systematic errors, and a integral field spectrograph/polarimeter to image and characterize target planetary systems. We predict that GPI will be able to detect planets with brightness less than 10{sup -7} of their parent star, sufficient to observe warm self-luminous planets around a large population of targets.

  3. Direct observation of extrasolar planets and the development of the gemini planet imager integral field spectrograph

    NASA Astrophysics Data System (ADS)

    Chilcote, Jeffrey Kaplan

    This thesis is focused on the development and testing of a new instrument capable of finding and characterizing recently-formed Jupiter-sized planets orbiting other stars. To observe these planets, I present the design, construction and testing of the Gemini Planet Imager (GPI) Integral Field Spectrograph (IFS). GPI is a facility class instrument for the Gemini Observatory with the primary goal of directly detecting young Jovian planets. The GPI IFS utilizes an infrared transmissive lenslet array to sample a rectangular 2.7 x 2.7 arcsecond field of view and provide low-resolution spectra across five bands between 1 and 2.5 mum. The dispersing element can be replaced with a Wollaston prism to provide broadband polarimetry across the same five filter bands. The IFS construction was based at the University of California, Los Angeles in collaboration with the Universite de Montreal, Immervision and Lawrence Livermore National Laboratory. I will present performance results, from in-lab testing, of the Integral Field Spectrograph (IFS) for the Gemini Planet Imager (GPI). The IFS is a large, complex, cryogenic, optical system requiring several years of development and testing. I will present the design and integration of the mechanical and optical performance of the spectrograph optics. The IFS passed its pre-ship review in 2011 and was shipped to University of California, Santa Cruz for integration with the remaining sub-systems of GPI. The UCLA built GPI IFS was integrated with the rest of GPI and is delivering high quality spectral datacubes of GPI's coronagraphic field. Using the NIRC2 instrument located at the Keck Observatory, my collaborators and I observed the planetary companion to beta Pictoris in L' (3.5--4.1mum). Observations taken in the fall of 2009 and 2012 are used to find the location and inclination of the planet relative to the massive debris disk orbiting beta Pictoris. We find that the planet's orbit has a position angle on the sky of 211.9+/-0.4 degrees, making the planet misaligned by 2.9+/-0.5 degrees from the main disk, consistent with other observations that beta Pic b is misaligned with the main disk, and part of the misaligned inner disk. In 2009 & 2012 we find a projected orbital separation of 312.8 +/- 18.3 and 466.35 +/- 8.4 milliarcseconds consistent with an orbital period of ˜ 20 years, and a semi-major axis of ˜ 9 AU as found by Macintosh et al. (2014). During the first commissioning observations with the Gemini Planet Imager (GPI), my collaborators and I took the first H-band spectrum of the planetary companion to the nearby young star beta Pictoris. The spectrum has a resolving power of ˜ 45 and demonstrates the distinctive triangular shape of a cool substellar object with low surface gravity. Using atmospheric models, we find an effective temperature of 1650 +/- 50K and a surface gravity of log(g) = 4.0 +/- 0.25 (cgs units). These values agree well with predictions from planetary evolution models for a gas giant with mass between 10 and 12 MJup and age between 10 and 20 Myrs. The spectrum is very similar to a known low mass field brown dwarf but has more flux at the long wavelength end of the filters compared to models. Given the very high signal-to-noise of our spectrum this likely indicates additional physics such as patchy clouds that need to be included in the model.

  4. Ground-Based Direct Detection of Exoplanets with the Gemini Planet Imager (GPI)

    E-print Network

    James R. Graham; Bruce Macintosh; Rene Doyon; Don Gavel; James Larkin; Marty Levine; Ben Oppenheimer; David Palmer; Les Saddlemyer; Anand Sivaramakrishnan; Jean-Pierre Veran; Kent Wallace

    2007-04-11

    The Gemini Planet (GPI) imager is an "extreme" adaptive optics system being designed and built for the Gemini Observatory. GPI combines precise and accurate wavefront control, diffraction suppression, and a speckle-suppressing science camera with integral field and polarimetry capabilities. GPI's primary science goal is the direct detection and characterization of young, Jovian-mass exoplanets. For systems younger than 2 Gyr exoplanets more massive than 6 MJ and semimajor axes beyond 10 AU are detected with completeness greater than 50%. GPI will also discover faint debris disks, explore icy moons and minor planets in the solar system, reveal high dynamic range main-sequence binaries, and study mass loss from evolved stars. This white paper explains the role of GPI in exoplanet discovery and characterization and summarizes our recommendations to the NSF-NASA-DOE Astronomy and Astrophysics Advisory Committee ExoPlanet Task Force.

  5. Ground-Based Direct Detection of Exoplanets with the Gemini Planet Imager (GPI)

    E-print Network

    Graham, James R; Doyon, Rene; Gavel, Don; Larkin, James; Levine, Marty; Oppenheimer, Ben; Palmer, David; Saddlemyer, Les; Sivaramakrishnan, Anand; Veran, Jean-Pierre; Wallace, Kent

    2007-01-01

    The Gemini Planet (GPI) imager is an "extreme" adaptive optics system being designed and built for the Gemini Observatory. GPI combines precise and accurate wavefront control, diffraction suppression, and a speckle-suppressing science camera with integral field and polarimetry capabilities. GPI's primary science goal is the direct detection and characterization of young, Jovian-mass exoplanets. For systems younger than 2 Gyr exoplanets more massive than 6 MJ and semimajor axes beyond 10 AU are detected with completeness greater than 50%. GPI will also discover faint debris disks, explore icy moons and minor planets in the solar system, reveal high dynamic range main-sequence binaries, and study mass loss from evolved stars. This white paper explains the role of GPI in exoplanet discovery and characterization and summarizes our recommendations to the NSF-NASA-DOE Astronomy and Astrophysics Advisory Committee ExoPlanet Task Force.

  6. A Gemini Planet Imager investigation of the atmosphere of the HD 95086b planet

    NASA Astrophysics Data System (ADS)

    De Rosa, Robert J.; Pueyo, Laurent; Patience, Jenny; Graham, James R.; Gemini Planet Imager Team

    2015-01-01

    We present Gemini Planet Imager (GPI) near-infrared observations of the ~5 Mjup companion to the young, dusty A-type star HD 95086, observed during the course of the verification and commissioning of the instrument. By combining binned low-resolution H and K-band IFS spectra from GPI, with literature near and mid-IR photometry, we have undertaken the most comprehensive analysis of the spectral energy distribution of HD 95086 b to-date. Comparing these observational results with atmospheric models, we constrain key parameters such as the effective temperature and surface gravity, and place the results in the context of analyses of other directly imaged planetary-mass companions (e.g. HR 8799 bcde, ? Pic b), and other substellar companions at a similar age (e.g. HD 106906 b, GQ Lup b). We also comment on the sensitivity of companions interior and exterior to HD 95086 b. Lastly, we present the color-corrections derived during the course of this study that are required to transform photometry obtained with GPI in the K1 and K2 filters into both the MKO and 2MASS photometric systems, essential for the propoer interpretation of K-band photometry measurements obtained with GPI.

  7. Characterizing Young Giant Planets with the Gemini Planet Imager: An Iterative Approach to Planet Characterization

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2015-01-01

    After discovery, the first task of exoplanet science is characterization. However experience has shown that the limited spectral range and resolution of most directly imaged exoplanet data requires an iterative approach to spectral modeling. Simple, brown dwarf-like models, must first be tested to ascertain if they are both adequate to reproduce the available data and consistent with additional constraints, including the age of the system and available limits on the planet's mass and luminosity, if any. When agreement is lacking, progressively more complex solutions must be considered, including non-solar composition, partial cloudiness, and disequilibrium chemistry. Such additional complexity must be balanced against an understanding of the limitations of the atmospheric models themselves. For example while great strides have been made in improving the opacities of important molecules, particularly NH3 and CH4, at high temperatures, much more work is needed to understand the opacity of atomic Na and K. The highly pressure broadened fundamental band of Na and K in the optical stretches into the near-infrared, strongly influencing the spectral shape of Y and J spectral bands. Discerning gravity and atmospheric composition is difficult, if not impossible, without both good atomic opacities as well as an excellent understanding of the relevant atmospheric chemistry. I will present examples of the iterative process of directly imaged exoplanet characterization as applied to both known and potentially newly discovered exoplanets with a focus on constraints provided by GPI spectra. If a new GPI planet is lacking, as a case study I will discuss HR 8799 c and d will explain why some solutions, such as spatially inhomogeneous cloudiness, introduce their own additional layers of complexity. If spectra of new planets from GPI are available I will explain the modeling process in the context of understanding these new worlds.

  8. The use of a high-order MEMS deformable mirror in the Gemini Planet Imager

    SciTech Connect

    Poyneer, L A; Bauman, B; Cornelissen, S; Jones, S; Macintosh, B; Palmer, D; Isaacs, J

    2010-12-17

    We briefly review the development history of the Gemini Planet Imager's 4K Boston Micromachines MEMS deformable mirror. We discuss essential calibration steps and algorithms to control the MEMS with nanometer precision, including voltage-phase calibration and influence function characterization. We discuss the integration of the MEMS into GPI's Adaptive Optics system at Lawrence Livermore and present experimental results of 1.5 kHz closed-loop control. We detail mitigation strategies in the coronagraph to reduce the impact of abnormal actuators on final image contrast.

  9. Peering into the Giant-planet-forming Region of the TW Hydrae Disk with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Rapson, Valerie A.; Kastner, Joel H.; Millar-Blanchaer, Maxwell A.; Dong, Ruobing

    2015-12-01

    We present Gemini Planet Imager (GPI) adaptive optics near-infrared images of the giant-planet-forming regions of the protoplanetary disk orbiting the nearby (D = 54 pc), pre-main-sequence (classical T Tauri) star TW Hydrae. The GPI images, which were obtained in coronagraphic/polarimetric mode, exploit starlight scattered off small dust grains to elucidate the surface density structure of the TW Hya disk from ?80 AU to within ?10 AU of the star at ?1.5 AU resolution. The GPI polarized intensity images unambiguously confirm the presence of a gap in the radial surface brightness distribution of the inner disk. The gap is centered near ?23 AU, with a width of ?5 AU and a depth of ?50%. In the context of recent simulations of giant-planet formation in gaseous, dusty disks orbiting pre-main-sequence stars, these results indicate that at least one young planet with a mass ?0.2 MJ could be present in the TW Hya disk at an orbital semimajor axis similar to that of Uranus. If this (proto)planet is actively accreting gas from the disk, it may be readily detectable by GPI or a similarly sensitive, high-resolution infrared imaging system.

  10. Peering into the Giant Planet Forming Region of the TW Hydrae Disk with the Gemini Planet Imager

    E-print Network

    Rapson, Valerie A; Millar-Blanchaer, Maxwell A; Dong, Ruobing

    2015-01-01

    We present Gemini Planet Imager (GPI) adaptive optics near-infrared images of the giant planet-forming regions of the protoplanetary disk orbiting the nearby (D = 54 pc), pre-main sequence (classical T Tauri) star TW Hydrae. The GPI images, which were obtained in coronagraphic/polarimetric mode, exploit starlight scattered off small dust grains to elucidate the surface density structure of the TW Hya disk from 80 AU to within 10 AU of the star at 1.5 AU resolution. The GPI polarized intensity images unambiguously con?rm the presence of a gap in the radial surface brightness distribution of the inner disk. The gap is centered near 23 AU, with a width of 5 AU and a depth of 50%. In the context of recent simulations of giant planet formation in gaseous, dusty disks orbiting pre-main sequence stars, these results indicate that at least one young planet with a mass 0.2 M_J could be present in the TW Hya disk at an orbital semi-major axis similar to that of Uranus. If this (proto)planet is actively accreting gas fr...

  11. The Gemini Deep Planet Survey

    NASA Astrophysics Data System (ADS)

    Lafrenière, David; Doyon, René; Marois, Christian; Nadeau, Daniel; Oppenheimer, Ben R.; Roche, Patrick F.; Rigaut, François; Graham, James R.; Jayawardhana, Ray; Johnstone, Doug; Kalas, Paul G.; Macintosh, Bruce; Racine, René

    2007-12-01

    We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around 85 nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope, and angular differential imaging was used to suppress the speckle noise of the central star. Typically, the observations are sensitive to angular separations beyond 0.5" with 5 ? contrast sensitivities in magnitude difference at 1.6 ?m of 9.5 at 0.5", 12.9 at 1", 15.0 at 2", and 16.5 at 5". These sensitivities are sufficient to detect planets more massive than 2 MJ with a projected separation in the range 40-200 AU around a typical target. Second-epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results is presented. Assuming a planet mass distribution dn/dm~m-1.2 and a semimajor-axis distribution dn/da~a-1, the 95% credible upper limits on the fraction of stars with at least one planet of mass 0.5-13 MJ are 0.28 for the range 10-25 AU, 0.13 for 25-50 AU, and 0.093 for 50-250 AU; this result is weakly dependent on the semimajor-axis distribution power-law index. The 95% credible interval for the fraction of stars with at least one brown dwarf companion having a semimajor axis in the range 25-250 AU is 0.019+0.083-0.015, irrespective of any assumption on the mass and semimajor-axis distributions. The observations made as part of this survey have resolved the stars HD 14802, HD 166181, and HD 213845 into binaries for the first time. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

  12. Characterizing Exoplanet Motions Using Random Orbit Generation for the Gemini Planet Imager Exoplanet Survey

    NASA Astrophysics Data System (ADS)

    Blunt, Sarah Caroline; Nielsen, Eric; Marchis, Franck; De Rosa, Robert; Konopacky, Quinn; Macintosh, Bruce; Wang, Jason; Marois, Christian; Pueyo, Laurent; Rameau, Julien; Graham, James R.; GPIES Collaboration

    2016-01-01

    Next generation planet-finders like the Gemini Planet Imager (GPI) allow for direct imaging of exoplanets that are close enough to their host stars to undergo detectable orbital motion on monthly timescales, creating a need for methods that rapidly characterize newly discovered planets using short astrometric baselines. We present a computationally efficient Monte Carlo method that fits randomly generated orbital parameters to astrometry of directly imaged exoplanets from a fraction of an orbit. This code quickly and efficiently produces distributions of plausible orbital parameters, while a traditional Markov-Chain Monte Carlo algorithm would take much longer to converge given the same inputs (future work will directly compare the computational efficiencies and outputs of both algorithms).This technique allows us to predict the future motion of a planet by randomly generating plausible orbits that fit just a few epochs of astrometry, or even a single epoch. We first applied this method to predicting the future position of 51 Eri b, a giant exoplanet discovered by GPIES, using astrometry with only a 1-month baseline. Subsequent observations of 51 Eri b after seven months found the planet at the peak of the probability distributions predicting future motion. We demonstrate how this method can be applied to GPIES and the future WFIRST-AFTA space mission, from distinguishing bound planets from background objects to constraining orbital parameters given data from only a few observational epochs after discovery.This material is based on work supported by the National Science Foundation REU Program under Grant No. AST-1359346.

  13. Gemini Planet Imager observational calibrations I: Overview of the GPI data reduction pipeline

    NASA Astrophysics Data System (ADS)

    Perrin, Marshall D.; Maire, Jérôme; Ingraham, Patrick; Savransky, Dmitry; Millar-Blanchaer, Max; Wolff, Schuyler G.; Ruffio, Jean-Baptiste; Wang, Jason J.; Draper, Zachary H.; Sadakuni, Naru; Marois, Christian; Rajan, Abhijith; Fitzgerald, Michael P.; Macintosh, Bruce; Graham, James R.; Doyon, René; Larkin, James E.; Chilcote, Jeffrey K.; Goodsell, Stephen J.; Palmer, David W.; Labrie, Kathleen; Beaulieu, Mathilde; De Rosa, Robert J.; Greenbaum, Alexandra Z.; Hartung, Markus; Hibon, Pascale; Konopacky, Quinn; Lafreniere, David; Lavigne, Jean-Francois; Marchis, Franck; Patience, Jenny; Pueyo, Laurent; Rantakyrö, Fredrik T.; Soummer, Rémi; Sivaramakrishnan, Anand; Thomas, Sandrine; Ward-Duong, Kimberly; Wiktorowicz, Sloane

    2014-07-01

    The Gemini Planet Imager (GPI) has as its science instrument an infrared integral field spectrograph/polarimeter (IFS). Integral field spectrographs are scientificially powerful but require sophisticated data reduction systems. For GPI to achieve its scientific goals of exoplanet and disk characterization, IFS data must be reconstructed into high quality astrometrically and photometrically accurate datacubes in both spectral and polarization modes, via flexible software that is usable by the broad Gemini community. The data reduction pipeline developed by the GPI instrument team to meet these needs is now publicly available following GPI's commissioning. This paper, the first of a series, provides a broad overview of GPI data reduction, summarizes key steps, and presents the overall software framework and implementation. Subsequent papers describe in more detail the algorithms necessary for calibrating GPI data. The GPI data reduction pipeline is open source, available from planetimager.org, and will continue to be enhanced throughout the life of the instrument. It implements an extensive suite of task primitives that can be assembled into reduction recipes to produce calibrated datasets ready for scientific analysis. Angular, spectral, and polarimetric differential imaging are supported. Graphical tools automate the production and editing of recipes, an integrated calibration database manages reference files, and an interactive data viewer customized for high contrast imaging allows for exploration and manipulation of data.

  14. The Gemini Planet Imager Exoplanet Survey and the discovery of the young Jupiter analog 51 Eridani b

    NASA Astrophysics Data System (ADS)

    Macintosh, Bruce; Gemini Planet Imager Exoplanet Survey

    2016-01-01

    The Gemini Planet Imager Exoplanet Survey has been began in November 2014 and has surveyed more than 100 young nearby stars. I will present an updated status of the survey, including instrument performance and completeness limits. We reported our first new exoplanet discovery, the 20 Myr planet 51 Eri b, in August of 2015. J and H band spectra show that it is among the coolest and lowest-luminosity exoplanets yet imaged, with strong methane absorption and a luminosity consistent with low-entropy formation. I will give an overview of the planet's properties, and results from observations in the second half of 2015.

  15. Gemini Planet Imager Observations of the AU Microscopii Debris Disk: Asymmetries within One Arcsecond

    NASA Astrophysics Data System (ADS)

    Wang, Jason J.; Graham, James R.; Pueyo, Laurent; Nielsen, Eric L.; Millar-Blanchaer, Max; De Rosa, Robert J.; Kalas, Paul; Ammons, S. Mark; Bulger, Joanna; Cardwell, Andrew; Chen, Christine; Chiang, Eugene; Chilcote, Jeffrey K.; Doyon, René; Draper, Zachary H.; Duchêne, Gaspard; Esposito, Thomas M.; Fitzgerald, Michael P.; Goodsell, Stephen J.; Greenbaum, Alexandra Z.; Hartung, Markus; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Larkin, James E.; Macintosh, Bruce; Maire, Jerome; Marchis, Franck; Marois, Christian; Matthews, Brenda C.; Morzinski, Katie M.; Oppenheimer, Rebecca; Patience, Jenny; Perrin, Marshall D.; Rajan, Abhijith; Rantakyrö, Fredrik T.; Sadakuni, Naru; Serio, Andrew; Sivaramakrishnan, Anand; Soummer, Rémi; Thomas, Sandrine; Ward-Duong, Kimberly; Wiktorowicz, Sloane J.; Wolff, Schuyler G.

    2015-10-01

    We present Gemini Planet Imager (GPI) observations of AU Microscopii, a young M dwarf with an edge-on, dusty debris disk. Integral field spectroscopy and broadband imaging polarimetry were obtained during the commissioning of GPI. In our broadband imaging polarimetry observations, we detect the disk only in total intensity and find asymmetries in the morphology of the disk between the southeast (SE) and northwest (NW) sides. The SE side of the disk exhibits a bump at 1? (10 AU projected separation) that is three times more vertically extended and three times fainter in peak surface brightness than the NW side at similar separations. This part of the disk is also vertically offset by 69 ± 30 mas to the northeast at 1? when compared to the established disk midplane and is consistent with prior Atacama Large Millimeter/submillimeter Array and Hubble Space Telescope/Space Telescope Imaging Spectrograph observations. We see hints that the SE bump might be a result of detecting a horizontal sliver feature above the main disk that could be the disk backside. Alternatively, when including the morphology of the NW side, where the disk midplane is offset in the opposite direction ?50 mas between 0.?4 and 1.?2, the asymmetries suggest a warp-like feature. Using our integral field spectroscopy data to search for planets, we are 50% complete for ?4 MJup planets at 4 AU. We detect a source, resolved only along the disk plane, that could either be a candidate planetary mass companion or a compact clump in the disk.

  16. Resolving the HD 100546 Protoplanetary System with the Gemini Planet Imager: Evidence for Multiple Forming, Accreting Planets

    E-print Network

    Currie, Thayne; Brittain, Sean; Grady, Carol; Burrows, Adam; Muto, Takayuki; Kenyon, Scott J; Kuchner, Marc J

    2015-01-01

    We report Gemini Planet Imager H band high-contrast imaging/integral field spectroscopy and polarimetry of the HD 100546, a 10 $Myr$-old early-type star recently confirmed to host a thermal infrared bright (super)jovian protoplanet at wide separation, HD 100546 b. We resolve the inner disk cavity in polarized light, recover the thermal-infrared (IR) bright arm, and identify one additional spiral arm. We easily recover HD 100546 b and show that much of its emission originates an unresolved, point source. HD 100546 b likely has extremely red infrared colors compared to field brown dwarfs, qualitatively similar to young cloudy superjovian planets, however, these colors may instead indicate that HD 100546 b is still accreting material from a circumplanetary disk. Additionally, we identify a second point source-like peak at $r_{proj}$ $\\sim$ 13 AU, located just interior to or at inner disk wall consistent with being a 10--20 $M_{J}$ candidate second protoplanet-- "HD 100546 c" -- and lying within a weakly polarize...

  17. Gemini Planet Imager Observations of the AU Microscopii Debris Disk: Asymmetries within One Arcsecond

    E-print Network

    Wang, Jason J; Pueyo, Laurent; Nielsen, Eric L; Millar-Blanchaer, Max; De Rosa, Robert J; Kalas, Paul; Ammons, S Mark; Bulger, Joanna; Cardwell, Andrew; Chen, Christine; Chiang, Eugene; Chilcote, Jeffrey K; Doyon, René; Draper, Zachary H; Duchêne, Gaspard; Esposito, Thomas M; Fitzgerald, Michael P; Goodsell, Stephen J; Greenbaum, Alexandra Z; Hartung, Markus; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Larkin, James E; Macintosh, Bruce; Maire, Jerome; Marchis, Franck; Marois, Christian; Matthews, Brenda C; Morzinski, Katie M; Oppenheimer, Rebecca; Patience, Jenny; Perrin, Marshall D; Rajan, Abhijith; Rantakyrö, Fredrik T; Sadakuni, Naru; Serio, Andrew; Sivaramakrishnan, Anand; Soummer, Rémi; Thomas, Sandrine; Ward-Duong, Kimberly; Wiktorowicz, Sloane J; Wolff, Schuyler G

    2015-01-01

    We present Gemini Planet Imager (GPI) observations of AU Microscopii, a young M dwarf with an edge-on, dusty debris disk. Integral field spectroscopy and broadband imaging polarimetry were obtained during the commissioning of GPI. In our broadband imaging polarimetry observations, we detect the disk only in total intensity and find asymmetries in the morphology of the disk between the southeast and northwest sides. The southeast side of the disk exhibits a bump at 1$''$ (10 AU projected separation) that is three times more vertically extended and three times fainter in peak surface brightness than the northwest side at similar separations. This part of the disk is also vertically offset by 69$\\pm$30 mas to the northeast at 1$''$ when compared to the established disk mid-plane and consistent with prior ALMA and Hubble Space Telescope/STIS observations. We see hints that the southeast bump might be a result of detecting a horizontal sliver feature above the main disk that could be the disk backside. Alternative...

  18. Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Nielsen, Eric Ludwig; Blunt, Sarah; De Rosa, Robert; Konopacky, Quinn; Graham, James R.; Macintosh, Bruce; Marchis, Franck; Wang, Jason; Pueyo, Laurent; Rameau, Julien; Marois, Christian

    2015-12-01

    The Gemini Planet Imager Exoplanet Survey discovered the young, 2 Jupiter mass planet 51 Eri b based on observations conducted in December 2014 and January 2015. It is the lowest mass extrasolar planet ever detected by direct imaging and shows strong methane absorption, and is at a projected separation of just 13 AU from its host star. We present new astrometry from late 2015 that confirms 51 Eri b is a bound planet and not an interloping brown dwarf. Orbital motion is detected despite monitoring the system for less than a year. We have implemented a computationally efficient Monte Carlo technique for fitting a range of possible orbital motion based on astrometry covering a small fraction of the period and producing distributions of orbital parameters consistent with the measurements. We apply this technique to the astrometry of 51 Eri b and present preliminary orbital parameter distributions of this intriguing planet.

  19. Resolving the HD 100546 Protoplanetary System with the Gemini Planet Imager: Evidence for Multiple Forming, Accreting Planets

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Cloutier, Ryan; Brittain, Sean; Grady, Carol; Burrows, Adam; Muto, Takayuki; Kenyon, Scott J.; Kuchner, Marc J.

    2015-12-01

    We report Gemini Planet Imager H-band high-contrast imaging/integral field spectroscopy and polarimetry of the HD 100546, a 10 Myr old early-type star recently confirmed to host a thermal infrared (IR) bright (super-)Jovian protoplanet at wide separation, HD 100546 b. We resolve the inner disk cavity in polarized light, recover the thermal IR-bright arm, and identify one additional spiral arm. We easily recover HD 100546 b and show that much of its emission plausibly originates from an unresolved point source. The point-source component of HD 100546 b has extremely red IR colors compared to field brown dwarfs, qualitatively similar to young cloudy super-Jovian planets; however, these colors may instead indicate that HD 100546 b is still accreting material from a circumplanetary disk. Additionally, we identify a second point-source-like peak at rproj ? 14 AU, located just interior to or at the inner disk wall consistent with being a <10–20 MJ candidate second protoplanet—“HD 100546 c”—and lying within a weakly polarized region of the disk but along an extension of the thermal IR-bright spiral arm. Alternatively, it is equally plausible that this feature is a weakly polarized but locally bright region of the inner disk wall. Astrometric monitoring of this feature over the next 2 years and emission line measurements could confirm its status as a protoplanet, rotating disk hot spot that is possibly a signpost of a protoplanet, or a stationary emission source from within the disk.

  20. First Scattered-light Image of the Debris Disk around HD 131835 with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Hung, Li-Wei; Duchêne, Gaspard; Arriaga, Pauline; Fitzgerald, Michael P.; Maire, Jérôme; Marois, Christian; Millar-Blanchaer, Maxwell A.; Bruzzone, Sebastian; Rajan, Abhijith; Pueyo, Laurent; Kalas, Paul G.; De Rosa, Robert J.; Graham, James R.; Konopacky, Quinn; Wolff, Schuyler G.; Ammons, S. Mark; Chen, Christine H.; Chilcote, Jeffrey K.; Draper, Zachary H.; Esposito, Thomas M.; Gerard, Benjamin; Goodsell, Stephen; Greenbaum, Alexandra; Hibon, Pascale; Hinkley, Sasha; Macintosh, Bruce; Marchis, Franck; Metchev, Stanimir; Nielsen, Eric L.; Oppenheimer, Rebecca; Patience, Jennifer L.; Perrin, Marshall D.; Rantakyrö, Fredrik T.; Sivaramakrishnan, Anand; Wang, Jason J.; Ward-Duong, Kimberly; Wiktorowicz, Sloane J.

    2015-12-01

    We present the first scattered-light image of the debris disk around HD 131835 in the H band using the Gemini Planet Imager. HD 131835 is a ?15 Myr old A2IV star at a distance of ?120 pc in the Sco-Cen OB association. We detect the disk only in polarized light and place an upper limit on the peak total intensity. No point sources resembling exoplanets were identified. Compared to its mid-infrared thermal emission, in scattered light the disk shows similar orientation but different morphology. The scattered-light disk extends from ?75 to ?210 AU in the disk plane with roughly flat surface density. Our Monte Carlo radiative transfer model can describe the observations with a model disk composed of a mixture of silicates and amorphous carbon. In addition to the obvious brightness asymmetry due to stronger forward scattering, we discover a weak brightness asymmetry along the major axis, with the northeast side being 1.3 times brighter than the southwest side at a 3? level.

  1. First Scattered-Light Image of the Debris Disk around HD 131835 with the Gemini Planet Imager

    E-print Network

    Hung, Li-Wei; Arriaga, Pauline; Fitzgerald, Michael P; Maire, Jérôme; Marois, Christian; Millar-Blanchaer, Maxwell A; Bruzzone, Sebastian; Rajan, Abhijith; Pueyo, Laurent; Kalas, Paul G; De Rosa, Robert J; Graham, James R; Konopacky, Quinn; Wolff, Schuyler G; Ammons, S Mark; Chen, Christine; Chilcote, Jeffrey K; Draper, Zachary H; Esposito, Thomas M; Gerard, Benjamin; Goodsell, Stephen; Greenbaum, Alexandra; Hibon, Pascale; Hinkley, Sasha; Macintosh, Bruce; Marchis, Franck; Metchev, Stanimir; Nielsen, Eric L; Oppenheimer, Rebecca; Patience, Jenny; Perrin, Marshall; Rantakyrö, Fredrik T; Sivaramakrishnan, Anand; Wang, Jason J; Ward-Duong, Kimberly; Wiktorowicz, Sloane J

    2015-01-01

    We present the first scattered-light image of the debris disk around HD 131835 in $H$ band using the Gemini Planet Imager. HD 131835 is a $\\sim$15 Myr old A2IV star at a distance of $\\sim$120 pc in the Sco-Cen OB association. We detect the disk only in polarized light and place an upper limit on the peak total intensity. No point sources resembling exoplanets were identified. Compared to its mid-infrared thermal emission, the disk in scattered light shows similar orientation but different morphology. The scattered-light disk extends from $\\sim$75 to $\\sim$210 AU in the disk plane with roughly flat surface density. Our Monte Carlo radiative transfer model can well describe the observations with a model disk composed of a mixture of silicates and amorphous carbon. In addition to the obvious brightness asymmetry due to stronger forward scattering, we discover a weak brightness asymmetry along the major axis with the northeast side being 1.3 times brighter than the southwest side at a 3-{\\sigma} level.

  2. The Gemini Deep Planet Survey -- GDPS

    E-print Network

    Lafreniere, David; Marois, Christian; Nadeau, Daniel; Oppenheimer, Ben R; Roche, Patrick F; Rigaut, Francois; Graham, James R; Jayawardhana, Ray; Johnstone, Doug; Kalas, Paul G; Macintosh, Bruce; Racine, Rene

    2007-01-01

    We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope and angular differential imaging was used to suppress the speckle noise of the central star. Detection limits for the 85 stars observed are presented, along with a list of all faint point sources detected around them. Typically, the observations are sensitive to angular separations beyond 0.5" with 5-sigma contrast sensitivities in magnitude difference at 1.6 micron of 9.6 at 0.5", 12.9 at 1", 15 at 2", and 16.6 at 5". For the typical target of the survey, a 100 Myr old K0 star located 22 pc from the Sun, the observations are sensitive enough to detect planets more massive than 2 Mjup with a projected separation in the range 40-200 AU. Second epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated backgro...

  3. Near-infrared detection and characterization of the exoplanet HD 95086 b with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Galicher, R.; Rameau, J.; Bonnefoy, M.; Baudino, J.-L.; Currie, T.; Boccaletti, A.; Chauvin, G.; Lagrange, A.-M.; Marois, C.

    2014-05-01

    HD 95086 is an intermediate-mass debris-disk-bearing star. VLT/NaCo 3.8 ?m observations revealed it hosts a 5 ± 2 MJup companion (HD 95086 b) at ?56 AU. Follow-up observations at 1.66 and 2.18 ?m yielded a null detection, suggesting extremely red colors for the planet and the need for deeper direct-imaging data. In this Letter, we report H-(1.7 ?m) and K1-(2.05 ?m) band detections of HD 95086 b from Gemini Planet Imager (GPI) commissioning observations taken by the GPI team. The planet position in both spectral channels is consistent with the NaCo measurements and we confirm it to be comoving. Our photometry yields colors of H - L' = 3.6 ± 1.0 mag and K1 - L' = 2.4 ± 0.7 mag, consistent with previously reported 5-? upper limits in H and Ks. The photometry of HD 95086 b best matches that of 2M 1207 b and HR 8799 cde. Comparing its spectral energy distribution with the BT-SETTL and LESIA planet atmospheric models yields Teff ~ 600-1500 K and log g ~ 2.1-4.5. Hot-start evolutionary models yield M = 5 ± 2 MJup. Warm-start models reproduce the combined absolute fluxes of the object for M = 4-14 MJup for a wide range of plausible initial conditions (Sinit = 8-13 kB/baryon). The color-magnitude diagram location of HD 95086 b and its estimated Teff and log g suggest that the planet is a peculiar L - T transition object with an enhanced amount of photospheric dust. Based on public data taken at the GPI commissioning.

  4. A COMBINED VERY LARGE TELESCOPE AND GEMINI STUDY OF THE ATMOSPHERE OF THE DIRECTLY IMAGED PLANET, ? PICTORIS b

    SciTech Connect

    Currie, Thayne; Jayawardhana, Ray; Burrows, Adam; Madhusudhan, Nikku; Fukagawa, Misato; Girard, Julien H.; Dawson, Rebekah; Murray-Clay, Ruth; Kenyon, Scott; Kuchner, Marc; Matsumura, Soko; Chambers, John; Bromley, Ben

    2013-10-10

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet ? Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While ? Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects—i.e., ? And b and 1RXJ 1609B—match ? Pic b's JHK{sub s}L' photometry and its 3.1 ?m and 5 ?m photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (?60 ?m) dust grains fail to reproduce the ? Pic b spectrum. However, models incorporating thick clouds similar to those found for HR 8799 bcde, but also with small (a few microns) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles ((a) = 4 ?m), we derive atmosphere parameters of log (g) = 3.8 ± 0.2 and T{sub eff} = 1575-1650 K, an inferred mass of 7{sup +4}{sub -3} M{sub J} , and a luminosity of log(L/L{sub ?}) ?–3.80 ± 0.02. The best-estimated planet radius, ?1.65 ± 0.06 R{sub J} , is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if ? Pic b is younger than ?7 Myr, consistent with a late formation well after its host star's birth ?12{sup +8}{sub -4} Myr ago.

  5. A Combined Very Large Telescope and Gemini Study of the Atmosphere of the Directly Imaged Planet, ? Pictoris b

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Burrows, Adam; Madhusudhan, Nikku; Fukagawa, Misato; Girard, Julien H.; Dawson, Rebekah; Murray-Clay, Ruth; Kenyon, Scott; Kuchner, Marc; Matsumura, Soko; Jayawardhana, Ray; Chambers, John; Bromley, Ben

    2013-10-01

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet ? Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While ? Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects—i.e., ? And b and 1RXJ 1609B—match ? Pic b's JHKsL' photometry and its 3.1 ?m and 5 ?m photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (~60 ?m) dust grains fail to reproduce the ? Pic b spectrum. However, models incorporating thick clouds similar to those found for HR 8799 bcde, but also with small (a few microns) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles (langarang = 4 ?m), we derive atmosphere parameters of log (g) = 3.8 ± 0.2 and T eff = 1575-1650 K, an inferred mass of 7^{+4}_{-3} MJ , and a luminosity of log(L/L ?) ~-3.80 ± 0.02. The best-estimated planet radius, ?1.65 ± 0.06 RJ , is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if ? Pic b is younger than ?7 Myr, consistent with a late formation well after its host star's birth ~12^{+8}_{-4} Myr ago.

  6. A Combined Very Large Telescope and Gemini Study of the Atmosphere of the Directly Imaged Planet, Beta Pictoris b

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Burrows, Adam; Madhusudhan, Nikku; Fukagawa, Misato; Girard, Julien H.; Dawson, Rebekah; Murray-Clay, Ruth; Kenyon, Scott; Kuchner, Marc J.; Matsumura, Soko; Jayawardhana, Ray; Chambers, John; Bromley, Ben

    2013-01-01

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet Beta Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While Beta Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects-i.e., ? And b and 1RXJ 1609B-match Beta Pic b's JHKsL photometry and its 3.1 micron and 5 micron photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (approx. 60 micron)dust grains fail to reproduce the Beta Pic b spectrum. However, models incorporating thick clouds similar to those found forHR8799 bcde, but also with small (a fewmicrons) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles (a = 4 micron), we derive atmosphere parameters of log(g) = 3.8 +/- 0.2 and Teff = 1575-1650 K, an inferred mass of 7+4 -3 MJ, and a luminosity of log(L/L) approx. -3.80 +/- 0.02. The best-estimated planet radius, is approx. equal to 1.65 +/- 0.06 RJ, is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if Beta Pic b is younger than is approx. equal to 7 Myr, consistent with a late formation well after its host star's birth approx. 12+8 -4 Myr ago.

  7. Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    De Rosa, Robert J.; Nielsen, Eric L.; Blunt, Sarah C.; Graham, James R.; Konopacky, Quinn M.; Marois, Christian; Pueyo, Laurent; Rameau, Julien; Ryan, Dominic M.; Wang, Jason J.; Bailey, Vanessa; Chontos, Ashley; Fabrycky, Daniel C.; Follette, Katherine B.; Macintosh, Bruce; Marchis, Franck; Ammons, S. Mark; Arriaga, Pauline; Chilcote, Jeffrey K.; Cotten, Tara H.; Doyon, René; Duchêne, Gaspard; Esposito, Thomas M.; Fitzgerald, Michael P.; Gerard, Benjamin; Goodsell, Stephen J.; Greenbaum, Alexandra Z.; Hibon, Pascale; Ingraham, Patrick; Johnson-Groh, Mara; Kalas, Paul G.; Lafrenière, David; Maire, Jerome; Metchev, Stanimir; Millar-Blanchaer, Maxwell A.; Morzinski, Katie M.; Oppenheimer, Rebecca; Patel, Rahul I.; Patience, Jennifer L.; Perrin, Marshall D.; Rajan, Abhijith; Rantakyrö, Fredrik T.; Ruffio, Jean-Baptiste; Schneider, Adam C.; Sivaramakrishnan, Anand; Song, Inseok; Tran, Debby; Vasisht, Gautam; Ward-Duong, Kimberly; Wolff, Schuyler G.

    2015-11-01

    We present new Gemini Planet Imager observations of the young exoplanet 51 Eridani b that provide further evidence that the companion is physically associated with 51 Eridani. Combining this new astrometric measurement with those reported in the literature, we significantly reduce the posterior probability that 51 Eridani b is an unbound foreground or background T-dwarf in a chance alignment with 51 Eridani to 2 × 10?7, an order of magnitude lower than previously reported. If 51 Eridani b is indeed a bound object, then we have detected orbital motion of the planet between the discovery epoch and the latest epoch. By implementing a computationally efficient Monte Carlo technique, preliminary constraints are placed on the orbital parameters of the system. The current set of astrometric measurements suggest an orbital semimajor axis of {14}-3+7 AU, corresponding to a period of {41}-12+35 years (assuming a mass of 1.75 M? for the central star), and an inclination of {138}-13+15 deg. The remaining orbital elements are only marginally constrained by the current measurements. These preliminary values suggest an orbit that does not share the same inclination as the orbit of the distant M-dwarf binary, GJ 3305, which is a wide physically bound companion to 51 Eridani.

  8. The Gemini Deep Planet Survey - GDPS

    SciTech Connect

    Lafreniere, D; Doyon, R; Marois, C; Nadeau, D; Oppenheimer, B R; Roche, P F; Rigaut, F; Graham, J R; Jayawardhana, R; Johnstone, D; Kalas, P G; Macintosh, B; Racine, R

    2007-06-01

    We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope and angular differential imaging was used to suppress the speckle noise of the central star. Detection limits for the 85 stars observed are presented, along with a list of all faint point sources detected around them. Typically, the observations are sensitive to angular separations beyond 0.5-inch with 5{sigma} contrast sensitivities in magnitude difference at 1.6 {micro}m of 9.6 at 0.5-inch, 12.9 at 1-inch, 15 at 2-inch, and 16.6 at 5-inch. For the typical target of the survey, a 100 Myr old K0 star located 22 pc from the Sun, the observations are sensitive enough to detect planets more massive than 2 M{sub Jup} with a projected separation in the range 40-200 AU. Depending on the age, spectral type, and distance of the target stars, the minimum mass that could be detected with our observations can be {approx}1 M{sub Jup}. Second epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results, which provide upper limits on the fractions of stars with giant planet or low mass brown dwarf companions, is presented. Assuming a planet mass distribution dn/dm {proportional_to} m{sup -1.2} and a semi-major axis distribution dn/da {proportional_to} a{sup -1}, the upper limits on the fraction of stars with at least one planet of mass 0.5-13 M{sub Jup} are 0.29 for the range 10-25 AU, 0.13 for 25-50 AU, and 0.09 for 50-250 AU, with a 95% confidence level; this result is weakly dependent on the semi-major axis distribution power-law index. Without making any assumption on the mass and semi-major axis distributions, the fraction of stars with at least one brown dwarf companion having a semi-major axis in the range 25-200 AU is 0.018{sub -0.014}{sup +0.078}, with a 95% confidence level. The observations made as part of this survey have resolved the stars HD 14802, HD 135363, HD 160934, HD 166181, and HD 213845 into close binaries for the first time.

  9. The Gemini Deep Planet Survey -- GDPS

    E-print Network

    David Lafreniere; Rene Doyon; Christian Marois; Daniel Nadeau; Ben R. Oppenheimer; Patrick F. Roche; Francois Rigaut; James R. Graham; Ray Jayawardhana; Doug Johnstone; Paul G. Kalas; Bruce Macintosh; Rene Racine

    2007-08-23

    We present the results of the Gemini Deep Planet Survey, a near-infrared adaptive optics search for giant planets and brown dwarfs around nearby young stars. The observations were obtained with the Altair adaptive optics system at the Gemini North telescope and angular differential imaging was used to suppress the speckle noise of the central star. Detection limits for the 85 stars observed are presented, along with a list of all faint point sources detected around them. Typically, the observations are sensitive to angular separations beyond 0.5" with 5-sigma contrast sensitivities in magnitude difference at 1.6 micron of 9.5 at 0.5", 12.9 at 1", 15.0 at 2", and 16.5 at 5". For the typical target of the survey, a 100 Myr old K0 star located 22 pc from the Sun, the observations are sensitive enough to detect planets more massive than 2 Mjup with a projected separation in the range 40-200 AU. Second epoch observations of 48 stars with candidates (out of 54) have confirmed that all candidates are unrelated background stars. A detailed statistical analysis of the survey results, yielding upper limits on the fractions of stars with giant planet or low mass brown dwarf companions, is presented. Assuming a planet mass distribution dN/dm m^{-1.2} and a semi-major axis distribution dN/da a^{-1}, the 95% credible upper limits on the fraction of stars with at least one planet of mass 0.5-13 Mjup are 0.28 for the range 10-25 AU, 0.13 for 25-50 AU, and 0.093 for 50-250 AU. The 95% credible interval for the fraction of stars with at least one brown dwarf companion having a semi-major axis in the range 25-250 AU is 0.019 (-0.015/+0.083), irrespective of any assumption on the mass and semi-major axis distributions. The stars HD 14802, HD 166181, and HD 213845 have been resolved into binaries for the first time.

  10. 1 to 2.4 microns spectrum and orbital properties of the Giant Planet Beta Pictoris b obtained with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Chilcote, Jeffrey; Millar-Blanchaer, Max; Barman, Travis; Fitzgerald, Michael P.; Graham, James R.; Larkin, James; Kalas, Paul G.; dawson, Rebekah; Wang, Jason; Perrin, Marshall; Moon, Dae-Sik; Macintosh, Bruce

    2015-12-01

    We present a low-resolution multi-band spectrum of the planetary companion to the nearby young star beta Pictoris using the Gemini Planet Imager (GPI). GPI is designed to image and provide low-resolution spectra of Jupiter sized, self-luminous planetary companions around young nearby stars. While H-bandis the primary workhorse for the GPI Exoplanet Survey, the instrument is capable of observing in the near infrared covering Y, J, H, and K bands. These observations of Beta Pic Pictoris b were taken covering multiple bands as part of GPI’s verification and commissioning phase in 2013 and 2014. Using atmospheric models along with the H-band data we recently reported an effective temperature of 1600-1700 K and a surface gravity of log (g) = 3.5-4.5 (cgs units). A similar exercise was also carried out by an independent team using the J band data, and did yield similar conclusions. These values agree well with ”hot-start” predictions from planetary evolution models for a gas giant with mass between 10 and 12 M Jup and age between 10 and 20 Myr. Here we revisit these conclusions in light of a joint analysis of these two datasets along with the longer wavelength GPI spectrum in K band, and present refined constraints on the atmospheric properties of this giant planet. In addition, we present an updated orbit for Beta Pictoris b based on astrometric measurements taken using commissioning and subsequent monitoring observations, spanning 14 months. The planet has a semi-major axis of 9.2 (+1.5 ?0.4) AU, with an eccentricity e? 0.26. The position angle of the ascending node is ?=31.75 deg±0.15, offset from both the outer main disk and the inner disk seen in the GPI image. We finally discuss these properties in the context of planet-disk dynamical interactions.

  11. Polarimetry with the Gemini Planet Imager: Methods, Performance at First Light, and the Circumstellar Ring around HR 4796A

    NASA Astrophysics Data System (ADS)

    Perrin, Marshall D.; Duchene, Gaspard; Millar-Blanchaer, Max; Fitzgerald, Michael P.; Graham, James R.; Wiktorowicz, Sloane J.; Kalas, Paul G.; Macintosh, Bruce; Bauman, Brian; Cardwell, Andrew; Chilcote, Jeffrey; De Rosa, Robert J.; Dillon, Daren; Doyon, René; Dunn, Jennifer; Erikson, Darren; Gavel, Donald; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; Ingraham, Patrick; Kerley, Daniel; Konapacky, Quinn; Larkin, James E.; Maire, Jérôme; Marchis, Franck; Marois, Christian; Mittal, Tushar; Morzinski, Katie M.; Oppenheimer, B. R.; Palmer, David W.; Patience, Jennifer; Poyneer, Lisa; Pueyo, Laurent; Rantakyrö, Fredrik T.; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Soummer, Rémi; Sivaramakrishnan, Anand; Song, Inseok; Thomas, Sandrine; Wallace, J. Kent; Wang, Jason J.; Wolff, Schuyler G.

    2015-02-01

    We present the first results from the polarimetry mode of the Gemini Planet Imager (GPI), which uses a new integral field polarimetry architecture to provide high contrast linear polarimetry with minimal systematic biases between the orthogonal polarizations. We describe the design, data reduction methods, and performance of polarimetry with GPI. Point-spread function (PSF) subtraction via differential polarimetry suppresses unpolarized starlight by a factor of over 100, and provides sensitivity to circumstellar dust reaching the photon noise limit for these observations. In the case of the circumstellar disk around HR 4796A, GPI's advanced adaptive optics system reveals the disk clearly even prior to PSF subtraction. In polarized light, the disk is seen all the way in to its semi-minor axis for the first time. The disk exhibits surprisingly strong asymmetry in polarized intensity, with the west side >~ 9 times brighter than the east side despite the fact that the east side is slightly brighter in total intensity. Based on a synthesis of the total and polarized intensities, we now believe that the west side is closer to us, contrary to most prior interpretations. Forward scattering by relatively large silicate dust particles leads to the strong polarized intensity on the west side, and the ring must be slightly optically thick in order to explain the lower brightness in total intensity there. These findings suggest that the ring is geometrically narrow and dynamically cold, perhaps shepherded by larger bodies in the same manner as Saturn's F ring.

  12. Polarized Light Imaging of the HD 142527 Transition Disk with the Gemini Planet Imager: Dust around the Close-in Companion

    NASA Astrophysics Data System (ADS)

    Rodigas, Timothy J.; Follette, Katherine B.; Weinberger, Alycia; Close, Laird; Hines, Dean C.

    2014-08-01

    When giant planets form, they grow by accreting gas and dust. HD 142527 is a young star that offers a scaled-up view of this process. It has a broad, asymmetric ring of gas and dust beyond ~100 AU and a wide inner gap. Within the gap, a low-mass stellar companion orbits the primary star at just ~12 AU, and both the primary and secondary are accreting gas. In an attempt to directly detect the dusty counterpart to this accreted gas, we have observed HD 142527 with the Gemini Planet Imager in polarized light at Y band (0.95-1.14 ?m). We clearly detect the companion in total intensity and show that its position and photometry are generally consistent with the expected values. We also detect a point source in polarized light that may be spatially separated by ~ a few AU from the location of the companion in total intensity. This suggests that dust is likely falling onto or orbiting the companion. Given the possible contribution of scattered light from this dust to previously reported photometry of the companion, the current mass limits should be viewed as upper limits only. If the dust near the companion is eventually confirmed to be spatially separated, this system would resemble a scaled-up version of the young planetary system inside the gap of the transition disk around LkCa 15. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministrio da Cincia, Tecnologia e Inovao (Brazil), and Ministerio de Ciencia, Tecnologa e Innovacin Productiva (Argentina).

  13. Infrared Polarimetry of Self-Luminous Exoplanets with the Gemini Planet Imager

    NASA Astrophysics Data System (ADS)

    Jensen-Clem, Rebecca M.; Millar-Blanchaer, Max; Mawet, Dimitri; Graham, James R.; Knutson, Heather; Wiktorowicz, Sloane; Perrin, Marshall D.; Macintosh, Bruce; Hinkley, Sasha; Wallace, J. Kent; GPI Team

    2016-01-01

    Detecting polarized light from self-luminous exoplanets has the potential to provide key information about rotation, surface gravity, cloud grain size, and cloud coverage. While field brown dwarfs with polarized emission are common, no exoplanet or substellar companion has yet been detected in polarized light. With careful treatment of instrumental polarization, such a detection is now within the capabilities of modern high contrast imaging spectro-polarimeters such as GPI and SPHERE. Here, we present preliminary results from our 2015B GPI pilot program to search for polarized emission from known exoplanets and brown dwarf companions. We describe the effects of speckle noise and instrumental polarization on our analysis methods and discuss our results in the context of substellar cloud models and photometric variability.

  14. Astrometric Calibration of the Gemini NICI Planet-Finding Campaign

    E-print Network

    Hayward, Thomas L; Liu, Michael C; Nielsen, Eric L; Wahhaj, Zahed; Chun, Mark; Ftaclas, Christ; Hartung, Markus; Toomey, Douglas W

    2014-01-01

    We describe the astrometric calibration of the Gemini NICI Planet-Finding Campaign. The Campaign requires a relative astrometric accuracy of $\\approx$ 20 mas across multi-year timescales in order to distinguish true companions from background stars by verifying common proper motion and parallax with their parent stars. The calibration consists of a correction for instrumental optical image distortion, plus on-sky imaging of astrometric fields to determine the pixel scale and image orientation. We achieve an accuracy of $\\lesssim 7$ mas between the center and edge of the 18$''$ NICI field, meeting the 20 mas requirement. Most of the Campaign data in the Gemini Science Archive are accurate to this level but we identify a number of anomalies and present methods to correct the errors.

  15. POLARIZED LIGHT IMAGING OF THE HD 142527 TRANSITION DISK WITH THE GEMINI PLANET IMAGER: DUST AROUND THE CLOSE-IN COMPANION

    SciTech Connect

    Rodigas, Timothy J.; Weinberger, Alycia; Follette, Katherine B.; Close, Laird; Hines, Dean C.

    2014-08-20

    When giant planets form, they grow by accreting gas and dust. HD 142527 is a young star that offers a scaled-up view of this process. It has a broad, asymmetric ring of gas and dust beyond ?100 AU and a wide inner gap. Within the gap, a low-mass stellar companion orbits the primary star at just ?12 AU, and both the primary and secondary are accreting gas. In an attempt to directly detect the dusty counterpart to this accreted gas, we have observed HD 142527 with the Gemini Planet Imager in polarized light at Y band (0.95-1.14 ?m). We clearly detect the companion in total intensity and show that its position and photometry are generally consistent with the expected values. We also detect a point source in polarized light that may be spatially separated by ? a few AU from the location of the companion in total intensity. This suggests that dust is likely falling onto or orbiting the companion. Given the possible contribution of scattered light from this dust to previously reported photometry of the companion, the current mass limits should be viewed as upper limits only. If the dust near the companion is eventually confirmed to be spatially separated, this system would resemble a scaled-up version of the young planetary system inside the gap of the transition disk around LkCa 15.

  16. Final A&T stages of the Gemini Planet Finder

    NASA Astrophysics Data System (ADS)

    Hartung, Markus; Macintosh, Bruce; Poyneer, Lisa; Savransky, Dimitri; Gavel, Donald; Palmer, Dave; Thomas, Sandrine; Dillon, Daren; Chilcote, Jeffrey; Ingraham, Patrick; Sadakuni, Naru; Wallace, Kent; Perrin, Marshall; Marois, Christian; Maire, Jerome; Rantakyro, Fredrik; Hibon, Pascale; Saddlemyer, Les; Goodsell, Stephen

    2013-12-01

    The Gemini Planet Finder (GPI) is currently in its final Acceptance & Testing stages at the University of Santa Cruz, California. GPI is an XAO system based on a tweeter & woofer architecture (43 & 9 actuators across the pupil), with the tweeter being a Boston Michromachines 64^2 MEMS device. The XAO AO system is tightly integrated with a Lyot apodizing coronagraph. Acceptance has started in February 2013. After the conclusive acceptance review shipment is scheduled mid 2013 to ensure readiness for commissioning at the Gemini South telescope on Cerro Pachon, Chile, end of 2013, matching the summer window of the southern hemisphere. According to current estimates the 3 year (~800 allocated hours) planet finding campaign might discover, image, and spectroscopically analyze 20 to 40 new exo-planets.Final acceptance testing of the integrated instrument can always emerge a number of unforeseen challenges as we are eventually using cold chamber and flexure rig installations. The latest developments will be reported. Also, we will give an overview of GPI's lab performance, the interplay between subsystems such as the calibration unit (CAL) with the AO bench. (The CAL principal purpose is to maintain a clean and centered XAO PSF on the coronagraph.) We report on-going optimizations on the AO controler loop to filter vibrations and last but not least achieved contrast performance applying speckle nulling. Furthermore, we will give an outlook of possible but challenging future upgrades as the implementation of a predictive controler or exchanging the conventional 48x48 SH WFS with a pyramid. With the ELT area arising, GPI will proof as a versatile and path-finding testbed for AO technologies on the next generation of ground-based telescopes.

  17. The Gemini Planet-finding Campaign: The Frequency Of Giant Planets around Debris Disk Stars

    NASA Astrophysics Data System (ADS)

    Wahhaj, Zahed; Liu, Michael C.; Nielsen, Eric L.; Biller, Beth A.; Hayward, Thomas L.; Close, Laird M.; Males, Jared R.; Skemer, Andrew; Ftaclas, Christ; Chun, Mark; Thatte, Niranjan; Tecza, Matthias; Shkolnik, Evgenya L.; Kuchner, Marc; Reid, I. Neill; de Gouveia Dal Pino, Elisabete M.; Alencar, Silvia H. P.; Gregorio-Hetem, Jane; Boss, Alan; Lin, Douglas N. C.; Toomey, Douglas W.

    2013-08-01

    We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.''5 and 14.1 mag at 1'' separation. Follow-up observations of the 66 candidates with projected separation <500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known ? Pictoris and the HR 8799 planets. Our results show at 95% confidence that <13% of debris disk stars have a >=5 M Jup planet beyond 80 AU, and <21% of debris disk stars have a >=3 M Jup planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly imaged planets as d 2 N/dMdavpropm ? a ?, where m is planet mass and a is orbital semi-major axis (with a maximum value of a max). We find that ? < -0.8 and/or ? > 1.7. Likewise, we find that ? < -0.8 and/or a max < 200 AU. For the case where the planet frequency rises sharply with mass (? > 1.7), this occurs because all the planets detected to date have masses above 5 M Jup, but planets of lower mass could easily have been detected by our search. If we ignore the ? Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that <20% of debris disk stars have a >=3 M Jup planet beyond 10 AU, and ? < -0.8 and/or ? < -1.5. Likewise, ? < -0.8 and/or a max < 125 AU. Our Bayesian constraints are not strong enough to reveal any dependence of the planet frequency on stellar host mass. Studies of transition disks have suggested that about 20% of stars are undergoing planet formation; our non-detections at large separations show that planets with orbital separation >40 AU and planet masses >3 M Jup do not carve the central holes in these disks. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  18. THE GEMINI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF GIANT PLANETS AROUND DEBRIS DISK STARS

    SciTech Connect

    Wahhaj, Zahed; Liu, Michael C.; Nielsen, Eric L.; Ftaclas, Christ; Chun, Mark; Biller, Beth A.; Hayward, Thomas L.; Thatte, Niranjan; Tecza, Matthias; Shkolnik, Evgenya L.; Kuchner, Marc; Reid, I. Neill; De Gouveia Dal Pino, Elisabete M.; Gregorio-Hetem, Jane; Boss, Alan; Lin, Douglas N. C.; and others

    2013-08-20

    We have completed a high-contrast direct imaging survey for giant planets around 57 debris disk stars as part of the Gemini NICI Planet-Finding Campaign. We achieved median H-band contrasts of 12.4 mag at 0.''5 and 14.1 mag at 1'' separation. Follow-up observations of the 66 candidates with projected separation <500 AU show that all of them are background objects. To establish statistical constraints on the underlying giant planet population based on our imaging data, we have developed a new Bayesian formalism that incorporates (1) non-detections, (2) single-epoch candidates, (3) astrometric and (4) photometric information, and (5) the possibility of multiple planets per star to constrain the planet population. Our formalism allows us to include in our analysis the previously known {beta} Pictoris and the HR 8799 planets. Our results show at 95% confidence that <13% of debris disk stars have a {>=}5 M{sub Jup} planet beyond 80 AU, and <21% of debris disk stars have a {>=}3 M{sub Jup} planet outside of 40 AU, based on hot-start evolutionary models. We model the population of directly imaged planets as d {sup 2} N/dMda{proportional_to}m {sup {alpha}} a {sup {beta}}, where m is planet mass and a is orbital semi-major axis (with a maximum value of a{sub max}). We find that {beta} < -0.8 and/or {alpha} > 1.7. Likewise, we find that {beta} < -0.8 and/or a{sub max} < 200 AU. For the case where the planet frequency rises sharply with mass ({alpha} > 1.7), this occurs because all the planets detected to date have masses above 5 M{sub Jup}, but planets of lower mass could easily have been detected by our search. If we ignore the {beta} Pic and HR 8799 planets (should they belong to a rare and distinct group), we find that <20% of debris disk stars have a {>=}3 M{sub Jup} planet beyond 10 AU, and {beta} < -0.8 and/or {alpha} < -1.5. Likewise, {beta} < -0.8 and/or a{sub max} < 125 AU. Our Bayesian constraints are not strong enough to reveal any dependence of the planet frequency on stellar host mass. Studies of transition disks have suggested that about 20% of stars are undergoing planet formation; our non-detections at large separations show that planets with orbital separation >40 AU and planet masses >3 M{sub Jup} do not carve the central holes in these disks.

  19. Results from the Gemini NICI Planet-Finding Campaign

    NASA Astrophysics Data System (ADS)

    Biller, Beth A.; Liu, Michael C.; Wahhaj, Zahed; Nielsen, Eric L.; Hayward, Thomas L.; Chun, Mark R.; Close, Laird M.; Ftaclas, Christ; Males, Jared R.; Hartung, Markus; Reid, I. N.; Shkolnik, Evgenya; Skemer, Andrew J.; Tecza, Matthias; Thatte, Niranjan A.; Clarke, Fraser; Toomey, Douglas

    2014-08-01

    From 2008 December to 2012 September, the NICI (Near-Infrared Coronagraphic Imager at the Gemini-South 8.1-m) Planet-Finding Campaign (Liu et al. 2010) obtained deep, high-contrast AO imaging of a carefully selected sample of over 200 young, nearby stars. In the course of the campaign, we discovered four co-moving brown dwarf companions: PZ Tel B (36+/-6 MJup, 16.4+/-1.0 AU), CD-35 2722B (31+/-8 MJup, 67+/-4 AU), HD 1160B (33+12 -9 MJup, 81+/- AU), and HIP 79797Bb (55+20-19MJup, 3 AU from the previously known brown dwarf companion HIP 79797Ba), as well as numerous stellar binaries. Three survey papers have been published to date, covering: 1) high mass stars (Nielsen et al. 2013), 2) debris disk stars (Wahhaj et al. 2013), and 3) stars which are members of nearby young moving groups (Biller et al. 2013). In addition, the Campaign has yielded new orbital constraints for the ~8-10 MJup planet Pic ? (Nielsen et al. 2014) and a high precision measurement of the star-disk offset for the well-known disk around HR 4796A (Wahhaj et al. 2014). Here we discuss constraints placed on the distribution of wide giant exoplanets from the NICI Campaign, new substellar companion discoveries, and characterization both of exoplanets and circumstellar disks.

  20. Astrometric Confirmation and Preliminary Orbital Parameters of the Young Exoplanet 51 Eridani b with the Gemini Planet Imager

    E-print Network

    De Rosa, Robert J; Blunt, Sarah C; Graham, James R; Konopacky, Quinn M; Marois, Christian; Pueyo, Laurent; Rameau, Julien; Wang, Jason J; Bailey, Vanessa; Chontos, Ashley; Fabrycky, Daniel C; Follette, Katherine B; Macintosh, Bruce; Marchis, Franck; Ammons, S Mark; Arriaga, Pauline; Chilcote, Jeffrey K; Doyon, René; Duchêne, Gaspard; Esposito, Thomas M; Fitzgerald, Michael P; Gerard, Benjamin; Goodsell, Stephen J; Greenbaum, Alexandra Z; Hibon, Pascale; Ingraham, Patrick; Johnson-Groh, Mara; Kalas, Paul G; Lafrenière, David; Maire, Jerome; Metchev, Stanimir; Millar-Blanchaer, Maxwell A; Morzinski, Katie M; Oppenheimer, Rebecca; Patel, Rahul I; Patience, Jennifer L; Perrin, Marshall D; Rajan, Abhijith; Rantakyrö, Fredrik T; Ruffio, Jean-Baptiste; Schneider, Adam C; Sivaramakrishnan, Anand; Song, Inseok; Tran, Debby; Ward-Duong, Kimberly; Wolff, Schuyler G

    2015-01-01

    We present new GPI observations of the young exoplanet 51 Eridani b which provide further evidence that the companion is physically associated with 51 Eridani. Combining this new astrometric measurement with those reported in the literature, we significantly reduce the posterior probability that 51 Eridani b is an unbound foreground or background T-dwarf in a chance alignment with 51 Eridani to $2\\times10^{-7}$, an order of magnitude lower than previously reported. If 51 Eridani b is indeed a bound object, then we have detected orbital motion of the planet between the discovery epoch and the latest epoch. By implementing a computationally efficient Monte Carlo technique, preliminary constraints are placed on the orbital parameters of the system. The current set of astrometric measurements suggest an orbital semi-major axis of $14^{+7}_{-3}$ AU, corresponding to a period of $41^{+35}_{-12}$ yr (assuming a mass of $1.75$ M$_{\\odot}$ for the central star), and an inclination of $138^{+15}_{-13}$ deg. The remaini...

  1. The Gemini NICI Planet-Finding Campaign: The Companion Detection Pipeline

    NASA Astrophysics Data System (ADS)

    Wahhaj, Zahed; Liu, Michael C.; Biller, Beth A.; Nielsen, Eric L.; Close, Laird M.; Hayward, Thomas L.; Hartung, Markus; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2013-12-01

    We present high-contrast image processing techniques used by the Gemini NICI Planet-Finding Campaign to detect faint companions to bright stars. The Near-Infrared Coronographic Imager (NICI) is an adaptive optics instrument installed on the 8 m Gemini South telescope, capable of angular and spectral difference imaging and specifically designed to image exoplanets. The Campaign data pipeline achieves median contrasts of 12.6 mag at 0.''5 and 14.4 mag at 1'' separation, for a sample of 45 stars (V = 4.3-13.9 mag) from the early phase of the campaign. We also present a novel approach to calculating contrast curves for companion detection based on 95% completeness in the recovery of artificial companions injected into the raw data, while accounting for the false-positive rate. We use this technique to select the image processing algorithms that are more successful at recovering faint simulated point sources. We compare our pipeline to the performance of the Locally Optimized Combination of Images (LOCI) algorithm for NICI data and do not find significant improvement with LOCI. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  2. Performance of the Near-infrared coronagraphic imager on Gemini-South

    E-print Network

    Mark Chun; Doug Toomey; Zahed Wahhaj; Beth Biller; Etienne Artigau; Tom Hayward; Mike Liu; Laird Close; Markus Hartung; Francois Rigaut; Christ Ftaclas

    2008-09-17

    We present the coronagraphic and adaptive optics performance of the Gemini-South Near-Infrared Coronagraphic Imager (NICI). NICI includes a dual-channel imager for simultaneous spectral difference imaging, a dedicated 85-element curvature adaptive optics system, and a built-in Lyot coronagraph. It is specifically designed to survey for and image large extra-solar gaseous planets on the Gemini Observatory 8-meter telescope in Chile. We present the on-sky performance of the individual subsystems along with the end-to-end contrast curve. These are compared to our model predictions for the adaptive optics system, the coronagraph, and the spectral difference imaging.

  3. The Gemini NICI planet-finding campaign: The companion detection pipeline

    SciTech Connect

    Wahhaj, Zahed; Liu, Michael C.; Nielsen, Eric L.; Chun, Mark; Ftaclas, Christ; Biller, Beth A.; Close, Laird M.; Hayward, Thomas L.; Hartung, Markus

    2013-12-10

    We present high-contrast image processing techniques used by the Gemini NICI Planet-Finding Campaign to detect faint companions to bright stars. The Near-Infrared Coronographic Imager (NICI) is an adaptive optics instrument installed on the 8 m Gemini South telescope, capable of angular and spectral difference imaging and specifically designed to image exoplanets. The Campaign data pipeline achieves median contrasts of 12.6 mag at 0.''5 and 14.4 mag at 1'' separation, for a sample of 45 stars (V = 4.3-13.9 mag) from the early phase of the campaign. We also present a novel approach to calculating contrast curves for companion detection based on 95% completeness in the recovery of artificial companions injected into the raw data, while accounting for the false-positive rate. We use this technique to select the image processing algorithms that are more successful at recovering faint simulated point sources. We compare our pipeline to the performance of the Locally Optimized Combination of Images (LOCI) algorithm for NICI data and do not find significant improvement with LOCI.

  4. THE GEMINI NICI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF GIANT PLANETS AROUND YOUNG B AND A STARS

    SciTech Connect

    Nielsen, Eric L.; Liu, Michael C.; Chun, Mark; Ftaclas, Christ; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Hartung, Markus; Alencar, Silvia H. P.; Artymowicz, Pawel; Boss, Alan; Clarke, Fraser; De Gouveia Dal Pino, Elisabete; Gregorio-Hetem, Jane; Kuchner, Marc; Lin, Douglas N. C.; and others

    2013-10-10

    We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. Our survey represents the largest, deepest survey for planets around high-mass stars (?1.5-2.5 M{sub ?}) conducted to date and includes the planet hosts ? Pic and Fomalhaut. We obtained follow-up astrometry of all candidate companions within 400 AU projected separation for stars in uncrowded fields and identified new low-mass companions to HD 1160 and HIP 79797. We have found that the previously known young brown dwarf companion to HIP 79797 is itself a tight (3 AU) binary, composed of brown dwarfs with masses 58{sup +21}{sub -20} M{sub Jup} and 55{sup +20}{sub -19} M{sub Jup}, making this system one of the rare substellar binaries in orbit around a star. Considering the contrast limits of our NICI data and the fact that we did not detect any planets, we use high-fidelity Monte Carlo simulations to show that fewer than 20% of 2 M{sub ?} stars can have giant planets greater than 4 M{sub Jup} between 59 and 460 AU at 95% confidence, and fewer than 10% of these stars can have a planet more massive than 10 M{sub Jup} between 38 and 650 AU. Overall, we find that large-separation giant planets are not common around B and A stars: fewer than 10% of B and A stars can have an analog to the HR 8799 b (7 M{sub Jup}, 68 AU) planet at 95% confidence. We also describe a new Bayesian technique for determining the ages of field B and A stars from photometry and theoretical isochrones. Our method produces more plausible ages for high-mass stars than previous age-dating techniques, which tend to underestimate stellar ages and their uncertainties.

  5. The Gemini NICI planet-finding campaign: The offset ring of HR 4796 A

    NASA Astrophysics Data System (ADS)

    Wahhaj, Zahed; Liu, Michael C.; Biller, Beth A.; Nielsen, Eric L.; Hayward, Thomas L.; Kuchner, Marc; Close, Laird M.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2014-07-01

    We present J,H, CH4 short (1.578 ?m), CH4 long (1.652 ?m) and Ks-band images of the dust ring around the 10 Myr old star HR 4796 A obtained using the Near Infrared Coronagraphic Imager (NICI) on the Gemini-South 8.1 m Telescope. Our images clearly show for the first time the position of the star relative to its circumstellar ring thanks to NICI's translucent focal plane occulting mask. We employ a Bayesian Markov chain Monte Carlo method to constrain the offset vector between the two. The resulting probability distribution shows that the ring center is offset from the star by 16.7 ± 1.3 milliarcseconds along a position angle of 26 ± 3°, along the PA of the ring, 26.47 ± 0.04°. We find that the size of this offset is not large enough to explain the brightness asymmetry of the ring. The ring is measured to have mostly red reflectivity across the JHKs filters, which seems to indicate micron-sized grains. Just like Neptune's 3:2 and 2:1 mean-motion resonances delineate the inner and outer edges of the classical Kuiper belt, we find that the radial extent of the HR 4796 A and the Fomalhaut rings could correspond to the 3:2 and 2:1 mean-motion resonances of hypothetical planets at 54.7 AU and 97.7 AU in the two systems, respectively. A planet orbiting HR 4796 A at 54.7 AU would have to be less massive than 1.6 MJup so as not to widen the ring too much by stirring. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).Tables 5 and 6 are available in electronic form at http://www.aanda.org

  6. The Gemini/NICI Planet-Finding Campaign: The Frequency of Planets around Young Moving Group Stars

    NASA Astrophysics Data System (ADS)

    Biller, Beth A.; Liu, Michael C.; Wahhaj, Zahed; Nielsen, Eric L.; Hayward, Thomas L.; Males, Jared R.; Skemer, Andrew; Close, Laird M.; Chun, Mark; Ftaclas, Christ; Clarke, Fraser; Thatte, Niranjan; Shkolnik, Evgenya L.; Reid, I. Neill; Hartung, Markus; Boss, Alan; Lin, Douglas; Alencar, Silvia H. P.; de Gouveia Dal Pino, Elisabete; Gregorio-Hetem, Jane; Toomey, Douglas

    2013-11-01

    We report results of a direct imaging survey for giant planets around 80 members of the ? Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the Gemini/NICI Planet-Finding Campaign. For this sample, we obtained median contrasts of ?H = 13.9 mag at 1'' in combined CH4 narrowband ADI+SDI mode and median contrasts of ?H = 15.1 mag at 2'' in H-band ADI mode. We found numerous (>70) candidate companions in our survey images. Some of these candidates were rejected as common-proper motion companions using archival data; we reobserved with Near-Infrared Coronagraphic Imager (NICI) all other candidates that lay within 400 AU of the star and were not in dense stellar fields. The vast majority of candidate companions were confirmed as background objects from archival observations and/or dedicated NICI Campaign followup. Four co-moving companions of brown dwarf or stellar mass were discovered in this moving group sample: PZ Tel B (36 ± 6 M Jup, 16.4 ± 1.0 AU), CD-35 2722B (31 ± 8 M Jup, 67 ± 4 AU), HD 12894B (0.46 ± 0.08 M ?, 15.7 ± 1.0 AU), and BD+07 1919C (0.20 ± 0.03 M ?, 12.5 ± 1.4 AU). From a Bayesian analysis of the achieved H band ADI and ASDI contrasts, using power-law models of planet distributions and hot-start evolutionary models, we restrict the frequency of 1-20 M Jup companions at semi-major axes from 10-150 AU to <18% at a 95.4% confidence level using DUSTY models and to <6% at a 95.4% using COND models. Our results strongly constrain the frequency of planets within semi-major axes of 50 AU as well. We restrict the frequency of 1-20 M Jup companions at semi-major axes from 10-50 AU to <21% at a 95.4% confidence level using DUSTY models and to <7% at a 95.4% using COND models. This survey is the deepest search to date for giant planets around young moving group stars. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  7. Instrumentation at Gemini Observatory

    NASA Astrophysics Data System (ADS)

    Kleinman, S. J.; Boccas, Maxime; Goodsell, Stephen J.; Gomez, Percy; Murowinski, Rick; Chené, André-Nicolas; Henderson, David

    2014-07-01

    Gemini South's instrument suite has been completely transformed since our last biennial update. We commissioned the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and its associated Gemini South Adaptive Optics Imager (GSAOI) as well as Flamingos-2, our long-slit and multi-object infrared imager and spectrograph, and the Gemini Planet Imager (GPI). We upgraded the CCDs in GMOS-S, our multi-object optical imager and spectrograph, with the GMOS-N CCD upgrade scheduled for 2015. Our next instrument, the Gemini High-resolution Optical SpecTrograph (GHOST) is in its preliminary design stage and we are making plans for the instrument to follow:Gen4#3.

  8. THE GEMINI/NICI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF PLANETS AROUND YOUNG MOVING GROUP STARS

    SciTech Connect

    Biller, Beth A.; Ftaclas, Christ; Liu, Michael C.; Wahhaj, Zahed; Nielsen, Eric L.; Hayward, Thomas L.; Hartung, Markus; Chun, Mark; Clarke, Fraser; Thatte, Niranjan; Shkolnik, Evgenya L.; Reid, I. Neill; Boss, Alan; Lin, Douglas; Alencar, Silvia H. P.; De Gouveia Dal Pino, Elisabete; Gregorio-Hetem, Jane [Universidade de Sao Paulo, IAG and others

    2013-11-10

    We report results of a direct imaging survey for giant planets around 80 members of the ? Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra moving groups, observed as part of the Gemini/NICI Planet-Finding Campaign. For this sample, we obtained median contrasts of ?H = 13.9 mag at 1'' in combined CH{sub 4} narrowband ADI+SDI mode and median contrasts of ?H = 15.1 mag at 2'' in H-band ADI mode. We found numerous (>70) candidate companions in our survey images. Some of these candidates were rejected as common-proper motion companions using archival data; we reobserved with Near-Infrared Coronagraphic Imager (NICI) all other candidates that lay within 400 AU of the star and were not in dense stellar fields. The vast majority of candidate companions were confirmed as background objects from archival observations and/or dedicated NICI Campaign followup. Four co-moving companions of brown dwarf or stellar mass were discovered in this moving group sample: PZ Tel B (36 ± 6 M{sub Jup}, 16.4 ± 1.0 AU), CD–35 2722B (31 ± 8 M{sub Jup}, 67 ± 4 AU), HD 12894B (0.46 ± 0.08 M{sub ?}, 15.7 ± 1.0 AU), and BD+07 1919C (0.20 ± 0.03 M{sub ?}, 12.5 ± 1.4 AU). From a Bayesian analysis of the achieved H band ADI and ASDI contrasts, using power-law models of planet distributions and hot-start evolutionary models, we restrict the frequency of 1-20 M{sub Jup} companions at semi-major axes from 10-150 AU to <18% at a 95.4% confidence level using DUSTY models and to <6% at a 95.4% using COND models. Our results strongly constrain the frequency of planets within semi-major axes of 50 AU as well. We restrict the frequency of 1-20 M{sub Jup} companions at semi-major axes from 10-50 AU to <21% at a 95.4% confidence level using DUSTY models and to <7% at a 95.4% using COND models. This survey is the deepest search to date for giant planets around young moving group stars.

  9. The Gemini NICI Planet-Finding Campaign: The Offset Ring of HR 4796 A

    NASA Technical Reports Server (NTRS)

    Wahhaj, Zahed; Liu, Michael C.; Biller, Beth A.; Nielsen, Eric L.; Hayward, Thomas L.; Kuchner, Marc J.; Close, Laird M.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2014-01-01

    We present J, H, CH4 short (1.578 micrometers), CH4 long (1.652 micrometers) and K(sub s)-band images of the dust ring around the 10 Myr old star HR 4796 A obtained using the Near Infrared Coronagraphic Imager (NICI) on the Gemini-South 8.1 m Telescope. Our images clearly show for the first time the position of the star relative to its circumstellar ring thanks to NICI's translucent focal plane occulting mask. We employ a Bayesian Markov chain Monte Carlo method to constrain the offset vector between the two. The resulting probability distribution shows that the ring center is offset from the star by 16.7 +/- 1.3 milliarcseconds along a position angle of 26 +/- 3deg, along the PA of the ring, 26.47 +/- 0.04deg. We find that the size of this offset is not large enough to explain the brightness asymmetry of the ring. The ring is measured to have mostly red reflectivity across the JHKs filters, which seems to indicate micron-sized grains. Just like Neptune's 3:2 and 2:1 mean-motion resonances delineate the inner and outer edges of the classical Kuiper belt, we find that the radial extent of the HR 4796 A and the Fomalhaut rings could correspond to the 3:2 and 2:1 mean-motion resonances of hypothetical planets at 54.7 AU and 97.7 AU in the two systems, respectively. A planet orbiting HR 4796 A at 54.7 AU would have to be less massive than 1.6 Jup mass so as not to widen the ring too much by stirring.

  10. Wide Giant Planets are Rare: Planet Demographics from Direct Imaging

    NASA Astrophysics Data System (ADS)

    Biller, Beth

    2015-08-01

    The previous generation of direct imaging surveys probed samples of 100-200 stars with AO-driven coronagraphic imaging and advanced techniques such as Angular Differential Imaging (ADI) (e.g. surveys such as SEEDS, IDPS, the NICI Science Campaign, among others). These surveys found that wide giant planets are comparatively rare, especially at separations > 50 AU: for instance, Biller et al. 2013 find for a sample of 78 young moving group stars that the the frequency of 1-20 M Jup companions at semi-major axes from 10-150 AU is <18% at a 95.4% confidence level using DUSTY models and <6% at a 95.4% using COND models. As next generation planet-finding cameras such as GPI at Gemini, SPHERE at VLT, project 1640, and SceXAO at Suburu come online, our understanding of wide planet populations is likely to undergo a rapid evolution, especially for planets at separations of 10-50 AU. New large-scale surveys (400-500 stars) are now underway with these new instruments, e.g. NIRSUR with SPHERE and GPIES with GPI. In this talk, I will review the previous generation of surveys and the statistical results that they have yielded. I will also discuss prospects for the new generation of ongoing surveys.

  11. Direct imaging of multiple planets orbiting the star HR 8799.

    PubMed

    Marois, Christian; Macintosh, Bruce; Barman, Travis; Zuckerman, B; Song, Inseok; Patience, Jennifer; Lafrenière, David; Doyon, René

    2008-11-28

    Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step toward imaging Earth-like planets. Imaging detections are challenging because of the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our solar system. PMID:19008415

  12. Direct imaging of multiple planets orbiting the star HR 8799

    SciTech Connect

    Marois, C; Macintosh, B; Barman, T; Zuckerman, B; Song, I; Patience, J; Lafreniere, D; Doyon, R

    2008-10-14

    Direct imaging of exoplanetary systems is a powerful technique that can reveal Jupiter-like planets in wide orbits, can enable detailed characterization of planetary atmospheres, and is a key step towards imaging Earth-like planets. Imaging detections are challenging due to the combined effect of small angular separation and large luminosity contrast between a planet and its host star. High-contrast observations with the Keck and Gemini telescopes have revealed three planets orbiting the star HR 8799, with projected separations of 24, 38, and 68 astronomical units. Multi-epoch data show counter-clockwise orbital motion for all three imaged planets. The low luminosity of the companions and the estimated age of the system imply planetary masses between 5 and 13 times that of Jupiter. This system resembles a scaled-up version of the outer portion of our Solar System.

  13. The Planet Formation Imager

    NASA Astrophysics Data System (ADS)

    Kraus, S.; Buscher, D. F.; Monnier, J. D.; PFI Science, the; Technical Working Group

    2014-04-01

    Among the most fascinating and hotly-debated areas in contemporary astrophysics are the means by which planetary systems are assembled from the large rotating disks of gas and dust which attend a stellar birth. Although important work is being done both in theory and observation, a full understanding of the physics of planet formation can only be achieved by opening observational windows able to directly witness the process in action. The key requirement is then to probe planet-forming systems at the natural spatial scales over which material is being assembled. By definition, this is the so-called Hill Sphere which delineates the region of influence of a gravitating body within its surrounding environment. The Planet Formation Imager project has crystallized around this challenging goal: to deliver resolved images of Hill-Sphere-sized structures within candidate planet-hosting disks in the nearest star-forming regions. In this contribution we outline the primary science case of PFI and discuss how PFI could significantly advance our understanding of the architecture and potential habitability of planetary systems. We present radiation-hydrodynamics simulations from which we derive preliminary specifications that guide the design of the facility. Finally, we give an overview about the interferometric and non-interferometric technologies that we are investigating in order to meet the specifications.

  14. The Gemini NICI planet-finding campaign: the orbit of the young exoplanet ? Pictoris b

    SciTech Connect

    Nielsen, Eric L.; Liu, Michael C.; Chun, Mark; Ftaclas, Christ; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Kuchner, Marc J.; Rodigas, Timothy J.; Toomey, Douglas W.

    2014-10-20

    We present new astrometry for the young (12-21 Myr) exoplanet ? Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of ? Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.1{sub ?0.5}{sup +5.3} AU and orbital eccentricity <0.15 at 68% confidence (with 95% confidence intervals of 8.2-48 AU and 0.00-0.82 for semi-major axis and eccentricity, respectively, due to a long narrow degenerate tail between the two). We find that the planet has reached its maximum projected elongation, enabling higher precision determination of the orbital parameters than previously possible, and that the planet's projected separation is currently decreasing. With unsaturated data of the entire ? Pic system (primary star, planet, and disk) obtained thanks to NICI's semi-transparent focal plane mask, we are able to tightly constrain the relative orientation of the circumstellar components. We find the orbital plane of the planet lies between the inner and outer disks: the position angle (P.A.) of nodes for the planet's orbit (211.8 ± 0.°3) is 7.4? greater than the P.A. of the spine of the outer disk and 3.2? less than the warped inner disk P.A., indicating the disk is not collisionally relaxed. Finally, for the first time we are able to dynamically constrain the mass of the primary star ? Pic to 1.76{sub ?0.17}{sup +0.18} M {sub ?}.

  15. The Gemini NICI Planet-Finding Campaign: The Orbit of the Young Exoplanet Beta Pictoris b

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric L.; Liu, Michael C.; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Males, Jared R.; Close, Laird M.; Morzinski, Katie M.; Skemer, Andrew J.; Kuchner, Marc J.; Rodigas, Timothy J.; Hinz, Philip M.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2014-01-01

    We present new astrometry for the young (12-21 Myr) exoplanet beta Pictoris b taken with the Gemini/NICI and Magellan/MagAO instruments between 2009 and 2012. The high dynamic range of our observations allows us to measure the relative position of beta Pic b with respect to its primary star with greater accuracy than previous observations. Based on a Markov Chain Monte Carlo analysis, we find the planet has an orbital semi-major axis of 9.1 (+ 5.3 / - 0.5) AU and orbital eccentricity less than 0.15 at 68% confidence (with 95% confidence intervals of 8.2 - 48 AU and 0.00 - 0.82 for semi-major axis and eccentricity, respectively, due to a long narrow degenerate tail between the two). We find that the planet has reached its maximum projected elongation, enabling higher precision determination of the orbital parameters than previously possible, and that the planet's projected separation is currently decreasing. With unsaturated data of the entire beta Pic system (primary star, planet, and disk) obtained thanks to NICI's semitransparent focal plane mask, we are able to tightly constrain the relative orientation of the circumstellar components. We find the orbital plane of the planet lies between the inner and outer disks: the position angle (P.A.) of nodes for the planet's orbit (211.8 +/- 0.3 deg) is 7.4 sigma greater than the P.A. of the spine of the outer disk and 3.2 sigma less than the warped inner disk P.A., indicating the disk is not collisionally relaxed. Finally, for the first time we are able to dynamically constrain the mass of the primary star beta Pic to 1.76 (+0.18 / -0.27) solar mass.

  16. Image resolutions for ERTS, SKYLAB and GEMINI/APOLLO

    USGS Publications Warehouse

    Colvocoresses, Alden P.

    1972-01-01

    Early in 1972 the first Earth Resource Technology Satellite (ERTS-A) is scheduled for launch in near-polar orbit. It will carry three return-beam-vidicon (RBV) TB cameras and a multispectral scanner (MSS). In 1973 a post-Apollo manned space flight called SKYLAB will orbit the earth at an inclination of 50° to the Equator. In addition to other sensors it will carry a battery of six multispectral cameras identified as experiment S190. This paper compares the images expected from ERTS and SKYLAB with those already obtained from GEMINI/APOLLO, all in terms of the photographic criterion of resolution. Recently provided data have led to several changes in the resolution of ERTS-A forecast a year ago (Colvocoresses, 1970).

  17. The Gemini NICI Planet-finding Campaign: Discovery of a Close Substellar Companion to the Young Debris Disk Star PZ Tel

    NASA Astrophysics Data System (ADS)

    Biller, Beth A.; Liu, Michael C.; Wahhaj, Zahed; Nielsen, Eric L.; Close, Laird M.; Dupuy, Trent J.; Hayward, Thomas L.; Burrows, Adam; Chun, Mark; Ftaclas, Christ; Clarke, Fraser; Hartung, Markus; Males, Jared; Reid, I. Neill; Shkolnik, Evgenya L.; Skemer, Andrew; Tecza, Matthias; Thatte, Niranjan; Alencar, Silvia H. P.; Artymowicz, Pawel; Boss, Alan; de Gouveia Dal Pino, Elisabete; Gregorio-Hetem, Jane; Ida, Shigeru; Kuchner, Marc J.; Lin, Douglas; Toomey, Douglas

    2010-09-01

    We report the discovery of a tight substellar companion to the young solar analog PZ Tel, a member of the ? Pic moving group observed with high-contrast adaptive optics imaging as part of the Gemini Near-Infrared Coronagraphic Imager Planet-Finding Campaign. The companion was detected at a projected separation of 16.4 ± 1.0 AU (0farcs33 ± 0farcs01) in 2009 April. Second-epoch observations in 2010 May demonstrate that the companion is physically associated and shows significant orbital motion. Monte Carlo modeling constrains the orbit of PZ Tel B to eccentricities >0.6. The near-IR colors of PZ Tel B indicate a spectral type of M7 ± 2 and thus this object will be a new benchmark companion for studies of ultracool, low-gravity photospheres. Adopting an age of 12+8 -4 Myr for the system, we estimate a mass of 36 ± 6 M Jup based on the Lyon/DUSTY evolutionary models. PZ Tel B is one of the few young substellar companions directly imaged at orbital separations similar to those of giant planets in our own solar system. Additionally, the primary star PZ Tel A shows a 70 ?m emission excess, evidence for a significant quantity of circumstellar dust that has not been disrupted by the orbital motion of the companion. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  18. The Gemini NICI Planet-Finding Campaign: Discovery of a Multiple System Orbiting the Young A Star HD 1160

    NASA Astrophysics Data System (ADS)

    Nielsen, Eric L.; Liu, Michael C.; Wahhaj, Zahed; Biller, Beth A.; Hayward, Thomas L.; Boss, Alan; Bowler, Brendan; Kraus, Adam; Shkolnik, Evgenya L.; Tecza, Matthias; Chun, Mark; Clarke, Fraser; Close, Laird M.; Ftaclas, Christ; Hartung, Markus; Males, Jared R.; Reid, I. Neill; Skemer, Andrew J.; Alencar, Silvia H. P.; Burrows, Adam; de Gouveia Dal Pino, Elisabethe; Gregorio-Hetem, Jane; Kuchner, Marc; Thatte, Niranjan; Toomey, Douglas W.

    2012-05-01

    We report the discovery of two low-mass companions to the young A0V star HD 1160 at projected separations of 81 ± 5 AU (HD 1160 B) and 533 ± 25 AU (HD 1160 C) by the Gemini NICI Planet-Finding Campaign. Very Large Telescope images of the system taken over a decade for the purpose of using HD 1160 A as a photometric calibrator confirm that both companions are physically associated. By comparing the system to members of young moving groups and open clusters with well-established ages, we estimate an age of 50+50 - 40 Myr for HD 1160 ABC. While the UVW motion of the system does not match any known moving group, the small magnitude of the space velocity is consistent with youth. Near-IR spectroscopy shows HD 1160 C to be an M3.5 ± 0.5 star with an estimated mass of 0.22+0.03 - 0.04 M ?, while NIR photometry of HD 1160 B suggests a brown dwarf with a mass of 33+12 - 9 M Jup. The very small mass ratio (0.014) between the A and B components of the system is rare for A star binaries, and would represent a planetary-mass companion were HD 1160 A to be slightly less massive than the Sun.

  19. THE GEMINI NICI PLANET-FINDING CAMPAIGN: DISCOVERY OF A MULTIPLE SYSTEM ORBITING THE YOUNG A STAR HD 1160

    SciTech Connect

    Nielsen, Eric L.; Liu, Michael C.; Wahhaj, Zahed; Bowler, Brendan; Kraus, Adam; Chun, Mark; Ftaclas, Christ; Biller, Beth A.; Hayward, Thomas L.; Shkolnik, Evgenya L.; Tecza, Matthias; Clarke, Fraser; Close, Laird M.; Hartung, Markus; Males, Jared R.; Skemer, Andrew J.; Reid, I. Neill; Alencar, Silvia H. P.; Burrows, Adam; and others

    2012-05-01

    We report the discovery of two low-mass companions to the young A0V star HD 1160 at projected separations of 81 {+-} 5 AU (HD 1160 B) and 533 {+-} 25 AU (HD 1160 C) by the Gemini NICI Planet-Finding Campaign. Very Large Telescope images of the system taken over a decade for the purpose of using HD 1160 A as a photometric calibrator confirm that both companions are physically associated. By comparing the system to members of young moving groups and open clusters with well-established ages, we estimate an age of 50{sup +50}{sub -40} Myr for HD 1160 ABC. While the UVW motion of the system does not match any known moving group, the small magnitude of the space velocity is consistent with youth. Near-IR spectroscopy shows HD 1160 C to be an M3.5 {+-} 0.5 star with an estimated mass of 0.22{sup +0.03}{sub -0.04} M{sub Sun }, while NIR photometry of HD 1160 B suggests a brown dwarf with a mass of 33{sup +12}{sub -9} M{sub Jup}. The very small mass ratio (0.014) between the A and B components of the system is rare for A star binaries, and would represent a planetary-mass companion were HD 1160 A to be slightly less massive than the Sun.

  20. Planet Imager Discovers Young Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    A debris disk just discovered around a nearby star is the closest thing yet seen to a young version of the Kuiper belt. This disk could be a key to better understanding the interactions between debris disks and planets, as well as how our solar system evolved early on in its lifetime.Hunting for an analogThe best way to understand how the Kuiper belt home to Pluto and thousands of other remnants of early icy planet formation in our solar system developed would be to witness a similar debris disk in an earlier stage of its life. But before now, none of the disks weve discovered have been similar to our own: the rings are typically too large, the central star too massive, or the stars exist in regions very unlike what we think our Suns birthplace was like.A collaboration led by Thayne Currie (National Astronomical Observatory of Japan) has changed this using the Gemini Planet Imager (GPI), part of a new generation of extreme adaptive-optics systems. The team discovered a debris disk of roughly the same size as the Kuiper belt orbiting the star HD 115600, located in the nearest OB association. The star is only slightly more massive than our Sun, and it lives in a star-forming region similar to the early Suns environment. HD 115600 is different in one key way, however: it is only 15 million years old. This means that observing it gives us the perfect opportunity to observe how our solar system might have behaved when it was much younger.A promising futureGPIs spatially-resolved spectroscopy, combined with measurements of the reflectivity of the disk, have led the team to suspect that the disk might be composed partly of water ice, just as the Kuiper belt is. The disk also shows evidence of having been sculpted by the motions of giant planets orbiting the central star, in much the same way as the outer planets of our solar system may have shaped the Kuiper belt.The observations of HD 115600 are some of the very first to emerge from GPI and the new generation of planet-hunting instruments. The detection of this disk provides a promising outlook on what we can expect to discover in the future with these systems.Citation:Thayne Currie et al.2015 ApJ 807 L7 doi:10.1088/2041-8205/807/1/L7

  1. Planet Imager Discovers Young Kuiper Belt

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-07-01

    A debris disk just discovered around a nearby star is the closest thing yet seen to a young version of the Kuiper belt. This disk could be a key to better understanding the interactions between debris disks and planets, as well as how our solar system evolved early on in its lifetime. Hunting for an analog The best way to understand how the Kuiper belt — home to Pluto and thousands of other remnants of early icy planet formation in our solar system — developed would be to witness a similar debris disk in an earlier stage of its life. But before now, none of the disks we've discovered have been similar to our own: the rings are typically too large, the central star too massive, or the stars exist in regions very unlike what we think our Sun's birthplace was like. A collaboration led by Thayne Currie (National Astronomical Observatory of Japan) has changed this using the Gemini Planet Imager (GPI), part of a new generation of extreme adaptive-optics systems. The team discovered a debris disk of roughly the same size as the Kuiper belt orbiting the star HD 115600, located in the nearest OB association. The star is only slightly more massive than our Sun, and it lives in a star-forming region similar to the early Sun's environment. HD 115600 is different in one key way, however: it is only 15 million years old. This means that observing it gives us the perfect opportunity to observe how our solar system might have behaved when it was much younger. A promising future GPI's spatially-resolved spectroscopy, combined with measurements of the reflectivity of the disk, have led the team to suspect that the disk might be composed partly of water ice, just as the Kuiper belt is. The disk also shows evidence of having been sculpted by the motions of giant planets orbiting the central star, in much the same way as the outer planets of our solar system may have shaped the Kuiper belt. The observations of HD 115600 are some of the very first to emerge from GPI and the new generation of planet-hunting instruments. The detection of this disk provides a promising outlook on what we can expect to discover in the future with these systems. Citation: Thayne Currie et al. 2015 ApJ 807 L7 doi:10.1088/2041-8205/807/1/L7

  2. Adaptive Wavefront Calibration and Control for the Gemini Planet Imager

    SciTech Connect

    Poyneer, L A; Veran, J

    2007-02-02

    Quasi-static errors in the science leg and internal AO flexure will be corrected. Wavefront control will adapt to current atmospheric conditions through Fourier modal gain optimization, or the prediction of atmospheric layers with Kalman filtering.

  3. RECOVERY OF THE CANDIDATE PROTOPLANET HD 100546 b WITH GEMINI/NICI AND DETECTION OF ADDITIONAL (PLANET-INDUCED?) DISK STRUCTURE AT SMALL SEPARATIONS

    SciTech Connect

    Currie, Thayne; Kudo, Tomoyuki; Muto, Takayuki; Honda, Mitsuhiko; Brandt, Timothy D.; Grady, Carol; Fukagawa, Misato; Burrows, Adam; Janson, Markus; Kuzuhara, Masayuki; McElwain, Michael W.; Follette, Katherine; Hashimoto, Jun; Henning, Thomas; Kandori, Ryo; Kusakabe, Nobuhiko; Morino, Jun-ichi; Nishikawa, Jun; Kwon, Jungmi; Mede, Kyle; and others

    2014-12-01

    We report the first independent, second epoch (re-)detection of a directly imaged protoplanet candidate. Using L' high-contrast imaging of HD 100546 taken with the Near-Infrared Coronagraph and Imager on Gemini South, we recover ''HD 100546 b'' with a position and brightness consistent with the original Very Large Telescope/NAos-COnica detection from Quanz et al., although data obtained after 2013 will be required to decisively demonstrate common proper motion. HD 100546 b may be spatially resolved, up to ?12-13 AU in diameter, and is embedded in a finger of thermal IR-bright, polarized emission extending inward to at least 0.''3. Standard hot-start models imply a mass of ?15 M{sub J} . However, if HD 100546 b is newly formed or made visible by a circumplanetary disk, both of which are plausible, its mass is significantly lower (e.g., 1-7 M{sub J} ). Additionally, we discover a thermal IR-bright disk feature, possibly a spiral density wave, at roughly the same angular separation as HD 100546 b but 90° away. Our interpretation of this feature as a spiral arm is not decisive, but modeling analyses using spiral density wave theory implies a wave launching point exterior to ?0.''45 embedded within the visible disk structure: plausibly evidence for a second, hitherto unseen, wide-separation planet. With one confirmed protoplanet candidate and evidence for one to two others, HD 100546 is an important evolutionary precursor to intermediate-mass stars with multiple super-Jovian planets at moderate/wide separations like HR 8799.

  4. Infrared imaging of extrasolar planets

    NASA Technical Reports Server (NTRS)

    Diner, David J.; Tubbs, Eldred F.; Gaiser, Steven L.; Korechoff, Robert P.

    1991-01-01

    An optical system for direct detection, in the infrared, of planets orbiting other stars is described. The proposed system consists of a large aperture (about 16 m) space-based telescope to which is attached a specialized imaging instrument containing a set of optical signal processing elements to suppress diffracted light from the central star. Starlight suppression is accomplished using coronagraphic apodization combined with rotational shearing interferometry. The possibility of designing the large telescope aperture to be of a deployable, multiarm configuration is examined, and it is shown that there is some sacrifice in performance relative to a filled, circular aperture.

  5. Cryogenic mechanical design of the Gemini South Adaptive Optics Imager (GSAOI)

    NASA Astrophysics Data System (ADS)

    Stevanovic, Dejan; Hart, John

    2004-09-01

    The Research School of Astronomy and Astrophysics (RSAA) of the Australian National University (ANU) has designed and constructed The Gemini South Adaptive Optics Imager (GSAOI) that will be used with the Multi-Conjugate Adaptive Optics system on the Gemini South telescope in Chile. GSAOI contains three cryogenic mechanisms; two filter wheels and a utility wheel. An approach to the athermalization of cryogenic mechanisms is presented. The 280 mm diameter filter wheels are athermalized using bi-material conical bearing seats where the bearing preload is constant, irrespective of temperature. The lens mounting method is also described. Lenses up to 170 mm in diameter are mounted within precision cells such that radial clearances reduce to zero at operating temperature. The method used to derive the room-temperature lens and cell dimensions is described. Lenses are preloaded axially against conical seats using wave washers. This technique has been used successfully to mount lenses of ~100 mm diameter in the Gemini Near-infrared Integral Field Spectrograph (NIFS), also designed and constructed by RSAA.

  6. Beta Pictoris planet finally imaged?

    NASA Astrophysics Data System (ADS)

    2008-11-01

    A team of French astronomers using ESO's Very Large Telescope have discovered an object located very close to the star Beta Pictoris, and which apparently lies inside its disc. With a projected distance from the star of only 8 times the Earth-Sun distance, this object is most likely the giant planet suspected from the peculiar shape of the disc and the previously observed infall of comets onto the star. It would then be the first image of a planet that is as close to its host star as Saturn is to the Sun. Sharpening Up Jupiter ESO PR Photo 42a/08 Beta Pictoris as seen in infrared light The hot star Beta Pictoris is one of the best-known examples of stars surrounded by a dusty 'debris' disc. Debris discs are composed of dust resulting from collisions among larger bodies like planetary embryos or asteroids. They are a bigger version of the zodiacal dust in our Solar System. Its disc was the first to be imaged -- as early as 1984 -- and remains the best-studied system. Earlier observations showed a warp of the disc, a secondary inclined disc and infalling comets onto the star. "These are indirect, but tell-tale signs that strongly suggest the presence of a massive planet lying between 5 and 10 times the mean Earth-Sun distance from its host star," says team leader Anne-Marie Lagrange. "However, probing the very inner region of the disc, so close to the glowing star, is a most challenging task." In 2003, the French team used the NAOS-CONICA instrument (or NACO [1]), mounted on one of the 8.2 m Unit Telescopes of ESO's Very Large Telescope (VLT), to benefit from both the high image quality provided by the Adaptive Optics system at infrared wavelengths and the good dynamics offered by the detector, in order to study the immediate surroundings of Beta Pictoris. Recently, a member of the team re-analysed the data in a different way to seek the trace of a companion to the star. Infrared wavelengths are indeed very well suited for such searches. "For this, the real challenge is to identify and subtract as accurately as possible the bright stellar halo," explains Lagrange. "We were able to achieve this after a precise and drastic selection of the best images recorded during our observations." The strategy proved very rewarding, as the astronomers were able to discern a feeble, point-like glow well inside the star's halo. To eliminate the possibility that this was an artefact and not a real object, a battery of tests was conducted and several members of the team, using three different methods, did the analysis independently, always with the same success. Moreover, the companion was also discovered in other data sets, further strengthening the team's conclusion: the companion is real. "Our observations point to the presence of a giant planet, about 8 times as massive as Jupiter and with a projected distance from its star of about 8 times the Earth-Sun distance, which is about the distance of Saturn in our Solar System [2]," says Lagrange. "We cannot yet rule out definitively, however, that the candidate companion could be a foreground or background object," cautions co-worker Gael Chauvin. "To eliminate this very small possibility, we will need to make new observations that confirm the nature of the discovery." The team also dug into the archives of the Hubble Space Telescope but couldn't see anything, "while most possible foreground or background objects would have been detected", remarks another team member, David Ehrenreich. The fact that the candidate companion lies in the plane of the disc also strongly implies that it is bound to the star and its proto-planetary disc. "Moreover, the candidate companion has exactly the mass and distance from its host star needed to explain all the disc's properties. This is clearly another nail in the coffin of the false alarm hypothesis," adds Lagrange. When confirmed, this candidate companion will be the closest planet from its star ever imaged. In particular, it will be located well inside the orbits of

  7. The Gemini NICI Planet-Finding Campaign: asymmetries in the HD 141569 disc

    NASA Astrophysics Data System (ADS)

    Biller, Beth A.; Liu, Michael C.; Rice, Ken; Wahhaj, Zahed; Nielsen, Eric; Hayward, Thomas; Kuchner, Marc J.; Close, Laird M.; Chun, Mark; Ftaclas, Christ; Toomey, Douglas W.

    2015-07-01

    We report here the highest resolution near-IR imaging to date of the HD 141569A disc taken as part of the NICI (near infrared coronagraphic imager) Science Campaign. We recover four main features in the NICI images of the HD 141569 disc discovered in previous Hubble Space Telescope (HST) imaging: (1) an inner ring/spiral feature. Once deprojected, this feature does not appear circular. (2) An outer ring which is considerably brighter on the western side compared to the eastern side, but looks fairly circular in the deprojected image. (3) An additional arc-like feature between the inner and outer ring only evident on the east side. In the deprojected image, this feature appears to complete the circle of the west side inner ring and (4) an evacuated cavity from 175 au inwards. Compared to the previous HST imaging with relatively large coronagraphic inner working angles (IWA), the NICI coronagraph allows imaging down to an IWA of 0.3 arcsec. Thus, the inner edge of the inner ring/spiral feature is well resolved and we do not find any additional disc structures within 175 au. We note some additional asymmetries in this system. Specifically, while the outer ring structure looks circular in this deprojection, the inner bright ring looks rather elliptical. This suggests that a single deprojection angle is not appropriate for this system and that there may be an offset in inclination between the two ring/spiral features. We find an offset of 4 ± 2 au between the inner ring and the star centre, potentially pointing to unseen inner companions.

  8. High Contrast Imaging of Extrasolar Planets

    E-print Network

    John H. Debes; Jian Ge

    2003-01-03

    Gaussian aperture pupil masks (GAPMs) can in theory achieve the contrast requisite for directly imaging an extrasolar planet. We use lab tests and simulations to further study their possible place as a high contrast imaging technique. We present lab comparisons with traditional Lyot coronagraphs and simulations of GAPMs and other high contrast imaging techniques on HST.

  9. Direct Imaging of Warm Extrasolar Planets

    SciTech Connect

    Macintosh, B

    2005-04-11

    One of the most exciting scientific discoveries in the last decade of the twentieth century was the first detection of planets orbiting a star other than our own. By now more than 130 extrasolar planets have been discovered indirectly, by observing the gravitational effects of the planet on the radial velocity of its parent star. This technique has fundamental limitations: it is most sensitive to planets close to their star, and it determines only a planet's orbital period and a lower limit on the planet's mass. As a result, all the planetary systems found so far are very different from our own--they have giant Jupiter-sized planets orbiting close to their star, where the terrestrial planets are found in our solar system. Such systems have overturned the conventional paradigm of planet formation, but have no room in them for habitable Earth-like planets. A powerful complement to radial velocity detections of extrasolar planets will be direct imaging--seeing photons from the planet itself. Such a detection would allow photometric measurements to determine the temperature and radius of a planet. Also, direct detection is most sensitive to planets in wide orbits, and hence more capable of seeing solar systems resembling our own, since a giant planet in a wide orbit does not preclude the presence of an Earth-like planet closer to the star. Direct detection, however, is extremely challenging. Jupiter is roughly a billion times fainter than our sun. Two techniques allowed us to overcome this formidable contrast and attempt to see giant planets directly. The first is adaptive optics (AO) which allows giant earth-based telescopes, such as the 10 meter W.M. Keck telescope, to partially overcome the blurring effects of atmospheric turbulence. The second is looking for young planets: by searching in the infrared for companions to young stars, we can see thermal emission from planets that are still warm with the heat of their formation. Together with a UCLA team that leads the field of young-star identification, we carried out a systematic near-infrared search for young planetary companions to {approx}200 young stars. We also carried out targeted high-sensitivity observations of selected stars surrounded by circumstellar dust rings. We developed advanced image processing techniques to allow detection of even fainter sources buried in the noisy halo of scattered starlight. Even with these techniques, around most of our targets our search was only sensitive to planets in orbits significantly wider than our solar system. With some carefully selected targets--very young dusty stars in the solar neighborhood--we reach sensitivities sufficient to see solar systems like our own. Although we discovered no unambiguous planets, we can significantly constrain the frequency of such planets in wide (>50 AU) orbits, which helps determine which models of planet formation remain plausible. Successful modeling of our observations has led us to the design of a next-generation AO system that will truly be capable of exploring solar systems resembling our own.

  10. Polarization of Directly Imaged Young Giant Planets as a Probe of Mass, Rotation, and Clouds

    NASA Technical Reports Server (NTRS)

    Marley, Mark Scott; Sengupta, Sujan

    2012-01-01

    Young, hot gas giant planets at large separations from their primaries have been directly imaged around several nearby stars. More such planets will likely be detected by ongoing and new imaging surveys with instruments such as the Gemini Planet Imager (GPI). Efforts continue to model the spectra of these planets in order to constrain their masses, effective temperatures, composition, and cloud structure. One potential tool for analyzing these objects, which has received relatively less attention, is polarization. Linear polarization of gas giant exoplanets can arise from the combined influences of light scattering by atmospheric dust and a rotationally distorted shape. The oblateness of gas giant planet increases of course with rotation rate and for fixed rotation also rises with decreasing gravity. Thus young, lower mass gas giant planets with youthful inflated radii could easily have oblateness greater than that of Saturn s 10%. We find that polarizations of over 1% may easily be produced in the near-infrared in such cases. This magnitude of polarization may be measurable by GPI and other instruments. Thus if detected, polarization of a young Jupiter places constraints on the combination of its gravity, rotation rate, and degree of cloudiness. We will present results of our multiple scattering analysis coupled with a self-consistent dusty atmospheric models to demonstrate the range of polarizations that might be expected from resolved exoplanets and the range of parameter space that such observations may inform.

  11. Gemini Mid-Infrared Imaging of Massive Young Stellar Objects in NGC 3576

    E-print Network

    C. L. Barbosa; A. Damineli; R. D. Blum; P. S. Conti

    2003-08-11

    We present a mid-infrared study of NGC 3576. The high-resolution images were taken at the Gemini South Observatory through narrow and broad band filters centered between 7.9 micron and 18 micron. The nearly diffraction limited images show IRS 1 resolved into 4 sources for the first time in the 10 micron band. The positions of the sources are coincident with massive young stellar objects detected previously in the near infrared. The properties of each object, such as spectral energy distribution, silicate absorption feature, color temperature and luminosities were obtained and are discussed. We also report observations of two other YSO candidates and the detection of a new diffuse MIR source without a NIR counterpart. We conclude that none of these sources contributes significantly to the ionization of the HII region. A possible location for the ionization source of NGC 3576 is suggested based on both radio and infrared data.

  12. Pupil Replication for exo-planet imaging

    E-print Network

    Greenaway, Alan

    Pupil Replication for exo-planet imaging Frank Spaan Alan Greenaway #12;14-15 December 2005 Durham replication helps 0 5 10 15 20 -12 -10 -8 -6 -4 -2 0 Off Axis Distance LogIntensity(normalised) diffraction · Start with normal telescope · Include replication optics and second imaging lens. · Axial wavefront

  13. A bright future for direct imaging of extrasolar planets

    E-print Network

    Guyon, Olivier

    photometry & polarization exozodi map planet position Direct imaging (Visible or IR) Planet formation models planetary formation models · CHARACTERIZATION: · Study planet formation by imaging both disks and planets & fabrication for Space 1st generation optics (diamond turned Al) 2nd generation optics (Zerodur) #12;PIAA

  14. Direct imaging of extra-solar planets

    SciTech Connect

    Olivier, S.S.; Max, V.E.; Brase, J.M.; Caffano, C.J.; Gavel, D.T.; Macintosh, B.A.

    1997-03-01

    Direct imaging of extra-solar planets may be possible with the new generation of large ground-based telescopes equipped with state- of- the-art adaptive optics (AO) systems to compensate for the blurring effect of the Earth`s atmosphere. The first of these systems is scheduled to begin operation in 1998 on the 10 in Keck II telescope. In this paper, general formulas for high-contrast imaging with AO systems are presented and used to calculate the sensitivity of the Keck AO system. The results of these calculations show that the Keck AO system should achieve the sensitivity necessary to detect giant planets around several nearby bright stars.

  15. Imaging Spectroscopy for Extrasolar Planet Detection

    E-print Network

    William B. Sparks; Holland C. Ford

    2002-09-04

    Coronagraphic imaging in combination with moderate to high spectral resolution may prove more effective in both detecting extrasolar planets and characterizing them than a standard coronagraphic imaging approach. We envisage an integral-field spectrograph coupled to a coronagraph to produce a 3D datacube. For the idealised case where the spectrum of the star is well-known and unchanging across the field, we discuss the utility of cross-correlation to seek the extrasolar planet signal, and describe a mathematical approach to completely eliminate stray light from the host star (although not its Poisson noise). For the case where the PSF is dominated by diffraction and scattering effects, and comprises a multitude of speckles within an Airy pattern typical of a space-based observation, we turn the wavelength dependence of the PSF to advantage and present a general way to eliminate the contribution from the star while preserving both the flux and spectrum of the extrasolar planet. We call this method `spectral deconvolution'. We illustrate the dramatic gains by showing an idealized simulation that results in a 20-sigma detection of a Jovian planet at 2 pc with a 2-m coronagraphic space telescope, even though the planet's peak flux is only 1% that of the PSF wings of the host star. This scales to detection of a terrestrial extrasolar planet at 2 pc with an 8-m coronagraphic Terrestrial Planet Finder (TPF) in ~7 hr (or less with appropriate spatial filtering). Data on the spectral characteristics of the extrasolar planet and hence on its atmospheric constituents and possible biomarkers are obtained naturally as part of this process.

  16. High S/N Keck and Gemini AO imaging of Uranus during 2012-2014: New cloud patterns, increasing activity, and improved wind measurements

    E-print Network

    Sromovsky, L A; Fry, P M; Hammel, H B; Marcus, P

    2015-01-01

    We imaged Uranus in the near infrared from 2012 into 2014, using the Keck/NIRC2 camera and Gemini/NIRI camera, both with adaptive optics. We obtained exceptional signal to noise ratios by averaging 8-16 individual exposures in a planet-fixed coordinate system. noise-reduced images revealed many low-contrast discrete features and large scale cloud patterns not seen before, including scalloped waveforms just south of the equator. In all three years numerous small (600-700 km wide) and mainly bright discrete features were seen within the north polar region (north of about 55\\deg N). Over 850 wind measurements were made, the vast majority of which were in the northern hemisphere. These revealed an extended region of solid body rotation between 62\\deg N and at least 83\\deg N, at a rate of 4.08$\\pm0.015$\\deg/h westward relative to the planet's interior (radio) rotation of 20.88\\deg/h westward. Near-equatorial speeds measured with high accuracy give different results for waves and small discrete features, with eastw...

  17. Imaging planets around nearby white dwarfs

    E-print Network

    M. R. Burleigh; F. J. Clarke; S. T. Hodgkin

    2002-02-09

    We suggest that Jovian planets will survive the late stages of stellar evolution, and that white dwarfs will retain planetary systems in wide orbits (>5AU). Utilising evolutionary models for Jovian planets, we show that infra-red imaging with 8m class telescopes of suitable nearby white dwarfs should allow us to resolve and detect companions >3Mjup. Detection of massive planetary companions to nearby white dwarfs would prove that such objects can survive the final stages of stellar evolution, place constraints on the frequency of main sequence stars with planetary systems dynamically similar to our own and allow direct spectroscopic investigation of their composition and structure.

  18. OCTOCAM: a fast multi-channel imager and spectrograph for the Gemini telescopes

    NASA Astrophysics Data System (ADS)

    de Ugarte Postigo, Antonio

    2015-08-01

    OCTOCAM has been proposed as a future instrument for Gemini and is currently going through a feasibility study phase. Its a multi-channel instrument based on the use of high-efficiency dichroics to divide the light into eight optical and near-infrared arms. In its imaging mode it has a field of view of 3’x3’ that is simultaneously observed in eight bands. It is also designed to obtain spectroscopy from 370 to 2,400 nm in a single shot, with a spectral resolution of ~3,000. OCTOCAM will be capable of obtaining full-Stokes spectropolarimetry to study geometry and magnetic fields of astrophysical phenomena. It will be equipped with a mini-IFU (Integral Field Unit) to perform resolved spectroscopic studies in an area of a few arcseconds. Furthermore, thanks to the use of state of the art detectors, it will be able to reach high readout speeds, allowing science cases aimed at high time-resolution. We expect full frame rate reaching speeds of tens of Hertz, which will be even higher for windowed modes. This will also mean that OCTOCAM will virtually eliminate dead times in most observing modes, allowing duty cycles of roughly 100%. In this way, OCTOCAM will cover a region of the (spectral-resolution)-(spectral-coverage)-(temporal-resolution) diagram that is not occupied by any other single instrument in the world.

  19. Herschel Imaging of Debris Disks: Resolved Planet-Bearing Disks and a Planet-Disk Correlation

    NASA Astrophysics Data System (ADS)

    Bryden, Geoffrey

    2015-12-01

    We will present Herschel images from a far-IR survey of known planet-bearing systems. Among the systems with detectable debris disks, 15 such disks are spatially resolved, with radii of ~100 AU. Although this orbiting material is well separated from any radial-velocity-discovered planets in the same system, we nevertheless find a strong correlation between inner planets and outer disks, with disks around planet-bearing stars tending to be much brighter than those not known to have planets.

  20. HOW DO MOST PLANETS FORM?-CONSTRAINTS ON DISK INSTABILITY FROM DIRECT IMAGING

    SciTech Connect

    Janson, Markus; Bonavita, Mariangela; Klahr, Hubert; Lafreniere, David

    2012-01-20

    Core accretion and disk instability have traditionally been regarded as the two competing possible paths of planet formation. In recent years, evidence has accumulated in favor of core accretion as the dominant mode, at least for close-in planets. However, it might be hypothesized that a significant population of wide planets formed by disk instabilities could exist at large separations, forming an invisible majority. In previous work, we addressed this issue through a direct imaging survey of B2-A0-type stars and concluded that <30% of such stars form and retain planets and brown dwarfs through disk instability, leaving core accretion as the likely dominant mechanism. In this paper, we extend this analysis to FGKM-type stars by applying a similar analysis to the Gemini Deep Planet Survey sample. The results strengthen the conclusion that substellar companions formed and retained around their parent stars by disk instabilities are rare. Specifically, we find that the frequency of such companions is <8% for FGKM-type stars under our most conservative assumptions, for an outer disk radius of 300 AU, at 99% confidence. Furthermore, we find that the frequency is always <10% at 99% confidence independently of outer disk radius, for any radius from 5 to 500 AU. We also simulate migration at a wide range of rates and find that the conclusions hold even if the companions move substantially after formation. Hence, core accretion remains the likely dominant formation mechanism for the total planet population, for every type of star from M-type through B-type.

  1. New, Near-to-Mid Infrared High-Contrast Imaging of the Young Extrasolar Planets, HR 8799 bcde

    NASA Astrophysics Data System (ADS)

    Currie, Thayne M.; Burrows, Adam Seth; Girard, Julien; Cloutier, Ryan; Fukagawa, Misato; Sorahana, Satoko; Kuchner, Marc J.; Kenyon, Scott; Madhusudhan, Nikku; Itoh, Yoichi; Jayawardhana, Ray; Matsumura, Soko; Pyo, Tae-Soo

    2015-01-01

    We present new thermal IR imaging for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo and Subaru/IRCS. We easily detect all four HR 8799 planets but fail to identify a fifth planet, "HR 8799 f", at r < 15 AU at a 5-sigma confidence level. We rule out an HR 8799 f with mass of 5 MJ (7 MJ), 7 MJ (10 MJ), and 12 MJ (13 MJ) at rproj ˜ 12 AU, 9 AU, and 5 AU, respectively. All four HR 8799 planets have red early T dwarf-like L? - [4.05] colors. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 bc's photometry/spectra, evidence for it from HR 8799 de's photometry is weaker. Pending execution of upcoming observations, we will also present unpublished imaging of HR 8799 with the Gemini Planet Imager (GPI) and Subaru Coronagraphic Extreme Adaptive Optics project (SCExAO): two of a new generation of dedicated extreme-AO facilities.

  2. The Gemini NICI Planet-finding Campaign: Discovery of a Substellar L Dwarf Companion to the Nearby Young M Dwarf CD-35 2722

    NASA Astrophysics Data System (ADS)

    Wahhaj, Zahed; Liu, Michael C.; Biller, Beth A.; Clarke, Fraser; Nielsen, Eric L.; Close, Laird M.; Hayward, Thomas L.; Mamajek, Eric E.; Cushing, Michael; Dupuy, Trent; Tecza, Matthias; Thatte, Niranjan; Chun, Mark; Ftaclas, Christ; Hartung, Markus; Reid, I. Neill; Shkolnik, Evgenya L.; Alencar, Silvia H. P.; Artymowicz, Pawel; Boss, Alan; de Gouveia Dal Pino, Elisabethe; Gregorio-Hetem, Jane; Ida, Shigeru; Kuchner, Marc; Lin, Douglas N. C.; Toomey, Douglas W.

    2011-03-01

    We present the discovery of a wide (67 AU) substellar companion to the nearby (21 pc) young solar-metallicity M1 dwarf CD-35 2722, a member of the ?100 Myr AB Doradus association. Two epochs of astrometry from the NICI Planet-Finding Campaign confirm that CD-35 2722 B is physically associated with the primary star. Near-IR spectra indicate a spectral type of L4±1 with a moderately low surface gravity, making it one of the coolest young companions found to date. The absorption lines and near-IR continuum shape of CD-35 2722 B agree especially well the dusty field L4.5 dwarf 2MASS J22244381-0158521, while the near-IR colors and absolute magnitudes match those of the 5 Myr old L4 planetary-mass companion, 1RXS J160929.1-210524 b. Overall, CD-35 2722 B appears to be an intermediate-age benchmark for L dwarfs, with a less peaked H-band continuum than the youngest objects and near-IR absorption lines comparable to field objects. We fit Ames-Dusty model atmospheres to the near-IR spectra and find T eff= 1700-1900 K and log(g)= 4.5 ± 0.5. The spectra also show that the radial velocities of components A and B agree to within ±10 km s-1, further confirming their physical association. Using the age and bolometric luminosity of CD-35 2722 B, we derive a mass of 31 ± 8 M Jup from the Lyon/Dusty evolutionary models. Altogether, young late-M to mid-L type companions appear to be overluminous for their near-IR spectral type compared with field objects, in contrast to the underluminosity of young late-L and early-T dwarfs. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  3. Direct Imaging and Distant Planets: A Path Towards a Full View of Planet Populations

    NASA Astrophysics Data System (ADS)

    LAGRANGE, Anne-Marie

    2015-12-01

    ost of exo-planets have been found so far by indirect techniques, at separations typically less than 5 AU. Direct imaging offers the possibility to detect and study longer period planets. The few planets found so far, all giants, bring new challenges to the theories of planet formation and evolution. I will review the challenges associated to direct imaging, and the results obtained until today on these distant planets. I will stress on the opportunities offered by the new, extreme AO-fed, high contrasts imagers such as SPHERE and GPI and show the first results obtained with these instruments.I will also show how coupling imaging and indirect techniques can now help, for the first time, to investigate the population of giant planets, from a fraction up to hundreds of AU of some stars, giving the opportunity to estimate more accurately the frequency of giant planets around stars.I will finally propose a reasonable, longer term roadmap towards telluric planet imaging with the ELTs.

  4. Project Gemini online digital archive

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-01-01

    An archive containing the first high-resolution digital scans of the original flight films from Project Gemini, the second U.S. human spaceflight program, was unveiled by the NASA Johnson Space Center and Arizona State University's (ASU) School of Earth and Space Exploration on 6 January. The archive includes images from 10 flights. Project Gemini, which ran from 1964 to 1966, followed Project Mercury and preceded the Apollo spacecraft. Mercury and Apollo imagery are also available through ASU. For more information, see http://tothemoon.ser.asu.edu/gallery/gemini and http://apollo.sese.asu.edu/index.html.

  5. Gemini/GMOS imaging of globular cluster systems in five early-type galaxies

    NASA Astrophysics Data System (ADS)

    Faifer, Favio R.; Forte, Juan C.; Norris, Mark A.; Bridges, Terry; Forbes, Duncan A.; Zepf, Stephen E.; Beasley, Mike; Gebhardt, Karl; Hanes, David A.; Sharples, Ray M.

    2011-09-01

    In this paper, we present deep high-quality photometry of globular cluster systems (GCSs) belonging to five early-type galaxies, covering a range of mass and environment. Photometric data were obtained with the Gemini North and Gemini South telescopes in the filter passbands g', r' and i'. The combination of these filters with good seeing conditions allows an excellent separation between globular cluster (GC) candidates and unresolved field objects. In fact, our previously published spectroscopic data indicate a contamination level of only ˜10 per cent in our sample of GC candidates. Bimodal GC colour distributions are found in all five galaxies. Most of the GCSs appear bimodal even in the (g'-r') versus (r'-i') plane. A population of resolved/marginally resolved GC and ultracompact dwarf candidates was found in all the galaxies. A search for the so-called 'blue tilt' in the colour-magnitude diagrams reveals that NGC 4649 clearly shows this phenomenon, although no conclusive evidence was found for the other galaxies in the sample. This 'blue tilt' translates into a mass-metallicity relation given by Z?M0.28 ±0.03. This dependence was found using a new empirical (g'-i') versus [Z/H] relation, which relies on an homogeneous sample of GC colours and metallicities. In this paper, we also explore the radial trends in both colour and surface density for the blue (metal-poor) and red (metal-rich) GC subpopulations. As usual, the red GCs show a steeper radial distribution than the blue GCs. Evidence of galactocentric colour gradients is found in some of the GCSs, which is more significant for the two S0 galaxies in the sample. Red GC subpopulations show similar colours and gradients to the galaxy halo stars in their inner region. A GC mean colour-galaxy luminosity relation, consistent with [Z/H]?L0.26 ±0.08B, is present for the red GCs. Estimates of the total GC populations and specific frequency SN values are presented for NGC 3115, 3923 and 4649. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation (NSF) on behalf of the Gemini partnership: the NSF (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  6. Planet Signatures in Collisionally Active Debris Discs: scattered light images

    E-print Network

    Thebault, Philippe; Ertel, Steve

    2012-01-01

    Planet perturbations are often invoked as a potential explanation for many spatial structures that have been imaged in debris discs. So far this issue has been mostly investigated with collisionless N-body numerical models. We numerically investigate how the coupled effect of collisions and radiation pressure can affect the formation and survival of radial and azimutal structures in a disc perturbed by a planet. We consider two set-ups: a planet embedded within an extended disc and a planet exterior to an inner debris ring. We use the DyCoSS code of Thebault(2012) and derive synthetic images of the system in scattered light. The planet's mass and orbit, as well as the disc's collisional activity are explored as free parameters. We find that collisions always significantly damp planet-induced structures. For the case of an embedded planet, the planet's signature, mostly a density gap around its radial position, should remain detectable in head-on images if M_planet > M_Saturn. If the system is seen edge-on, ho...

  7. Images of a fourth planet orbiting HR 8799.

    PubMed

    Marois, Christian; Zuckerman, B; Konopacky, Quinn M; Macintosh, Bruce; Barman, Travis

    2010-12-23

    High-contrast near-infrared imaging of the nearby star HR 8799 has shown three giant planets. Such images were possible because of the wide orbits (>25?astronomical units, where 1?au is the Earth-Sun distance) and youth (<100?Myr) of the imaged planets, which are still hot and bright as they radiate away gravitational energy acquired during their formation. An important area of contention in the exoplanet community is whether outer planets (>10?au) more massive than Jupiter form by way of one-step gravitational instabilities or, rather, through a two-step process involving accretion of a core followed by accumulation of a massive outer envelope composed primarily of hydrogen and helium. Here we report the presence of a fourth planet, interior to and of about the same mass as the other three. The system, with this additional planet, represents a challenge for current planet formation models as none of them can explain the in situ formation of all four planets. With its four young giant planets and known cold/warm debris belts, the HR 8799 planetary system is a unique laboratory in which to study the formation and evolution of giant planets at wide (>10?au) separations. PMID:21150902

  8. Automatic technique for accurately locating planet centers in Voyager images

    NASA Technical Reports Server (NTRS)

    Lorre, J. J.

    1980-01-01

    An algorithm has been developed for locating with sub-pixel accuracy planet centers in the Voyager images of the Jovian system based upon automatic recognition of the planet limb. The planet center finder, called FARENC (for far encounter imaging mode), is a single VICAR program operating on IBM 360/65 computer. FARENC is designed to handle images of the order of 800 to 1000 pixels, to operate unaided in a batch environment, and to complete the process reliably in 2 minutes or less. The procedure is outlined step by step and limitations of the algorithm are discussed.

  9. A UNIFORM ANALYSIS OF 118 STARS WITH HIGH-CONTRAST IMAGING: LONG-PERIOD EXTRASOLAR GIANT PLANETS ARE RARE AROUND SUN-LIKE STARS

    SciTech Connect

    Nielsen, Eric L.; Close, Laird M.

    2010-07-10

    We expand on the results of Nielsen et al., using the null result for giant extrasolar planets around the 118 target stars from the Very Large Telescope (VLT) NACO H- and Ks-band planet search (conducted by Masciadri and collaborators in 2003 and 2004), the VLT and MMT Simultaneous Differential Imager survey, and the Gemini Deep Planet Survey to set constraints on the population of giant extrasolar planets. Our analysis is extended to include the planet luminosity models of Fortney et al., as well as the correlation between stellar mass and frequency of giant planets found by Johnson et al. Doubling the sample size of FGKM stars strengthens our conclusions: a model for extrasolar giant planets with power laws for mass and semimajor axis as given by Cumming et al. cannot, with 95% confidence, have planets beyond 65 AU, compared to the value of 94 AU reported by Nielsen et al., using the models of Baraffe et al. When the Johnson et al. correction for stellar mass (which gives fewer Jupiter-mass companions to M stars with respect to solar-type stars) is applied, however, this limit moves out to 82 AU. For the relatively new Fortney et al. models, which predict fainter planets across most of parameter space, these upper limits, with and without a correction for stellar mass, are 182 and 234 AU, respectively.

  10. Laboratory tests of planet signal extraction in high contrast images

    NASA Astrophysics Data System (ADS)

    Baudoz, Pierre; Mazoyer, Johan; Galicher, Raphael

    2013-12-01

    Understanding the formation, evolution and surprising diversity of exoplanetary system is recognized as one of the few major challenges of current astrophysics. While a large number of planets are discovered thanks to techniques like radial velocity and transits, only a few of them have clear measurements of their atmospheric components. Besides, these latter have been studied on transiting planets with very short orbits. Study of planets at larger separations requires direct imaging, which has enabled detection of a handful of exoplanets. This number will dramatically increase with the arrival in 2013 of SPHERE and GPI instruments that will give access to a large class of self-luminous young exoplanets. Characterization of mature planets or even massive rocky planets is expected for the next generation of planet finders that will be installed on Extremely Large Telescopes (ELT).On ELT, even with Adaptive Optics (AO) working at their best, using smart wavefront sensor and correction strategy, it is expected that the residual speckles in the images will still be a factor 100 brighter than the planet signal. This level composed of slow quasi static speckles not detected by the wavefront sensor and the rapidly varying wavefront errors that cannot be corrected by the AO loop frequency. Solutions are actually studied to calibrate these speckles and make sure that we can differentiate them from planet signal. One of the best solution is to use the signal of focal plane wavefront sensors that can help suppressing the quasi-static speckles but also help to extract the planet signal in the final images.After describing the benefit of focal plane wavefront sensor for data extraction, we will describe our laboratory test bench which uses the Self-Coherent Camera as focal plane wavefront sensor. The principle of the data processing used to extract the planet signal will be presented together with laboratory results on very high contrast images.

  11. ALMA images of discs: are all gaps carved by planets?

    NASA Astrophysics Data System (ADS)

    Gonzalez, J.-F.; Laibe, G.; Maddison, S. T.; Pinte, C.; Ménard, F.

    2015-11-01

    Protoplanetary discs are now routinely observed and exoplanets, after the numerous indirect discoveries, are starting to be directly imaged. To better understand the planet formation process, the next step is the detection of forming planets or of signposts of young planets still in their disc, such as gaps. A spectacular example is the Atacama Large Millimeter/submillimeter Array (ALMA) science verification image of HL Tau showing numerous gaps and rings in its disc. To study the observability of planet gaps, we ran 3D hydrodynamical simulations of a gas and dust disc containing a 5 MJ gap-opening planet and characterized the spatial distribution of migrating, growing and fragmenting dust grains. We then computed the corresponding synthetic images for ALMA. For a value of the dust fragmentation threshold of 15 m s-1 for the collisional velocity, we identify for the first time a self-induced dust pile-up in simulations taking fragmentation into account. This feature, in addition to the easily detected planet gap, causes a second apparent gap that could be mistaken for the signature of a second planet. It is therefore essential to be cautious in the interpretation of gap detections.

  12. Exozodiacal Dust and Direct Imaging of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2008-01-01

    Direct imaging of extrasolar planets means contending with dust from extrasolar asteroids and comets. This 'exozodiacal dust' creates a structured background light that can easily outshine the light from an exoEarth and confuse a planet-search mission like TPF or TOPS. But exozodiacal dust can be both friend and foe: planets can stir dust clouds into patterns that reveal the presence of the planet and constrain its mass and orbit. I'll describe some recent research on this topic: 3-D dynamical models of dust clouds with planets and searches for exozodiacal dust with the Keck Interferometer. The author also offers a prediction for the typical zodiacal dust background found around solar analogs, based on seafloor sediment data.

  13. Gemini Space Program emblem

    NASA Technical Reports Server (NTRS)

    1965-01-01

    The insignia of the Gemini space program is a disc of dark blue as a background for a gold Zodiac Gemini symbol. A white star on each of the two vertical curves of the Gemini symbol represent the Gemini twins, Pollux and Castor.

  14. Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Burrows, Adam; Girard, Julien H.; Cloutier, Ryan; Fukagawa, Misato; Sorahana, Satoko; Kuchner, Marc; Kenyon, Scott J.; Madhusudhan, Nikku; Itoh, Yoichi; Jayawardhana, Ray; Matsumura, Soko; Pyo, Tae-Soo

    2014-01-01

    We present new L' (3.8 micrometer) and Br alpha (4.05 micrometer) data and reprocessed archival L' data for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo, and Subaru/IRCS. We detect all four HR 8799 planets in each data set at a moderate to high signal-to-noise ratio (S/N approximately greater than 6-15).We fail to identify a fifth planet, "HR 8799 f," at r less than 15AU at a 5 sigma confidence level: one suggestive, marginally significant residual at 0".2 is most likely a pointspread function artifact. Assuming companion ages of 30 Myr and the Baraffe planet cooling models, we rule out an HR 8799 f with a mass of 5 M(sub J) (7 MJ ), 7 M(sub J) (10 M(sub J)), or 12 M(sub J) (13 M(sub J)) at r(sub proj) approximately 12AU, 9AU, and 5AU, respectively. All four HR 8799 planets have red early T dwarf-like L'- [4.05] colors, suggesting that their spectral energy distributions peak in between the L' and M' broadband filters.We find no statistically significant difference in HR 8799 cde's color. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 b and c's photometry/spectra, evidence for it from HR 8799 d and e's photometry is weaker. Future, deep-IR spectroscopy/spectrophotometry with the Gemini Planet Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are chemically similar or heterogeneous.

  15. Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Burrows, Adam; Girard, Julien H.; Cloutier, Ryan; Fukagawa, Misato; Sorahana, Satoko; Kuchner, Marc; Kenyon, Scott J.; Madhusudhan, Nikku; Itoh, Yoichi; Jayawardhana, Ray; Matsumura, Soko; Pyo, Tae-Soo

    2014-11-01

    We present new L' (3.8 ?m) and Br? (4.05 ?m) data and reprocessed archival L' data for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo, and Subaru/IRCS. We detect all four HR 8799 planets in each data set at a moderate to high signal-to-noise ratio (S/N >~ 6-15). We fail to identify a fifth planet, "HR 8799 f," at r < 15 AU at a 5? confidence level: one suggestive, marginally significant residual at 0.''2 is most likely a point-spread function artifact. Assuming companion ages of 30 Myr and the Baraffe planet cooling models, we rule out an HR 8799 f with a mass of 5 MJ (7 MJ ), 7 MJ (10 MJ ), or 12 MJ (13 MJ ) at r proj ~ 12 AU, 9 AU, and 5 AU, respectively. All four HR 8799 planets have red early T dwarf-like L' - [4.05] colors, suggesting that their spectral energy distributions peak in between the L' and M' broadband filters. We find no statistically significant difference in HR 8799 cde's color. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 b and c's photometry/spectra, evidence for it from HR 8799 d and e's photometry is weaker. Future, deep-IR spectroscopy/spectrophotometry with the Gemini Planet Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are chemically similar or heterogeneous.

  16. Deep thermal infrared imaging of HR 8799 bcde: new atmospheric constraints and limits on a fifth planet

    SciTech Connect

    Currie, Thayne; Cloutier, Ryan; Jayawardhana, Ray; Burrows, Adam; Girard, Julien H.; Fukagawa, Misato; Sorahana, Satoko; Kuchner, Marc; Kenyon, Scott J.; Madhusudhan, Nikku; Itoh, Yoichi; Matsumura, Soko; Pyo, Tae-Soo

    2014-11-10

    We present new L' (3.8 ?m) and Br? (4.05 ?m) data and reprocessed archival L' data for the young, planet-hosting star HR 8799 obtained with Keck/NIRC2, VLT/NaCo, and Subaru/IRCS. We detect all four HR 8799 planets in each data set at a moderate to high signal-to-noise ratio (S/N ? 6-15). We fail to identify a fifth planet, 'HR 8799 f', at r < 15 AU at a 5? confidence level: one suggestive, marginally significant residual at 0.''2 is most likely a point-spread function artifact. Assuming companion ages of 30 Myr and the Baraffe planet cooling models, we rule out an HR 8799 f with a mass of 5 M{sub J} (7 M{sub J} ), 7 M{sub J} (10 M{sub J} ), or 12 M{sub J} (13 M{sub J} ) at r {sub proj} ? 12 AU, 9 AU, and 5 AU, respectively. All four HR 8799 planets have red early T dwarf-like L' – [4.05] colors, suggesting that their spectral energy distributions peak in between the L' and M' broadband filters. We find no statistically significant difference in HR 8799 cde's color. Atmosphere models assuming thick, patchy clouds appear to better match HR 8799 bcde's photometry than models assuming a uniform cloud layer. While non-equilibrium carbon chemistry is required to explain HR 8799 b and c's photometry/spectra, evidence for it from HR 8799 d and e's photometry is weaker. Future, deep-IR spectroscopy/spectrophotometry with the Gemini Planet Imager, SCExAO/CHARIS, and other facilities may clarify whether the planets are chemically similar or heterogeneous.

  17. Planet Diversity Yields with Space-based Direct Imaging Telescopes

    NASA Astrophysics Data System (ADS)

    Domagal-Goldman, Shawn; Kopparapu, Ravi Kumar; Hébrard, Eric; Stark, Chris; Robinson, Tyler D.; Roberge, Aki; Mandell, Avi; McElwain, Michael W.; Clampin, Mark; Meadows, Victoria; Arney, Giada; Advanced Technology Large Aperture Space Telescope Science Team, Exoplanet Climate Group

    2016-01-01

    In this presentation, we will estimate the yield for a diversity of planets from future space-based flagship telescopes. We first divvy up planets into categories that are based on current observables, and that should impact the spectra we hope to observe in the future. The two main classification parameters we use here are the size of a planet and the energy flux into the planet's atmosphere. These two parameters are measureable or inferable from present-day observations, and should have a strong influence on future spectroscopy observations from JWST, WFIRST (with a coronagraph and/or starshade), and concept flagship missions that would fly some time after WFIRST. This allows us to calculate "?planet" values for each kind of planet. These ? values then allow calculations of the expected yields from direct imaging missions, by leveraging the models and prior work by Stark and colleagues (2014, 2015). That work estimated the yields for potentially Earth-like worlds (i.e. of a size and stellar irradiation consistent with definitions of the habitable zone) for telescopes with a variety of observational parameters. We will do the same thing here, but for a wider variety of planets. This will allow us to discuss the implications of architecture and instrument properties on the diversity of worlds that future direct imaging missions would observe.

  18. Direct imaging and spectroscopic characterization of habitable planets with ELTs

    NASA Astrophysics Data System (ADS)

    Guyon, Olivier; Jovanovic, Nemanja; Lozi, Julien

    2015-12-01

    While the ~1e10 reflected light contrast between Earth-like planets and Sun-like stars is extremely challenging to overcome for ground-based telescopes, habitable planets around lower-mass stars can be "only" a 10 million times fainter than their host stars. Thanks to the small angular resolution offered by upcoming extremely large telescopes (ELTs) and recent advances in wavefront control and coronagraphic techniques, direct imaging and spectroscopic characterization of habitable planets will be possible around nearby M-type stars. Deep (~1e-8) contrast can be achieved by combining (1) sensitive fast visible light wavefront sensing (extreme-AO) with (2) kHz speckle control in the near-IR and (3) high efficiency coronagraphy. Spectroscopy will measure abundances of water, oxygen and methane, measure the planet rotation period, orbit, and identify main surface features through time-domain spectrophotometry.The Subaru Coronagraphic Extreme AO (SCExAO) system is a technology precursor to such a habitable planet imager for ELTs, and is currently under active development. By combining small inner working angle coronagraphy, visible-WFS based extreme-AO and fast speckle control, it will include the key elements of a future ELT system able to image and characterize habitable planets. We describe a technical plan to evolve SCExAO into a habitable planet imager for the Thirty Meter Telescope (TMT), which is aimed at providing such scientific capability during the 2020 decade, and inform the design, deployment and scientific operation of a more capable Extreme-AO instrument.

  19. Entry pupil processing approaches for exo-planet imaging

    NASA Astrophysics Data System (ADS)

    Hyland, David C.

    2005-08-01

    In contrast to standard Michelson interferometry, the idea of entry pupil processing is to somehow convert light gathered at each telescope (of a multi-spacecraft array) into data, then process the data from several telescopes to compute the mutual coherence values needed for image reconstruction. Some advantages are that weak beams of collected light do not have to be propagated to combiners, extreme precision relative path length control among widely separated spacecraft is unnecessary, losses from beam splitting are eliminated, etc. This paper reports our study of several entry pupil processing approaches, including direct electric field reconstruction, optical heterodyne systems and intensity correlation interferometry using the Hanbury Brown-Twiss effect. For all these cases and for amplitude interferometry, we present image plane signal-to-noise (SNR) results for exo-planet imaging, both in the case of planet emissions and for imaging the limb of planets executing a transit across their stars. We particularly consider terrestrial-class planets at a range of 15 pc or less. Using the SNR and related models, we assess the relative advantages and drawbacks of all methods with respect to necessary aperture sizes, imager sensitivity, performance trends with increasing number of measurement baselines, relative performance in visible and in IR, relative positioning and path length control requirements and metrology requirements. The resulting comparisons present a picture of the performance and complexity tradeoffs among several imaging system architectures. The positive conclusion of this work is that, thanks to advances in optoelectronics and signal processing, there exist a number of promising system design alternatives for exo- planet imaging.

  20. Gemini Frontier Fields: Wide-field Adaptive Optics Ks-band Imaging of the Galaxy Clusters MACS J0416.1-2403 and Abell 2744

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Carrasco, E. R.; Pessev, P.; Garrel, V.; Winge, C.; Neichel, B.; Vidal, F.

    2015-04-01

    We have observed two of the six Frontier Fields galaxy clusters, MACS J0416.1-2403 and Abell 2744, using the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager (GSAOI). With 0.? 08-0.? 10 FWHM our data are nearly diffraction-limited over a 100\\prime\\prime × 100\\prime\\prime wide area. GeMS/GSAOI complements the Hubble Space Telescope (HST) redwards of 1.6 ?m with twice the angular resolution. We reach a 5? depth of {{K}s}˜ 25.6 mag (AB) for compact sources. In this paper, we describe the observations, data processing, and initial public data release. We provide fully calibrated, co-added images matching the native GSAOI pixel scale as well as the larger plate scales of the HST release, adding to the legacy value of the Frontier Fields. Our work demonstrates that even for fields at high galactic latitude where natural guide stars are rare, current multi-conjugated adaptive optics technology at 8 m telescopes has opened a new window on the distant universe. Observations of a third Frontier Field, Abell 370, are planned. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). Based on observations made with ESO Telescopes at the La Silla and Paranal Observatories, Chile.

  1. The lowest mass giant planet ever imaged around a star

    NASA Astrophysics Data System (ADS)

    Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Boccaletti, A.; Quanz, S. P.; Bonnefoy, M.; Girard, J. H.; Delorme, P.; Desidera, S.; Klahr, H.; Mordasini, C.; Dumas, C.; Bonavita, M.

    2013-09-01

    Understanding planetary systems formation and evolution has become one of the challenges in astronomy, since the discovery of the first exoplanet around the solar-type star 51 Peg in the 90's. While more than 800 planets (mostly giants) closer than a few AU have been identified with radial velocity and transit techniques, very few have been imaged and definitely confirmed around stars, at separations below a hundred of astronomical units. Direct imaging detection of exoplanet is indeed a major frontier in planetary astrophysics. It surveys a region of semi-major axes (> 5 AU) that is almost inaccessible to other methods. Moreover, the planets imaged so far orbit young stars; indeed the young planets are still hot and the planetstar contrasts are compatible with the detection limits currently achievable, in contrast with similar planets in older systems. Noticeably, the stars are of early-types, and surrounded by debris disks, i.e. disks populated at least by small grains with lifetimes so short that they must be permanently produced, probably by destruction (evaporation, collisions) of larger solid bodies. Consequently, every single discovery has a tremendous impact on the understanding of the formation, the dynamical evolution, and the physics of giant planets. In this context, I will present our recent discovery of one faint companion to a nearby, dusty, and young A-type star (at 56 AU projected separation). Background contaminants are rejected with high confidence level based on both astrometry and photometry with three dataset at more than a yeartime-laps and two different wavelength regimes. From the system age (10 to 17 Myr) and from model-dependent luminosity estimates, we derive mass of 4 to 5 Jupiter mass. This planet is therefore the one with the lowest mass ever imaged around a star. Given its orbital and physical properties, I will discuss the implication on its atmosphere with respect to other imaged companions but also on its formation which is not straightforward assuming standard mechanisms. This planet will be of great interest for future planets imagers to search for additional close-in and lower mass companions but also for spectral characterization.

  2. Advanced image slicers for integral field spectroscopy with UKIRT and GEMINI

    NASA Astrophysics Data System (ADS)

    Content, Robert

    1998-08-01

    The new design of image slicer developed at Durham University for 2D area spectroscopy is described. The unit acts as a coupler between the telescope and a spectrograph to reformat a square or rectangular field into a long slit. Its advantages over previous designs of image slicers and other methods using fibers, lenses or narrow-band filtering are discussed, mainly: large field, high spatial resolution, large number of spectral resolution elements, high transmission, and the small size of the instrument. The system is also easy to cool and is then well suited for IR spectroscopy. The proposed design is a new type of image slicer in which the original 2D image is sliced into narrow sub-images that are re-imaged side by side to form a long 1D image at the spectrograph input. The flexibility of the concept at the base of this new design is highlighted through the description of 5 different slicer designs. Three of these are for future instruments now at the design phase: the CGS4 slicer, the UIST slicer and the GNIRS slicer; the two others are studies for possible future slicers on GMOS and NGST. These designs show how easily our slicer can be added to an existing instrument, how it can be incorporated to the slit wheel of future instruments, and how multi-slit reformatting permits a much larger field of view.

  3. High S/N Keck and Gemini AO imaging of Uranus during 2012-2014: New cloud patterns, increasing activity, and improved wind measurements

    NASA Astrophysics Data System (ADS)

    Sromovsky, L. A.; de Pater, I.; Fry, P. M.; Hammel, H. B.; Marcus, P.

    2015-09-01

    We imaged Uranus in the near infrared from 2012 into 2014, using the Keck/NIRC2 camera and Gemini/NIRI camera, both with adaptive optics. We obtained exceptional signal to noise ratios by averaging 8-16 individual exposures in a planet-fixed coordinate system. These noise-reduced images revealed many low-contrast discrete features and large scale cloud patterns not seen before, including scalloped waveforms just south of the equator, and an associated transverse ribbon wave near 6°S. In all three years numerous small (600-700 km wide) and mainly bright discrete features were seen within the north polar region (north of about 55°N). Two small dark spots with bright companions were seen at middle latitudes. Over 850 wind measurements were made, the vast majority of which were in the northern hemisphere. Winds at high latitudes were measured with great precision, revealing an extended region of solid body rotation between 62°N and at least 83°N, at a rate of 4.08 ± 0.015°/h westward relative to the planet's interior (radio) rotation of 20.88°/h westward. Near-equatorial speeds measured with high accuracy give different results for waves and small discrete features, with eastward drift rates of 0.4°/h and 0.1°/h respectively. The region of polar solid body rotation is a close match to the region of small-scale polar cloud features, suggesting a dynamical relationship. The winds from prior years and those from 2012-2014 are consistent with a mainly symmetric wind profile up to middle latitudes, with a small asymmetric component of ?0.09°/h peaking near ±30°, and about 60% greater amplitude if only prior years are included, suggesting a declining mid-latitude asymmetry. While winds at high southern latitudes (50-90°S) are unconstrained by groundbased observations, a recent reanalysis of 1986 Voyager 2 observations by Karkoschka (Karkoschka [2015]. Icarus 250, 294-307) has revealed an extremely large north-south asymmetry in this region, which might be seasonal. Greatly increased activity was seen in 2014, including the brightest ever feature seen in K? images (de Pater et al. [2015]. Icarus 252, 121-128), as well as other significant features, some of which had long lives. Over the 2012-2014 period we identified six persistent discrete features. Three were tracked for more than 2 years, two more for more than 1 year, and one for at least 5 months and continuing. Several drifted in latitude towards the equator, and others appeared to exhibit latitudinal oscillations with long periods. We found two pairs of long-lived features that survived multiple passages within their own diameters of each other. Zonally averaged cloud patterns were found to persist over 2012-2014. When averaged over longitude, there is a brightness variation with latitude from 55°N to the pole that is similar to effective methane mixing ratio variations with latitude derived from 2012 STIS observations (Sromovsky et al. [2014]. Icarus 238, 137-155).

  4. The science case for the Planet Formation Imager (PFI)

    NASA Astrophysics Data System (ADS)

    Kraus, Stefan; Monnier, John; Harries, Tim; Dong, Ruobing; Bate, Matthew; Whitney, Barbara; Zhu, Zhaohuan; Buscher, David; Berger, Jean-Philippe; Haniff, Chris; Ireland, Mike; Labadie, Lucas; Lacour, Sylvestre; Petrov, Romain; Ridgway, Steve; Surdej, Jean; ten Brummelaar, Theo; Tuthill, Peter; van Belle, Gerard

    2014-07-01

    Among the most fascinating and hotly-debated areas in contemporary astrophysics are the means by which planetary systems are assembled from the large rotating disks of gas and dust which attend a stellar birth. Although important work has already been, and is still being done both in theory and observation, a full understanding of the physics of planet formation can only be achieved by opening observational windows able to directly witness the process in action. The key requirement is then to probe planet-forming systems at the natural spatial scales over which material is being assembled. By definition, this is the so-called Hill Sphere which delineates the region of influence of a gravitating body within its surrounding environment. The Planet Formation Imager project (PFI; http://www.planetformationimager.org) has crystallized around this challenging goal: to deliver resolved images of Hill-Sphere-sized structures within candidate planethosting disks in the nearest star-forming regions. In this contribution we outline the primary science case of PFI. For this purpose, we briefly review our knowledge about the planet-formation process and discuss recent observational results that have been obtained on the class of transition disks. Spectro-photometric and multi-wavelength interferometric studies of these systems revealed the presence of extended gaps and complex density inhomogeneities that might be triggered by orbiting planets. We present detailed 3-D radiation-hydrodynamic simulations of disks with single and multiple embedded planets, from which we compute synthetic images at near-infrared, mid-infrared, far-infrared, and sub-millimeter wavelengths, enabling a direct comparison of the signatures that are detectable with PFI and complementary facilities such as ALMA. From these simulations, we derive some preliminary specifications that will guide the array design and technology roadmap of the facility.

  5. Direct Imaging Search for Extrasolar Planets in the Pleiades

    NASA Technical Reports Server (NTRS)

    Yamamoto, Kodai; Matsuo, Taro; Shibai, Hiroshi; Itoh, Yoichi; Konishi, Mihokko; Sudo, Jun; Tanii, Ryoko; Fukagawa, Misato; Sumi, Takahiro; Kudo, Tomoyuki; Hashimoto, Jun; Kusakabe, Nobuhiko; Abe, Lyn; Brandner, Wolfgang; Brandt, Timothy D.; Carson, Joseph; Currie, Thayne; Egner, Sebastian E,; Feldt, Markus; Goto, Miwa; Grady, Carol; Guyon, Olivier; Hayano, Yutaka; McElwain, Mike; Serabyn, Eugene

    2013-01-01

    We carried out an imaging survey for extrasolar planets around stars in the Pleiades (125 Myr, 135 pc) in the H and K(sub S) bands using HiCIAO combined with adaptive optics, AO188, on the Subaru telescope. We found 13 companion candidates fainter than 14.5 mag in the H band around 9 stars. Five of these 13 were confirmed to be background stars by measurement of their proper motion. One was not found in the second epoch observation, and thus was not a background or companion object. One had multi-epoch images, but the precision of its proper motion was not sufficient to conclude whether it was a background object. Four other candidates are waiting for second-epoch observations to determine their proper motion. Finally, the remaining two were confirmed to be 60 M(sub J) brown dwarf companions orbiting around HD 23514 (G0) and HII 1348 (K5), respectively, as had been reported in previous studies. In our observations, the average detection limit for a point source was 20.3 mag in the H band beyond 1.'' 5 from the central star. On the basis of this detection limit, we calculated the detection efficiency to be 90% for a planet with 6 to 12 Jovian masses and a semi-major axis of 50–1000 AU. For this reason we extrapolated the distribution of the planet mass and the semi-major axis derived from radial velocity observations, and adopted the planet evolution model Baraffe et al. (2003, A&A, 402, 701). Since there was no detection of a planet, we estimated the frequency of such planets to be less than 17.9% (2 sigma) around one star of the Pleiades cluster.

  6. Outer planet Pioneer imaging communications system study. [data compression

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The effects of different types of imaging data compression on the elements of the Pioneer end-to-end data system were studied for three imaging transmission methods. These were: no data compression, moderate data compression, and the advanced imaging communications system. It is concluded that: (1) the value of data compression is inversely related to the downlink telemetry bit rate; (2) the rolling characteristics of the spacecraft limit the selection of data compression ratios; and (3) data compression might be used to perform acceptable outer planet mission at reduced downlink telemetry bit rates.

  7. GEOMETRIC PROCESSING OF DIGITAL IMAGES OF THE PLANETS.

    USGS Publications Warehouse

    Edwards, Kathleen

    1987-01-01

    New procedures and software have been developed for geometric transformations of images to support digital cartography of the planets. The procedures involve the correction of spacecraft camera orientation of each image with the use of ground control and the transformation of each image to a Sinusoidal Equal-Area map projection with an algorithm which allows the number of transformation calculations to vary as the distortion varies within the image. When the distortion is low in an area of an image, few transformation computations are required, and most pixels can be interpolated. When distortion is extreme, the location of each pixel is computed. Mosaics are made of these images and stored as digital databases.

  8. CONFIRMATION OF THE PLANET AROUND HD 95086 BY DIRECT IMAGING

    SciTech Connect

    Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Boccaletti, A.; Quanz, S. P.; Currie, T.; Mawet, D.; Girard, J. H.; Bonnefoy, M.

    2013-12-20

    VLT/NaCo angular differential imaging at L' (3.8 ?m) revealed a probable giant planet comoving with the young and early-type HD 95086, also known to harbor an extended debris disk. The discovery was based on the proper motion analysis of two datasets spanning 15 months. However, the second dataset suffered from bad atmospheric conditions, which limited the significance of the re-detection at the 3? level. In this Letter, we report new VLT/NaCo observations of HD 95086 obtained on 2013 June 26 and 27 at L' to recover the planet candidate. We unambiguously re-detect the companion HD 95086 b with multiple independent pipelines at a signal-to-noise ratio greater than or equal to 5. Combined with previously reported measurements, our astrometry decisively shows that the planet is comoving with HD 95086 and inconsistent with a background object. With a revised mass of 5 ± 2 Jupiter masses, estimated from its L' photometry and ''hot-start'' models at 17 ± 4 Myr, HD 95086 b becomes a new benchmark for further physical and orbital characterization of young giant planets.

  9. Imaging The Candidate Proto-planet HL Tau B

    NASA Astrophysics Data System (ADS)

    Greaves, Jane; Rice, K.; Richards, A.; Muxlow, T.; Forgan, D.; Sibthorpe, B.

    2011-09-01

    Our VLA and MERLIN radio images of the HL Tau system trace the emission from the proto-planetary disc at ultra-high resolution. A candidate proto-planet is seen at tens of AU from the star, at these long wavelengths where it stands out from the bright background disc. A simulation shows that gravitational instability within the disc is capable of forming this 10 Jupiter-mass object. Submillimetre images made recently with SCUBA-2 show that HL Tau's disc is perturbed by an interaction with XZ Tau, and this may have helped trigger disc fragmentation, in a flyby event as recent as a few thousand years ago.

  10. Interpreting the photometry and spectroscopy of directly imaged planets: a new atmospheric model applied to ? Pictoris b and SPHERE observations

    NASA Astrophysics Data System (ADS)

    Baudino, J.-L.; Bézard, B.; Boccaletti, A.; Bonnefoy, M.; Lagrange, A.-M.; Galicher, R.

    2015-10-01

    Context. Since the end of 2013 a new generation of instruments optimized to image young giant planets around nearby stars directly is becoming available on 8-m class telescopes, both at Very Large Telescope and Gemini in the southern hemisphere. Beyond the achievement of high contrast and the discovery capability, these instruments are designed to obtain photometric and spectral information to characterize the atmospheres of these planets. Aims: We aim to interpret future photometric and spectral measurements from these instruments, in terms of physical parameters of the planets, with an atmospheric model using a minimal number of assumptions and parameters. Methods: We developed the Exoplanet Radiative-convective Equilibrium Model (Exo-REM) to analyze the photometric and spectroscopic data of directly imaged planets. The input parameters are a planet's surface gravity (g), effective temperature (Teff), and elemental composition. The model predicts the equilibrium temperature profile and mixing ratio profiles of the most important gases. Opacity sources include the H2-He collision-induced absorption and molecular lines from eight compounds (including CH4 updated with the Exomol line list). Absorption by iron and silicate cloud particles is added above the expected condensation levels with a fixed scale height and a given optical depth at some reference wavelength. Scattering was not included at this stage. Results: We applied Exo-REM to photometric and spectral observations of the planet ? Pictoris b obtained in a series of near-infrared filters. We derived Teff = 1550 ± 150 K, log (g) = 3.5 ± 1, and radius R = 1.76 ± 0.24 RJup (2? error bars from photometric measurements). These values are comparable to those found in the literature, although with more conservative error bars, consistent with the model accuracy. We were able to reproduce, within error bars, the J- and H-band spectra of ? Pictoris b. We finally investigated the precision to which the above parameters can be constrained from SPHERE measurements using different sets of near-infrared filters as well as low-resolution spectroscopy.

  11. Predictions for shepherding planets in scattered light images of debris disks

    SciTech Connect

    Rodigas, Timothy J.; Hinz, Philip M.; Malhotra, Renu

    2014-01-01

    Planets can affect debris disk structure by creating gaps, sharp edges, warps, and other potentially observable signatures. However, there is currently no simple way for observers to deduce a disk-shepherding planet's properties from the observed features of the disk. Here we present a single equation that relates a shepherding planet's maximum mass to the debris ring's observed width in scattered light, along with a procedure to estimate the planet's eccentricity and minimum semimajor axis. We accomplish this by performing dynamical N-body simulations of model systems containing a star, a single planet, and an exterior disk of parent bodies and dust grains to determine the resulting debris disk properties over a wide range of input parameters. We find that the relationship between planet mass and debris disk width is linear, with increasing planet mass producing broader debris rings. We apply our methods to five imaged debris rings to constrain the putative planet masses and orbits in each system. Observers can use our empirically derived equation as a guide for future direct imaging searches for planets in debris disk systems. In the fortuitous case of an imaged planet orbiting interior to an imaged disk, the planet's maximum mass can be estimated independent of atmospheric models.

  12. Gemini-north multiobject spectrograph optical performance

    NASA Astrophysics Data System (ADS)

    Murowinski, Richard G.; Allington-Smith, Jeremy R.; Crampton, David; Davies, Roger L.; Fletcher, J. Murray; Henry, David M.; Hook, Isobel; Jorgensen, Inger; Juneau, S.; Morbey, Christopher L.; Stilburn, James R.; Szeto, Kei

    2003-03-01

    The Gemini Multiobject Spectrographs (GMOS) were designed to take advantage of the exquisite image quality expected of the Gemini telescopes. To achieve this, two of the many requirements placed on the optical system was that it not degrade the best image quality expected of the telescope by more than 10% while delivering a throughput of about 80% over the entire 0.4-1 ?m waveband. In this paper, key components of the design and execution of this optical system are discussed and test results are presented demonstrating that it meets these requirements on Gemini today. Among other characteristics, we look at the image quality performance as a function of colour and field angle, the measured throughput, and the focalplane flatness on the detectors.

  13. Study of spin-scan imaging for outer planets missions. [imaging techniques for Jupiter orbiter missions

    NASA Technical Reports Server (NTRS)

    Russell, E. E.; Chandos, R. A.; Kodak, J. C.; Pellicori, S. F.; Tomasko, M. G.

    1974-01-01

    The constraints that are imposed on the Outer Planet Missions (OPM) imager design are of critical importance. Imager system modeling analyses define important parameters and systematic means for trade-offs applied to specific Jupiter orbiter missions. Possible image sequence plans for Jupiter missions are discussed in detail. Considered is a series of orbits that allow repeated near encounters with three of the Jovian satellites. The data handling involved in the image processing is discussed, and it is shown that only minimal processing is required for the majority of images for a Jupiter orbiter mission.

  14. MEMS-based extreme adaptive optics for planet detection

    SciTech Connect

    Macintosh, B A; Graham, J R; Oppenheimer, B; Poyneer, L; Sivaramakrishnan, A; Veran, J

    2005-11-18

    The next major step in the study of extrasolar planets will be the direct detection, resolved from their parent star, of a significant sample of Jupiter-like extrasolar giant planets. Such detection will open up new parts of the extrasolar planet distribution and allow spectroscopic characterization of the planets themselves. Detecting Jovian planets at 5-50 AU scale orbiting nearby stars requires adaptive optics systems and coronagraphs an order of magnitude more powerful than those available today--the realm of ''Extreme'' adaptive optics. We present the basic requirements and design for such a system, the Gemini Planet Imager (GPI.) GPI will require a MEMS-based deformable mirror with good surface quality, 2-4 micron stroke (operated in tandem with a conventional low-order ''woofer'' mirror), and a fully-functional 48-actuator-diameter aperture.

  15. Imaging exo-solar planetary systems with Terrestrial Planet Finder

    NASA Astrophysics Data System (ADS)

    Eatchel, Andrew Lynn

    The concept of building a space based telescope capable of directly imaging extra-solar planetary systems has been in existence for more than a decade. While the basic ideas of how such an instrument might work have already been discussed in the literature, specific details of the design have not been addressed that will enable a telescope of this class to be functionally realized. A straw man configuration of the instrument is examined here for its ability to acquire data of sufficient informational content and quality to produce images and spectra of distant planetary systems and to find what technical problems arise from analyzing the interferograms it delivers. Computer programs that simulate the signals expected to be produced by a structurally connected instrument (SCI) version of Terrestrial Planet Finder (TPF) and reconstruct images from those signals will be presented along with programs that extract planetary parameters. An abbreviated radiometric performance analysis will also be provided that will assist astronomers in designing an appropriate mission.

  16. Grand Tour outer planet missions definition phase. Part 1: Quantitative imaging of the outer planets and their satellites

    NASA Technical Reports Server (NTRS)

    Belton, M. J. S.; Aksnes, K.; Davies, M. E.; Hartmann, W. K.; Millis, R. L.; Owen, T. C.; Reilly, T. H.; Sagan, C.; Suomi, V. E.; Collins, S. A., Jr.

    1972-01-01

    A recommended imaging system is outlined for use aboard the Outer Planet Grand Tour Explorer. The system features the high angular resolution capacity necessary to accommodate large encounter distances, and to satisfy the demand for a reasonable amount of time coverage. Specifications for all components within the system are provided in detail.

  17. ONE-SIDED ACHROMATIC PHASE APODIZATION FOR IMAGING OF EXTRASOLAR PLANETS Weidong Yang and Alexander B. Kostinski

    E-print Network

    Kostinski, Alex

    ONE-SIDED ACHROMATIC PHASE APODIZATION FOR IMAGING OF EXTRASOLAR PLANETS Weidong Yang and Alexander to direct imaging of extrasolar planets: one-sided phase apodization. It is based on a discovery suppression sufficient for imaging of extrasolar planets. Calculations with specific square-pupil (side D

  18. ATMOSPHERIC DYNAMICS OF BROWN DWARFS AND DIRECTLY IMAGED GIANT PLANETS

    SciTech Connect

    Showman, Adam P.; Kaspi, Yohai

    2013-10-20

    A variety of observations provide evidence for vigorous motion in the atmospheres of brown dwarfs and directly imaged giant planets. Motivated by these observations, we examine the dynamical regime of the circulation in the atmospheres and interiors of these objects. Brown dwarfs rotate rapidly, and for plausible wind speeds, the flow at large scales will be rotationally dominated. We present three-dimensional, global, numerical simulations of convection in the interior, which demonstrate that at large scales, the convection aligns in the direction parallel to the rotation axis. Convection occurs more efficiently at high latitudes than low latitudes, leading to systematic equator-to-pole temperature differences that may reach ?1 K near the top of the convection zone. The interaction of convection with the overlying, stably stratified atmosphere will generate a wealth of atmospheric waves, and we argue that, as in the stratospheres of planets in the solar system, the interaction of these waves with the mean flow will cause a significant atmospheric circulation at regional to global scales. At large scales, this should consist of stratified turbulence (possibly organizing into coherent structures such as vortices and jets) and an accompanying overturning circulation. We present an approximate analytic theory of this circulation, which predicts characteristic horizontal temperature variations of several to ?50 K, horizontal wind speeds of ?10-300 m s{sup –1}, and vertical velocities that advect air over a scale height in ?10{sup 5}-10{sup 6} s. This vertical mixing may help to explain the chemical disequilibrium observed on some brown dwarfs. Moreover, the implied large-scale organization of temperature perturbations and vertical velocities suggests that near the L/T transition, patchy clouds can form near the photosphere, helping to explain recent observations of brown-dwarf variability in the near-IR.

  19. High-resolution multi-band imaging for validation and characterization of small Kepler planets

    SciTech Connect

    Everett, Mark E.; Silva, David R.; Barclay, Thomas; Howell, Steve B.; Ciardi, David R.; Horch, Elliott P.; Crepp, Justin R.

    2015-02-01

    High-resolution ground-based optical speckle and near-infrared adaptive optics images are taken to search for stars in close angular proximity to host stars of candidate planets identified by the NASA Kepler Mission. Neighboring stars are a potential source of false positive signals. These stars also blend into Kepler light curves, affecting estimated planet properties, and are important for an understanding of planets in multiple star systems. Deep images with high angular resolution help to validate candidate planets by excluding potential background eclipsing binaries as the source of the transit signals. A study of 18 Kepler Object of Interest stars hosting a total of 28 candidate and validated planets is presented. Validation levels are determined for 18 planets against the likelihood of a false positive from a background eclipsing binary. Most of these are validated at the 99% level or higher, including five newly validated planets in two systems: Kepler-430 and Kepler-431. The stellar properties of the candidate host stars are determined by supplementing existing literature values with new spectroscopic characterizations. Close neighbors of seven of these stars are examined using multi-wavelength photometry to determine their nature and influence on the candidate planet properties. Most of the close neighbors appear to be gravitationally bound secondaries, while a few are best explained as closely co-aligned field stars. Revised planet properties are derived for each candidate and validated planet, including cases where the close neighbors are the potential host stars.

  20. Design and Verification of External Occulters for Direct Imaging of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Cady, Eric

    2011-01-01

    An occulter is an optical element which is placed in front of the telescope to block most of the light from a star before it reaches the optics inside, without blocking the planet.In our case, we use two spacecraft ying in formation: First has its edge shaped to cancel the starlight Second is the telescope which images the star and planet

  1. A giant planet imaged in the disk of the young star beta Pictoris.

    PubMed

    Lagrange, A-M; Bonnefoy, M; Chauvin, G; Apai, D; Ehrenreich, D; Boccaletti, A; Gratadour, D; Rouan, D; Mouillet, D; Lacour, S; Kasper, M

    2010-07-01

    Here, we show that the approximately 10-million-year-old beta Pictoris system hosts a massive giant planet, beta Pictoris b, located 8 to 15 astronomical units from the star. This result confirms that gas giant planets form rapidly within disks and validates the use of disk structures as fingerprints of embedded planets. Among the few planets already imaged, beta Pictoris b is the closest to its parent star. Its short period could allow for recording of the full orbit within 17 years. PMID:20538914

  2. Observational Signatures of Planets in Protoplanetary Disks: Spiral Arms Observed in Scattered Light Imaging Can Be Induced by Planets

    NASA Astrophysics Data System (ADS)

    Dong, Ruobing; Zhu, Zhaohuan; Rafikov, Roman R.; Stone, James M.

    2015-08-01

    Using 3D global hydro simulations coupled with radiative transfer calculations, we study the appearance of density waves induced by giant planets in direct imaging observations at near-infrared wavelengths. We find that a 6{M}{{J}} planet in a typical disk around a 1{M}? star can produce prominent and detectable spiral arms both interior and exterior to its orbit. The inner arms have (1) two well separated arms in roughly m = 2 symmetry, (2) exhibit ?10°–15° pitch angles, (3) ?180°–270° extension in the azimuthal direction, and (4) ? 150% surface brightness enhancement, all broadly consistent with observed spiral arms in the SAO 206462 and MWC 758 systems. The outer arms cannot explain observations as they are too tightly wound given typical disk scale height. We confirm previous results that the outer density waves excited by a 1{M}{{J}} planet exhibit low contrast in the IR and are practically not detectable. We also find that 3D effects of the waves are important. Compared to isothermal models, density waves in adiabatic disks exhibit weaker contrast in surface density but stronger contrast in scattered light images, due to a more pronounced vertical structure in the former caused by shock heating and maybe hydraulic jump effect. To drive observed pairs of arms with an external companion on a circular orbit, a massive planet, possibly a brown dwarf, is needed at around [r? 0\\buildrel{\\prime\\prime}\\over{.} 7, {PA}? 10^\\circ ] (position angle PA from north to east) in SAO 206462 and [r? 0\\buildrel{\\prime\\prime}\\over{.} 6, {PA}? 10^\\circ ] in MWC 758. Their existence may be confirmed by direct imaging planet searches.

  3. Imaging Extra-Solar Planets with an Ultra-Large Space Telescope

    NASA Technical Reports Server (NTRS)

    Taylor, Charles R.

    1998-01-01

    NASA's Origins Program is directed toward two main goals: Imaging of galactic evolution in the early universe, and searching for planets orbiting nearby stars. The Next-Generation Space Telescope (NGST), operating at low temperature with an 8-m aperture, is well designed to meet the first goal. The goal of imaging planets orbiting nearby stars is more problematic. One line of investigation has been the ULTIMA concept (Ultra-Large Telescope, Integrated Missions in Astronomy). In this report, I will lay out the resolution requirements for telescopes to achieve the imaging of extrasolar planets, and describe a modeling tool created to investigate the requirements for imaging a planet when it is very near a much brighter star.

  4. Direct imaging and spectroscopy of habitable planets using JWST and a starshade

    E-print Network

    Soummer, Rémi

    A starshade with the James Webb Space Telescope (JWST) is the only possible path forward in the next decade to obtain images and spectra of a planet similar to the Earth, to study its habitability, and search for signs of ...

  5. Directly Imaged Giant Planets: What Do We Hope to Learn?

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2015-01-01

    As we move into an era when GPI and SPHERE are (hopefully) discovering and characterizing new young giant planets, it is worthwhile to step back and review our science goals for young giant planets. Of course for individual planets we ideally would hope to measure mass, radius, atmospheric composition, temperature, and cloud properties, but how do these characteristics fit into our broader understanding of planetary system origin and evolution theories? In my presentation I will review both the specifics of what we hope to learn from newly discovered young worlds as well as how these characteristics inform our broader understanding of giant planets and planetary systems. Finally I will consider the limitations realistic datasets will place on our ability to understand newly discovered planets, illustrating with data from any new such worlds that are available by the conference date.

  6. Influence of Stellar Multiplicity on Planet Formation. IV. Adaptive Optics Imaging of Kepler Stars with Multiple Transiting Planet Candidates

    NASA Astrophysics Data System (ADS)

    Wang, Ji; Fischer, Debra A.; Xie, Ji-Wei; Ciardi, David R.

    2015-11-01

    The Kepler mission provides a wealth of multiple transiting planet systems (MTPSs). The formation and evolution of multi-planet systems are likely to be influenced by companion stars given the abundance of multiple stellar systems. We study the influence of stellar companions by measuring the stellar multiplicity rate of MTPSs. We select 138 bright (KP < 13.5) Kepler MTPSs and search for stellar companions with adaptive optics (AO) imaging data and archival radial velocity data. We obtain new AO images for 73 MTPSs. Other MTPSs in the sample have archival AO imaging data from the Kepler Community Follow-up Observation Program. From these imaging data, we detect 42 stellar companions around 35 host stars. For stellar separation 1 AU < a < 100 AU, the stellar multiplicity rate is 5.2 ± 5.0% for MTPSs, which is 2.8? lower than 21.1 ± 2.8% for the control sample, i.e., the field stars in the solar neighborhood. We identify two origins for the deficit of stellar companions within 100 AU of MTPSs: (1) a suppressive planet formation and (2) the disruption of orbital coplanarity due to stellar companions. To distinguish between the two origins, we compare the stellar multiplicity rates of MTPSs and single transiting planet systems (STPSs). However, current data are not sufficient for this purpose. For 100 AU < a < 2000 AU, the stellar multiplicity rates are comparable for MTPSs (8.0 ± 4.0%), STPSs (6.4 ± 5.8%), and the control sample (12.5 ± 2.8%).

  7. Deep L' and M-band Imaging for Planets Around Vega and epsilon Eridani

    E-print Network

    A. N. Heinze; Philip M. Hinz; Matthew Kenworthy; Douglas Miller; Suresh Sivanandam

    2008-07-24

    We have obtained deep Adaptive Optics (AO) images of Vega and epsilon Eri to search for planetary-mass companions. We observed at the MMT in the L' (3.8 micron) and M (4.8 micron) bands using Clio, a recently commissioned imager optimized for these wavelengths. Observing at these long wavelengths represents a departure from the H band (1.65 microns) more commonly used for AO imaging searches for extrasolar planets. The long wavelengths offer better predicted planet/star flux ratios and cleaner (higher Strehl) AO images, at the cost of lower diffraction limited resolution and higher sky background. We have not detected any planets or planet candidates around Vega or epsilon Eri. We report the sensitivities obtained around both stars, which correspond to upper limits on any planetary companions which may exist. The sensitivities of our L' and M band observations are comparable to those of the best H-regime observations of these stars. For epsilon Eri our M band observations deliver considerably better sensitivity to close-in planets than any previously published results, and we show that the M band is by far the best wavelength choice for attempts at ground-based AO imaging of the known planet epsilon Eri b. The Clio camera itself with MMTAO may be capable of detecting epsilon Eri b at its 2010 apastron, given a multi-night observing campaign. Clio appears to be the only currently existing AO imager that has a realistic possibility of detecting epsilon Eri b.

  8. Computer vision applications for coronagraphic optical alignment and image processing

    E-print Network

    Savransky, Dmitry; Poyneer, Lisa A; Macintosh, Bruce A; 10.1364/AO.52.003394

    2013-01-01

    Modern coronagraphic systems require very precise alignment between optical components and can benefit greatly from automated image processing. We discuss three techniques commonly employed in the fields of computer vision and image analysis as applied to the Gemini Planet Imager, a new facility instrument for the Gemini South Observatory. We describe how feature extraction and clustering methods can be used to aid in automated system alignment tasks, and also present a search algorithm for finding regular features in science images used for calibration and data processing. Along with discussions of each technique, we present our specific implementation and show results of each one in operation.

  9. Direct Exoplanet Imaging with JWST NIRCam: Low-Mass Stars, Low-Mass Planets, and Critical Constraints on Planet Formation

    NASA Astrophysics Data System (ADS)

    Schlieder, Joshua E.; Meyer, Michael; Reggiani, Maddalena; Quanz, Sascha; Beichman, Charles A.; Greene, Thomas P.; Burrows, Adam Seth

    2016-01-01

    As next generation exoplanet imagers are making their first discoveries, the largest population of stars in the Galaxy, the M dwarfs, are largely unaccounted for in their surveys. However, RV trends and micro lensing have revealed that M dwarfs host a substantial population of Neptune to Jupiter mass planets between ~1-10 AU. The unprecedented sensitivity of NIRCam on the JWST provides direct access to this population of gas-giants. A NIRCam 3 - 5 ?m survey for such planets will place critical constraints on planet formation by: 1) measuring the luminosities of young, sub-Jupiter mass planets, 2) providing constraints on the peak in the companion surface density vs. separation distribution, and 3) measuring the frequency of ?Jupiter mass giants in the outskirts of these systems (>10 AU). We have carefully constructed a sample of nearby, young, late-type stars, performed NIRCam survey simulations, and will report on the expected yield and advantages of JWST compared to current ground based capabilities.

  10. Drag-o-llision Models of Extrasolar Planets in Debris Disks

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2009-01-01

    An extrasolar planet sculpts the famous debris disk around Fomalhaut; probably many other debris disks contain planets that we could locate if only we could better recognize their signatures in the dust that surrounds them. But the interaction between planets and debris disks involves both orbital resonances and collisions among grains and rocks in the disks---difficult processes to model simultaneously. The author describes new 3-D models of debris disk dynamics, Drag-o-llision models, that incorporate both collisions and resonant trapping of dust for the first time. The author also discusses the implications of these models for coronagraphic imaging with Gemini and other telescopes.

  11. Gemini Scout Control Software

    SciTech Connect

    2010-11-23

    The Gemini Scout Control Software consists of two Windows applications that allow the Gemini Scout vehicle to be controlled by an operator. The Embedded application runs on the vehicle's Gemini Scout Control Software onboard computer and controls the vehicle's various motors and sensors. This application reports the vehicle's status and receives vehicle commands overthe local-area-network. The Embedded applicationalso allows the user to control the vehicle using a USB game-pad connected directly to the vehicle. The Operator Control Unit (OCU) application runs on an external PC and communicates with the vehicle via an Ethernet connection. The OCU application sends commands to and receives data from the Embedded application running on the vehicle. The OCU application also communicates directly with the digital video encoders and radios in order to display video from the vehicle's cameras and the status of the radio link. The OCU application has a graphical user interface (GUI) that displays the vehicle's status and allows the user to change various vehicle settings. Finally, the OCU application receives input from a USB game-pad connected to the PC in order to control the vehicle's functions.

  12. Gemini Scout Control Software

    Energy Science and Technology Software Center (ESTSC)

    2010-11-23

    The Gemini Scout Control Software consists of two Windows applications that allow the Gemini Scout vehicle to be controlled by an operator. The Embedded application runs on the vehicle's Gemini Scout Control Software onboard computer and controls the vehicle's various motors and sensors. This application reports the vehicle's status and receives vehicle commands overthe local-area-network. The Embedded applicationalso allows the user to control the vehicle using a USB game-pad connected directly to the vehicle. Themore »Operator Control Unit (OCU) application runs on an external PC and communicates with the vehicle via an Ethernet connection. The OCU application sends commands to and receives data from the Embedded application running on the vehicle. The OCU application also communicates directly with the digital video encoders and radios in order to display video from the vehicle's cameras and the status of the radio link. The OCU application has a graphical user interface (GUI) that displays the vehicle's status and allows the user to change various vehicle settings. Finally, the OCU application receives input from a USB game-pad connected to the PC in order to control the vehicle's functions.« less

  13. The Effect of Photochemistry and Quenching on the Atmospheric Composition of Young Directly Imaged Giant Planets

    NASA Astrophysics Data System (ADS)

    Moses, Julianne I.; Line, Michael R.; Visscher, Channon; Marley, Mark S.; Fortney, Jonathan J.; Lewis, Nikole K.; Wolff, Michael J.

    2015-11-01

    The last decade has seen significant progress on the direct detection and characterization of young, self-luminous giant planets at wide orbital separation from their host stars. Several of these planets show evidence for disequilibrium processes like transport-induced quenching in their atmospheres, which affects the relative abundances of methane and carbon monoxide and has other compositional consequences. Photochemistry is also potentially important on many of these planets, despite their large orbital distance, because the young host stars often have prodigious UV output. Disequilibrium chemical processes such as the above can alter the expected spectroscopic signatures of the planets and potentially confuse determinations of bulk elemental ratios, which provide important insights into planet-formation mechanisms. We use a thermochemical and photochemical kinetics and transport model to investigate the effects of photochemistry and quenching on young, directly imaged planets. Results for specific exoplanets such as the HR 8799 planets and 51 Eri b will be presented, as will more general trends as a function of planet mass, orbital distance, bulk atmospheric abundances, and stellar properties.

  14. Observational Signatures of Planets in Protoplanetary Disks: Spiral Arms Observed in Scattered Light Imaging Can be Induced by Planets

    E-print Network

    Dong, Ruobing; Rafikov, Roman; Stone, James

    2015-01-01

    Using 3D global hydro simulations coupled with radiative transfer calculations, we study the appearance of density waves induced by giant planets in direct imaging observations at near infrared wavelengths. We find that a 6 MJ planet in a typical disk around a 1 M_sun star can produce prominent and detectable spiral arms both interior and exterior to its orbit. The inner arms have (1) two well separated arms in roughly m=2 symmetry, (2) exhibit ~10-15 degrees pitch angles, (3) ~180-270 degrees extension in the azimuthal direction, and (4) ~150% surface brightness enhancement, all broadly consistent with observed spiral arms in the SAO 206462 and MWC 758 systems. The outer arms cannot explain observations as they are too tightly wound given typical disk scale height. We confirm previous results that the outer density waves excited by a 1 MJ planet exhibit low contrast in the IR and are practically not detectable. We also find that 3D effects of the waves are important. Compared to isothermal models, density wa...

  15. Planet Formation Instrument for the Thirty Meter Telescope

    SciTech Connect

    Macintosh, B; Troy, M; Graham, J; Doyon, R

    2006-02-22

    In the closing years of the 20th Century humankind began its exploration of the planetary systems in the solar neighborhood. Precision radial velocity measurements have now yielded the discovery of over 160 planets. Direct imaging of these planets, as opposed to detection of the effects of orbital motion on their parent star, is now feasible, and the first young planet in a wide orbit may have been detected using adaptive optics systems. Gemini and the VLT are building the first generation of high contrast adaptive optics systems, which deliver planet-imaging performance within few Airy rings of the host star. These systems will make the first surveys of the outer regions of solar systems by detecting the self-luminous radiation of young planets. These instruments will establish whether Jovian planets form predominantly through 'top-down' (global gravitational instability) or 'bottom-up' (core accretion) processes. The 8-m 'extreme' AO systems cannot see close enough to the host stars to image Doppler planets, and they cannot reach the relatively distant, young clusters and associations where planets are forming. The Planet Formation Instrument will use the nearly four-fold improved angular resolution of TMT to peer into the inner solar systems of Doppler-planet bearing stars to yield a unified sample of planets with known Keplerian orbital elements and atmospheric properties. In star formation regions, where T Tauri stars (young solar type stars) are found in abundance, PFI can see into the snow line, where the icy cores of planets like Jupiter must have formed. Thus, TMT will be the first facility to witness the formation of new planets.

  16. High-Contrast Imaging using Adaptive Optics for Extrasolar Planet Detection

    SciTech Connect

    Evans, J W

    2006-08-18

    Direct imaging of extrasolar planets is an important, but challenging, next step in planetary science. Most planets identified to date have been detected indirectly--not by emitted or reflected light but through the effect of the planet on the parent star. For example, radial velocity techniques measure the doppler shift in the spectrum of the star produced by the presence of a planet. Indirect techniques only probe about 15% of the orbital parameter space of our solar system. Direct methods would probe new parameter space, and the detected light can be analyzed spectroscopically, providing new information about detected planets. High contrast adaptive optics systems, also known as Extreme Adaptive Optics (ExAO), will require contrasts of between 10{sup -6} and 10{sup -7} at angles of 4-24 {lambda}/D on an 8-m class telescope to image young Jupiter-like planets still warm with the heat of formation. Contrast is defined as the intensity ratio of the dark wings of the image, where a planet might be, to the bright core of the star. Such instruments will be technically challenging, requiring high order adaptive optics with > 2000 actuators and improved diffraction suppression. Contrast is ultimately limited by residual static wavefront errors, so an extrasolar planet imager will require wavefront control with an accuracy of better than 1 nm rms within the low- to mid-spatial frequency range. Laboratory demonstrations are critical to instrument development. The ExAO testbed at the Laboratory for Adaptive Optics was designed with low wavefront error and precision optical metrology, which is used to explore contrast limits and develop the technology needed for an extrasolar planet imager. A state-of-the-art, 1024-actuator micro-electrical-mechanical-systems (MEMS) deformable mirror was installed and characterized to provide active wavefront control and test this novel technology. I present 6.5 x 10{sup -8} contrast measurements with a prolate shaped pupil and flat mirror demonstrating that the testbed can operate in the necessary contrast regime. Wavefront measurements and simulations indicate that contrast is limited by wavefront error, not diffraction. I demonstrate feasibility of the MEMS deformable mirror for meeting the stringent residual wavefront error requirements of an extrasolar planet imager with closed-loop results of 0.54 nm rms within controllable spatial frequencies. Individual contributors to final wavefront quality have been identified and characterized. I also present contrast measurements of 2 x 10{sup -7} made with the MEMS device and identify amplitude errors as the limiting error source. Closed-loop performance and simulated far-field measurements using a Kolmogorov phase plate to introduce atmosphere-like optical errors are also presented.

  17. The SEEDS Direct Imaging Survey for Planets and Scattered Dust Emission in Debris Disk Systems

    NASA Technical Reports Server (NTRS)

    Janson, Markus; Brandt, Timothy; Moro-Martin, Amaya; Usuda, Tomonori; Thalmann, Christian; Carson, Joseph C.; Goto, Miwa; Currie, Thayne; McElwain, M. W.; Itoh, Yoichi; Fukagawa, Misato; Crepp, Justin; Kuzuhara, Masayuki; Hashimoto, Jun; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Abe, Lyu; Brandner, Wolfgang; Egner, Sebastian; Fedlt, Markus; Grady, Carol A.; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiro; Hayashi, Saeko

    2013-01-01

    Debris disks around young main-sequence stars often have gaps and cavities which for a long time have been interpreted as possibly being caused by planets. In recent years, several giant planet discoveries have been made in systems hosting disks of precisely this nature, further implying that interactions with planets could be a common cause of such disk structures. As part of the SEEDS high-contrast imaging survey, we are surveying a population of debris disk-hosting stars with gaps and cavities implied by their spectral energy distributions, in order to attempt to spatially resolve the disk as well as to detect any planets that may be responsible for the disk structure. Here we report on intermediate results from this survey. Five debris disks have been spatially resolved, and a number of faint point sources have been discovered, most of which have been tested for common proper motion, which in each case has excluded physical companionship with the target stars. From the detection limits of the 50 targets that have been observed, we find that beta Pic b-like planets (approximately 10M(sub jup) planets around G-A-type stars) near the gap edges are less frequent than 15-30%, implying that if giant planets are the dominant cause of these wide (27 AU on average) gaps, they are generally less massive than beta Pic b.

  18. THE SEEDS DIRECT IMAGING SURVEY FOR PLANETS AND SCATTERED DUST EMISSION IN DEBRIS DISK SYSTEMS

    SciTech Connect

    Janson, Markus; Brandt, Timothy D.; Moro-Martin, Amaya; Usuda, Tomonori; Kudo, Tomoyuki; Egner, Sebastian; Thalmann, Christian; Carson, Joseph C.; Goto, Miwa; Currie, Thayne; McElwain, M. W.; Itoh, Yoichi; Fukagawa, Misato; Crepp, Justin; Kuzuhara, Masayuki; Hashimoto, Jun; Kusakabe, Nobuhiko; Abe, Lyu; Brandner, Wolfgang; Feldt, Markus; and others

    2013-08-10

    Debris disks around young main-sequence stars often have gaps and cavities which for a long time have been interpreted as possibly being caused by planets. In recent years, several giant planet discoveries have been made in systems hosting disks of precisely this nature, further implying that interactions with planets could be a common cause of such disk structures. As part of the SEEDS high-contrast imaging survey, we are surveying a population of debris-disk-hosting stars with gaps and cavities implied by their spectral energy distributions, in order to attempt to spatially resolve the disk as well as to detect any planets that may be responsible for the disk structure. Here, we report on intermediate results from this survey. Five debris disks have been spatially resolved, and a number of faint point sources have been discovered, most of which have been tested for common proper motion, which in each case has excluded physical companionship with the target stars. From the detection limits of the 50 targets that have been observed, we find that {beta} Pic b-like planets ({approx}10 M{sub jup} planets around G-A-type stars) near the gap edges are less frequent than 15%-30%, implying that if giant planets are the dominant cause of these wide (27 AU on average) gaps, they are generally less massive than {beta} Pic b.

  19. Sky Background Variability Measured on Maunakea at Gemini North Observatory

    NASA Astrophysics Data System (ADS)

    Smith, Adam B.; Roth, Katherine; Stephens, Andrew W.

    2016-01-01

    Gemini North has recently implemented a Quality Assessment Pipeline (QAP) that automatically reduces images in realtime to determine sky condition quantities, including background sky brightness from the optical to near-infrared. Processing archived images through the QAP and mining the results allows us to look for trends and systematic issues with the instruments and optics during the first decade of Gemini.Here we present the results of using the QAP calculated values to quantify how airglow affects the background sky brightness of images taken with Gemini's imaging instruments, GMOS and NIRI, as well as searching for other factors that may cause changes in the sky brightness. By investigating the dependence of measured sky brightness as a function of a variety of variables, including time after twilight, airmass, season, distance from the moon, air temperature, etc., we quantify the effect of sky brightness and its impact on the sensitivity of Gemini optical and near-infrared imaging data. These measurements will be used to determine new sky background relationships for Maunakea, and to improve the Gemini Integration Time Calculators (ITCs).

  20. ON THE MISALIGNMENT OF THE DIRECTLY IMAGED PLANET {beta} PICTORIS b WITH THE SYSTEM'S WARPED INNER DISK

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Fabrycky, Daniel C.

    2011-12-10

    The vertical warp in the debris disk {beta} Pictoris-an inclined inner disk extending into a flat outer disk-has long been interpreted as the signpost of a planet on an inclined orbit. Direct images spanning 2004-2010 have revealed {beta} Pictoris b, a planet with a mass and orbital distance consistent with this picture. However, it was recently reported that the orbit of planet b is aligned with the flat outer disk, not the inclined inner disk, and thus lacks the inclination to warp the disk. We explore three scenarios for reconciling the apparent misalignment of the directly imaged planet {beta} Pictoris b with the warped inner disk of {beta} Pictoris: observational uncertainty, an additional planet, and damping of planet b's inclination. We find that, at the extremes of the uncertainties, the orbit of {beta} Pictoris b has the inclination necessary to produce the observed warp. We also find that if planet b were aligned with the flat outer disk, it would prevent another planet from creating a warp with the observed properties; therefore planet b itself must be responsible for the warp. Finally, planet b's inclination could have been damped by dynamical friction and still produce the observed disk morphology, but the feasibility of damping depends on disk properties and the presence of other planets. More precise observations of the orbit of planet b and the position angle of the outer disk will allow us to distinguish between the first and third scenarios.

  1. LGS-AO Imaging of Every Kepler Planet Candidate: the Robo-AO KOI Survey

    NASA Astrophysics Data System (ADS)

    Baranec, Christoph; Law, Nicholas; Morton, Timothy; Ziegler, Carl; Nofi, Larissa; Atkinson, Dani; Riddle, Reed

    2015-12-01

    The Robo-AO Kepler Planetary Candidate Survey is observing every Kepler planet candidate host star with laser adaptive optics imaging, to search for blended nearby stars which may be physically associated companions and/or responsible for transit false positives. We will present the results from searching for companions around over 3,000 Kepler planet hosts in 2012-2015. We will describe our first data release covering 715 planet candidate hosts, and give a preview of ongoing results including improved statistics on the likelihood of false positive planet detections in the Kepler dataset, many new planets in multiple star systems, and new exotic multiple star systems containing Kepler planets. We will also describe the automated Robo-AO survey data reduction methods, including a method of using the large ensemble of target observations as mutual point-spread-function references, along with a new automated companion-detection algorithm designed for extremely large adaptive optics surveys. Our first data release covered 715 objects, searching for companions from 0.15” to 2.5” separation with contrast up to 6 magnitudes. We measured the overall nearby-star-probability for Kepler planet candidates to be 7.4+/-1.0%, and we will detail the variations in this number with stellar host parameters. We will also discuss plans to extend the survey to other transiting planet missions such as K2 and TESS as Robo-AO is in the process of being re-deployed to the 2.1-m telescope at Kitt Peak for 3 years and a higher-contrast Robo-AO system is being developed for the 2.2-m UH telescope on Maunakea.

  2. Janus and Gemini Nanoplates

    NASA Astrophysics Data System (ADS)

    Cheng, Zhengdong; Mejia, Andres; Chang, Ya-Wen; He, Peng; Diaz, Agustin; Clearfield, Abraham

    2011-03-01

    Janus particles were used to make stable Pickering emulsions (emulsions stabilized by particles). Here we demonstrated a novel method to produce high aspect ratio Janus plates with atomic thickness. Gemini plates with only the edges functionalized are also fabricated. These novel nanoplates are observed to have super surface activity. Most importantly, these particles overcome the two opposite effects in the stabilization of Pickering emulsions using spherical particles: stabilization requires particles as small as possible; but smaller particles are easy to escape the interface due to Brownian motion since the adsorption energy to the oil-water interface is proportional to the diameter of the spheres. Our nanoplates have a large aspect ratio due to the extremely thin thickness, which offers extraordinary stability to the liquid film between two emulsions to prevent coalescence. In the meantime, their large lateral surface area offers strong adsorption energy at the oil-water interface.

  3. Gemini-IFU Spectroscopy of HH 111

    NASA Astrophysics Data System (ADS)

    Cerqueira, A. H.; Vasconcelos, M. J.; Raga, A. C.; Feitosa, J.; Plana, H.

    2015-03-01

    We present new optical observations of the Herbig-Haro (HH) 111 jet using the Gemini Multi Object Spectrograph in its Integral Field Unit mode. Eight fields of 5\\prime\\prime × 3\\buildrel{\\prime\\prime}\\over{.} 5 have been positioned along and across the HH 111 jet, covering the spatial region from knot E to L in HH 111 (namely, knots E, F, G, H, J, K, and L). We present images and velocity channel maps for the [O i] 6300+6360, H?, [N ii] 6548+6583, and [S ii] 6716+6730 lines, as well as for the [S ii] 6716/6730 line ratio. We find that the HH 111 jet has an inner region with lower excitation and higher radial velocity, surrounded by a broader region of higher excitation and lower radial velocity. Also, we find higher electron densities at lower radial velocities. These results imply that the HH 111 jet has a fast, axial region with lower velocity shocks surrounded by a lower velocity sheath with higher velocity shocks. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  4. User Interface for the Control of the Gemini Telescopes S. S. Smith and K. Gillies

    E-print Network

    from pre­existing databases; guide, wavefront and scientific detector image data; as well as operating. INTRODUCTION The Gemini Telescopes operator interface is designed to provide quick access to the tools needed design of the Gemini software system requires each principle system work package ­ Telescope Control

  5. User Interface for the Control of the Gemini Telescopes S. S. Smith and K. Gillies

    E-print Network

    support associate (operator) interface. A second major consideration is that the Gemini design anticipates from pre-existing databases guide, wavefront and scienti c detector image data as well as operating The Gemini Telescopes operator interface is designed to provide quick access to the tools needed for normal

  6. Direct and interferometric imaging approaches for detecting earth-like extrasolar planets

    NASA Technical Reports Server (NTRS)

    Diner, D. J.; Van Zyl, J.; Jones, D. L.; Tubbs, E.; Wright, V.

    1988-01-01

    This paper discusses functional requirements of space-based observational systems with sufficient sensitivity, resolution, and dynamic range to image earth-like extrasolar planets within a search radius of 10 parsecs from the sun. Both direct and interferometric systems operating at visible and infrared wavelengths are evaluated, and the methods used to establish the system tolerances are presented. Due to the more favorable star/planet contrast ratio in the infrared, optical tolerance requirements are less stringent than in the visible. However, reduction of thermal radiation from the telescope requires cooling of the primary optics. Other tradeoffs between various approaches are enumerated.

  7. Gemini 9 spacecraft recovery operations

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The Gemini 9-A spacecraft, with Astronauts Thomas Stafford and Eugene Cernan still inside, in water as the aircraft carrier U.S.S. Wasp, the recovery ship, comes alongside to recover the astronauts and their spaceship.

  8. Inferring Planet Mass from Spiral Structures in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Fung, Jeffrey; Dong, Ruobing

    2015-12-01

    Recent observations of protoplanetary disk have reported spiral structures that are potential signatures of embedded planets, and modeling efforts have shown that a single planet can excite multiple spiral arms, in contrast to conventional disk–planet interaction theory. Using two and three-dimensional hydrodynamics simulations to perform a systematic parameter survey, we confirm the existence of multiple spiral arms in disks with a single planet, and discover a scaling relation between the azimuthal separation of the primary and secondary arm, {? }{{sep}}, and the planet-to-star mass ratio q: {? }{{sep}}=102^\\circ {(q/0.001)}0.2 for companions between Neptune mass and 16 Jupiter masses around a 1 solar mass star, and {? }{{sep}}=180^\\circ for brown dwarf mass companions. This relation is independent of the disk’s temperature, and can be used to infer a planet’s mass to within an accuracy of about 30% given only the morphology of a face-on disk. Combining hydrodynamics and Monte-Carlo radiative transfer calculations, we verify that our numerical measurements of {? }{{sep}} are accurate representations of what would be measured in near-infrared scattered light images, such as those expected to be taken by Gemini/GPI, Very Large Telescope/SPHERE, or Subaru/SCExAO in the future. Finally, we are able to infer, using our scaling relation, that the planet responsible for the spiral structure in SAO 206462 has a mass of about 6 Jupiter masses.

  9. Combining high-dispersion spectroscopy with high contrast imaging: Probing rocky planets around our nearest neighbors

    NASA Astrophysics Data System (ADS)

    Snellen, I.; de Kok, R.; Birkby, J. L.; Brandl, B.; Brogi, M.; Keller, C.; Kenworthy, M.; Schwarz, H.; Stuik, R.

    2015-04-01

    Context. Ground-based high-dispersion (R ~ 100 000) spectroscopy (HDS) is proving to be a powerful technique with which to characterize extrasolar planets. The planet signal is distilled from the bright starlight, combining ral and time-differential filtering techniques. In parallel, high-contrast imaging (HCI) is developing rapidly, aimed at spatially separating the planet from the star. While HDS is limited by the overwhelming noise from the host star, HCI is limited by residual quasi-static speckles. Both techniques currently reach planet-star contrast limits down to ~10-5, albeit for very different types of planetary systems. Aims: In this work, we discuss a way to combine HDS and HCI (HDS+HCI). For a planet located at a resolvable angular distance from its host star, the starlight can be reduced up to several orders of magnitude using adaptive optics and/or coronography. In addition, the remaining starlight can be filtered out using high-dispersion spectroscopy, utilizing the significantly different (or Doppler shifted) high-dispersion spectra of the planet and star. In this way, HDS+HCI can in principle reach contrast limits of ~10-5 × 10-5, although in practice this will be limited by photon noise and/or sky-background. In contrast to current direct imaging techniques, such as Angular Differential Imaging and Spectral Differential Imaging, it will work well at small working angles and is much less sensitive to speckle noise. For the discovery of previously unknown planets HDS+HCI requires a high-contrast adaptive optics system combined with a high-dispersion R ~ 100 000 integral field spectrograph (IFS). This combination currently does not exist, but is planned for the European Extremely Large Telescope. Methods: We present simulations of HDS+HCI observations with the E-ELT, both probing thermal emission from a planet at infrared wavelengths, and starlight reflected off a planet atmosphere at optical wavelengths. For the infrared simulations we use the baseline parameters of the E-ELT and METIS instrument, with the latter combining extreme adaptive optics with an R = 100 000 IFS. We include realistic models of the adaptive optics performance and atmospheric transmission and emission. For the optical simulation we also assume R = 100 000 IFS with adaptive optics capabilities at the E-ELT. Results: One night of HDS+HCI observations with the E-ELT at 4.8 ?m (?? = 0.07 ?m) can detect a planet orbiting ? Cen A with a radius of R = 1.5 Rearth and a twin-Earth thermal spectrum of Teq = 300 K at a signal-to-noise (S/N) of 5. In the optical, with a Strehl ratio performance of 0.3, reflected light from an Earth-size planet in the habitable zone of Proxima Centauri can be detected at a S/N of 10 in the same time frame. Recently, first HDS+HCI observations have shown the potential of this technique by determining the spin-rotation of the young massive exoplanet ? Pictoris b. Conclusions: The exploration of the planetary systems of our neighbor stars is of great scientific and philosophical value. The HDS+HCI technique has the potential to detect and characterize temperate rocky planets in their habitable zones. Exoplanet scientists should not shy away from claiming a significant fraction of the future ELTs to make such observations possible.

  10. How to Directly Image a Habitable Planet Around Alpha Centauri with a 30cm Space Telescope.

    NASA Astrophysics Data System (ADS)

    Belikov, R.; Bendek, E.; Thomas, S.; Black, D.

    2014-12-01

    More than 1,700 exoplanets have been discovered to date, including a handful of potentially habitable ones. There is on average more than one planet per star, and estimates of occurrence rates for potentially habitable planets (eta_Earth) from the Kepler mission range between 5 and 50%. Several mission concepts have been studied to directly image planets around nearby stars. Direct imaging enables spectroscopic detection of biomarkers such as atmospheric oxygen and methane, which would be highly suggestive of extraterrestrial life. It is commonly thought that directly imaging a potentially habitable exoplanet requires telescopes with apertures of at least 1m, costing at least $1B, and launching no earlier than the 2020s. A notable exception to this is Alpha Centauri. The system contains two Sun-like stars with a wide separation that allows dynamically stable habitable zones around either star. Habitable zones span about 0.5-1" in stellocentric angle, 3x wider than around any other FGKM star. A 30cm visible light space telescope is sufficient to resolve the habitable zone and detect a potentially habitable planet in minutes with ideal components, or days with realistic ones. We are developing a mission concept called ACEND (Alpha Centauri Direct Imager) consisting of a 30cm primary, a Phase-Induced Amplitude Apodization coronagraph, and a wavefront control system. It is designed to suppress the light leak from both stars and directly image their planetary systems in 3 color channels, including the capability to detect potentially habitable planets. Color imaging is sufficient to differentiate Venus-like, Earth-like, and Mars-like planets from each other and establish the presence of Earth-pressure atmosphere through Rayleigh scattering. Two factors make it possible to realize the requirements of ACEND (most notably 10^10 contrast) on a small budget and fast schedule: (a) ACEND will collect a long continuous sequence of images on Alpha Centauri A and B for 2 years, enabling much better speckle subtraction than missions that have many targets, thus greatly relaxing the requirements on the raw contrast of the coronagraph; (b) the small scale regime implies greater rigidity and stability, as well as smaller optics with better wavefronts.

  11. Scattered light images of spiral arms in marginally gravitationally unstable discs with an embedded planet

    NASA Astrophysics Data System (ADS)

    Pohl, A.; Pinilla, P.; Benisty, M.; Ataiee, S.; Juhász, A.; Dullemond, C. P.; Van Boekel, R.; Henning, T.

    2015-10-01

    Scattered light images of transition discs in the near-infrared often show non-axisymmetric structures in the form of wide-open spiral arms in addition to their characteristic low-opacity inner gap region. We study self-gravitating discs and investigate the influence of gravitational instability on the shape and contrast of spiral arms induced by planet-disc interactions. Two-dimensional non-isothermal hydrodynamical simulations including viscous heating and a cooling prescription are combined with three-dimensional dust continuum radiative transfer models for direct comparison to observations. We find that the resulting contrast between the spirals and the surrounding disc in scattered light is by far higher for pressure scaleheight variations, i.e. thermal perturbations, than for pure surface density variations. Self-gravity effects suppress any vortex modes and tend to reduce the opening angle of planet-induced spirals, making them more tightly wound. If the disc is only marginally gravitationally stable with a Toomre parameter around unity, an embedded massive planet (planet-to-star mass ratio of 10-2) can trigger gravitational instability in the outer disc. The spirals created by this instability and the density waves launched by the planet can overlap resulting in large-scale, more open spiral arms in the outer disc. The contrast of these spirals is well above the detection limit of current telescopes.

  12. WFIRST Exoplanet Imaging: Can Broadband Colors Efficiently Descriminate Planets from the Background?

    NASA Astrophysics Data System (ADS)

    Turnbull, Margaret C.; Kotulla, Ralf C.; Gallagher, John S.; Merrelli, Aronne; L'Ecuyer, Tristan; Fu, Guangwei; Hu, Renyu

    2016-01-01

    As part of the WFIRST Preparatory Science program, we have begun exploring the broadband color combinations for WFIRST that will most efficiently (1) descriminate planets from background sources in a single image and (2) shed some light on the nature of those planets. This is a first look at the color-color space, and color-magnitude space, occupied by planets orbiting nearby K-F main sequence stars. We explore (1) Solar System analog planets, (2) a variety of Earths/Super-Earths having optically thin or partially cloudy Earth-like atmospheres over desert/forest/ocean/icey surfaces, and (3) mini-Neptunes through Jupiter-mass planets at a range of temperatures where they would potentially be detectable to WFIRST. These colors are compared to the expected Galactic and extragalactic background sources for the Galactic coordinates of high priority targets. We offer some preliminary conclusions about the expected background contamination in these fields and how well color information can be used to mitigate that threat to WFIRST's exoplanet science.

  13. Beyond Kepler: Direct Imaging of Earth-like Planets

    NASA Technical Reports Server (NTRS)

    Belikov, Ruslan

    2012-01-01

    Is there another Earth out there? Is there life on it? People have been asking these questions for over two thousand years, and we finally stand on the verge of answering them. The Kepler space telescope is NASA's first mission designed to study Earthlike exoplanets (exo-Earths), and it will soon tell us how often exo-Earths occur in the habitable zones of their stars. The next natural step after Kepler is spectroscopic characterization of exo-Earths, which would tell us whether they possess an atmosphere, oxygen, liquid water, as well as other biomarkers. In order to do this, directly imaging an exo-Earth may be necessary (at least for Sun-like stars). Directly imaging an exo-Earth is challenging and likely requires a flagship-size optical space telescope with an unprecedented imaging system capable of achieving contrasts of 1(exp 10) very close to the diffraction limit. Several coronagraphs and external occulters have been proposed to meet this challenge and are in development. After first overviewing the history and current state of the field, my talk will focus on the work proceeding at the Ames Coronagraph Experiment (ACE) at the NASA Ames Research Center, where we are developing the Phase Induced Amplitude Apodization (PIAA) coronagraph in a collaboration with JPL. PIAA is a powerful technique with demonstrated aggressive performance that defines the state of the art at small inner working angles. At ACE, we have achieved contrasts of 2(exp -8) with an inner working angle of 2 lambda/D and 1(exp -6) at 1.4 lambda/D. On the path to exo-Earth imaging, we are also pursuing a smaller telescope concept called EXCEDE (EXoplanetary Circumstellar Environments and Disk Explorer), which was recently selected for technology development (Category III) by NASA's Explorer program. EXCEDE will do fundamental science on debris disks as well as serve as a technological and scientific pathfinder for an exo-Earth imaging mission.

  14. The LEECH Exoplanet Imaging Survey. Further constraints on the planet architecture of the HR 8799 system

    NASA Astrophysics Data System (ADS)

    Maire, A.-L.; Skemer, A. J.; Hinz, P. M.; Desidera, S.; Esposito, S.; Gratton, R.; Marzari, F.; Skrutskie, M. F.; Biller, B. A.; Defrère, D.; Bailey, V. P.; Leisenring, J. M.; Apai, D.; Bonnefoy, M.; Brandner, W.; Buenzli, E.; Claudi, R. U.; Close, L. M.; Crepp, J. R.; De Rosa, R. J.; Eisner, J. A.; Fortney, J. J.; Henning, T.; Hofmann, K.-H.; Kopytova, T. G.; Males, J. R.; Mesa, D.; Morzinski, K. M.; Oza, A.; Patience, J.; Pinna, E.; Rajan, A.; Schertl, D.; Schlieder, J. E.; Su, K. Y. L.; Vaz, A.; Ward-Duong, K.; Weigelt, G.; Woodward, C. E.

    2015-04-01

    Context. Astrometric monitoring of directly imaged exoplanets allows the study of their orbital parameters and system architectures. Because most directly imaged planets have long orbital periods (>20 AU), accurate astrometry is challenging when based on data acquired on timescales of a few years and usually with different instruments. The LMIRCam camera on the Large Binocular Telescope is being used for the LBT Exozodi Exoplanet Common Hunt (LEECH) survey to search for and characterize young and adolescent exoplanets in L' band (3.8 ?m), including their system architectures. Aims: We first aim to provide a good astrometric calibration of LMIRCam. Then, we derive new astrometry, test the predictions of the orbital model of 8:4:2:1 mean motion resonance proposed for the system, and perform new orbital fitting of the HR 8799 bcde planets. We also present deep limits on a putative fifth planet inside the known planets. Methods: We use observations of HR 8799 and the ?1 Ori C field obtained during the same run in October 2013. Results: We first characterize the distortion of LMIRCam. We determine a platescale and a true north orientation for the images of 10.707 ± 0.012 mas/pix and -0.430 ± 0.076°, respectively. The errors on the platescale and true north orientation translate into astrometric accuracies at a separation of 1'' of 1.1 mas and 1.3 mas, respectively. The measurements for all planets agree within 3? with a predicted ephemeris. The orbital fitting based on the new astrometric measurements favors an architecture for the planetary system based on 8:4:2:1 mean motion resonance. The detection limits allow us to exclude a fifth planet slightly brighter or more massive than HR 8799 b at the location of the 2:1 resonance with HR 8799 e (~9.5 AU) and about twice as bright as HR 8799 cde at the location of the 3:1 resonance with HR 8799 e (~7.5 AU). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

  15. Estimates of the Planet Yield from Ground-based High-contrast Imaging Observations as a Function of Stellar Mass

    NASA Astrophysics Data System (ADS)

    Crepp, Justin R.; Johnson, John Asher

    2011-06-01

    We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into consideration the important factors that govern the likelihood for imaging a planet, including the statistical properties of stars in the solar neighborhood, correlations between star and planet properties, observational effects, and selection criteria. We consider several different ground-based surveys, both biased and unbiased, and express the resulting planet yields as a function of stellar mass. Selecting targets based on their youth and visual brightness, we find that strong correlations between star mass and planet properties are required to reproduce high-contrast imaging results to date (i.e., HR 8799, ? Pic). Using the most recent empirical findings for the occurrence rate of gas-giant planets from radial velocity (RV) surveys, our simulations indicate that naive extrapolation of the Doppler planet population to semimajor axes accessible to high-contrast instruments provides an excellent agreement between simulations and observations using present-day contrast levels. In addition to being intrinsically young and sufficiently bright to serve as their own beacon for adaptive optics correction, A-stars have a high planet occurrence rate and propensity to form massive planets in wide orbits, making them ideal targets. The same effects responsible for creating a multitude of detectable planets around massive stars conspire to reduce the number orbiting low-mass stars. However, in the case of a young stellar cluster, where targets are approximately the same age and situated at roughly the same distance, MK-stars can easily dominate the number of detections because of an observational bias related to small number statistics. The degree to which low-mass stars produce the most planet detections in this special case depends upon whether multiple formation mechanisms are at work. Upon relaxing our assumption that planets in ultra-wide (a > 100 AU) orbits resemble the RV sample, our simulations suggest that the companions found orbiting late-type stars (AB Pic, 1RXSJ1609, GSC 06214, etc.) are consistent with a formation channel distinct from that of RV planets. These calculations explain why planets have thus far been imaged preferentially around A-stars and K-, M-stars, but no spectral types in between, despite concerted efforts targeting F-, G-stars.

  16. ESTIMATES OF THE PLANET YIELD FROM GROUND-BASED HIGH-CONTRAST IMAGING OBSERVATIONS AS A FUNCTION OF STELLAR MASS

    SciTech Connect

    Crepp, Justin R.; Johnson, John Asher

    2011-06-01

    We use Monte Carlo simulations to estimate the number of extrasolar planets that are directly detectable in the solar neighborhood using current and forthcoming high-contrast imaging instruments. Our calculations take into consideration the important factors that govern the likelihood for imaging a planet, including the statistical properties of stars in the solar neighborhood, correlations between star and planet properties, observational effects, and selection criteria. We consider several different ground-based surveys, both biased and unbiased, and express the resulting planet yields as a function of stellar mass. Selecting targets based on their youth and visual brightness, we find that strong correlations between star mass and planet properties are required to reproduce high-contrast imaging results to date (i.e., HR 8799, {beta} Pic). Using the most recent empirical findings for the occurrence rate of gas-giant planets from radial velocity (RV) surveys, our simulations indicate that naive extrapolation of the Doppler planet population to semimajor axes accessible to high-contrast instruments provides an excellent agreement between simulations and observations using present-day contrast levels. In addition to being intrinsically young and sufficiently bright to serve as their own beacon for adaptive optics correction, A-stars have a high planet occurrence rate and propensity to form massive planets in wide orbits, making them ideal targets. The same effects responsible for creating a multitude of detectable planets around massive stars conspire to reduce the number orbiting low-mass stars. However, in the case of a young stellar cluster, where targets are approximately the same age and situated at roughly the same distance, MK-stars can easily dominate the number of detections because of an observational bias related to small number statistics. The degree to which low-mass stars produce the most planet detections in this special case depends upon whether multiple formation mechanisms are at work. Upon relaxing our assumption that planets in ultra-wide (a > 100 AU) orbits resemble the RV sample, our simulations suggest that the companions found orbiting late-type stars (AB Pic, 1RXSJ1609, GSC 06214, etc.) are consistent with a formation channel distinct from that of RV planets. These calculations explain why planets have thus far been imaged preferentially around A-stars and K-, M-stars, but no spectral types in between, despite concerted efforts targeting F-, G-stars.

  17. ADAPTIVE OPTICS IMAGES. II. 12 KEPLER OBJECTS OF INTEREST AND 15 CONFIRMED TRANSITING PLANETS

    SciTech Connect

    Adams, E. R.; Dupree, A. K.; Kulesa, C.; McCarthy, D.

    2013-07-01

    All transiting planet observations are at risk of contamination from nearby, unresolved stars. Blends dilute the transit signal, causing the planet to appear smaller than it really is, or producing a false positive detection when the target star is blended with an eclipsing binary. High spatial resolution adaptive optics images are an effective way of resolving most blends. Here we present visual companions and detection limits for 12 Kepler planet candidate host stars, of which 4 have companions within 4''. One system (KOI 1537) consists of two similar-magnitude stars separated by 0.''1, while KOI 174 has a companion at 0.''5. In addition, observations were made of 15 transiting planets that were previously discovered by other surveys. The only companion found within 1'' of a known planet is the previously identified companion to WASP-2b. An additional four systems have companions between 1'' and 4'': HAT-P-30b (3.''7, {Delta}Ks = 2.9), HAT-P-32b (2.''9, {Delta}Ks = 3.4), TrES-1b (2.''3, {Delta}Ks = 7.7), and WASP-P-33b (1.''9, {Delta}Ks = 5.5), some of which have not been reported previously. Depending on the spatial resolution of the transit photometry for these systems, these companion stars may require a reassessment of the planetary parameters derived from transit light curves. For all systems observed, we report the limiting magnitudes beyond which additional fainter objects located 0.''1-4'' from the target may still exist.

  18. Connecting Young Brown Dwarfs and Directly Imaged Gas-Giant Planets

    NASA Astrophysics Data System (ADS)

    Liu, Michael; Dupuy, Trent; Allers, Katelyn; Aller, Kimberly; Best, William; Magnier, Eugene

    2015-12-01

    Direct detections of gas-giant exoplanets and discoveries of young (~10-100 Myr) field brown dwarfs from all-sky surveys are strengthening the link between the exoplanet and brown dwarf populations, given the overlapping ages, masses, temperatures, and surface gravities. In light of the relatively small number of directly imaged planets and the modest associated datasets, the large census of young field brown dwarfsprovides a compelling laboratory for enriching our understanding of both classes of objects. However, work to date on young field objects has typically focused on individual discoveries.We present a large comprehensive study of the youngest field brown dwarfs, comprising both previously known objects and our new discoveries from the latest wide-field surveys (Pan-STARRS-1 and WISE). With masses now extending down to ~5 Jupiter masses, these objects have physical properties that largely overlap young gas-giant planets and thus are promising analogs for studying exoplanet atmospheres at unparalleled S/N, spectral resolution, and wavelength coverage. We combine high-quality spectra and parallaxes to determine spectral energy distributions, luminosities, temperatures, and ages for young field objects. We demonstrate that this population spans a continuum in the color-magnitude diagram, thereby forming a bridge between the hot and cool extremes of directly imaged planets. We find that the extremely dusty properties of the planets around 2MASS J1207-39 and HR 8799 do occur in some young brown dwarfs, but these properties do not have a simple correspondence with age, perhaps contrary to expectations. We find young field brown dwarfs can have unusually low temperatures and suggest a new spectral type-temperature scale appropriate for directly imaged planets.To help provide a reference for extreme-contrast imaging surveys, we establish a grid of spectral standards and benchmarks, based on membership in nearby young moving groups, in order to calibrate gravity (age) and temperature diagnostics from near-IR spectroscopy. Finally, we use our data to critically examine the possibility that free-floating objects and companions may share different evolutionary histories, thereby complicating the brown dwarf-exoplanet connection.

  19. Imaging the Sources and Full Extent of the Sodium Tail of the Planet Mercury

    NASA Technical Reports Server (NTRS)

    Baumgardner, Jeffrey; Wilson, Jody; Mendillo, Michael

    2008-01-01

    Observations of sodium emission from Mercury can be used to describe the spatial and temporal patterns of sources and sinks in the planet s surface-boundary-exosphere. We report on new data sets that provide the highest spatial resolution of source regions at polar latitudes, as well as the extraordinary length of a tail of escaping Na atoms. The tail s extent of approx.1.5 degrees (nearly 1400 Mercury radii) is driven by radiation pressure effects upon Na atoms sputtered from the surface in the previous approx.5 hours. Wide-angle filtered-imaging instruments are thus capable of studying the time history of sputtering processes of sodium and other species at Mercury from ground-based observatories in concert with upcoming satellite missions to the planet. Plasma tails produced by photo-ionization of Na and other gases in Mercury s neutral tails may be observable by in-situ instruments.

  20. Extreme coronagraphy with an adaptive hologram Simulations of exo-planet imaging

    E-print Network

    Ricci, D; Labeyrie, A; 10.1051/0004-6361/200811529

    2009-01-01

    Aims. We present a solution to improve the performance of coronagraphs for the detection of exo-planets. Methods. We simulate numerically several kinds of coronagraphic systems, with the aim of evaluating the gain obtained with an adaptive hologram. Results. The detection limit in flux ratio between a star and a planet (Fs/Fp) observed with an apodized Lyot coronagraph characterized by wavefront bumpiness imperfections of lambda/20 (resp. lambda/100) turns out to be increased by a factor of 10^3.4 (resp. 10^5.1) when equipped with a hologram. Conclusions. This technique could provide direct imaging of an exo-Earth at a distance of 11 parsec with a 6.5m space telescope such as the JWST with the optical quality of the HST.

  1. A Laboratory Demonstration of the Capability to Image an Earth-like Extrasolar Planet

    NASA Technical Reports Server (NTRS)

    Trauger, John T.; Wesley, A. Traub

    2007-01-01

    The detection and characterization of an Earth-like planet orbiting a nearby star requires a telescope with an extraordinarily large contrast at small angular separations. At visible wavelengths, an Earth-like planet would be 1 times 10-10 times fainter than the star at angular separations of typically 0.1 arcsecond or less. There are several proposed space telescope systems that could, in principle, achieve this. Here we report a laboratory experiment that reaches these limits. We have suppressed the diffracted and scattered light near a star-like source to a level of 6 times 10-10 times the peak intensity in individual coronagraph images. In a series of such images, together with simple image processing, we have effectively reduced this to a residual noise level of about 0.1 times 10-10. This demonstrates that a coronagraphic telescope in space could detect and spectroscopically characterize nearby exoplanetary systems, with the sensitivity to image an 'Earth-twin' orbiting a nearby star.

  2. The Planets Around Low-Mass Stars (PALMS) Direct Imaging Survey

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.; Liu, M. C.; Shkolnik, E.; Mann, A.; Tamura, M.

    2013-01-01

    Direct imaging is the only method to study the outer architecture (>10 AU) of extrasolar planetary systems in a targeted fashion. Previous imaging surveys have primarily focused on intermediate- and high-mass stars because of the relative dearth of known nearby young M dwarfs. As a result, even though M dwarfs make up 70% of stars in our galaxy, there are few constraints on the population of giant planets at moderate separations (10-100 AU) in this stellar mass regime. We present results from an ongoing high-contrast adaptive optics imaging survey targeting newly identified nearby (<35 pc) young (<300 Myr) M dwarfs with Keck-2/NIRC2 and Subaru/HiCIAO. We have already discovered four young brown dwarf companions with masses between 30-70 Mjup; two of these are members of the ~120 Myr AB Dor moving group, and another one will yield a dynamical mass in the near future. Follow-up optical and near-infrared spectroscopy of these companions reveal spectral types of late-M to early-L and spectroscopic indicators of youth such as angular H-band morphologies, weak J-band alkali lines, and Li absorption and Halpha emission in one target. Altogether our survey is sensitive to planet masses a few times that of Jupiter at separations down to ~10 AU. With a sample size of roughly 80 single M dwarfs, this program represents the deepest and most extensive imaging search for planets around young low-mass stars to date.

  3. Planet Masses from Disk Spirals

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    Young, forming planets can generate immense spiral structures within their protoplanetary disks. A recent study has shown that observations of these spiral structures may allow astronomers to measure the mass of the planets that create them.Spirals From WavesSnapshots of the surface density of a protoplanetary disk in a 2D simulation, 3D simulation, and synthesized scattered-light image. Click for a closer look! [Fung Dong, 2015]Recent studies have shown that a single planet, if it is massive enough, can excite multiple density waves within a protoplanetary disk as it orbits. These density waves can then interfere to produce a multiple-armed spiral structure in the disk inside of the planets orbit a structure which can potentially be observed in scattered-light images of the disk.But what do these arms look like, and what factors determine their structure? In a recently published study, Jeffrey Fung and Ruobing Dong, two researchers at the University of California at Berkeley, have modeled the spiral arms in an effort to answer these questions.Arms Provide AnswersA useful parameter for describing the structure is the azimuthal separation (sep) between the primary and secondary spiral arms. If you draw a circle within the disk and measure the angle between the two points where the primary and secondary arms cross it, thats sep.Azimuthal separation of the primary and secondary spiral arms, as a function of the planet-to-star mass ratio q. The different curves represent different disk aspect ratios. [Fung Dong, 2015]The authors find thatsep stays roughly constant for different radii, but its strongly dependent on the planets mass: for larger planets, sep increases. They discover that sep scales as a power of the planet mass for companions between Neptune mass and 16 Jupiter masses, orbiting around a solar-mass star. For larger, brown-dwarf-size companions, sep is a constant 180.If this new theory is confirmed, it could have very interesting implications for observations of protoplanetary disks: this would give us the ability to measure the mass of a planet in a disk without ever needing to directly observe the planet itself!Modeling ObservationsFung and Dong confirm their models by additionally running 3D simulations, which yield very similar outcomes. From these simulation results, they then synthesize scattered-light images similar to what we would expect to be able to observe with telescopes like the VLT, Gemini, or Subaru. The authors demonstrate that from these scattered-light images, they can correctly retrieve the planets mass to within 30%.Finally, as a proof-of-concept, the authors apply this modeling to an actual system: SAO 206462, a nearly face-on protoplanetary disk with an observed two-armed spiral within it. From the measured azimuthal separation of the two arms, the authors estimate that it contains a planet of about 6 Jupiter masses.CitationJeffrey Fung () and Ruobing Dong () 2015 ApJ 815 L21. doi:10.1088/2041-8205/815/2/L21

  4. Planet Masses from Disk Spirals

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-12-01

    Young, forming planets can generate immense spiral structures within their protoplanetary disks. A recent study has shown that observations of these spiral structures may allow astronomers to measure the mass of the planets that create them.Spirals From WavesSnapshots of the surface density of a protoplanetary disk in a 2D simulation, 3D simulation, and synthesized scattered-light image. Click for a closer look! [Fung Dong, 2015]Recent studies have shown that a single planet, if it is massive enough, can excite multiple density waves within a protoplanetary disk as it orbits. These density waves can then interfere to produce a multiple-armed spiral structure in the disk inside of the planets orbit a structure which can potentially be observed in scattered-light images of the disk.But what do these arms look like, and what factors determine their structure? In a recently published study, Jeffrey Fung and Ruobing Dong, two researchers at the University of California at Berkeley, have modeled the spiral arms in an effort to answer these questions.Arms Provide AnswersA useful parameter for describing the structure is the azimuthal separation (sep) between the primary and secondary spiral arms. If you draw a circle within the disk and measure the angle between the two points where the primary and secondary arms cross it, thats sep.Azimuthal separation of the primary and secondary spiral arms, as a function of the planet-to-star mass ratio q. The different curves represent different disk aspect ratios. [Fung Dong, 2015]The authors find thatsep stays roughly constant for different radii, but its strongly dependent on the planets mass: for larger planets, sep increases. They discover that sep scales as a power of the planet mass for companions between Neptune mass and 16 Jupiter masses, orbiting around a solar-mass star. For larger, brown-dwarf-size companions, sep is a constant 180.If this new theory is confirmed, it could have very interesting implications for observations of protoplanetary disks: this would give us the ability to measure the mass of a planet in a disk without ever needing to directly observe the planet itself!Modeling ObservationsFung and Dong confirm their models by additionally running 3D simulations, which yield very similar outcomes. From these simulation results, they then synthesize scattered-light images similar to what we would expect to be able to observe with telescopes like the VLT, Gemini, or Subaru. The authors demonstrate that from these scattered-light images, they can correctly retrieve the planets mass to within 30%.Finally, as a proof-of-concept, the authors apply this modeling to an actual system: SAO 206462, a nearly face-on protoplanetary disk with an observed two-armed spiral within it. From the measured azimuthal separation of the two arms, the authors estimate that it contains a planet of about 6 Jupiter masses.CitationJeffrey Fung () and Ruobing Dong () 2015 ApJ 815 L21. doi:10.1088/2041-8205/815/2/L21

  5. Influence of Stellar Multiplicity On Planet Formation. IV. Adaptive Optics Imaging of Kepler Stars With Multiple Transiting Planet Candidates

    E-print Network

    Wang, Ji; Xie, Ji-Wei; Ciardi, David R

    2015-01-01

    The Kepler mission provides a wealth of multiple transiting planet systems (MTPS). The formation and evolution of multi-planet systems are likely to be influenced by companion stars given the abundance of multi stellar systems. We study the influence of stellar companions by measuring the stellar multiplicity rate of MTPS. We select 138 bright (KP solar neighborhood. We identify two origins for the deficit of stellar companions within 100 AU to MTPS: (1) a sup...

  6. How to Directly Image a Habitable Planet Around Alpha Centauri with a ~30cm Space Telescope

    NASA Astrophysics Data System (ADS)

    Belikov, Ruslan; Acend Team, Acesat Team

    2015-01-01

    Several mission concepts are being studied to directly image planets around nearby stars. Direct imaging enables spectroscopic detection of biomarkers such as atmospheric oxygen and methane, which would be highly suggestive of extraterrestrial life. It is commonly thought that directly imaging a potentially habitable exoplanet requires telescopes with apertures of at least 1m, costing at least 1B, and launching no earlier than the 2020s.A notable exception to this is Alpha Centauri (A and B), which is an extreme outlier among FGKM stars in terms of apparent habitable zone size. Specifically, Alpha Centauri habitable zones span about 0.5-1' in stellocentric angle, ~3x wider than around any other FGKM star. This enables a ~30cm visible light space telescope equipped with a modern high performance coronagraph or starshade to resolve the habitable zone at high contrast and directly image any potentially habitable planet that may exist in the system. Due to the extreme apparent brightness of the stars, exposure times can be as short as minutes with ideal components, or days with realistic ones. This makes it possible to do color photometry on potentially habitable planets sufficient to differentiate Venus-like, Earth-like, and Mars-like planets from each other and establish the presence of Earth-pressure atmosphere through Rayleigh scattering.The raw contrast requirements for such an instrument can be relaxed to 1e-8 if the mission spends 2 years collecting tens of thousands of images on the same target, enabling a factor of 500-1000 speckle suppression in post processing. The light leak from both stars is controllable with a special wavefront control algorithm known as Multi-Star Wavefront Control (MSWC), which independently suppresses diffraction and aberrations from both stars using independent modes on the deformable mirror (see Thomas et al. at this conference).The presentation will describe the general studies and calculations in more detail and briefly present examples of small coronagraphic mission concepts currently being developed to take advantage of this opportunity. (For more detail about one such concept, see Bendek et al. at this conference).

  7. BIGRE: a low cross-talk integral field unit tailored for extrasolar planets imaging spectroscopy

    E-print Network

    Antichi, Jacopo; Gratton, Raffaele G; Mesa, Dino; Claudi, Riccardo U; Giro, Enrico; Boccaletti, Anthony; Mouillet, David; Puget, Pascal; Beuzit, Jean-Luc

    2009-01-01

    Integral field spectroscopy (IFS) represents a powerful technique for the detection and characterization of extrasolar planets through high contrast imaging, since it allows to obtain simultaneously a large number of monochromatic images. These can be used to calibrate and then to reduce the impact of speckles, once their chromatic dependence is taken into account. The main concern in designing integral field spectrographs for high contrast imaging is the impact of the diffraction effects and the non-common path aberrations together with an efficient use of the detector pixels. We focus our attention on integral field spectrographs based on lenslet-arrays, discussing the main features of these designs: the conditions of appropriate spatial and spectral sampling of the resulting spectrograph's slit functions and their related cross-talk terms when the system works at the diffraction limit. We present a new scheme for the integral field unit (IFU) based on a dual-lenslet device (BIGRE), that solves some of the ...

  8. Spiral arms in scattered light images of protoplanetary discs: are they the signposts of planets?

    NASA Astrophysics Data System (ADS)

    Juhász, A.; Benisty, M.; Pohl, A.; Dullemond, C. P.; Dominik, C.; Paardekooper, S.-J.

    2015-08-01

    One of the striking discoveries of protoplanetary disc research in recent years are the spiral arms seen in several transitional discs in polarized scattered light. An interesting interpretation of the observed spiral features is that they are density waves launched by one or more embedded (proto)planets in the disc. In this paper, we investigate whether planets can be held responsible for the excitation mechanism of the observed spirals. We use locally isothermal hydrodynamic simulations as well as analytic formulae to model the spiral waves launched by planets. Then H-band scattered light images are calculated using a 3D continuum radiative transfer code to study the effect of surface density and pressure scaleheight perturbation on the detectability of the spirals. We find that a relative change of ˜3.5 in the surface density (??/?) is required for the spirals to be detected with current telescopes in the near-infrared for sources at the distance of typical star-forming regions (140 pc). This value is a factor of 8 higher than what is seen in hydrodynamic simulations. We also find that a relative change of only 0.2 in pressure scaleheight is sufficient to create detectable signatures under the same conditions. Therefore, we suggest that the spiral arms observed to date in protoplanetary discs are the results of changes in the vertical structure of the disc (e.g. pressure scaleheight perturbation) instead of surface density perturbations.

  9. Planet formation in action: resolved gas and dust images of a transitional disk and its cavity

    NASA Astrophysics Data System (ADS)

    van der Marel, Nienke; van Dishoeck, Ewine F.; Bruderer, Simon; Birnstiel, Til; Pinilla, Paola; Dullemond, Cornelis P.; van Kempen, Tim A.; Schmalzl, Markus; Brown, Joanna M.; Herczeg, Gregory J.; Mathews, Geoffrey S.; Geers, Vincent

    2014-01-01

    Planet formation and clearing of protoplanetary disks is one of the long standing problems in disk evolution theory. The best test of clearing scenarios is observing systems that are most likely to be actively forming planets: the transitional disks with large inner dust cavities. We present the first results of our ALMA (Atacama Large Millimeter/submillimeter Array) Cycle 0 program using Band 9, imaging the Herbig Ae star Oph IRS 48 in CO 6-5 and the submillimeter continuum in the extended configuration. The resulting ~0.2'' spatial resolution completely resolves the cavity of this disk in the gas and the dust. The gas cavity of IRS 48 is half as large as the dust cavity, ruling out grain growth and photoevaporation as the primary cause of the truncation. On the other hand, the continuum emission reveals an unexpected large azimuthal asymmetry and steep edges in the dust distribution along the ring, suggestive of dust trapping. We will discuss the implications of the combined gas and dust distribution for planet formation at a very early stage. This is one of the first transition disks with spatially resolved gas inside the cavity, demonstrating the superb capabilities of the Band 9 receivers.

  10. Design Study of the GNIRS Bracket Structure Optical Sciences Center, University of Arizona and Gemini 8m Telescopes

    E-print Network

    Design Study of the GNIRS Bracket Structure Myung Cho Optical Sciences Center, University a Optical Sciences Center, University of Arizona and Gemini 8m Telescopes Project, Tucson AZ 85726 b in the GNIRS to exploit the high image quality of the Gemini telescope. The initial concept for the structure

  11. Direct imaging of extra-solar planets with stationary occultations viewed by a space telescope

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.

    1978-01-01

    The use of a telescope in space to detect planets outside the solar system by means of imaging at optical wavelengths is discussed. If the 'black' limb of the moon is utilized as an occulting edge, a hypothetical Jupiter-Sun system could be detected at a distance as great as 10 pc, and a signal-to-noise ratio of 9 could be achieved in less than 20 min with a 2.4 m telescope in space. An orbit for the telescope is proposed; this orbit could achieve a stationary lunar occultation of any star for a period of nearly two hours.

  12. The trends high-contrast imaging survey. IV. The occurrence rate of giant planets around M dwarfs

    SciTech Connect

    Montet, Benjamin T.; Crepp, Justin R.; Johnson, John Asher; Howard, Andrew W.; Marcy, Geoffrey W.

    2014-01-20

    Doppler-based planet surveys have discovered numerous giant planets but are incomplete beyond several AU. At larger star-planet separations, direct planet detection through high-contrast imaging has proven successful, but this technique is sensitive only to young planets and characterization relies upon theoretical evolution models. Here we demonstrate that radial velocity measurements and high-contrast imaging can be combined to overcome these issues. The presence of widely separated companions can be deduced by identifying an acceleration (long-term trend) in the radial velocity of a star. By obtaining high spatial resolution follow-up imaging observations, we rule out scenarios in which such accelerations are caused by stellar binary companions with high statistical confidence. We report results from an analysis of Doppler measurements of a sample of 111 M-dwarf stars with a median of 29 radial velocity observations over a median time baseline of 11.8 yr. By targeting stars that exhibit a radial velocity acceleration ({sup t}rend{sup )} with adaptive optics imaging, we determine that 6.5% ± 3.0% of M-dwarf stars host one or more massive companions with 1 < m/M{sub J} < 13 and 0 < a < 20 AU. These results are lower than analyses of the planet occurrence rate around higher-mass stars. We find the giant planet occurrence rate is described by a double power law in stellar mass M and metallicity F ? [Fe/H] such that f(M,F)=0.039{sub ?0.028}{sup +0.056}M{sup 0.8{sub ?}{sub 0}{sub .}{sub 9}{sup +{sup 1{sup .{sup 1}}}}}10{sup (3.8±1.2)F}. Our results are consistent with gravitational microlensing measurements of the planet occurrence rate; this study represents the first model-independent comparison with microlensing observations.

  13. A method to directly image exoplanets in multi-star systems such as Alpha-Centauri

    E-print Network

    Thomas, Sandrine J; Bendek, Eduardo

    2015-01-01

    Direct imaging of extra-solar planets is now a reality, especially with the deployment and commissioning of the first generation of specialized ground-based instruments such as the Gemini Planet Imager and SPHERE. These systems will allow detection of Jupiter-like planets $10^7$ times fainter than their host star. Obtaining this contrast level and beyond requires the combination of a coronagraph to suppress light coming from the host star and a wavefront control system including a deformable mirror (DM) to remove residual starlight (speckles) created by the imperfections of telescope. However, all these current and future systems focus on detecting faint planets around single host stars, while several targets or planet candidates are located around nearby binary stars such as our neighboring star Alpha Centauri. Here, we present a method to simultaneously correct aberrations and diffraction of light coming from the target star as well as its companion star in order to reveal planets orbiting the target star. ...

  14. Shape model and rotational state of dwarf planet Ceres from Dawn FC stereo images

    NASA Astrophysics Data System (ADS)

    Preusker, F.; Scholten, F.; Matz, K.-D.; Roatsch, T.; Elgner, S.; Jaumann, R.; Joy, S. P.; Polanskey, C. A.; Raymond, C. A.; Russell, C. T.

    2015-10-01

    In 2012, the Dawn mission completed its 14-month observation campaign at asteroid (4) Vesta and entered in March 2015 successfully into the orbit around its final target - the dwarf planet Ceres. Similar to the mapping strategy at Vesta, Ceres will be imaged in three different altitude orbits [1] Survey, High Altitude Mapping Orbit (HAMO), and Low Altitude Mapping Orbit (LAMO) using the onboard camera Dawn FC [2]. In June 2015 Dawn is going to start its Survey orbit and will acquire about 920 clear filter images with a resolution of about 400 m/pixel in eight different cycles. In each cycle Ceres will be mapped completely under similar illumination conditions (Sun elevation and azimuth), but different viewing conditions (by slewing the spacecraft offnadir). This will allow us to analyze the images stereoscopically and to construct stereo topographic maps. The topography is particularly important because it is essential for derivation of physical properties of Ceres, precise ortho-image registration, mosaicking, and map generation of monochrome/color FC images and VIR images [3]. Furthermore we will determine a precise description of the rotational state of Ceres.

  15. Adaptive Optics for the Gemini Telescopes

    NASA Astrophysics Data System (ADS)

    Ridgway, S.

    1993-12-01

    Adaptive optics will play a critical role in achieving the highest possible image quality for the Gemini telescopes. An Adaptive Optics Working Group (R. Racine - chair, B. Ellerbroek, E. Kibblewhite, D. McCarthy, R. Myers, S. Ridgway, F. Roddier) is preparing to recommend an implementation strategy. The recommendations are still under discussion (the prospects for laser beacons are evolving rapidly). Current information will be presented in the poster. The working group is considering multiple stages of correction including a low order of correction at the secondary mirror, and a by-passable AO system with both medium and high order correction incorporated in the instrument support structure. It is proposed that a tilt reference sensor be provided in the acquisition and guiding unit, and that high order wavefront sensing should be provided in and optimized for each instrument which will use AO. The order of correction is to be optimized to the application. Low order correction can be implemented with natural reference stars and should be most effective at infrared wavelengths and over moderate fields. High order correction has the potential to provide excellent images at visible and red wavelengths over a small field, but will be more expensive and require bright reference stars or a laser beacon system. The Gemini project currently expects to initially provide tilting secondaries for both telescopes and AO for the Mauna Kea telescope. Issues of priority and strategy are still under active discussion, as the cost of the full proposed AO implementation likely exceeds available resources. This poster will describe recommendations for a phased implementation of adaptive optics and laser beacons, the projected performance, and possible instrument and telescope configurations.

  16. GAPS IN THE HD 169142 PROTOPLANETARY DISK REVEALED BY POLARIMETRIC IMAGING: SIGNS OF ONGOING PLANET FORMATION?

    SciTech Connect

    Quanz, Sascha P.; Avenhaus, Henning; Garufi, Antonio; Schmid, Hans Martin; Buenzli, Esther; Wolf, Sebastian

    2013-03-20

    We present H-band Very Large Telescope/NACO polarized light images of the Herbig Ae/Be star HD 169142 probing its protoplanetary disk as close as {approx}0.''1 to the star. Our images trace the face-on disk out to {approx}1.''7 ({approx}250 AU) and reveal distinct substructures for the first time: (1) the inner disk ({approx}<20 AU) appears to be depleted in scattering dust grains; (2) an unresolved disk rim is imaged at {approx}25 AU; (3) an annular gap extends from {approx}40 to 70 AU; (4) local brightness asymmetries are found on opposite sides of the annular gap. We discuss different explanations for the observed morphology among which ongoing planet formation is a tempting, but yet to be proven, one. Outside of {approx}85 AU the surface brightness drops off roughly {proportional_to}r {sup -3.3}, but describing the disk regions between 85-120 AU and 120-250 AU separately with power laws {proportional_to}r {sup -2.6} and {proportional_to}r {sup -3.9} provides a better fit hinting toward another discontinuity in the disk surface. The flux ratio between the disk-integrated polarized light and the central star is {approx}4.1 Multiplication-Sign 10{sup -3}. Finally, combining our results with those from the literature, {approx}40% of the scattered light in the H band appears to be polarized. Our results emphasize that HD 169142 is an interesting system for future planet formation or disk evolution studies.

  17. Scattered light images of spiral arms in marginally gravitationally unstable discs with an embedded planet

    E-print Network

    Pohl, A; Benisty, M; Ataiee, S; Juhasz, A; Dullemond, C P; Van Boekel, R; Henning, T

    2015-01-01

    Scattered light images of transition discs in the near-infrared often show non-axisymmetric structures in the form of wide-open spiral arms in addition to their characteristic low-opacity inner gap region. We study self-gravitating discs and investigate the influence of gravitational instability on the shape and contrast of spiral arms induced by planet-disc interactions. Two-dimensional non-isothermal hydrodynamical simulations including viscous heating and a cooling prescription are combined with three-dimensional dust continuum radiative transfer models for direct comparison to observations. We find that the resulting contrast between the spirals and the surrounding disc in scattered light is by far higher for pressure scale height variations, i.e. thermal perturbations, than for pure surface density variations. Self-gravity effects suppress any vortex modes and tend to reduce the opening angle of planet-induced spirals, making them more tightly wound. If the disc is only marginally gravitationally stable ...

  18. Direct imaging and spectroscopy of terrestrial planets with JWST and a starsahde

    NASA Astrophysics Data System (ADS)

    Soummer, R.; Valenti, J.; Brown, R. A.; Seager, S.; Tumlinson, J.; Cash, W.; Jordan, I.; Postman, M.; Mountain, M.; Glassman, T.; Pueyo, L.; Roberge, A.; NWP Team

    2010-10-01

    We present a study for using a starshade with the James Webb Space Telescope (JWST). This concept would enable imaging and spectroscopy of a planet similar to the Earth, the study of its habitability, and the search for signs of alien life. JWST was not specifically designed to observe with a starshade, but its instrumentation and its great sensitivity make it capable of achieving major results in the study of terrestrial-mass exoplanets. However, there are some challenges for the starshade designs mainly due to the very large wavelength sensitivity of the HgCdTe detectors. We discuss the combination of a starshade with internal filters in NIRCam and NIRSpec to optimize both science return and starshade performance. We discuss a possible filter upgrade to enable feasible observations of Earth-like planets and in particular spectroscopic characterization in the near infrared. The new filter would not affect NIRSpec's scientific performance nor its operations, but it would dramatically reduce the risk of adding a starshade to JWST in the future and enhance the performance of any starshade that is built.

  19. A History of the NASA Planetary Data System (PDS) Imaging Node's Map-A-Planet Legacy Web Services

    NASA Astrophysics Data System (ADS)

    Garcia, P. A.; Isbell, C. E.; Gaddis, L. R.

    2015-06-01

    NASA Planetary Data System (PDS) Imaging Node’s Map-A-Planet Legacy Web Services have served the planetary data community for more than fifteen years. Here we look back at the evolution and development of the services over the that time.

  20. ExSPO: A Discovery Class Apodized Square Aperture (ASA) Expo-Planet Imaging Space Telescope Concept

    NASA Technical Reports Server (NTRS)

    Gezari, D.; Harwit, M.; Lyon, R.; Melnick, G.; Papaliolos, G.; Ridgeway, S.; Woodruff, R.; Nisenson, P.; Oegerle, William (Technical Monitor)

    2002-01-01

    ExSPO is a Discovery Class (approx. 4 meter) apodized square aperture (ASA) space telescope mission designed for direct imaging of extrasolar Earth-like planets, as a precursor to TPF. The ASA telescope concept, instrument design, capabilities, mission plan and science goals are described.

  1. The Planet Pipeline: enabling data mining and citizen science with Hubble images of the Solar System

    NASA Astrophysics Data System (ADS)

    Mutchler, M.; Wong, M. H.; Higgins, J.; Gay, P. L.; Conti, A.; Deustua, S.; Golombek, D.; Grunsfeld, J.; Lerner, T.

    2011-10-01

    In 15 years of service, the Wide Field Planetary Camera 2 (WFPC2) onboard the Hubble Space Telescope (HST) obtained over 10,000 frames of Solar System data. Since standard data reduction pipelines are typically not optimized for movingtarget data, our "planet pipeline" will uniformly reprocess and catalog this WFPC2 image collection to make it more immediately science-ready. Some of our processing steps will utilize citizen scientists to perform visual inspections. Our corresponding database will enable robust queries which are more specific to planetary science, helping archival researchers quickly find and utilize the prepared images within our collection for a wide range of scientific analyses. We welcome suggestions (especially from veteran WFPC2 users) on the optimal treatment and organization of this data collection, and also to identify a broad range of analyses that might only be possible with visual inspections by citizen scientists. Our processed images and associated catalogs will be made available as High Level Science Products (HLSP) in the Multimission Archive at STScI (MAST): http://archive.stsci.edu/prepds/planetpipeline

  2. Bringing "The Moth" to Light: A Planet-Perturbed Disk Scenario for the HD 61005 System

    NASA Astrophysics Data System (ADS)

    Esposito, Thomas M.; Fitzgerald, Michael P.; Graham, James R.; Kalas, Paul G.; Millar-Blanchaer, Max; Wang, Jason

    2015-12-01

    The HD 61005 debris disk ("The Moth") is notable for its unusual swept-back "wing" morphology, brightness asymmetries, dust ring offset, and a cleared region inside of ~50 AU. Here we present Gemini Planet Imager data that reveal this disk in scattered light down to Jupiter-like separations of <10 AU. Complementary W.M. Keck NIRC2/AO J,H,K imaging shows the disk's outer regions with high angular resolution. Based on these data, we propose a new explanation for the disk's features: that of an unseen planet on an inclined, eccentric orbit perturbing the disk material. To test this scenario, we used secular perturbation theory to construct 3-D dust distributions that informed 2-D scattered-light models, which we then compared with the data via an MCMC analysis. We found that the best-fit models reproduced morphological disk features similar to those observed, indicating that the perturber scenario is plausible for this system.

  3. Gemini

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    (the Twins; abbrev. Gem, gen. Geminorum; area 514 sq. deg.) A northern zodiacal constellation which lies between Auriga and Canis Minor, and culminates at midnight in early January. It represents Castor and Pollux, the twin sons of Leda, Queen of Sparta, in Greek mythology, whose brotherly love was rewarded by a place among the stars. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) ...

  4. Direct imaging and spectroscopy of habitable planets using JWST and a starshade

    NASA Astrophysics Data System (ADS)

    Soummer, Rémi; Valenti, Jeff; Brown, Robert A.; Seager, Sara; Tumlinson, Jason; Cash, Webster; Jordan, Ian; Postman, Marc; Mountain, Matt; Glassman, Tiffany; Pueyo, Laurent; Roberge, Aki

    2010-07-01

    A starshade with the James Webb Space Telescope (JWST) is the only possible path forward in the next decade to obtain images and spectra of a planet similar to the Earth, to study its habitability, and search for signs of alien life. While JWST was not specifically designed to observe using a starshade, its near-infrared instrumentation is in principle capable of doing so and could achieve major results in the study of terrestrialmass exoplanets. However, because of technical reasons associated with broadband starlight suppression and filter red-leak, NIRSpec would need a slight modification to one of its target acquisition filters to enable feasible observations of Earth-like planets. This upgrade would 1) retire the high risk associated with the effects of the current filter red leak which are difficult to model given the current state of knowledge on instrument stray light and line spread function at large separation angles, 2) enable access to the oxygen band at 0.76 ?m in addition to the 1.26 ?m band, 3) enable a smaller starshade by relaxing requirements on bandwidth and suppression 4) reduce detector saturation and associated long recovery times. The new filter would not affect neither NIRSpecs scientific performance nor its operations, but it would dramatically reduce the risk of adding a starshade to JWST in the future and enhance the performance of any starshade that is built. In combination with a starshade, JWST could be the most capable and cost effective of all the exoplanet hunting missions proposed for the next decade, including purpose built observatories for medium-size missions.

  5. Obtaining coincident image observations for Mission to Planet Earth science data return

    NASA Technical Reports Server (NTRS)

    Newman, Lauri Kraft; Folta, David C.; Farrell, James P.

    1994-01-01

    One objective of the Mission to Planet Earth (MTPE) program involves comparing data from various instruments on multiple spacecraft to obtain a total picture of the Earth's systems. To correlate image data from instruments on different spacecraft, these spacecraft must be able to image the same location on the Earth at approximately the same time. Depending on the orbits of the spacecraft involved, complicated operational details must be considered to obtain such observations. If the spacecraft are in similar orbits, close formation flying or synchronization techniques may be used to assure coincident observations. If the orbits are dissimilar, the launch time of the second satellite may need to be restricted in order to align its orbit with that of the first satellite launched. This paper examines strategies for obtaining coincident observations for spacecraft in both similar and dissimilar orbits. Although these calculations may be performed easily for coplanar spacecraft, the non-coplanar case involves additional considerations which are incorporated into the algorithms presented herein.

  6. Fellow astronauts join Gemini 7 crew for preflight breakfast

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Fellow astronauts join the Gemini 7 prime crew for breakfeast in the Manned Spacecraft Operations Building, Merritt Island, on the day of the Gemini 7 launch. Clockwise around table, starting lower left, are Astronauts James A. Lovell Jr., Gemini 7 prime crew pilot; Walter M. Schirra Jr., Donald K. Slayton, MSC Assistant Director for Flight Crew Operations; Richard F. Gordon Jr., Gemini 8 backup crew pilot; Virgil I. Grissom, Charles Conrad Jr., and Frank Borman, Gemini 7 prime crew command pilot.

  7. The Planet Pipeline: data curation and mining of Solar System images from WFPC2

    NASA Astrophysics Data System (ADS)

    Mutchler, Max

    2010-09-01

    With the removal of the Wide Field Planetary Camera 2 {WFPC2} in May 2009, during Hubble Space Telescope {HST} Servicing Mission 4 {SM4}, came the end of a remarkable scientific tour-de-force. The collection of WFPC2 Solar System observations is enormous and diverse: on the order of 10,000 individual exposures spanning over 15 years. It includes long-term monitoring of planetary surfaces and atmospheres, targeted and serendipitous observations of moons, and many cometary targets-of-opportunity. Some of these observations were taken to support the planning of other NASA and ESA planetary missions, and to complement the data they obtain. The standard HST data pipelines, which calibrate and combine images, are largely optimized for the processing of fixed-target data. Moving-target data cannot be simply combined and cleaned, due to the rapid motion and rotation of the targets. New multi-extension FITS formats and recent improvements to basic WFPC2 calibrations means that the entire data set can now be reduced better than ever before. We propose to take full advantage of this by creating a comprehensive, uniformly processed, well documented, and searchable collection of Solar System data. Our "planet pipeline" will populate the image headers with information unique to planetary data, to produce a truly science-ready collection of WFPC2 Solar System imaging data. Our final data products will be ingested into the Multimission Archive at Space Telescope {MAST}, as High Level Science Products {HLSP}. We will conduct new scientific analyses of our own, but we expect our data products to enable a wide range of analyses by other researchers for many years to come, and form an essential piece of Hubble's archival legacy.

  8. Effects of latent heating on driving atmospheric circulation of brown dwarfs and directly imaged giant planets

    NASA Astrophysics Data System (ADS)

    Tan, Xianyu; Showman, Adam P.

    2015-12-01

    Growing observations of brown dwarfs (BDs) and directly imaged extrasolar giant planets (EGPs), such as brightness variability and surface maps have provided evidence for strong atmospheric circulation on these worlds. Previous studies that serve to understand the atmospheric circulation of BDs include modeling of convection from the interior and its interactions with stably stratified atmospheres. These models show that such interactions can drive an atmospheric circulation, forming zonal jets and/or vortices. However, these models are dry, not including condensation of various chemical species. Latent heating from condensation of water has previously been shown to play an important role on driving the zonal jets on four giant planets in our solar system. As such, condensation cycles of various chemical species are believed to be an important source in driving the atmospheric circulation of BDs and directly imaged EGPs. Here we present results from three-dimensional simulations for the atmospheres of BDs and EGPs based on a general circulation model that includes the effect of a condensate cycle. Large-scale latent heating and molecular weight effect due to condensation of a single species are treated explicitly. We examine the circulation patterns caused by large-scale latent heating which results from condensation of silicate vapor in hot dwarfs and water vapor in the cold dwarfs. By varying the abundance of condensable vapor and the radiative timescale, we conclude that under normal atmospheric conditions of BDs (hot and thus with relatively short radiative timescale), latent heating alone by silicate vapor is unable to drive a global circulation, leaving a quiescent atmosphere, because of the suppression to moist instability by downward transport of dry air. Models with relatively long radiative timescale, which may be the case for cooler bodies, tend to maintain an active hydrological cycle and develop zonal jets. Once condensation happens, storms driven by moist instability can extend vertically over several pressure scale heights, reaching the photospheres and being able to induce flux variabilities — helping to explain patchy clouds inferred from near-IR light curves and inferred surface map of BDs.

  9. The Gemini Observatory fast turnaround program

    NASA Astrophysics Data System (ADS)

    Mason, R. E.; Côté, S.; Kissler-Patig, M.; Levenson, N. A.; Adamson, A.; Emmanuel, C.; Crabtree, D.

    2014-08-01

    Gemini's Fast Turnaround program is intended to greatly decrease the time from having an idea to acquiring the supporting data. The scheme will offer monthly proposal submission opportunities, and proposals will be reviewed by the principal investigators or co-investigators of other proposals submitted during the same round. Here, we set out the design of the system and outline the plan for its implementation, leading to the launch of a pilot program at Gemini North in January 2015.

  10. Schirra, Stafford and Gemini on Deck

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut Walter H. Schirra Jr. (on right), Command pilot, climbs from his Gemini VI spacecraft as he and Astronaut Thomas P. Stafford (not in view) arrive aboard the aircraft carrier U.S.S. Wasp. They are assisted by various McDonell Douglas technicians. The Gemini VI spacecraft splashed down in the western Atlantic recover area at 10:29 a.m. (EST) December 16, 1965, after a successful 25 hr. 52 minute mission in space.

  11. Detection and characterization of the atmospheres of the HR 8799 b and c planets with high contrast HST/WFC3 imaging

    NASA Astrophysics Data System (ADS)

    Rajan, Abhijith; Barman, Travis; Soummer, Remi; Pueyo, Laurent; Patience, Jenny; Brendan Hagan, J.; Macintosh, Bruce; Marois, Christian; Konopacky, Quinn M.

    2015-01-01

    We present results from our Hubble Space Telescope program to characterize the atmospheres of two planets, b and c, in the HR8799 system, the only directly imaged multi-planet system currently known. Images were taken in three near-infrared medium-band filters -- F098M, F127M and F137M -- using the Wide Field Camera 3. One of the three filters is sensitive to water absorption bands inaccessible from ground-based observations, providing a unique probe of the thermal emission from the atmospheres of these young, warm giant planets. To enable the detections, we utilized the exquisite pointing accuracy of HST in combination with an innovative pipeline designed to combine the dithered, angular differential imaging data which improved the image resolution while accurately capturing the photometric information. The program spanned 15 orbits and the full data set was analyzed with the Karhunen-Loeve Image Projection (KLIP) routine, an advanced image processing algorithm designed specifically to work with HST data. The results include the first images of the outer-most planet HR 8799 b in the water-band filter, and both the two outer planets in the J-band peak. By probing in regions of the planet spectral energy distribution previously unobservable, we place unique constraints on their atmospheric properties.

  12. The Atmospheres of Directly Imaged Planets: Where Has All the Methane Gone?

    NASA Technical Reports Server (NTRS)

    Marley, Mark S.; Zahnle, Kevin

    2014-01-01

    Methane and ammonia both first appear at lower effective temperatures in brown dwarf atmospheres than equilibrium chemistry models would suggest. This has traditionally been understood as a consequence of vertical mixing timescales being shorter than chemical equilibration timescales in brown dwarf photospheres. Indeed the eddy diffusivity, a variable accounting for the vigor of vertical mixing, has become a standard part of the description of brown dwarf atmosphere models, along with Teff and log g. While some models have suggested that methane is less favored at lower gravity, the almost complete absence of methane in the atmospheres of directly imaged planets, such as those orbiting HR 8799, even at effective temperatures where methane is readily apparent in brown dwarf spectra, has been puzzling. To better understand the paucity of methane in low gravity atmospheres we have revisited the problem of methane chemistry and mixing. We employed a 1-D atmospheric chemistry code augmented with an updated and complete network of the chemical reactions that link CO to CH4. We find the methane abundance at altitudes at or above the effective photosphere is a strong function of surface gravity because higher g shifts the p-T structure to higher pressures (i.e., a given optical depth is proportional to p/g, a relation mitigated somewhat by pressure broadening). Thus quenching in more massive brown dwarfs occurs at a lower temperature and higher pressure, both favoring CH4. We predict that in the lowest mass young giant planets, methane will appear very late, at effective temperatures as low as 600 K rather than the 1200 K seen among field brown dwarfs. This methane deficiency has important implications for the interpretation of spectra as well as methane-based planetary companion searches, such as the NICI survey. The GPI and SPHERE surveys will test these ideas and probe atmospheric chemistry and composition in an entire new range of parameter space. A caveat is that these calculations presume that the C to O ratio is comfortably less than one; the behavior is quite different if C and O are equally abundant, and of course CH4 is always present if C exceeds O.

  13. The International Deep Planet Survey I. The frequency of wide-orbit massive planets around A-stars

    E-print Network

    Vigan, A; Marois, C; Bonavita, M; De Rosa, R J; Macintosh, B; Song, I; Doyon, R; Zuckerman, B; Lafrenière, D; Barman, T

    2012-01-01

    Breakthrough direct detections of planetary companions orbiting A-type stars confirm the existence of massive planets at relatively large separations, but dedicated surveys are required to estimate the frequency of similar planetary systems. To measure the first estimation of the giant exoplanetary systems frequency at large orbital separation around A-stars, we have conducted a deep-imaging survey of young (8-400 Myr), nearby (19-84 pc) A- and F-stars to search for substellar companions in the 10-300 AU range. The sample of 42 stars combines all A-stars observed in previous AO planet search surveys reported in the literature with new AO observations from VLT/NaCo and Gemini/NIRI. It represents an initial subset of the International Deep Planet Survey (IDPS) sample of stars covering M- to B-stars. The data were obtained with diffraction-limited observations in H- and Ks-band combined with angular differential imaging to suppress the speckle noise of the central stars, resulting in typical 5-sigma detection li...

  14. 3D spectroscopy of z ˜ 1galaxies with gemini

    NASA Astrophysics Data System (ADS)

    Smith, Joanna; Bunker, Andrew; Bower, Richard

    2003-04-01

    Area spectroscopy has significant advantages over both traditional imaging and long-slit spectroscopy: it is more efficient in observing time, and yields substantially more information. Through Integral Field Units, area spectroscopy is becoming an essential part of new facility instruments on the latest large telescopes. We have been undertaking a programme on the Gemini 8-m telescopes to demonstrate the power of integral field spectroscopy, using the optical GMOS spectrograph, and the new CIRPASS instrument in the near-infrared. Here we present some preliminary results from 3D spectroscopy of z ˜ 1 objects, mapping the emission lines in a 3CR radio galaxy and in a gravitationally lensed arc.

  15. Understanding the Atmosphere of 51 Eri b: Do Photochemical Hazes Cloud the Planets Spectrum?

    NASA Technical Reports Server (NTRS)

    Marley, Mark Scott; Zahnle, Kevin; Moses, J.; Morley, C.

    2015-01-01

    The first young giant planet to be discovered by the Gemini Planet Imager was the (is) approximately 2MJ planet 51 Eri b. This approximately 20 Myr old young Jupiter is the first directly imaged planet to show unmistakable methane in H band. To constrain the planet's mass, atmospheric temperature, and composition, the GPI J and H band spectra as well as some limited photometric points were compared to the predictions of substellar atmosphere models. The best fitting models reported in the discovery paper (Macintosh et al. 2015) relied upon a combination of clear and cloudy atmospheric columns to reproduce the data. However for an object as cool as 700 K, the origin of the cloud coverage is somewhat puzzling, as the global silicate and iron clouds would be expected to have sunk well below the photosphere by this effective temperature. While strong vertical mixing in these low gravity atmospheres remains a plausible explanation, we have explored whether atmospheric photochemistry, driven by the UV flux from the primary star, may yield hazes that also influence the observed spectrum of the planet. To explore this possibility we have modeled the atmospheric photochemistry of 51 Eri b using two state-of-the-art photochemical models, both capable of predicting yields of complex hydrocarbons under various atmospheric conditions. In our presentation we will summarize the modeling approach employed to characterize 51 Eri b, explaining constraints on the planet's effective temperature, gravity, and atmospheric composition and also present results of our studies of atmospheric photochemistry. We will discuss whether photochemical hazes could indeed be responsible for the particulate opacity that apparently sculpts the spectrum of the planet.

  16. Revision of Earth-sized Kepler Planet Candidate Properties with High-resolution Imaging by the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Cartier, Kimberly M. S.; Gilliland, Ronald L.; Wright, Jason T.; Ciardi, David R.

    2015-05-01

    We present the results of our Hubble Space Telescope program and describe how our analysis methods were used to re-evaluate the habitability of some of the most interesting Kepler planet candidates. Our program observed 22 Kepler Object of Interest (KOI) host stars, several of which were found to be multiple star systems unresolved by Kepler. We use our high-resolution imaging to spatially resolve the stellar multiplicity of Kepler-296, KOI-2626, and KOI-3049, and develop a conversion to the Kepler photometry (Kp) from the F555W and F775W filters on WFC3/UVIS. The binary system Kepler-296 (five planets) has a projected separation of 0\\buildrel{\\prime\\prime}\\over{.} 217 (80 AU); KOI-2626 (one planet candidate) is a triple star system with a projected separation of 0\\buildrel{\\prime\\prime}\\over{.} 201 (70 AU) between the primary and secondary components and 0\\buildrel{\\prime\\prime}\\over{.} 161 (55 AU) between the primary and tertiary; and the binary system KOI-3049 (one planet candidate) has a projected separation of 0\\buildrel{\\prime\\prime}\\over{.} 464 (225 AU). We use our measured photometry to fit the separated stellar components to the latest Victoria-Regina Stellar Models with synthetic photometry to conclude that the systems are coeval. The components of the three systems range from mid-K dwarf to mid-M dwarf spectral types.We solved for the planetary properties of each system analytically and via an MCMC algorithm using our independent stellar parameters. The planets range from ˜ 1.6 to ˜ 4.2 {{R}\\oplus }, mostly Super Earths and mini-Neptunes. As a result of the stellar multiplicity, some planets previously in the Habitable Zone are, in fact, not, and other planets may be habitable depending on their assumed stellar host. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  17. Direct imaging of extra-solar planets in star forming regions. Lessons learned from a false positive around IM Lupi

    NASA Astrophysics Data System (ADS)

    Mawet, D.; Absil, O.; Montagnier, G.; Riaud, P.; Surdej, J.; Ducourant, C.; Augereau, J.-C.; Röttinger, S.; Girard, J.; Krist, J.; Stapelfeldt, K.

    2012-08-01

    Context. Most exoplanet imagers consist of ground-based adaptive optics coronagraphic cameras which are currently limited in contrast, sensitivity and astrometric precision, but advantageously observe in the near-infrared window (1-5 ?m). Because of these practical limitations, our current observational aim at detecting and characterizing planets puts heavy constraints on target selection, observing strategies, data reduction, and follow-up. Most surveys so far have thus targeted young systems (1-100 Myr) to catch the putative remnant thermal radiation of giant planets, which peaks in the near-infrared. They also favor systems in the solar neighborhood (d < 80 pc), which eases angular resolution requirements but also ensures a good knowledge of the distance and proper motion, which are critical to secure the planet status, and enable subsequent characterization. Aims: Because of their youth, it is very tempting to target the nearby star forming regions, which are typically twice as far as the bulk of objects usually combed for planets by direct imaging. Probing these interesting reservoirs sets additional constraints that we review in this paper by presenting the planet search that we initiated in 2008 around the disk-bearing T Tauri star IM Lup, which is part of the Lupus star forming region (140-190 pc). Methods: We show and discuss why age determination, the choice of evolutionary model for both the central star and the planet, precise knowledge of the host star proper motion, relative or absolute (between different instruments) astrometric accuracy (including plate scale calibration), and patience are the key ingredients for exoplanet searches around more distant young stars. Results: Unfortunately, most of the time, precision and perseverance are not paying off: we discovered a candidate companion around IM Lup in 2008, which we report here to be an unbound background object. We nevertheless review in details the lessons learned from our endeavor, and additionally present the best detection limits ever calculated for IM Lup. We also accessorily report on the successful use of innovative data reduction techniques, such as the damped-LOCI and iterative roll subtraction. Based on the ESO observing programs 380.C-0910, 084.C-0444, 287.C-5040; and HST observing program 10177.

  18. Women Astronomers at Gemini: A Success Story

    NASA Astrophysics Data System (ADS)

    Rodgers, Bernadette; Jorgensen, I.; Barker, N.; Edwards, M.; Trancho, G.

    2010-01-01

    Gemini Observatory has been very successful at attracting, hiring and retaining female Scientists. We present data on the growth of the scientific staff since the start of the Observatory, and science fellow recruiting from 2006-2008. At Gemini 31% of the Science Staff holding PhDs are female compared with 13.9% within the United States. The Science Management is 75% female, as is 50% of the Gemini Directorate. This critical mass of female representation within the science staff and management appears to have had a positive effect on female recruitment and hiring. The science fellow recruitment during the past 3 years has attracted 21-38% female applicants and 57% of new hires during this period have been female scientists. Perhaps even more significant, the retention rate of female science staff at Gemini is 88%, compared to 64% for male science staff. There are likely many factors that contribute to this success, but the conclusion is that Gemini has earned a reputation in the scientific community as a place where female scientists are valued and can be successful.

  19. Gemini Prime Focus Wavefront Sensor J. Sebag, D. Walther, P. Gigoux, J. M. Oschmann, C. Cavedoni

    E-print Network

    A Prime Focus Wavefront Sensor (PFWFS) has been designed and built at the Gemini Observatory. The system contains a Shack-Hartmann (SH) wavefront sensor and has been designed to use commercial components to the primary mirror and to retain the optics in place. 2) The guiding and image acquisition unit. Its function

  20. Future Gemini Instrumentation F.C. Gillett and C.M. Mountain

    E-print Network

    for the Mauna Kea AO system 2) A Near IR Coronagraph/Imager for Cerro Pachon 3) 1 ­ 2.5µm Multi for Optical and IR wavelengths at both Mauna Kea and Cerro Pachon 5) A High Stability Lab Optical Spectrometer for Cerro Pachon, with resolutions around 120K and >300K. 1. INTRODUCTION The Gemini telescopes on Mauna Kea

  1. Revision of Earth-sized Kepler Planet Candidate Properties with High Resolution Imaging by Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Star, Kimberly Michelle; Gilliland, Ronald L.

    2014-06-01

    In this paper we present the first results of our HST GO/SNAP program GO-12893 and describe how our image analysis using STScI's DrizzlePac software combined with our own empirical point spread function definition were used to re-evaluate the habitability of some of the most interesting Kepler planet candidates. We used our high resolution imaging to calibrate Kp to the F555W and F775W filters on WFC3/UVIS, and spatially resolved the stellar multiplicity of KOI-1422, KOI-2626, and KOI-3049. We found KOI-1422 to be a tight binary star system with a projected separation of 0.217’’ 90 AU). We found KOI-2626 to be a triple star system with a projected separation of 0.201’’ 110 AU) between the primary and secondary components and 0.161’’ 90 AU) between the primary and tertiary components. We found KOI-3049 to be a binary star system with a projected separation of 0.464’’ 330 AU). Using theoretical isochrones from the Dartmouth Stellar Evolution Database, we performed hierarchical fitting using our derived photometry and the synthetic photometry from the isochrones. Revised stellar parameters for the individual components of the systems show that the stars in these systems range from early-K dwarf to early-M dwarf spectral types. We report with high confidence that all three systems are bound and co-eval based on the tight isochrone fitting and false positive analysis. Using our best-fit stellar parameters from the isochrone matches, we solved for the properties of the planets in the three systems and found that the planets range in size from ~2REarth to ~4 REarth, placing them in the Super Earth/mini-Neptune range. Some planets analyzed here are potentially habitable depending on their stellar host and greenhouse effect level.

  2. How to Directly Image a Habitable Planet Around Alpha Centauri with a ~30-45cm Space Telescope

    E-print Network

    Belikov, Ruslan; Thomas, Sandrine; Males, Jared; Lozi, Julien

    2015-01-01

    Several mission concepts are being studied to directly image planets around nearby stars. It is commonly thought that directly imaging a potentially habitable exoplanet around a Sun-like star requires space telescopes with apertures of at least 1m. A notable exception to this is Alpha Centauri (A and B), which is an extreme outlier among FGKM stars in terms of apparent habitable zone size: the habitable zones are ~3x wider in apparent size than around any other FGKM star. This enables a ~30-45cm visible light space telescope equipped with a modern high performance coronagraph or starshade to resolve the habitable zone at high contrast and directly image any potentially habitable planet that may exist in the system. We presents a brief analysis of the astrophysical and technical challenges involved with direct imaging of Alpha Centauri with a small telescope and describe two new technologies that address some of the key technical challenges. In particular, the raw contrast requirements for such an instrument c...

  3. Execution of queuescheduled observations with the Gemini 8m telescopes

    E-print Network

    Execution of queue­scheduled observations with the Gemini 8m telescopes Phil Puxley Gemini 8m described. In this paper we discuss the philosophy and parameters which define its execution. Results from detailed simulations of the queue execution process are presented. Keywords: Gemini telescopes, telescope

  4. Radiation dosimetry for the Gemini program

    NASA Technical Reports Server (NTRS)

    Richmond, R. G.

    1972-01-01

    The principal source of radiation for low-earth-orbit, low inclination space flights is in the area of the South Atlantic magnetic anomaly. None of the Gemini dose measurements reported in the paper are of high enough intensity to be considered hazardous. There is a trend toward larger doses as missions are flown higher and longer. Extended orbital operations between 1400 and 4400 kilometers would encounter high interior radiation levels. Pronounced spacecraft geometry effects have been measured in manned spacecraft. Instrumentation for radiation measurements on Gemini spacecraft is described.

  5. Characterizing Extra-Solar Planets with Low Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rice, Emily L.; Oppenheimer, B. R.; Zimmerman, N.; Roberts, L. C., Jr.; Hinkley, S.

    2012-01-01

    In the next few years, several high contrast imaging instruments equipped with integral field spectrographs will allow the direct spectral characterization of a variety of companions, from low-mass stars to Jupiter-mass extra-solar planets, at Solar System-like separations (4-40 AU). The spectra obtained by these instruments will be low resolution (R 30-60), making detailed thermo-chemical analysis difficult. Therefore, we have developed a technique that quantitatively compares observed low-resolution spectra with a set of synthetic spectra in order to obtain physical parameters, such as temperature and surface gravity, quickly and robustly. The technique requires no assumptions about age, mass, radius or metallicity of the companion or the primary. We describe this technique and demonstrate its effectiveness with simulated and observed spectra from Project 1640, the high contrast imager and integral field spectrograph on Palomar. The technique can also be used to optimize observing efficiency by determining the ideal wavelength range (for multi-filter instruments such as the Gemini Planet Imager) and signal to noise ratio for a desired precision and accuracy of inferred parameters. The current analysis uses the PHOENIX models as a basis for comparison, but the technique can be applied to any set of models and even used to quantify the differences between models created by different groups. This tool provides a necessary, fast, and comprehensive method of characterizing faint companions of stars, whether they be stellar, sub-stellar or planetary in nature.

  6. Optical Images of an Exosolar Planet 25 Light-Years from Earth

    NASA Technical Reports Server (NTRS)

    Clampin, Mark

    2008-01-01

    Fomalhaut is a bright star 7.7 parsec (25 light year) from Earth that harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate. Fomalhaut b. In the plane of the belt, Fomalhaut b lies approximately 119 astronomical units (AU) from the star, and within 18 All of the dust belt. We detect counterclockwise orbital motion using Hubble Space Telescope observations separated by 1.73 years. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter for the belt to avoid gravitational disruption. The flux detected at 0.8 micron flux is also consistent with that of a planet with mass a few limes that of Jupiter. The brightness at 0.6 microns and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observed variability of unknown origin at 0.6 microns.

  7. Optical images of an exosolar planet 25 light-years from Earth.

    PubMed

    Kalas, Paul; Graham, James R; Chiang, Eugene; Fitzgerald, Michael P; Clampin, Mark; Kite, Edwin S; Stapelfeldt, Karl; Marois, Christian; Krist, John

    2008-11-28

    Fomalhaut, a bright star 7.7 parsecs (25 light-years) from Earth, harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. Fomalhaut b lies about 119 astronomical units (AU) from the star and 18 AU of the dust belt, matching predictions of its location. Hubble Space Telescope observations separated by 1.73 years reveal counterclockwise orbital motion. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter; a higher mass would lead to gravitational disruption of the belt, matching predictions of its location. The flux detected at 0.8 mum is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 mum and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observe variability of unknown origin at 0.6 mum. PMID:19008414

  8. Optical Images of an Exosolar Planet 25 Light Years from Earth

    NASA Technical Reports Server (NTRS)

    Kalas, Paul; Graham, James R.; Chiang, Eugene; Fitzgerald, Michael P.; Clampin, Mark; Kite, Edwin S.; Stapelfeldt, Karl; Marois, Christian; Krist, John

    2008-01-01

    Fomalhaut is a bright star 7.7 parsecs (25 light years) from Earth that harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. In the plane of the belt, Fomalhaut b lies approximately 119 astronomical units (AU) from the star and 18 AU from the dust belt, matching predictions. We detect counterclockwise orbital motion using Hubble Space Telescope observations separated by 1.73 years. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter for the belt to avoid gravitational disruption. The flux detected at 0.8 m is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 micron and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observed variability of unknown origin at 0.6 micron.

  9. Optical Images of an Exosolar Planet 25 Light Years from Earth

    SciTech Connect

    Kalas, P; Graham, J R; Chiang, E; Fitzgerald, M P; Clampin, M; Kite, E S; Stapelfeldt, K; Krist, J

    2008-11-12

    Fomalhaut is a bright star 7.7 parsec (25 light years) from Earth that harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. In the plane of the belt, Fomalhaut b lies approximately 119 astronomical units (AU) from the star, and within 18 AU of the dust belt. We detect counterclockwise orbital motion using Hubble Space Telescope observations separated by 1.73 years. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter for the belt to avoid gravitational disruption. The flux detected at 0.8 {micro}m is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 {micro}m and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observed variability of unknown origin at 0.6 {micro}m.

  10. Adsorption of Gemini surfactants onto clathrate hydrates.

    PubMed

    Salako, O; Lo, C; Couzis, A; Somasundaran, P; Lee, J W

    2013-12-15

    This work addresses the adsorption of two Gemini surfactants at the cyclopentane (CP) hydrate-water interface. The Gemini surfactants investigated here are Dowfax C6L and Dowfax 2A1 that have two anionic head groups and one hydrophobic tail group. The adsorption of these surfactants was quantified using adsorption isotherms and the adsorption isotherms were determined using liquid-liquid titrations. Even if the Gemini surfactant adsorption isotherms show multi-layer adsorption, they possess the first Langmuir layer with the second adsorption layer only evident in the 2A1 adsorption isotherm. Zeta potentials of CP hydrate particles in the surfactant solution of various concentrations of Dowfax C6L and Dowfax 2A1 were measured to further explain their adsorption behavior at the CP hydrate-water interface. Zeta potentials of alumina particles as a model particle system in different concentrations of sodium dodecyl sulfate (SDS), Dowfax C6L and Dowfax 2A1 were also measured to confirm the configuration of all the surfactants at the interface. The determination of the isotherms and zeta-potentials provides an understanding framework for the adsorption behavior of the two Gemini surfactants at the hydrate-water interface. PMID:24144366

  11. Geo-Engineering through Internet Informatics (GEMINI)

    SciTech Connect

    Doveton, John H.; Watney, W. Lynn

    2003-03-06

    The program, for development and methodologies, was a 3-year interdisciplinary effort to develop an interactive, integrated Internet Website named GEMINI (Geo-Engineering Modeling through Internet Informatics) that would build real-time geo-engineering reservoir models for the Internet using the latest technology in Web applications.

  12. Pointing and image stability for spaceborne sensors: from comet impactors to observations of extrasolar planets

    NASA Astrophysics Data System (ADS)

    Kendrick, Stephen E.; Stober, Jeremy; Gravseth, Ian

    2006-06-01

    From hitting a comet to long-term observations to find and characterize extrasolar planets, the spacecraft platform pointing accuracy and stability are fundamental. We describe the pointing requirements for Deep Impact, Kepler, and future extrasolar planet missions such as EPIC, and the approach to allow stable long-term measurements. The guidance, navigation, and control system consists of a suite of systems which can include star trackers, gyros, fine guidance sensors, reaction wheels, fast steering mirrors, and active and passive isolation features. One-fifth to one-twentieth of a pixel attitude determination may be needed with stabilities an order of magnitude tighter for observations that may last thousands of seconds. 1.5 milliarcsecond 3-sigma pointing stability can be achieved for the observatory enabling precision measurements by the scientific payloads.

  13. Radio-interferometric imaging of the subsurface emissions from the planet Mercury

    NASA Technical Reports Server (NTRS)

    Burns, J. O.; Zeilik, M.; Gisler, G. R.; Borovsky, J. E.; Baker, D. N.

    1987-01-01

    The distribution of total and polarized intensities from Mercury's subsurface layers have been mapped using VLA observations. The first detection of a hot pole along the Hermean equator is reported and modeled as black-body reradiation from preferential diurnal heating. These observations appear to rule out any internal sources of heat within Mercury. Polarized emission from the limb of the planet is also found, and is understood in terms of the dielectric properties of the Hermean surface.

  14. THE FIRST H-BAND SPECTRUM OF THE GIANT PLANET ? PICTORIS b

    SciTech Connect

    Chilcote, Jeffrey; Fitzgerald, Michael P.; Larkin, James E.; Barman, Travis; Graham, James R.; Kalas, Paul; Macintosh, Bruce; Ingraham, Patrick; Bauman, Brian; Burrows, Adam S.; Cardwell, Andrew; Hartung, Markus; Hibon, Pascale; De Rosa, Robert J.; Dillon, Daren; Gavel, Donald; Dunn, Jennifer; Erikson, Darren; Goodsell, Stephen J.; and others

    2015-01-01

    Using the recently installed Gemini Planet Imager (GPI), we have obtained the first H-band spectrum of the planetary companion to the nearby young star ? Pictoris. GPI is designed to image and provide low-resolution spectra of Jupiter-sized, self-luminous planetary companions around young nearby stars. These observations were taken covering the H band (1.65 ?m). The spectrum has a resolving power of ?45 and demonstrates the distinctive triangular shape of a cool substellar object with low surface gravity. Using atmospheric models, we find an effective temperature of 1600-1700 K and a surface gravity of log (g) = 3.5-4.5 (cgs units). These values agree well with ''hot-start'' predictions from planetary evolution models for a gas giant with mass between 10 and 12 M {sub Jup} and age between 10 and 20 Myr.

  15. The First H-band Spectrum of the Giant Planet ? Pictoris b

    NASA Astrophysics Data System (ADS)

    Chilcote, Jeffrey; Barman, Travis; Fitzgerald, Michael P.; Graham, James R.; Larkin, James E.; Macintosh, Bruce; Bauman, Brian; Burrows, Adam S.; Cardwell, Andrew; De Rosa, Robert J.; Dillon, Daren; Doyon, René; Dunn, Jennifer; Erikson, Darren; Gavel, Donald; Goodsell, Stephen J.; Hartung, Markus; Hibon, Pascale; Ingraham, Patrick; Kalas, Paul; Konopacky, Quinn; Maire, Jérôme; Marchis, Franck; Marley, Mark S.; Marois, Christian; Millar-Blanchaer, Max; Morzinski, Katie; Norton, Andrew; Oppenheimer, Rebecca; Palmer, David; Patience, Jennifer; Perrin, Marshall; Poyneer, Lisa; Pueyo, Laurent; Rantakyrö, Fredrik T.; Sadakuni, Naru; Saddlemyer, Leslie; Savransky, Dmitry; Serio, Andrew; Sivaramakrishnan, Anand; Song, Inseok; Soummer, Rémi; Thomas, Sandrine; Wallace, J. Kent; Wiktorowicz, Sloane; Wolff, Schuyler

    2015-01-01

    Using the recently installed Gemini Planet Imager (GPI), we have obtained the first H-band spectrum of the planetary companion to the nearby young star ? Pictoris. GPI is designed to image and provide low-resolution spectra of Jupiter-sized, self-luminous planetary companions around young nearby stars. These observations were taken covering the H band (1.65 ?m). The spectrum has a resolving power of ~45 and demonstrates the distinctive triangular shape of a cool substellar object with low surface gravity. Using atmospheric models, we find an effective temperature of 1600-1700 K and a surface gravity of log (g) = 3.5-4.5 (cgs units). These values agree well with "hot-start" predictions from planetary evolution models for a gas giant with mass between 10 and 12 M Jup and age between 10 and 20 Myr.

  16. IBIS: An Interferometer-Based Imaging System for Detecting Extrasolar Planets with a Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Diner, David J.

    1989-01-01

    The direct detection of extrasolar planetary systems is a challenging observational objective. The observing system must be able to detect faint planetary signals against the background of diffracted and scattered starlight, zodiacal light, and in the IR, mirror thermal radiation. As part of a JPL study, we concluded that the best long-term approach is a 10-20 m filled-aperture telescope operating in the thermal IR (10-15 microns). At these wavelengths, the star/planet flux ratio is on the order of 10(exp 6)-10(exp 8). Our study supports the work of Angel et al., who proposed a cooled 16-m IR telescope and a special apodization mask to suppress the stellar light within a limited angular region around the star. Our scheme differs in that it is capable of stellar suppression over a much broader field-of- view, enabling more efficient planet searches. To do this, certain key optical signal-processing components are needed, including a coronagraph to apodize the stellar diffraction pattern, an infrared interferometer to provide further starlight suppression, a complementary visible-wavelength interferometer to sense figure errors in the telescope optics, and a deformable mirror to adaptively compensate for these errors. Because of the central role of interferometry we have designated this concept the Interferometer-Based Imaging System (IBIS). IBIS incorporates techniques originally suggested by Ken Knight for extrasolar planet detection at visible wavelengths. The type of telescope discussed at this workshop is well suited to implementation of the IBIS concept.

  17. Observations Of The LCROSS Impact With NIFS On The Gemini North Telescope

    NASA Astrophysics Data System (ADS)

    Roth, Katherine; Stephens, A. W.; Trujillo, C. A.; McDermid, R. M.; Woodward, C. E.; Walls, B. D.; Coulson, D. M.; Matulonis, A. C.; Ball, J. G.; Wooden, D. H.

    2010-01-01

    The Lunar CRater Observation and Sensing Satellite (LCROSS) Centaur rocket impacted a permanently shadowed crater near the south pole of the Moon at 11:31 UTC 2009 October 09. Gemini, one of several telescopes in a coordinated network observing the impact, conducted observations using NIFS to obtain 3D K-band imaging spectroscopy to detect water ice in the ejected plume of material. The spectral slope of the NIFS data can constrain the grain size and height distribution as the plume evolves, measuring the total mass and the water ice concentration in the plume. These observations provided an engineering challenge for Gemini, including the need to track non-sidereal with constantly changing track rates and guide on small bright moon craters, in order to keep the impact site within the NIFS field-of-view. High quality images taken by GMOS-N, NIRI and the acquisition camera during engineering periods at specific lunar libration and illumination were also used by the LCROSS ground based observing team to supplement slit positioning and offset plans for other ground based observatories. LCROSS mission support and engineering has resulted in improved telescope functionality for non-sidereal targets, including the ability to upload and import target ephemerides directly into the TCS, starting in semester 2010B. In this poster we present the engineering results and observing improvements which will facilitate enhanced user capabilities of the Gemini telescopes arising from the intensive LCROSS support challenge. Gemini Observatory is operated by AURA, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NSF (United States), the STFC (United Kingdom), the NRC (Canada), CONICYT (Chile), the ARC (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). In part this research was supported by NASA through contracts to SWRI and NSF grant AST-0706980 to the U. Minnesota.

  18. The software design of the Gemini 8m telescopes Stephen Wampler

    E-print Network

    The software design of the Gemini 8m telescopes Stephen Wampler Gemini 8m Telescopes Project, 950 N. Cherry Ave, Tucson, AZ 85726 ABSTRACT The design of the software for the Gemini 8m Telescopes is nearly. Keywords: telescope software design, design processes, Gemini software 1. INTRODUCTION The Gemini 8m

  19. The Gemini Science Archive Data Dictionary

    NASA Astrophysics Data System (ADS)

    Goliath, S.; Damian, A.; Gaudet, S.; Hill, N.; Bohlender, D.; Melnychuk, G.; Aspin, C.

    2005-12-01

    The Gemini Science Archive (GSA) is a new science archive developed by the Canadian Astronomy Data Centre (CADC) to provide the scientific community with tools for effective on-line access to data collected by the Gemini telescopes. CADC has developed a MetaData Data Dictionary (MDDD) for the GSA to meet the goal of providing dependable and consistent archive data. This MDDD defines the rules that govern data manipulation on meta-data obtained from a variety of data sources. The MDDD is specified in XML, and so provides flexibility while reducing source code maintenance. The paper will discuss the rules that may be specified for the data sources and individual meta-data attributes, the role of the data dictionary in populating the GSA, verification of the consistency of the dictionary itself, and possible future improvements in the data dictionary.

  20. Instrument Performance Monitoring at Gemini North

    NASA Astrophysics Data System (ADS)

    Emig, Kimberly; Pohlen, M.; Chene, A.

    2014-01-01

    An instrument performance monitoring (IPM) project at the Gemini North Observatory evaluates the delivered throughput and sensitivity of, among other instruments, the Near-Infrared Integral Field Spectrometer (NIFS), the Gemini Near-Infrared Spectrograph (GNIRS), and the Gemini Multi-Object Spectrograph (GMOS-N). Systematic observations of standard stars allow the quality of the instruments and mirror to be assessed periodically. An automated pipeline has been implemented to process and analyze data obtained with NIFS, GNIRS cross-dispersed (XD) and long slit (LS) modes, and GMOS (photometry and spectroscopy). We focus the discussion of this poster on NIFS and GNIRS. We present the spectroscopic throughput determined for ZJHK bands on NIFS, the XJHKLM band for GNIRS XD mode and the K band for GNIRS LS. Additionally, the sensitivity is available for the JHK bands in NIFS and GNIRS XD, and for the K band in GNIRS LS. We consider data taken as early as March 2011. Furthermore, the pipeline setup and the methods used to determine throughput and sensitivity are described.

  1. A first-look atmospheric modeling study of the young directly imaged planet-mass companion, ROXS 42Bb

    SciTech Connect

    Currie, Thayne; Daemgen, Sebastian; Burrows, Adam

    2014-06-01

    We present and analyze JK{sub s}L' photometry and our previously published H-band photometry and K-band spectroscopy for ROXs 42Bb, an object Currie et al. first reported as a young directly imaged planet-mass companion. ROXs 42Bb exhibits IR colors redder than field L dwarfs but consistent with other planet-mass companions. From the H{sub 2}O-2 spectral index, we estimate a spectral type of L0 ± 1; weak detections/non-detections of the CO bandheads, Na I, and Ca I support evidence for a young, low surface gravity object primarily derived from the H{sub 2}(K) index. ROXs 42Bb's photometry/K-band spectrum are inconsistent with limiting cases of dust-free atmospheres (COND) and marginally inconsistent with the AMES/DUSTY models and the BT-SETTL models. However, ROXS 42Bb data are simultaneously fit by atmosphere models incorporating several micron-sized dust grains entrained in thick clouds, although further modifications are needed to better reproduce the K-band spectral shape. ROXs 42Bb's best-estimated temperature is T {sub eff} ? 1950-2000 K, near the low end of the empirically derived range in Currie et al. For an age of ?1-3 Myr and considering the lifetime of the protostar phase, ROXs 42Bb's luminosity of log(L/L {sub ?}) ? –3.07 ± 0.07 implies a mass of 9{sub ?3}{sup +3} M{sub J} , making it one of the lightest planetary-mass objects yet imaged.

  2. Gemini 10 prime crew during post flight press conference

    NASA Technical Reports Server (NTRS)

    1966-01-01

    At podium during Gemini 10 press conference are (l-r) Dr. Robert C. Seamans, Astronauts John Young and Michael Collins and Dr. Robert R. Gilruth (39895); Wide angle view of the Manned Spacecraft Center (MSC) News Center during the Gemini 10 prime crew post flight press conference (38786); Astronaut Young draws diagram on chalk board of tethered extravehicular activity accomplished during Gemini 10 flight (39897).

  3. The Transformation of Observatory Newsletters - A Gemini Perspective

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyu

    2015-08-01

    Astronomical observatories publish newsletters to communicate the observatory’s new discoveries and activities with its user communities, funding agencies, and general public. Gemini Observatory started publishing the newsletter in March 1992. Over the years, it transformed from a no-frills black and white publication to a full-color magazine type newsletter with a special name “GeminiFocus”. Since 2012, the contents of GeminiFocus moved from print to digital with an additional print issue of the Year in Review. The newsletter transformation is in sync with the rapid development of the internet technologies. We discuss here the evolvement of Gemini newsletter and the lessons learned.

  4. Management of the Gemini 8M Telescopes Project R. Kurz, M. Mountain

    E-print Network

    Management of the Gemini 8­M Telescopes Project R. Kurz, M. Mountain Gemini Telescopes Project, 950 Project Richard Kurz and Matt Mountain Gemini 8­M Telescopes Project 950 N. Cherry Avenue, Tucson, AZ

  5. Extreme Imaging: Revealing the structure of debris disks on solar systems scales with GPI

    NASA Astrophysics Data System (ADS)

    Kalas, Paul G.; Rajan, Abhijith; Wang, Jason; Millar-Blanchaer, Max; Duchene, Gaspard; Chen, Christine H.; Fitzgerald, Michael P.; Patience, Jennifer; Dong, Ruobing; Graham, James R.; Murray-Clay, Ruth; Macintosh, Bruce

    2015-12-01

    A new generation of extreme adaptive optics systems enables an unprecedented exploration of dusty debris disks on solar system scales. Here we review the new science derived from over a dozen debris disks imaged in total intensity and polarized intensity with the Gemini Planet Imager (GPI). These early results typically reveal narrow belts of material with evacuated regions roughly 50 AU in radius and with subtle asymmetries in structure. In many cases, complementary wider field images obtained with the Hubble Space Telescope uncover more extreme asymmetries in the distribution of dust on 100’s of AU scales. We will discuss the possible causes of these asymmetries, such as the dynamical upheavals that can occur via internal or external perturbations. In a few cases, a gas giant planet has also been imaged in the system, raising new questions about the possible dynamical co-evolution of exoplanets and debris disks.

  6. Planetcam UPV/EHU - A lucky imaging camera for multi-spectral observations of the Giant Planets in 0.38-1.7 microns

    NASA Astrophysics Data System (ADS)

    Hueso, R.; Mendikoa, I.; Sánchez-Lavega, A.; Pérez-Hoyos, S.; Rojas, J. F.; García-Melendo, E.

    2015-10-01

    PlanetCam UPV/EHU [1] is an astronomical instrument designed for high-resolution observations of Solar System planets. The main scientific themes are atmospheric dynamics and the vertical cloud structure of Jupiter and Saturn. The instrument uses a dichroic mirror to separate the light in two beams with spectral ranges from 380 nm to1 micron (visible channel) and from 1 to 1.7 microns (Short Wave InfraRed, SWIR channel) and two detectors working simultaneously with fast acquisition modes. High-resolution images are built using lucky imaging techniques [2]. Several hundred short exposed images are obtained and stored in fits files. Images are automatically reduced by a pipeline called PLAYLIST (written in IDL and requiring no interaction by the user)which selects the best frames and co-registers them using image correlation over several tie-points. The result is a high signal to noise ratio image that can be processed to show the faint structures in the data. PlanetCam is a visiting instrument mainly built for the 1.2 3 and 2.2m telescopes at Calar Alto Observatory in Spain but it has also been tested in the 1.5 m Telescope Carlos Sanchez in Tenerife and the 1.05 m Telescope at the Pic du Midi observatory.

  7. Direct imaging of exoplanets around multiple star systems

    NASA Astrophysics Data System (ADS)

    Thomas, Sandrine

    2015-01-01

    Direct imaging of extra-solar planets is now a reality, especially with the deployment and commissioning of the first generation of specialized ground-based instruments such as the Gemini Planet Imager and SPHERE. These systems will allow detection of Jupiter-like planets 10^7 times fainter than their host star. Obtaining this contrast level and beyond requires the combination of a coronagraph to suppress light coming from the host star and a wavefront control system including a deformable mirror (DM) to remove residual starlight (speckles) created by the imperfections of telescope. However, all these current and future systems focus on detecting faint planets around a single host star or unresolved binaries/multiples, while several targets or planet candidates are located around nearby binary stars such as our neighboring star Alpha Centauri.Here, we present a method to simultaneously correct aberrations and diffraction of light coming from the target star as well as its companion star in order to reveal planets orbiting the target star. This method works even if the companion star is outside the control region of the DM (beyond its half-Nyquist frequency), by taking advantage of aliasing effects.

  8. Suppressing Speckle Noise for Simultaneous Differential Extrasolar Planet Imaging (SDI) at the VLT and MMT

    E-print Network

    Beth A. Biller; Laird M. Close; Rainer Lenzen; Wolfgang Brandner; Donald McCarthy; Eric Nielsen; Stephan Kellner; Markus Hartung

    2006-01-03

    We discuss the instrumental and data reduction techniques used to suppress speckle noise with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT. SDI uses a double Wollaston prism and a quad filter to take 4 identical images simultaneously at 3 wavelengths surrounding the 1.62 um methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be significantly attenuated, resulting in photon noise limited data past 0.5''. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss a custom algorithm implemented in IDL to perform this reduction. The script performs basic data reduction tasks but also precisely aligns images taken in each of the filters using a custom shift and subtract routine. In our survey of nearby young stars at the VLT and MMT (see Biller et al., this conference), we achieved H band contrasts >25000 (5 sigma Delta F1(1.575 um) > 10.0 mag, Delta H > 11.5 mag for a T6 spectral type object) at a separation of 0.5" from the primary star. We believe that our SDI images are among the highest contrast astronomical images ever made from ground or space for methane rich companions.

  9. Gemini 4 prime crew in elevator at Pad 19 preparing to enter Gemini capsule

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts Edward H. White II and James A. McDivitt are shown in the elevator on their way to the white room as they prepare to enter the Gemini 4 spacecraft atop the Titan launch vehicle at Cape Kennedy, Florida.

  10. Gemini 4 prime crew in white room at Pad 19 preparing to enter Gemini capsule

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts Edward H. White II and James A. McDivitt are shown in the white room as they prepare to enter the Gemini 4 spacecraft atop the Titan launch vehicle at Cape Kennedy, Florida. The NASA Headquarters alternative photo number is 65-H-296.

  11. High-contrast imaging of Sirius A with VLT/SPHERE: looking for giant planets down to one astronomical unit

    NASA Astrophysics Data System (ADS)

    Vigan, A.; Gry, C.; Salter, G.; Mesa, D.; Homeier, D.; Moutou, C.; Allard, F.

    2015-11-01

    Sirius has always attracted a lot of scientific interest, especially after the discovery of a companion white dwarf at the end of the 19th century. Very early on, the existence of a potential third body was put forward to explain some of the observed properties of the system. We present new coronagraphic observations obtained with VLT/SPHERE (Very Large Telescope/Spectro-Polarimetric High-contrast Exoplanet REsearch) that explore, for the very first time, the innermost regions of the system down to 0.2 arcsec(0.5 au) from Sirius A. Our observations cover the near-infrared from 0.95 to 2.3 ?m and they offer the best on-sky contrast ever reached at these angular separations. After detailing the steps of our SPHERE/IRDIFS data analysis, we present a robust method to derive detection limits for multispectral data from high-contrast imagers and spectrographs. In terms of raw performance, we report contrasts of 14.3 mag at 0.2 arcsec, ˜16.3 mag in the 0.4-1.0 arcsec range and down to 19 mag at 3.7 arcsec. In physical units, our observations are sensitive to giant planets down to 11 MJup at 0.5 au, 6-7 MJup in the 1-2 au range and ˜4 MJup at 10 au. Despite the exceptional sensitivity of our observations, we do not report the detection of additional companions around Sirius A. Using a Monte Carlo orbital analysis, we show that we can reject, with about 50 per cent probability, the existence of an 8 MJup planet orbiting at 1 au.

  12. Direct Imaging of the Water Snow Line at the Time of Planet Formation using Two ALMA Continuum Bands

    NASA Astrophysics Data System (ADS)

    Banzatti, A.; Pinilla, P.; Ricci, L.; Pontoppidan, K. M.; Birnstiel, T.; Ciesla, F.

    2015-12-01

    Molecular snow lines in protoplanetary disks have been studied theoretically for decades because of their importance in shaping planetary architectures and compositions. The water snow line lies in the planet formation region at ?10 AU, and so far its location has been estimated only indirectly from spatially unresolved spectroscopy. This work presents a proof-of-concept method to directly image the water snow line in protoplanetary disks through its physical and chemical imprint on the local dust properties. We adopt a physical disk model that includes dust coagulation, fragmentation, drift, and a change in fragmentation velocities of a factor of 10 between dry silicates and icy grains as found by laboratory work. We find that the presence of a water snow line leads to a sharp discontinuity in the radial profile of the dust emission spectral index ?mm due to replenishment of small grains through fragmentation. We use the ALMA simulator to demonstrate that this effect can be observed in protoplanetary disks using spatially resolved ALMA images in two continuum bands. We explore the model dependence on the disk viscosity and find that the spectral index reveals the water snow line for a wide range of conditions, with opposite trends when the emission is optically thin rather than thick. If the disk viscosity is low (?visc < 10?3), the snow line produces a ringlike structure with a minimum at ?mm ? 2 in the optically thick regime, possibly similar to what has been measured with ALMA in the innermost region of the HL Tau disk.

  13. High-Contrast 3.8 Micron Imaging of the Brown Dwarf/Planet-Mass Companion to GJ 758

    NASA Technical Reports Server (NTRS)

    Currie, Thayne M.; Bailey, Vanessa; Fabrycky, Daniel; Murray-Clay, Ruth; Rodigas, Timothy; Hinz, Phil

    2011-01-01

    We present L' band (3.8 Micron) MMT/Clio high-contrast imaging data for the nearby star GJ 758, which was recently reported by Thalmann et al. (2009) to have one - possibly two - faint comoving companions (GJ 7588 and "C", respectively). GJ 758B is detected in two distinct datasets. Additionally, we report a \\textit{possible} detection of the object identified by Thalmann et al as "GJ 758C" in our more sensitive dataset, though it is likely a residual speckle. However, if it is the same object as that reported by Thalmann et al. it cannot be a companion in a bound orbit. GJ 7588 has a H-L' color redder than nearly all known L-T8 dwarfs. 8ased on comparisons with the COND evolutionary models, GJ 7588 has Te approx. 560 K (+150 K, -90 K) and a mass ranging from approx.10-20 Mj if it is approx.1 Gyr old to approx. 25-40 Mj if it is 8.7 Gyr old. GJ 7588 is likely in a highly eccentric orbit, e approx. 0.73 (+0.12,-0.21), with a semimajor axis of approx. 44 AU (+32 AU, -14 AU). Though GJ 7588 is sometimes discussed within the context of exoplanet direct imaging, its mass is likely greater than the deuterium-burning limit and its formation may resemble that of binary stars rather than that of jovian-mass planets.

  14. Revision of Earth-sized Kepler Planet Candidate Properties with High Resolution Imaging by Hubble Space Telescope

    E-print Network

    Star, Kimberly M; Wright, Jason T; Ciardi, David R

    2014-01-01

    We present the results of our Hubble Space Telescope program and describe how our image analysis methods were used to re-evaluate the habitability of some of the most interesting Kepler planet candidates. Our program observed 22 KOI hosts, several of which were found to be multiple star systems unresolved by Kepler. We use our high-resolution imaging to provide a conversion to the Kepler photometric bandpass (Kp) from the F555W and F775W filters on WFC3/UVIS, and spatially resolve the stellar multiplicity of Kepler-296, KOI-2626, and KOI-3049. The binary system Kepler-296 has a projected separation of 0.217" (80 AU); KOI-2626 is a triple star system with a projected separation of 0.201" (70 AU) between the primary and secondary components and 0.161" (55 AU) between the primary and tertiary components; and the binary system KOI-3049 has a projected separation of 0.464" (225 AU). Using theoretical isochrones from the latest Victoria-Regina Stellar Models, we performed hierarchical fitting using our derived phot...

  15. High-Contrast 3.8 Micron Imaging of the Brown Dwarf/Planet-Mass Companion to GJ 758

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Bailey, Vanessa; Fabrycky, Daniel; Murray-Clay, Ruth; Rodigas, Timothy; Hinz, Phil

    2010-01-01

    We present L' band (3.8 Micron) MMT/Clio high-contrast imaging data for the nearby star GJ 758, which was recently reported by Thalmann et al. (2009) to have one -- possibly two-- faint comoving companions (GJ 7588 and "C", respectively). GJ 758B is detected in two distinct datasets. Additionally, we report a \\textit(possible) detection of the object identified by Thalmann et al as "GJ 758C" in our more sensitive dataset, though it is likely a residual speckle. However, if it is the same object as that reported by Thalmann et al. it cannot be a companion in a bound orbit. GJ 758B has a H-L'color redder than nearly all known L--T8 dwarfs. Based on comparisons with the COND evolutionary models, GJ 758B has Te approx. 560 K (+150 K, -90 K) and a mass ranging from approx. 10-20 Mj if it is approx. 1 Gyr old to approx. 25-40 Mj if it is 8.7 Gyr old. GJ 758B is likely in a highly eccentric orbit, e approx. 0.73 (+0.12,-0.21), with a semimajor axis of approx. 44 AU (+32 AU, -14 AU). Though GJ 758B is sometimes discussed within the context of exoplanet direct imaging, its mass is likely greater than the deuterium-burning limit and its formation may resemble that of binary stars rather than that of jovian-mass planets.

  16. Participación argentina en el Gemini Observatory

    NASA Astrophysics Data System (ADS)

    Cellone, S. A.; Faifer, F. R.; Smith-Castelli, A. V.; Ferreiro, D.; Ferrero, G.

    Since the beginning of the present century; Argentina has access to two twin telescopes each 8.1m in diameter. The Observatory covers both celestial hemispheres; and is equipped with modern instrumentation spanning from the optical to the mid-infrared. This paper gives a brief description of present instruments as well as those available in the near future; pointing to their possible impact on different research lines. The present situation of the Argentine participation in Gemini is illustrated with a few relevant statistical data; focusing the attention on the new agreement that should be signed by all the partners in 2015. FULL TEXT IN SPANISH

  17. Gemini Observatory's Innovative Education and Outreach for 2006 and Beyond

    NASA Astrophysics Data System (ADS)

    Harvey, J.

    2006-08-01

    Gemini Observatory, in preparation for its bold informal science plan for the next five years, is making an exciting effort to bring education outside our typical borders and into our partner countries and beyond. We will introduce some of the innovative outreach programs that have been highly successful in Hawaii/US and explain how Gemini's PIO efforts will further develop new concepts as we move forward in our next phase of education and outreach. In this presentation we will highlight a few of Gemini's highly successful initiatives: - Stars Over Mauna Kea Newspaper Tabloid, the second bi-annual publication giving a comprehensive review of astronomy on Mauna Kea - Hawaii's Journey through the Universe program which has been touted as the flagship program in the US. I will discuss how we envision introducing this novel education approach to our seven partner countries. - StarTeachers International teacher's exchange - The newly developed partnership between the Imiloa Astronomy Education Center's planetarium and Gemini's StarLab programs. - Extension of our Family Astro programs internationally. - Gemini's student "Time on the Telescope" mentor program. - "Gemini Live," a videoconference between our astronomers at the control room of Gemini and classrooms around the world. - The unique partnership created between Gemini's PIO department and the Department of Education in Hawaii, and how other astronomical facilities could play a prominent role in their state's/country's informal science education development.

  18. Gemini-Titan 3 water landing recovery in Atlantic Ocean

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Navy swimmers are shown attaching a flotation collar to the Gemini 3 spacecraft during recovery operations following the successful Gemini-Titan 3 flight. A helicopter hovers in the background. Astronauts Virgil I. Grissom and John W. Young are still in the spacecraft.

  19. Suppressing Speckle Noise for Simultaneous Differential Extrasolar Planet Imaging (SDI) at the VLT and MMT

    E-print Network

    Biller, B A; Lenzen, R; Brandner, W; McCarthy, D; Nielsen, E; Kellner, S; Hartung, M; Biller, Beth A.; Close, Laird M.; Lenzen, Rainer; Brandner, Wolfgang; Carthy, Donald Mc; Nielsen, Eric; Kellner, Stephan; Hartung, Markus

    2006-01-01

    We discuss the instrumental and data reduction techniques used to suppress speckle noise with the Simultaneous Differential Imager (SDI) implemented at the VLT and the MMT. SDI uses a double Wollaston prism and a quad filter to take 4 identical images simultaneously at 3 wavelengths surrounding the 1.62 um methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be significantly attenuated, resulting in photon noise limited data past 0.5''. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss a custom algorithm implemented in IDL to perform this reduction. The script performs basic data reduction tasks but also precisely aligns images taken in each of the filters using a custom shift and subtract routine. In our survey of nearby young stars at the VLT and MMT (see Biller et al., this conference), we achieved H band contrasts >25000 (5 sigma D...

  20. Direct Imaging of an Asymmetric Debris Disk in the HD 106906 Planetary System

    NASA Astrophysics Data System (ADS)

    Kalas, Paul G.; Rajan, Abhijith; Wang, Jason J.; Millar-Blanchaer, Maxwell A.; Duchene, Gaspard; Chen, Christine; Fitzgerald, Michael P.; Dong, Ruobing; Graham, James R.; Patience, Jennifer; Macintosh, Bruce; Murray-Clay, Ruth; Matthews, Brenda; Rameau, Julien; Marois, Christian; Chilcote, Jeffrey; De Rosa, Robert J.; Doyon, René; Draper, Zachary H.; Lawler, Samantha; Ammons, S. Mark; Arriaga, Pauline; Bulger, Joanna; Cotten, Tara; Follette, Katherine B.; Goodsell, Stephen; Greenbaum, Alexandra; Hibon, Pascale; Hinkley, Sasha; Hung, Li-Wei; Ingraham, Patrick; Konapacky, Quinn; Lafreniere, David; Larkin, James E.; Long, Douglas; Maire, Jérôme; Marchis, Franck; Metchev, Stan; Morzinski, Katie M.; Nielsen, Eric L.; Oppenheimer, Rebecca; Perrin, Marshall D.; Pueyo, Laurent; Rantakyrö, Fredrik T.; Ruffio, Jean-Baptiste; Saddlemyer, Leslie; Savransky, Dmitry; Schneider, Adam C.; Sivaramakrishnan, Anand; Soummer, Rémi; Song, Inseok; Thomas, Sandrine; Vasisht, Gautam; Ward-Duong, Kimberly; Wiktorowicz, Sloane J.; Wolff, Schuyler G.

    2015-11-01

    We present the first scattered light detections of the HD 106906 debris disk using the Gemini/Gemini Planet Imager in the infrared and Hubble Space Telescope (HST)/Advanced Camera for Surveys in the optical. HD 106906 is a 13 Myr old F5V star in the Sco–Cen association, with a previously detected planet-mass candidate HD 106906b projected 650 AU from the host star. Our observations reveal a near edge-on debris disk that has a central cleared region with radius ?50 AU, and an outer extent >500 AU. The HST data show that the outer regions are highly asymmetric, resembling the “needle” morphology seen for the HD 15115 debris disk. The planet candidate is oriented ?21° away from the position angle of the primary’s debris disk, strongly suggesting non-coplanarity with the system. We hypothesize that HD 106906b could be dynamically involved in the perturbation of the primary’s disk, and investigate whether or not there is evidence for a circumplanetary dust disk or cloud that is either primordial or captured from the primary. We show that both the existing optical properties and near-infrared colors of HD 106906b are weakly consistent with this possibility, motivating future work to test for the observational signatures of dust surrounding the planet.

  1. Tracking performance of the Gemini 8-m telescopes

    NASA Astrophysics Data System (ADS)

    Burns, Michael K.

    1994-06-01

    The tracking simulation for the control system of the Gemini 8-M Telescopes is a nonlinear time-domain model with six degrees of freedom. Structural elements representing the telescope pier, mount, and tube have been obtained with the NASTRAN finite element analysis package and these results used to create a state-space description. The state-space matrices are used in the control package Matlab 4.0 to model the interaction of the telescope structure with linear and nonlinear elements such as bearing friction, encoder quantization, motor torque cogging and various noise sources. Line of sight image motion equations are used to produce an RMS image centroid error which is the metric by which performance is evaluated. The simulation includes the cassegrain rotator and the associated errors caused by spatial separation of the guide object and science object. A fourth-order tip-tilt secondary is modeled to show the effect of tip-tilt upon the image smear induced by other system components. While the rest of the simulation operates in the continuous domain, the tip-tilt controller is modeled in the discrete domain to include the errors and limitations associated with sampling at 200 Hz.

  2. The Astrometric Imaging Telescope - A space-based observatory for extra-solar planet detection

    NASA Technical Reports Server (NTRS)

    Pravdo, Steven H.

    1991-01-01

    The paper describes the objectives, techniques, instrumentation, and mission of the planned Astrometric Imaging Telescope. This space-based observatory is designed to detect and characterize extra-solar planetary systems. Results will contribute to the understanding of the astrophysics of stellar and planetary formation and provide an impetus for the study of exobiology.

  3. Mechanically selflocked chiral gemini-catenanes

    PubMed Central

    Li, Sheng-Hua; Zhang, Heng-Yi; Xu, Xiufang; Liu, Yu

    2015-01-01

    Mechanically interlocked and entangled molecular architectures represent one of the elaborate topological superstructures engineered at a molecular resolution. Here we report a methodology for fabricating mechanically selflocked molecules (MSMs) through highly efficient one-step amidation of a pseudorotaxane derived from dual functionalized pillar[5]arene (P[5]A) threaded by ?,?-diaminoalkane (DA-n; n=3–12). The monomeric and dimeric pseudo[1]catenanes thus obtained, which are inherently chiral due to the topology of P[5]A used, were isolated and fully characterized by NMR and circular dichroism spectroscopy, X-ray crystallography and DFT calculations. Of particular interest, the dimeric pseudo[1]catenane, named ‘gemini-catenane', contained stereoisomeric meso-erythro and dl-threo isomers, in which two P[5]A moieties are threaded by two DA-n chains in topologically different patterns. This access to chiral pseudo[1]catenanes and gemini-catenanes will greatly promote the practical use of such sophisticated chiral architectures in supramolecular and materials science and technology. PMID:26126502

  4. Tumbling and spaceflight: the Gemini VIII experience.

    PubMed

    Mohler, S R; Nicogossian, A E; McCormack, P D; Mohler, S R

    1990-01-01

    A malfunctioning orbital flight attitude thruster during the flight of Gemini VIII led to acceleration forces on astronauts Neil Armstrong (commander) and David Scott (pilot) that created the potential for derogation of oculo-vestibular and eye-hand coordination effects. The spacecraft attained an axial tumbling rotation of 50 rpm and would have exceeded this had not the commander accurately diagnosed the problem and taken immediate corrective action. By the time counter-measure controls were applied, both astronauts were experiencing vertigo and the physiological effects of the tumbling acceleration. Data from the recorders reveal that one astronaut experienced -Gy of 0.92 G-units, and the other +Gy of 0.92 for approximately 46 s. Both received a -Gz of 0.89 G-units from the waist up with a +Gz of 0.05 from the waist down. A substantial increase of time and/or an increase in rpm would ultimately have produced incapacitation of both astronauts. NASA corrected the Gemini thruster problem by changing the ignition system wiring. Future space-craft undertaking long-term missions could be equipped with unambiguous thruster fault displays and could have computer-controlled automatic cutoffs to control excessive thruster burns. PMID:2302130

  5. Self-Assembly of Gemini Surfactants

    NASA Astrophysics Data System (ADS)

    Yethiraj, Arun; Mondal, Jagannath; Mahanthappa, Mahesh

    2013-03-01

    The self-assembly behavior of Gemini (dimeric or twin-tail) dicarboxylate disodium surfactants is studied using molecular dynamics simulations. This gemini architecture, in which two single tailed surfactants are joined through a flexible hydrophobic linker, has been shown to exhibit concentration-dependent aqueous self-assembly into lyotropic phases including hexagonal, gyroid, and lamellar morphologies. Our simulations reproduce the experimentally observed phases at similar amphiphile concentrations in water, including the unusual ability of these surfactants to form gyroid phases over unprecedentedly large amphiphile concentration windows. We demonstrate quanitative agreement between the predicted and experimentally observed domain spacings of these nanostructured materials. Through careful conformation analyses of the surfactant molecules, we show that the gyroid phase is electrostatically stabilized related to the lamellar phase. By starting with a lamellar phase, we show that decreasing the charge on the surfactant headgroups by carboxylate protonation or use of a bulkier tetramethyl ammonium counterion in place of sodium drives the formation of a gyroid phase.

  6. A bright future for direct planets & disks

    E-print Network

    Guyon, Olivier

    ) · Characterization (spectroscopy) of Earth-mass planets in habitable zone · Simultaneous imaging of exozodi cloudA bright future for direct imaging of extrasolar planets & disks Olivier Guyon Center-IR, with Adaptive Optics) · Most sensitive to outer young planets: very complementary to Radial Velocity, astrometry

  7. A bright future for direct planets & disks

    E-print Network

    Guyon, Olivier

    ) · Characterization (spectroscopy) of Earth-mass planets in habitable zone · Simultaneous imaging of exozodi cloudA bright future for direct imaging of extrasolar planets & disks Olivier Guyon CenterAO) Pupil mapping Exoplanet Coronagraphic Observer (PECO) 2 Outline #12;Exoplanets How many planets around

  8. 880 {mu}m IMAGING OF A TRANSITIONAL DISK IN UPPER SCORPIUS: HOLDOVER FROM THE ERA OF GIANT PLANET FORMATION?

    SciTech Connect

    Mathews, Geoffrey S.; Williams, Jonathan P.; Menard, Francois

    2012-07-01

    We present 880 {mu}m images of the transition disk around the star [PZ99] J160421.7-213028, a solar mass star in the nearby Upper Scorpius association. With a resolution down to 0.''34, we resolve the inner hole in this disk, and via model fitting to the visibilities and spectral energy distribution we determine both the structure of the outer region and the presence of sparse dust within the cavity. The disk contains {approx}0.1 M{sub Jup} of millimeter-emitting grains, with an inner disk edge of about 70 AU. The inner cavity contains a small amount of dust with a depleted surface density in a region extending from about 20 to 70 AU. Taking into account prior observations indicating little to no stellar accretion, the lack of a binary companion, and the presence of dust near {approx}0.1 AU, we determine that the most likely mechanism for the formation of this inner hole is the presence of one or more giant planets.

  9. Direct imaging of the water snow line at the time of planet formation using two ALMA continuum bands

    E-print Network

    Banzatti, Andrea; Ricci, Luca; Pontoppidan, Klaus M; Birnstiel, Til; Ciesla, Fred

    2015-01-01

    Molecular snow lines in protoplanetary disks have been studied theoretically for decades because of their importance in shaping planetary architectures and compositions. The water snow line lies in the planet formation region at < 10 AU, and so far its location has been estimated only indirectly from spatially-unresolved spectroscopy. This work presents a proof-of-concept method to directly image the water snow line in protoplanetary disks through its physical and chemical imprint in the local dust properties. We adopt a physical disk model that includes dust coagulation, fragmentation, drift, and a change in fragmentation velocities of a factor 10 between dry silicates and icy grains as found by laboratory work. We find that the presence of a water snow line leads to a sharp discontinuity in the radial profile of the dust emission spectral index {\\alpha}_mm, due to replenishment of small grains through fragmentation. We use the ALMA simulator to demonstrate that this effect can be observed in protoplaneta...

  10. Validation of a Monte Carlo simulation of the Philips Allegro/GEMINI PET systems using GATE.

    PubMed

    Lamare, F; Turzo, A; Bizais, Y; Le Rest, C Cheze; Visvikis, D

    2006-02-21

    A newly developed simulation toolkit, GATE (Geant4 Application for Tomographic Emission), was used to develop a Monte Carlo simulation of a fully three-dimensional (3D) clinical PET scanner. The Philips Allegro/GEMINI PET systems were simulated in order to (a) allow a detailed study of the parameters affecting the system's performance under various imaging conditions, (b) study the optimization and quantitative accuracy of emission acquisition protocols for dynamic and static imaging, and (c) further validate the potential of GATE for the simulation of clinical PET systems. A model of the detection system and its geometry was developed. The accuracy of the developed detection model was tested through the comparison of simulated and measured results obtained with the Allegro/GEMINI systems for a number of NEMA NU2-2001 performance protocols including spatial resolution, sensitivity and scatter fraction. In addition, an approximate model of the system's dead time at the level of detected single events and coincidences was developed in an attempt to simulate the count rate related performance characteristics of the scanner. The developed dead-time model was assessed under different imaging conditions using the count rate loss and noise equivalent count rates performance protocols of standard and modified NEMA NU2-2001 (whole body imaging conditions) and NEMA NU2-1994 (brain imaging conditions) comparing simulated with experimental measurements obtained with the Allegro/GEMINI PET systems. Finally, a reconstructed image quality protocol was used to assess the overall performance of the developed model. An agreement of <3% was obtained in scatter fraction, with a difference between 4% and 10% in the true and random coincidence count rates respectively, throughout a range of activity concentrations and under various imaging conditions, resulting in <8% differences between simulated and measured noise equivalent count rates performance. Finally, the image quality validation study revealed a good agreement in signal-to-noise ratio and contrast recovery coefficients for a number of different volume spheres and two different (clinical level based) tumour-to-background ratios. In conclusion, these results support the accurate modelling of the Philips Allegro/GEMINI PET systems using GATE in combination with a dead-time model for the signal flow description, which leads to an agreement of <10% in coincidence count rates under different imaging conditions and clinically relevant activity concentration levels. PMID:16467589

  11. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (planets obey a kind of universal mass-radius relationship: an expansion whose first term is M approx. R(sup 3).

  12. Information extraction from digital images of the earth and the planets

    NASA Technical Reports Server (NTRS)

    Green, W. B.

    1978-01-01

    An overview is presented of recent developments at the JPL Image Processing Laboratory which emphasize the utilization of a digital computer to automate the process of information extraction from digital imagery. Consideration is given to: (1) the analysis of Viking Orbiter stereo imagery to determine elevation profiles of the Mars surface, (2) the use of Viking Lander stereo imagery to determine nonhazardous surface sample acquisition strategies, (3) the correlation of Landsat imagery with geographically referenced cultural data to determine land use trends, and (4) the generation of mosaics using digital computer techniques.

  13. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Modern theories of star and planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. The most detailed models of planetary growth are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed, and the methods that are being used and planned for detecting and characterizing extrasolar planets are reviewed.

  14. FFREE: a Fresnel-FRee Experiment for EPICS, the EELT planets imager

    E-print Network

    Antichi, Jacopo; Preis, Olivier; Delboulbé, Alain; Zins, Gérard; Rabou, Patrick; Beuzit, Jean-Luc; Dandy, Sarah; Sauvage, Jean-François; Fusco, Thierry; Aller-Carpentier, Emmanuel; Kasper, Markus; Hubin, Norbert

    2010-01-01

    The purpose of FFREE - the new optical bench devoted to experiments on high-contrast imaging at LAOG - consists in the validation of algorithms based on off-line calibration techniques and adaptive optics (AO) respectively for the wavefront measurement and its compensation. The aim is the rejection of the static speckles pattern arising in a focal plane after a diffraction suppression system (based on apodization or coronagraphy) by wavefront pre-compensation. To this aim, FFREE has been optimized to minimize Fresnel propagation over a large near infrared (NIR) bandwidth in a way allowing efficient rejection up to the AO control radius, it stands then as a demonstrator for the future implementation of the optics that will be common to the scientific instrumentation installed on EPICS.

  15. Geological interpretation of a Gemini photo

    USGS Publications Warehouse

    Hemphill, William R.; Danilchik, Walter

    1968-01-01

    Study of the Gemini V photograph of the Salt Range and Potwar Plateau, West Pakistan, indicates that small-scale orbital photographs permit recognition of the regional continuity of some geologic features, particularly faults and folds that could he easily overlooked on conventional air photographs of larger scale. Some stratigraphic relationships can also be recognized on the orbital photograph, but with only minimal previous geologic knowledge of the area, these interpretations are less conclusive or reliable than the interpretation of structure. It is suggested that improved atmospheric penetration could be achieved through the use of color infrared film. Photographic expression of topography could also be improved by deliberately photographing some areas during periods of low sun angle.

  16. Gemini: A long-range cargo transport

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The proposed Gemini, a long-range cargo transport, is designed as a high capacity, dedicated cargo transporter of 8'x8'x20' inter-modal containers, and long-range design. These requirements will result in a design that is larger than any existing aircraft. Due to the size, a conventional configuration would result in an aircraft unable to operate economically at existing airports. It is necessary to design for a minimum possible empty weight, wingspan, and landing gear track. After considering both a single fuselage biplane and a double fuselage biplane configuration, the design team choose the double fuselage biplane configuration. Both of these configuration choices result in a reduced wing root bending moment and subsequently in substantial savings in the wing weight. An overall decrease in the weight of the airplane, its systems, and fuel will be a direct result of the wing weight savings.

  17. Geo-Engineering through Internet Informatics (GEMINI)

    SciTech Connect

    Watney, W. Lynn; Doveton, John H.; Victorine, John R.; Bohling, Goeffrey C.; Bhattacharya, Saibal; Byers, Alan P.; Carr, Timothy R.; Dubois, Martin K.; Gagnon, Glen; Guy, Willard J.; Look, Kurt; Magnuson, Mike; Moore, Melissa; Olea, Ricardo; Pakalapadi, Jayprakash; Stalder, Ken; Collins, David R.

    2002-06-25

    GEMINI will resolve reservoir parameters that control well performance; characterize subtle reservoir properties important in understanding and modeling hydrocarbon pore volume and fluid flow; expedite recognition of bypassed, subtle, and complex oil and gas reservoirs at regional and local scale; differentiate commingled reservoirs; build integrated geologic and engineering model based on real-time, iterate solutions to evaluate reservoir management options for improved recovery; provide practical tools to assist the geoscientist, engineer, and petroleum operator in making their tasks more efficient and effective; enable evaluations to be made at different scales, ranging from individual well, through lease, field, to play and region (scalable information infrastructure); and provide training and technology transfer to evaluate capabilities of the client.

  18. Giant Planets

    NASA Astrophysics Data System (ADS)

    Lunine, J. I.

    Beyond the inner solar system's terrestrial planets, with their compact orbits and rock -metal compositions, lies the realm of the outer solar system and the giant planets. Here the distance between planets jumps by an order of magnitude relative to the spacing of the terrestrial planets, and the masses of the giants are one to two orders of magnitude greater than Venus and Earth - the largest terrestrial bodies. Composition changes as well, since the giant planets are largely gaseous, with inferred admixtures of ice, rock, and metal, while the terrestrial planets are essentially pure rock and metal. The giant planets have many more moons than do the terrestrial planets, and the range of magnetic field strengths is larger in the outer solar system. It is the giant planets that sport rings, ranging from the magnificent ones around Saturn to the variable ring arcs of Neptune. Were it not for the fact that only Earth supports abundant life (with life possibly existing, but not proved to exist, in the martian crust and liquid water regions underneath the ice of Jupiter's moon Europa), the terrestrial planets would pale in interest next to the giant planets for any extraterrestrial visitor.

  19. Atmospheres of Extrasolar Giant Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2006-01-01

    The next decade will almost certainly see the direct imaging of extrasolar giant planets around nearby stars. Unlike purely radial velocity detections, direct imaging will open the door to characterizing the atmosphere and interiors of extrasola planets and ultimately provide clues on their formation and evolution through time. This process has already begun for the transiting planets, placing new constraints on their atmospheric structure, composition, and evolution. Indeed the key to understanding giant planet detectability, interpreting spectra, and constraining effective temperature and hence evolution-is the atmosphere. I will review the universe of extrasolar giant planet models, focusing on what we have already learned from modeling and what we will likely be able to learn from the first generation of direct detection data. In addition to these theoretical considerations, I will review the observations and interpretation of the - transiting hot Jupiters. These objects provide a test of our ability to model exotic atmospheres and challenge our current understanding of giant planet evolution.

  20. Piercing the Glare: Direct Imaging Search for Planets in the Sirius System

    E-print Network

    Thalmann, Christian; Kenworthy, Matthew; Janson, Markus; Mamajek, Eric E; Brandner, Wolfgang; Dominik, Carsten; Goto, Miwa; Hayano, Yutaka; Henning, Thomas; Hinz, Phil M; Minowa, Yosuke; Tamura, Motohide

    2011-01-01

    Astrometric monitoring of the Sirius binary system over the past century has yielded several predictions for an unseen third system component, the most recent one suggesting a \\leq50 MJup object in a ~6.3-year orbit around Sirius A. Here we present two epochs of high-contrast imaging observations performed with Subaru IRCS and AO188 in the 4.05 \\mum narrow-band Br alpha filter. These data surpass previous observations by an order of magnitude in detectable companion mass, allowing us to probe the relevant separation range down to the planetary mass regime (6-12 M_Jup at 1", 2-4 M_Jup at 2", and 1.6 M_Jup beyond 4"). We complement these data with one epoch of M-band observations from MMT/AO Clio, which reach comparable performance. No dataset reveals any companion candidates above the 5-sigma level, allowing us to refute the existence of Sirius C as suggested by the previous astrometric analysis. Furthermore, our Br alpha photometry of Sirius B confirms the lack of an infrared excess beyond the white dwarf's b...

  1. Microlensing Extrasolar Planets

    E-print Network

    Gaudi, B. Scott

    Microlensing Searches for Extrasolar Planets Microlensing Searches for Extrasolar Planets Microlensing Searches for Extrasolar Planets, B. Scott Gaudi, IAS Scientific Frontiers in Research on Extrasolar Planets, June 19, 2002 #12;Microlensing and PlanetsMicrolensing and Planets Microlensing Searches

  2. View of Gemini 11 experiment S-13 Ultraviolet Astronomical Camera

    NASA Technical Reports Server (NTRS)

    1966-01-01

    View of Gemini 11 experiment S-13 Ultraviolet Astronomical Camera before flight. Its object was to obtain data on ultraviolet radiation of hot stars and to develop and evaluate basic techniques for photography of celestial objects from manned spacecraft.

  3. Food packets for use on the Gemini 3 flight

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Food packets for use on the Gemini 3 flight including dehydrated beef pot roast, bacon and egg bites, toasted bread cubes, orange juice and a wet wipe. Water is being inserted into the pouch of dehydrated food.

  4. Food packages for use on the Gemini 4 flight

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Food packages for use on the Gemini 4 flight. Packages include beef and gravy, peaches, strawberry cereal cubes and beef sandwiches. Water gun is used to reconstitute dehydrated food. Scissors are used to open the packages.

  5. Integral Field Spectroscopy with the Gemini 8-m Telescopes

    E-print Network

    Miller, B W; Takamiya, M; Simons, D A; Hook, I

    2002-01-01

    We give an overview of the current and future IFU capabilities on the Gemini 8-m telescopes. The telescopes are well-suited to integral field spectroscopy and both telescopes will have optical and near-infrared IFUs within the next few years. Commissioning for the GMOS IFU on Gemini North has begun recently and it is now available to the community. Future integral field instruments will take advantage of wide-field adaptive optics systems.

  6. Integral Field Spectroscopy with the Gemini 8-m Telescopes

    E-print Network

    B. W. Miller; J. Turner; M. Takamiya; D. Simons; I. Hook

    2002-03-20

    We give an overview of the current and future IFU capabilities on the Gemini 8-m telescopes. The telescopes are well-suited to integral field spectroscopy and both telescopes will have optical and near-infrared IFUs within the next few years. Commissioning for the GMOS IFU on Gemini North has begun recently and it is now available to the community. Future integral field instruments will take advantage of wide-field adaptive optics systems.

  7. Tracing Planet Orbits with WFIRST

    NASA Astrophysics Data System (ADS)

    Bryden, Geoffrey

    2015-08-01

    The WFIRST mission will directly image planets around nearby stars with a goal of not only detecting planets, but, more importantly, of characterizing their properties. Visible-light spectra will measure molecular abundances in planet atmospheres, while series of images will trace planetary orbits. Independent radial velocity measurements are needed to determine each planet's mass. This study considers the ability of a combined set of data - radial velocity plus direct-imaging astrometry - to constrain both the planet mass and its phase of illumination during each observation. The addition of pre- and post-mission radial velocity measurements in some cases allows for fewer WFIRST observations, maximizing the overall science yield of the mission.

  8. Properties of Ellipticity Correlation with Atmospheric Structure From Gemini South

    SciTech Connect

    Asztalos, Stephen J.; de Vries, W.H.; Rosenberg, L.J; Treadway, T.; Burke, D.; Claver, C.; Saha, A.; Puxley, P.; /Gemini Observ., La Serena

    2007-01-17

    Cosmic shear holds great promise for a precision independent measurement of {Omega}{sub m}, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extract the cosmic shear from the atmospheric component, though a measure of their success applied to a range of seeing conditions is lacking. To gain insight into atmospheric shear, Gemini South imaging in conjunction with ground condition and satellite wind data were obtained. We find that under good seeing conditions Point-Spread-Function (PSF) correlations persist well beyond the separation typical of high-latitude stars. Under these conditions, ellipticity residuals based on a simple PSF interpolation can be reduced to within a factor of a few of the shot-noise induced ellipticity floor. We also find that the ellipticity residuals are highly correlated with wind direction. Finally, we correct stellar shapes using a more sophisticated procedure and generate shear statistics from stars. Under all seeing conditions in our data set the residual correlations lie everywhere below the target signal level. For good seeing we find that the systematic error attributable to atmospheric turbulence is comparable in magnitude to the statistical error (shape noise) over angular scales relevant to present lensing surveys.

  9. GEMINI: Integrative Exploration of Genetic Variation and Genome Annotations

    PubMed Central

    Paila, Umadevi; Chapman, Brad A.; Kirchner, Rory; Quinlan, Aaron R.

    2013-01-01

    Modern DNA sequencing technologies enable geneticists to rapidly identify genetic variation among many human genomes. However, isolating the minority of variants underlying disease remains an important, yet formidable challenge for medical genetics. We have developed GEMINI (GEnome MINIng), a flexible software package for exploring all forms of human genetic variation. Unlike existing tools, GEMINI integrates genetic variation with a diverse and adaptable set of genome annotations (e.g., dbSNP, ENCODE, UCSC, ClinVar, KEGG) into a unified database to facilitate interpretation and data exploration. Whereas other methods provide an inflexible set of variant filters or prioritization methods, GEMINI allows researchers to compose complex queries based on sample genotypes, inheritance patterns, and both pre-installed and custom genome annotations. GEMINI also provides methods for ad hoc queries and data exploration, a simple programming interface for custom analyses that leverage the underlying database, and both command line and graphical tools for common analyses. We demonstrate GEMINI's utility for exploring variation in personal genomes and family based genetic studies, and illustrate its ability to scale to studies involving thousands of human samples. GEMINI is designed for reproducibility and flexibility and our goal is to provide researchers with a standard framework for medical genomics. PMID:23874191

  10. Extrasolar planets

    PubMed Central

    Lissauer, Jack J.; Marcy, Geoffrey W.; Ida, Shigeru

    2000-01-01

    The first known extrasolar planet in orbit around a Sun-like star was discovered in 1995. This object, as well as over two dozen subsequently detected extrasolar planets, were all identified by observing periodic variations of the Doppler shift of light emitted by the stars to which they are bound. All of these extrasolar planets are more massive than Saturn is, and most are more massive than Jupiter. All orbit closer to their stars than do the giant planets in our Solar System, and most of those that do not orbit closer to their star than Mercury is to the Sun travel on highly elliptical paths. Prevailing theories of star and planet formation, which are based on observations of the Solar System and of young stars and their environments, predict that planets should form in orbit about most single stars. However, these models require some modifications to explain the properties of the observed extrasolar planetary systems. PMID:11035782

  11. Planet X

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A name given to a hypothetical tenth major planet once believed to exist in the outer solar system, beyond the orbit of Neptune. The `X', which stood for `unknown', was also appropriate as the roman numeral for `ten'. The label `Planet X' was originated by Percival Lowell. From the late nineteenth century, he and others, including William H Pickering, worked out orbits for a large tenth planet wh...

  12. FIRST LIGHT LBT AO IMAGES OF HR 8799 bcde AT 1.6 AND 3.3 {mu}m: NEW DISCREPANCIES BETWEEN YOUNG PLANETS AND OLD BROWN DWARFS

    SciTech Connect

    Skemer, Andrew J.; Hinz, Philip M.; Rodigas, Timothy J.; Close, Laird; McCarthy, Don; Kulesa, Craig; Apai, Daniel; Bailey, Vanessa; Esposito, Simone; Arcidiacono, Carmelo; Mannucci, Filippo; Agapito, Guido; Argomedo, Javier; Briguglio, Runa; Burrows, Adam; Leisenring, Jarron; Skrutskie, Michael; Desidera, Silvano; Mesa, Dino; Boutsia, Konstantina; and others

    2012-07-01

    As the only directly imaged multiple planet system, HR 8799 provides a unique opportunity to study the physical properties of several planets in parallel. In this paper, we image all four of the HR 8799 planets at H band and 3.3 {mu}m with the new Large Binocular Telescope adaptive optics system, PISCES, and LBTI/LMIRCam. Our images offer an unprecedented view of the system, allowing us to obtain H and 3.3 {mu}m photometry of the innermost planet (for the first time) and put strong upper limits on the presence of a hypothetical fifth companion. We find that all four planets are unexpectedly bright at 3.3 {mu}m compared to the equilibrium chemistry models used for field brown dwarfs, which predict that planets should be faint at 3.3 {mu}m due to CH{sub 4} opacity. We attempt to model the planets with thick-cloudy, non-equilibrium chemistry atmospheres but find that removing CH{sub 4} to fit the 3.3 {mu}m photometry increases the predicted L' (3.8 {mu}m) flux enough that it is inconsistent with observations. In an effort to fit the spectral energy distribution of the HR 8799 planets, we construct mixtures of cloudy atmospheres, which are intended to represent planets covered by clouds of varying opacity. In this scenario, regions with low opacity look hot and bright, while regions with high opacity look faint, similar to the patchy cloud structures on Jupiter and L/T transition brown dwarfs. Our mixed-cloud models reproduce all of the available data, but self-consistent models are still necessary to demonstrate their viability.

  13. Testing of the Gemini secondary mirrors

    NASA Astrophysics Data System (ADS)

    Otto, Wolfgang

    1999-09-01

    The first 1-m secondary mirror for the Gemini 8-m telescopes project was delivered by Zeiss in 1998, and 2nd mirror will be delivered in the summer of 1999. For first use during commissioning we produced an extreme lightweight Zerodur solution prefabricated at Schott. To reach the 85 percent weight reduction a novel etching technique was used. INterferometric testing was done performing full aperture measurements using a concave matrix. In progress with the fabrication process of the matrix we applied 3D-mechanical measurements, IR-interferometry, and VIS-interferometry using null lenses to reach the final intrinsic quality of 6 nm rms. For interferometric testing of the secondaries phase shifting interferometry with a tunable laser diode was applied. The optical test results of the secondaries show, that the mirrors are well within specification. The finally achieved intrinsic surface quality is 17 nm rms for Unit 1 and 13 nm rms for Unit 2, dominated by cutting effects which were introduced by removing the oversize at the inner and outer edge of the mirror after the final polishing step.

  14. Progress in extra-solar planet detection

    NASA Technical Reports Server (NTRS)

    Brown, Robert A.

    1991-01-01

    Progress in extra-solar planet detection is reviewed. The following subject areas are covered: (1) the definition of a planet; (2) the weakness of planet signals; (3) direct techniques - imaging and spectral detection; and (4) indirect techniques - reflex motion and occultations.

  15. Debris Disks and Hidden Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2008-01-01

    When a planet orbits inside a debris disk like the disk around Vega or Beta Pictoris, the planet may be invisible, but the patterns it creates in the disk may give it away. Observing and decoding these patterns may be the only way we can detect exo-Neptunes orbiting more than 20 AU from their stars, and the only way we can spot planets in systems undergoing the late stages of planet formation. Fortunately, every few months, a new image of a debris disk appears with curious structures begging for explanation. I'll describe some new ideas in the theory of these planet-disk interactions and provide a buyers guide to the latest models (and the planets they predict).

  16. GEO-ENGINEERING MODELING THROUGH INTERNET INFORMATICS (GEMINI)

    SciTech Connect

    W. Lynn Watney; John H. Doveton

    2004-05-13

    GEMINI (Geo-Engineering Modeling through Internet Informatics) is a public-domain web application focused on analysis and modeling of petroleum reservoirs and plays (http://www.kgs.ukans.edu/Gemini/index.html). GEMINI creates a virtual project by ''on-the-fly'' assembly and analysis of on-line data either from the Kansas Geological Survey or uploaded from the user. GEMINI's suite of geological and engineering web applications for reservoir analysis include: (1) petrofacies-based core and log modeling using an interactive relational rock catalog and log analysis modules; (2) a well profile module; (3) interactive cross sections to display ''marked'' wireline logs; (4) deterministic gridding and mapping of petrophysical data; (5) calculation and mapping of layer volumetrics; (6) material balance calculations; (7) PVT calculator; (8) DST analyst, (9) automated hydrocarbon association navigator (KHAN) for database mining, and (10) tutorial and help functions. The Kansas Hydrocarbon Association Navigator (KHAN) utilizes petrophysical databases to estimate hydrocarbon pay or other constituent at a play- or field-scale. Databases analyzed and displayed include digital logs, core analysis and photos, DST, and production data. GEMINI accommodates distant collaborations using secure password protection and authorized access. Assembled data, analyses, charts, and maps can readily be moved to other applications. GEMINI's target audience includes small independents and consultants seeking to find, quantitatively characterize, and develop subtle and bypassed pays by leveraging the growing base of digital data resources. Participating companies involved in the testing and evaluation of GEMINI included Anadarko, BP, Conoco-Phillips, Lario, Mull, Murfin, and Pioneer Resources.

  17. OGLE-2012-BLG-0563Lb: a Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO imaging

    E-print Network

    Fukui, A; Sumi, T; Bennett, D P; Bond, I A; Han, C; Suzuki, D; Beaulieu, J -P; Batista, V; Udalski, A; Street, R A; Tsapras, Y; Hundertmark, M; Abe, F; Freeman, M; Itow, Y; Ling, C H; Koshimoto, N; Masuda, K; Matsubara, Y; Muraki, Y; Ohnishi, K; Philpott, L C; Rattenbury, N; Saito, T; Sullivan, D J; Tristram, P J; Yonehara, A; Choi, J -Y; Christie, G W; DePoy, D L; Dong, Subo; Drummond, J; Gaudi, B S; Hwang, K -H; Kavka, A; Lee, C U; McCormick, J; Natusch, T; Ngan, H; Park, H; Pogge, R W; Shin, I-G; Tan, T -G; Yee, J C; Szyma?ski, M K; Pietrzy?ski, G; Soszy?ski, I; Poleski, R; Koz?owski, S; Pietrukowicz, P; Ulaczyk, K; Bramich, ? Wyrzykowski D M; Browne, P; Dominik, M; Horne, K; Ipatov, S; Kains, N; Snodgrass, C; Steele, I A

    2015-01-01

    We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio ~1 x 10^{-3}. Intensive photometric observations of a high-magnification microlensing event allow us to detect a clear signal of the planet. Although no parallax signal is detected in the light curve, we instead succeed at detecting the flux from the host star in high-resolution JHK'-band images obtained by the Subaru/AO188 and IRCS instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of a spectroscopic information of the source star obtained during the high-magnification state by Bensby et al. (2013), we find that the lens system is located at 1.3^{+0.6}_{-0.8} kpc from us, and consists of an M dwarf (0.34^{+0.12}_{-0.20} M_sun) orbited by a Saturn-mass planet (0.39^{+0.14}_{-0.23} M_Jup) at the projected separation of 0.74^{+0.26}_{-0.42} AU (close model) or 4.3^{+1.5}_{-2.5} AU (wide model). The probability of contamination in the host star's flux...

  18. Extreme Planets

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This artist's concept depicts the pulsar planet system discovered by Aleksander Wolszczan in 1992. Wolszczan used the Arecibo radio telescope in Puerto Rico to find three planets - the first of any kind ever found outside our solar system - circling a pulsar called PSR B1257+12. Pulsars are rapidly rotating neutron stars, which are the collapsed cores of exploded massive stars. They spin and pulse with radiation, much like a lighthouse beacon. Here, the pulsar's twisted magnetic fields are highlighted by the blue glow.

    All three pulsar planets are shown in this picture; the farthest two from the pulsar (closest in this view) are about the size of Earth. Radiation from charged pulsar particles would probably rain down on the planets, causing their night skies to light up with auroras similar to our Northern Lights. One such aurora is illustrated on the planet at the bottom of the picture.

    Since this landmark discovery, more than 160 extrasolar planets have been observed around stars that are burning nuclear fuel. The planets spotted by Wolszczan are still the only ones around a dead star. They also might be part of a second generation of planets, the first having been destroyed when their star blew up. The Spitzer Space Telescope's discovery of a dusty disk around a pulsar might represent the beginnings of a similarly 'reborn' planetary system.

  19. Gemini optical observations of binary millisecond pulsars

    NASA Astrophysics Data System (ADS)

    Testa, V.; Mignani, R. P.; Pallanca, C.; Corongiu, A.; Ferraro, F. R.

    2015-11-01

    Millisecond pulsars (MSPs) are rapidly spinning neutron stars, with spin periods Ps ? 10 ms, which have been most likely spun up after a phase of matter accretion from a companion star. In this work, we present the results of the search for the companion stars of four binary MSPs, carried out with archival data from the Gemini South telescope. Based upon a very good positional coincidence with the pulsar radio coordinates, we likely identified the companion stars to three MSPs, namely PSR J0614-3329 (g = 21.95 ± 0.05), J1231-1411 (g = 25.40 ± 0.23), and J2017+0603 (g = 24.72 ± 0.28). For the last pulsar (PSR J0613-0200) the identification was hampered by the presence of a bright star (g = 16 ± 0.03) at ˜2 arcsec from the pulsar radio coordinates and we could only set 3? upper limits of g = 25.0, r = 24.3, and i = 24.2 on the magnitudes of its companion star. The candidate companion stars to PSR J0614-3329, J1231-1411, and J2017+0603 can be tentatively identified as He white dwarfs (WDs) on the basis of their optical colours and brightness and the comparison with stellar model tracks. From the comparison of our multiband photometry with stellar model tracks we also obtained possible ranges on the mass, temperature, and gravity of the candidate WD companions to these three MSPs. Optical spectroscopy observations are needed to confirm their possible classification as He WDs and accurately measure their stellar parameters.

  20. From Disks to Planets

    NASA Astrophysics Data System (ADS)

    Isella, Andrea

    2015-08-01

    The unprecedented imaging capabilities offered by the Atacama Large Millimeter Array (ALMA) and the Karl Jansky Very Large Array (JVLA) are transforming our understanding of planet formation. During my talk, I will review the most recent millimeter-wave observations of nearby young circumstellar disks that probe the spatial distribution and the physical properties of the circumstellar dust and gas, and reveal planetary systems in the act of forming. I will discuss these observations in the framework of star formation and disk evolution models, as well as of the demographics of the know exoplanetary systems and current planet formation scenarios.

  1. Astronaut James Lovell walks to elevator on Pad 19 before Gemini 7 launch

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut James A. Lovell Jr., pilot of the Gemini 7 space flight, walks to the elevator at Pad 19 one hour and forty minutes before launch of the spacecraft. He is dressed in the new Gemini space suit.

  2. Improving signal-to-noise in the direct imaging of exoplanets and circumstellar disks with MLOCI

    NASA Astrophysics Data System (ADS)

    Wahhaj, Zahed; Cieza, Lucas A.; Mawet, Dimitri; Yang, Bin; Canovas, Hector; de Boer, Jozua; Casassus, Simon; Ménard, François; Schreiber, Matthias R.; Liu, Michael C.; Biller, Beth A.; Nielsen, Eric L.; Hayward, Thomas L.

    2015-09-01

    We present a new algorithm designed to improve the signal-to-noise ratio (S/N) of point and extended source detections around bright stars in direct imaging data.One of our innovations is that we insert simulated point sources into the science images, which we then try to recover with maximum S/N. This improves the S/N of real point sources elsewhere in the field. The algorithm, based on the locally optimized combination of images (LOCI) method, is called Matched LOCI or MLOCI. We show with Gemini Planet Imager (GPI) data on HD 135344 B and Near-Infrared Coronagraphic Imager (NICI) data on several stars that the new algorithm can improve the S/N of point source detections by 30-400% over past methods. We also find no increase in false detections rates. No prior knowledge of candidate companion locations is required to use MLOCI. On the other hand, while non-blind applications may yield linear combinations of science images that seem to increase the S/N of true sources by a factor >2, they can also yield false detections at high rates. This is a potential pitfall when trying to confirm marginal detections or to redetect point sources found in previous epochs. These findings are relevant to any method where the coefficients of the linear combination are considered tunable, e.g., LOCI and principal component analysis (PCA). Thus we recommend that false detection rates be analyzed when using these techniques. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (USA), the Science and Technology Facilities Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  3. Irregular Satellites of the Planets

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    2005-01-01

    This proposal is directed towards the observational exploration of the irregular satellite systems of the planets. Primarily we use large-format CCD cameras on the world's largest telescopes, on Mauna Kea, to discover new irregular satellites and then to monitor their positions in order to ascertain their orbital characteristics. Separate observations are taken to determine the physical properties of the irregular satellites. The big picture science objective is to determine how these satellites were captures, and to use the properties of the satellites and their orbits to place constraints on early solar system (including formation) processes. Work in the first year has focussed on a major investigation of the Saturn irregular satellite system. We secured observing time on the Subaru and Gemini 8-m diameter telescopes in December 2004, January, February and March 2005 for the conduct of a deep, wide-area survey. This has resulted in the detection and orbit determination for 12 new satellites to be announced in the next week or two. Additional satellites were lost, temporarily, due to unusually poor weather conditions on Mauna Kea. These objects will be recovered and their orbits published next year. A separate survey of the Uranus irregular satellites was published (Sheppard, Jewitt and Kleyna 2005). Away from the telescope, we have discovered the amazing result that the four giant planets possess similar numbers of irregular satellites. This flies in the face of the standard gas-drag model for satellite capture, since only two of the giant planets are gas giants and the others (Uranus and Neptune) formed by a different process and in the absence of much gas. The constancy of the satellite number (each giant holds approximately 100 irregular satellites measured down to the kilometer scale) is either a coincidence, with different capture mechanisms at different planets giving by chance the same total numbers of irregular satellites, or indicates that the satellites were captured by a completely different process. We favor the latter (Jewitt and Sheppard 2005).

  4. A treatment procedure for Gemini North/NIFS data cubes: application to NGC 4151

    E-print Network

    Menezes, R B; Ricci, T V

    2014-01-01

    We present a detailed procedure for treating data cubes obtained with the Near-Infrared Integral Field Spectrograph (NIFS) of the Gemini North telescope. This process includes the following steps: correction of the differential atmospheric refraction, spatial re-sampling, Butterworth spatial filtering, 'instrumental fingerprint' removal and Richardson-Lucy deconvolution. The clearer contours of the structures obtained with the spatial re-sampling, the high spatial-frequency noise removed with the Butterworth spatial filtering, the removed 'instrumental fingerprints' (which take the form of vertical stripes along the images) and the improvement of the spatial resolution obtained with the Richardson-Lucy deconvolution result in images with a considerably higher quality. An image of the Br{\\gamma} emission line from the treated data cube of NGC 4151 allows the detection of individual ionized-gas clouds (almost undetectable without the treatment procedure) of the narrow-line region of this galaxy, which are also ...

  5. The Gemini Deep Deep Survey: VIII. When Did Early-type Galaxies Form?

    E-print Network

    Abraham, R G; Glazebrook, K; Mentuch, E; Nair, P; Yan, H; Savaglio, S; Crampton, D; Murowinski, R; Juneau, S; Le Borgne, D; Carlberg, R G; Jorgensen, I; Roth, K; Chen, H W; Marzke, R O; Abraham, Roberto G.; Carthy, Patrick J. Mc; Glazebrook, Karl; Mentuch, Erin; Nair, Preethi; Yan, Haojing; Savaglio, Sandra; Crampton, David; Murowinski, Richard; Juneau, Stephanie; Borgne, Damien Le; Jorgensen, Inger; Roth, Kathy; Chen, Hsiao-Wen; Marzke, Ronald O.

    2007-01-01

    We have used the Hubble Space Telescope's Advanced Camera for Surveys (Ford et al. 2003) to measure the cumulative mass density in morphologically-selected early-type galaxies over the redshift range 0.8 Deep Field campaigns. Our images contain 144 galaxies with ultra-deep spectroscopy obtained as part of the Gemini Deep Deep Survey. These images have been analyzed using a new purpose-written morphological analysis code which improves the reliability of morphological classifications by adopting a 'quasi-Petrosian' image thresholding technique. We find that at z \\~ 1 about 80% of the stars living in the most massive galaxies reside in early-type systems. This fraction is similar to that seen in the local Universe. However, we detect very rapid evolution in this fraction over the range 0.8 < z <...

  6. Planet formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1993-01-01

    Models of planetary formation are developed using the present single example of a planetary system, supplemented by limited astrophysical observations of star-forming regions and circumstellar disks. The solar nebula theory and the planetesimal hypothesis are discussed. The latter is found to provide a viable theory of the growth of the terrestrial planets, the cores of the giant planets, and the smaller bodies present in the solar system. The formation of solid bodies of planetary size should be a common event, at least around young stars which do not have binary companions orbiting at planetary distances. Stochastic impacts of large bodies provide sufficient angular momentum to produce the obliquities of the planets. The masses and bulk compositions of the planets can be understood in a gross sense as resulting from planetary growth within a disk whose temperature and surface density decreased with distance from the growing sun.

  7. Preliminary results of the 20012002 Gemini sodium monitoring campaign at Cerro Tololo, Chile

    E-print Network

    at the solstices 4 . Most of the short time scale abundance and mean altitude variations can be traced down are subsequently called ``sporadics''. The observation of sporadic layers has triggered a number of theories aimed, ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ *cdorgeville@gemini.edu; phone +1 808 974 2545; fax +1 808 935 9235; http://www.gemini.edu; Gemini Observatory

  8. Infrastructure of the Gemini Observatory Control System K. K. Gillies and S. Walker

    E-print Network

    Infrastructure of the Gemini Observatory Control System K. K. Gillies and S. Walker Gemini 8m Telescopes Project, 950 N. Cherry Ave., Tucson, AZ, 85719 Gemini Preprint # 31 #12; Infrastructure software infrastructure is required to support this comprehensive approach. New software technologies

  9. Infrastructure of the Gemini Observatory Control System K. K. Gillies and S. Walker

    E-print Network

    Infrastructure of the Gemini Observatory Control System K. K. Gillies and S. Walker Gemini 8m Telescopes Project, 950 N. Cherry Ave., Tucson, AZ, 85719 Gemini Preprint # 31 #12;Infrastructure software infrastructure is required to support this comprehensive approach. New software technologies

  10. Active Optics Performance Study of the Primary Mirror of the Gemini Telescopes Project

    E-print Network

    Active Optics Performance Study of the Primary Mirror of the Gemini Telescopes Project Myung K. Cho Optical Sciences Center in the University of Arizona Tucson, AZ 85721 and Gemini Telescopes Project P. O. Box 26732 Tucson, AZ 85726­6732 Gemini Preprint #9 #12; Active optics performance study of the primary

  11. Execution of queue-scheduled observations with the Gemini 8m telescopes

    E-print Network

    Execution of queue-scheduled observations with the Gemini 8m telescopes Phil Puxley Gemini 8m described. In this paper we discuss the philosophy and parameters which define its execution. Results from detailed simulations of the queue execution process are presented. Keywords: Gemini telescopes, telescope

  12. Gemini 4 astronauts relax aboard Navy helicopter after recovery

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Gemini 4 astronauts, James A. McDivitt (right), command pilot, and Edward H. White II, (left), pilot, relax aboard a U.S. Navy helicopter on their way to the aircraft carrier U.S.S. Wasp after recovery from the Gemini 4 spacecraft. They had been picked up out of the Atlantic Ocean following a successful splashdown (33532); White (left) and McDivitt listen to the voice of President Lyndon B. Johnson as he congratulated them by telephone on the successful mission. They are shown aboard the carrier U.S.S. Wasp just after their recovery (33533).

  13. DEPARTMENT OF PHYSICS AND ASTRONOMY Planet Hunting Techniques

    E-print Network

    Burleigh, Matt

    DEPARTMENT OF PHYSICS AND ASTRONOMY Planet Hunting Techniques iscience seminar Dr. Matt Burleigh imaging, Yellow: pulsar timing #12;Dr. Matt Burleigh #12;Dr. Matt Burleigh Planet Hunting: The Radial.37x105ms-1 Mpl sin i = 0.45Mjup #12;Dr. Matt Burleigh Planet Hunting 2: Transits Planets observed

  14. Extrasolar Planet Finding via Optimal Apodized and Shaped Pupil Coronagraphs

    E-print Network

    Vanderbei, Robert J.

    Extrasolar Planet Finding via Optimal Apodized and Shaped Pupil Coronagraphs N. Jeremy Kasdin Dept examine several different apodization approaches to achieving high-contrast imaging of extrasolar planets extrasolar planets discovered to date, interest in planet finding is becom- ing intense. Both the scientific

  15. Planet Formation

    NASA Astrophysics Data System (ADS)

    Chambers, J. E.

    2003-12-01

    Modern theories for the origin of the planets are based on observations of the solar system and star-forming regions elsewhere in the galaxy, together with the results of numerical models. Some key observations are: - The solar system contains eight large planets with roughly circular, coplanar orbits lying 0.4-30 AU from the Sun. There are few locations between the planets where additional large objects could exist on stable orbits. - The major planets are grouped: small volatile-poor planets lie close to the Sun, with large volatile-rich planets further out. The main asteroid belt (2-4 AU from the Sun) is substantially depleted in mass with respect to other regions. - The planets and asteroids are depleted in volatile elements compared to the Sun. The degree of fractionation decreases with distance: the terrestrial planets and inner-belt asteroids are highly depleted in volatiles, the outer-belt asteroids are less so, while many satellites in the outer solar system are ice rich. Primitive CI meteorites (probably from the outer asteroid belt) have elemental abundances very similar to the Sun except for highly volatile elements. - Ancient solid surfaces throughout the solar system are covered in impact craters (e.g., the Moon, Mercury, Mars, Callisto). Most of the planets have large axial tilts with respect to their orbits. Earth possesses a large companion with a mass ˜1% that of the planet itself. - The terrestrial planets and many asteroids have undergone differentiation. There is strong evidence that Saturn is highly centrally condensed, with a core of mass ˜10M?, and weaker evidence that Jupiter has a core of similar mass. These cores have masses comparable to Uranus and Neptune. - Meteorites from the main asteroid belt show evidence that they once contained short-lived radioactive isotopes with half-lives <10 Myr. The main components of primitive meteorites (chondrules and refractory inclusions) have sizes clustered around 1 mm. These components appear to have undergone rapid melting and cooling. - Young stars generally exist in gas- and dust-rich environments. Many young stars possess massive, optically thick disks with diameters of 10-1,000 AU. These disks are inferred to have lifetimes of ˜1-10 Myr. - At least 4% of main sequence (ordinary) stars have planetary-mass companions. The companions have masses of 0.1-10 Jupiter masses (the lower limit is the current detection threshhold), and orbital distances from 0.05 AU to 5 AU (the upper limit is the current detection threshhold).These observations have led to the development and refinement of a theory in which the planets formed from a disk-shaped protoplanetary nebula (Laplace) by pairwise accretion of small solid bodies (Safranov, 1969). A variant of the standard model invokes the gravitational collapse of portions of this disk to form gas giant planets directly. It should be pointed out that the standard model is designed to explain the planets observed in the solar system. Attempts to account for planetary systems recently discovered orbiting other stars suggest that planet formation is likely to differ in several respects from one system to another.

  16. Infrared and the search for extrasolar planets

    NASA Technical Reports Server (NTRS)

    Meinel, Aden B.; Meinel, Marjorie P.

    1991-01-01

    Search for evidence concerning the existence of extrasolar planets will involve both indirect detection as well as direct (imaging). Indirect detection may be possible using ground based instrumentation on the Keck telescope, Imaging probably will require an orbiting system. Characterizing other planets for complex molecules will require a large orbiting or lunar-based telescope or inteferometer. Cryogenic infrared techniques appear to be necessary. Planning for a NASA ground and space-based program, Toward Other Planet Systems (TOPS), is proceeding.

  17. Polarimetry of gas planets

    NASA Astrophysics Data System (ADS)

    Joos, Franco

    The quest for new worlds was not only an adventure at the times of Columbus. Also nowadays mankind searches for new, undiscovered territories. But today they lie no longer only on our Earth, but also well outside the solar system. There, new planets are sought and found. One of the challenges of modern astrophysics is the direct detection of extra- solar planets. To reach this goal, the largest available telescopes and most sophisticated detection techniques are required. A promising method to "see" and analyse extra-solar planets is based on the fact, that light reflected by a planet can be polarised. For its detection, accurate polarisation measurements are needed. This is one of the methods ESO intends to make use of to find new planets outside the solar system. The Institute of Astronomy of ETH Zürich contributes ZIMPOL to this planet-finder project. ZIMPOL is a very sensitive imaging polarimeter. This thesis is situated within the ESO-planet-finder project. It deals with two problems that are crucial for a successful mission: (1) Instrumental polarisation can seriously hamper the performance of the instrument. It is therefore essential, to keep instrumental polarisation very low. (2) A knowledge of the polarisation properties of our targets would be very helpful. For this reason the polarisation properties of our solar system planets are investigated. Promising candidates for a detection with ZIMPOL are large planets with atmospheres similar to those of our giant gas planets Jupiter, Saturn, Uranus and Neptune. In the first part of the thesis the planet-finder project is presented and the role of ZIMPOL is explained. To obtain the instrumental polarisation, the polarimetric properties of mirrors and other optical components of our planet- finder instrument are analysed. The instrumental polarisation for the wavelength range of 600 to 1000 nm and for all zenith distances is calculated with Mueller matrices. Methods for reducing the instrumental polarisation are proposed and checked by the renewed application of the Mueller calculus. The correction of the instrumental polarisation is divided into two parts. First, a combination of a rotating half-wave plate and a plane mirror compensate the polarisation introduced by the Nasmyth mirror. Secondly, a rotatable and tiltable glass plate compensates the residual polarisation introduced by oblique reflections on mirrors after the Nasmyth mirror. Further, possible aging effects of the mirrors are considered and consequences for the polarisation are highlighted. An error budget for non perfect retardation of the half-wave plate is also regarded, and the effects for the polarisation are calculated. In the second part spectropolarimetric measurements of the four gas planets Jupiter, Saturn, Uranus and Neptune for the wavelength range from 530 to 930 nm are presented. Our measurements of Uranus and Neptune are the first of their kind. For Uranus and Neptune a second-order scattering effect, leading to limb polarisation, has been measured. This effect is expected in atmospheres of Rayleigh scattering type and allows conclusions on the properties of the scatterers and the stratification inside the atmosphere. The limb polarisation reaches a maximum of more than 3% on Uranus. Spectropolarimetric plots for selected regions on Uranus and polarimetric profiles parallel to the spectrographic slits are presented. An enhanced polarisation in the methane absorption bands is detected. For both planets the limb polarisation decreases with wavelength. For Jupiter and Saturn profiles parallel to the slits and polarimetric spectra for some selected regions such as the poles of Jupiter or the ring system of Saturn are presented. The poles of Jupiter exhibit a large polarisation (up to 10%) perpendicular to the limb. In the methane absorption bands at the Jovian poles the polarisation is enhanced compared to the adjacent higher albedo regions. The polarisation decreases from short wavelengths towards longer wavelengths. Disc resolved spectropolarimetry of Saturn has not yet been publi

  18. Gemini photographs of the world: A complete index

    NASA Technical Reports Server (NTRS)

    Giddings, L. E.

    1977-01-01

    The most authoritative catalogs of photographs of all Gemini missions are assembled. Included for all photographs are JSC (Johnson Space Center) identification number, percent cloud cover, geographical area in sight, and miscellaneous information. In addition, details are given on cameras, filters, films, and other technical details.

  19. Designing Scalable PGAS Communication Subsystems on Cray Gemini Interconnect

    SciTech Connect

    Vishnu, Abhinav; Daily, Jeffrey A.; Palmer, Bruce J.

    2012-12-26

    The Cray Gemini Interconnect has been recently introduced as a next generation network architecture for building multi-petaflop supercomputers. Cray XE6 systems including LANL Cielo, NERSC Hopper, ORNL Titan and proposed NCSA BlueWaters leverage the Gemini Interconnect as their primary Interconnection network. At the same time, programming models such as the Message Passing Interface (MPI) and Partitioned Global Address Space (PGAS) models such as Unified Parallel C (UPC) and Co-Array Fortran (CAF) have become available on these systems. Global Arrays is a popular PGAS model used in a variety of application domains including hydrodynamics, chemistry and visualization. Global Arrays uses Aggregate Re- mote Memory Copy Interface (ARMCI) as the communication runtime system for Remote Memory Access communication. This paper presents a design, implementation and performance evaluation of scalable and high performance communication subsystems on Cray Gemini Interconnect using ARMCI. The design space is explored and time-space complexities of commu- nication protocols for one-sided communication primitives such as contiguous and uniformly non-contiguous datatypes, atomic memory operations (AMOs) and memory synchronization is presented. An implementation of the proposed design (referred as ARMCI-Gemini) demonstrates the efficacy on communication primitives, application kernels such as LU decomposition and full applications such as Smooth Particle Hydrodynamics (SPH) application.

  20. Gemini Series Experiment Data Reduction and Storage Techniques

    SciTech Connect

    R. A. Berglin

    2011-11-01

    The presentation covers data formats expected from Gemini experiments; data quick look vs. in-depth analysis; iPDV object-oriented data storage; iPDV's traceability of analysis results; optimizing object memory usage in iPDV; and long-term archival of data objects by iPDV.

  1. Classification of 3 DES supernovae by Gemini-North

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Foley, R. J.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.

    2015-11-01

    We report optical spectroscopy of 3 supernovae discovered by the Dark Energy Survey. The spectra (380-820nm) were obtained using GMOS on Gemini-North. Object classification was performed using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and superfit (Howell et al, 2005, ApJ, 634, 119), the details of which are reported in the table below.

  2. Gemini 12 crew arrives aboard U.S.S. Wasp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    A happy Gemini 12 prime crew arrives aboard the aircraft carrier, U.S.S. Wasp. Astronauts James A. Lovell Jr. (left), command pilot, and Edwin E. Aldrin Jr., pilot, had just been picked up from the splashdown area by helicopter.

  3. MagAO Imaging of Long-period Objects (MILO). I. A Benchmark M Dwarf Companion Exciting a Massive Planet around the Sun-like Star HD 7449

    E-print Network

    Rodigas, Timothy J; Faherty, Jackie; Anglada-Escude, Guillem; Kaib, Nathan; Butler, R Paul; Shectman, Stephen; Weinberger, Alycia; Males, Jared R; Morzinski, Katie M; Close, Laird M; Hinz, Philip M; Crane, Jeffrey D; Thompson, Ian; Teske, Johanna; Diaz, Matias; Minniti, Dante; Lopez-Morales, Mercedes; Adams, Fred C; Boss, Alan P

    2015-01-01

    We present high-contrast Magellan adaptive optics (MagAO) images of HD 7449, a Sun-like star with one planet and a long-term radial velocity (RV) trend. We unambiguously detect the source of the long-term trend from 0.6-2.15 \\microns ~at a separation of \\about 0\\fasec 54. We use the object's colors and spectral energy distribution to show that it is most likely an M4-M5 dwarf (mass \\about 0.1-0.2 \\msun) at the same distance as the primary and is therefore likely bound. We also present new RVs measured with the Magellan/MIKE and PFS spectrometers and compile these with archival data from CORALIE and HARPS. We use a new Markov chain Monte Carlo procedure to constrain both the mass ($> 0.17$ \\msun ~at 99$\\%$ confidence) and semimajor axis (\\about 18 AU) of the M dwarf companion (HD 7449B). We also refine the parameters of the known massive planet (HD 7449Ab), finding that its minimum mass is $7.8^{+3.7}_{-1.35}$ \\mj, its semimajor axis is $2.33^{+0.01}_{-0.02}$ AU, and its eccentricity is $0.8^{+0.08}_{-0.06}$. ...

  4. Observations of planet-building volatiles

    NASA Astrophysics Data System (ADS)

    Pontoppidan, Klaus Martin; Blevins, Sandra; Banzatti, Andrea; Zhang, Ke; Salyk, Colette; Blake, Geoffrey

    2015-08-01

    Water is observed to be a major constituent of planet-forming disks around young stars and its presence likely plays a major role in formation of planets and their atmospheres, including those destined to orbit in a habitable zone. Yet, the path from disks to planets is one fraught with complexity, making it difficult to derive precise theoretical predictions for planetary chemistry. Planet-forming disks are no longer considered uniform well-mixed structures; rather, they are complex worlds with many different heterogenous environments, most of which play some part in determining the composition of planetesimals and planets. Direct observations of atomic and molecular abundances on all size scales are therefore needed for understanding planet formation at a very fundamental level, and for answering the question of how chemically common the Earth is among exoplanets. In the past years, great progress has been made in observing protoplanetary chemistry, in particular in measuring the molecular composition in protoplanetary disks across the planet-forming regions from 1 to 10s of AU. We will present recent observations of water with Herschel, the VLT and Gemini in disks, and we will demonstrate how we retrieve the local abundances and radial distribution of water vapor and ice using detailed radiative transfer models. We find that most of the oxygen is likely bound in water near 1 AU in disks around solar-mass stars and that the disk surface composition at these radii is likely dominated by local gas-phase chemistry rather than by primordial material delivered from the interstellar medium. We discuss how these observations relate to complementary constraints from the solar system. We further discuss the implications for the observed composition of exoplanetary atmospheres.

  5. The structure and morphology of gold nanoparticles produced in cationic gemini surfactant systems

    NASA Astrophysics Data System (ADS)

    Murawska, Magdalena; Wiatr, Michalina; Nowakowski, Pawe?; Szutkowski, Kosma; Skrzypczak, Andrzej; Kozak, Maciej

    2013-12-01

    Potential applications of gold nanoparticles (GNP) are strictly connected with their size and shape. The influence of different dicationic (gemini) surfactants, alkyloxymethylimidazolium derivatives derivatives, on the structure and morphology of GNP was studied. The synthesis of nanoparticles was performed in the presence of various gemini surfactants—dodecyloxymethylimidazolium nitrate (IMI_NO3_C4_C12), propionate (IMI_PROP_C4_C12) and 3,3'-[1,9-(2,8-dioxanonane)]bis-(1-nonyloxymethylimidazolium) chloride (IMI_Cl_oxyC7_C9), used as stabilizers and templates for obtaining different size and shape of gold nanoparticles. The samples obtained were examined using transmission electron microscopy (TEM), small angle scattering of synchrotron radiation (SAXS), UV-vis spectroscopy and NMR PFG spectroscopy. For the obtained solutions of nanoparticles the plasmon resonance was observed at the wavelengths corresponding to the presence of gold nanoparticles of sizes ranging from 5-100 nm, with a significant shift towards higher wavelength for the samples prepared with addition of dicationic surfactants. TEM images evidence the presence of gold nanoparticles with tetrahedral and spherical morphology in solutions prepared with the surfactants IMI_PROP_C4_C12, IMI_NO3_C4_C12, and those of spherical morphology, but strongly aggregated, in the solution with the cationic surfactant IMI_Cl_oxyC7_C9.

  6. A New Family of Planets ? "Ocean Planets"

    E-print Network

    A. Leger; F. Selsis; C. Sotin; T. Guillot; D. Despois; H. Lammer; M. Ollivier; F. Brachet; A. Labeque; C. Valette

    2003-08-19

    A new family of planets is considered which is between rochy terrestrial planets and gaseous giant ones: "Ocean-Planets". We present the possible formation, composition and internal models of these putative planets, including that of their ocean, as well as their possible Exobiology interest. These planets should be detectable by planet detection missions such as Eddington and Kepler, and possibly COROT (lauch scheduled in 2006). They would be ideal targets for spectroscopic missions such as Darwin/TPF.

  7. Resolved debris disk emission around eta Tel: a young Solar System or ongoing planet formation?

    E-print Network

    R. Smith; L. J. Churcher; M. C. Wyatt; M. M. Moerchen; C. M. Telesco

    2008-10-28

    60% of the A star members of the 12 Myr old beta Pictoris moving group (BPMG) show significant excess emission in the mid-infrared, several million years after the proto-planetary disk is thought to disperse. Theoretical models suggest this peak may coincide with the formation of Pluto-sized planetesimals in the disk, stirring smaller bodies into collisional destruction. Here we present resolved mid-infrared imaging of the disk of eta Tel (A0V in the BPMG) and consider its implications for the state of planet formation in this system. eta Tel was observed at 11.7 and 18.3um using T-ReCS on Gemini South. The resulting images were compared to simple disk models to constrain the radial distribution of the emitting material. The emission observed at 18.3um is shown to be significantly extended beyond the PSF along a position angle 8 degrees. This is the first time dust emission has been resolved around eta Tel. Modelling indicates that the extension arises from an edge-on disk of radius 0.5 arcsec (~24 AU). Combining the spatial constraints from the imaging with those from the spectral energy distribution shows that >50% of the 18um emission comes from an unresolved dust component at ~4 AU. The radial structure of the eta Tel debris disk is reminiscent of the Solar System, suggesting that this is a young Solar System analogue. For an age of 12Myr, both the radius and dust level of the extended cooler component are consistent with self-stirring models for a protoplanetary disk of 0.7 times minimum mass solar nebula. The origin of the hot dust component may arise in an asteroid belt undergoing collisional destruction, or in massive collisions in ongoing terrestrial planet formation.

  8. Pluto: Planet or "Dwarf Planet"?

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.; de Araújo, M. S. T.

    2010-09-01

    In August 2006 during the XXVI General Assembly of the International Astronomical Union (IAU), taken place in Prague, Czech Republic, new parameters to define a planet were established. According to this new definition Pluto will be no more the ninth planet of the Solar System but it will be changed to be a "dwarf planet". This reclassification of Pluto by the academic community clearly illustrates how dynamic science is and how knowledge of different areas can be changed and evolves through the time, allowing to perceive Science as a human construction in a constant transformation, subject to political, social and historical contexts. These epistemological characteristics of Science and, in this case, of Astronomy, constitute important elements to be discussed in the lessons, so that this work contributes to enable Science and Physics teachers who perform a basic education to be always up to date on this important astronomical fact and, thereby, carry useful information to their teaching.

  9. Studying the Sky/Planets Can Drown You in Images: Machine Learning Solutions at JPL/Caltech

    NASA Technical Reports Server (NTRS)

    Fayyad, U. M.

    1995-01-01

    JPL is working to develop a domain-independent system capable of small-scale object recognition in large image databases for science analysis. Two applications discussed are the cataloging of three billion sky objects in the Sky Image Cataloging and Analysis Tool (SKICAT) and the detection of possibly one million small volcanoes visible in the Magellan synthetic aperture radar images of Venus (JPL Adaptive Recognition Tool, JARTool).

  10. Quick-MESS: A Fast Statistical Tool for Exoplanet Imaging Surveys

    NASA Astrophysics Data System (ADS)

    Bonavita, M.; de Mooij, E. J. W.; Jayawardhana, R.

    2013-07-01

    Several tools have been developed in the past few years for the statistical analysis of the exoplanet search surveys, mostly using a combination of Monte Carlo simulations or a Bayesian approach. Here we present Quick-MESS, a grid-based, non-Monte Carlo tool aimed to perform statistical analyses on results from direct imaging surveys, as well as help with the planning of these surveys. Quick-MESS uses the (expected) contrast curves for direct imaging surveys to assess for each target the probability that a planet of a given mass and semimajor axis can be detected. By using a grid-based approach, Quick-MESS is typically more than an order of magnitude faster than tools based on Monte Carlo sampling of the planet distribution. In addition, Quick-MESS is extremely flexible, enabling the study of a large range of parameter space for the mass and semimajor axes distributions without the need of resimulating the planet distribution. In order to show examples of the capabilities of Quick-MESS, we present the analysis of the Gemini Deep Planet Survey and the predictions for upcoming surveys with extreme-AO instruments.

  11. Direct Imaging of Exoplanets, from very large to extremely large telescopes

    NASA Astrophysics Data System (ADS)

    Kasper, M.

    2015-10-01

    Presently, dedicated instruments at 8-m class telescopes (SPHERE for the VLT, GPI for Gemini) are about to discover and explore self-luminous giant planets by direct imaging and spectroscopy. In a decade, the next generation of 30m-40m ground-based Extremely Large Telescopes (ELTs) have the potential to dramatically enlarge the discovery space towards older giant planets seen in the reflected light and ultimately even a small number of rocky planets. In order to fulfill the demanding contrast requirements of a part in a million to a part in a billion at separations of one tenth of an arcsecond, the seeing limited PSF contrast must gradually be improved by eXtreme Adaptive optics (XAO), non-common path aberration compensation, coronagraphy, and science image post-processing. None of these steps alone is sufficient to leap the enormous contrast. High-contrast imaging (HCI) from the ground encompasses all those disciplines which are to be considered in a system approach. The presentation will introduce the principle of HCI and present the current implementation in the SPHERE, ESO's imager for giant exoplanets at the VLT. It will then discuss requirements and necessary R&D to reach the ultimate goal, observing terrestrial Exoplanets with the next generation of instruments for the ELTs.

  12. Global stratigraphy of the dwarf planet Ceres from RC2 imaging data of the Dawn FC camera

    NASA Astrophysics Data System (ADS)

    Wagner, R. J.; Schmedemann, N.; Kneissl, T.; Stephan, K.; Otto, K.; Krohn, K.; Schröder, S.; Kersten, E.; Roatsch, T.; Jaumann, R.; Williams, D. A.; Yingst, R. A.; Crown, D.; Mest, S. C.; Russell, C. T.

    2015-10-01

    On March 6, 2015, the Dawn spacecraft was captured into orbit around Ceres. During its approach phase since Dec. 1, 2014, imaging data returned by the framing camera (FC) have increased in spatial resolution exceeding that of the Hubble Space Telescope. In this paper, we use these first images to identify and map global geologic units and to establish a stratigraphic sequence.

  13. Protostars and Planets VI

    NASA Astrophysics Data System (ADS)

    Beuther, Henrik; Klessen, Ralf S.; Dullemond, Cornelis P.; Henning, Thomas

    The Protostars and Planets book and conference series has been a long-standing tradition that commenced with the first meeting led by Tom Gehrels and held in Tucson, Arizona, in 1978. The goal then, as it still is today, was to bridge the gap between the fields of star and planet formation as well as the investigation of planetary systems and planets. As Tom Gehrels stated in the preface to the first Protostars and Planets book, "Cross-fertilization of information and understanding is bound to occur when investigators who are familiar with the stellar and interstellar phases meet with those who study the early phases of solar system formation." The central goal remained the same for the subsequent editions of the books and conferences Protostars and Planets II in 1984, Protostars and Planets III in 1990, Protostars and Planets IV in 1998, and Protostars and Planets V in 2005, but has now been greatly expanded by the flood of new discoveries in the field of exoplanet science. The original concept of the Protostars and Planets series also formed the basis for the sixth conference in the series, which took place on July 15-20, 2013. It was held for the first time outside of the United States in the bustling university town of Heidelberg, Germany. The meeting attracted 852 participants from 32 countries, and was centered around 38 review talks and more than 600 posters. The review talks were expanded to form the 38 chapters of this book, written by a total of 250 contributing authors. This Protostars and Planets volume reflects the current state-of-the-art in star and planet formation, and tightly connects the fields with each other. It is structured into four sections covering key aspects of molecular cloud and star formation, disk formation and evolution, planetary systems, and astrophysical conditions for life. All poster presentations from the conference can be found at www.ppvi.org. In the eight years that have passed since the fifth conference and book in the Protostars and Planets series, the field of star and planet formation has progressed enormously. The advent of new space observatories like Spitzer and more recently Herschel have opened entirely new windows to study the interstellar medium, the birthplaces of new stars, and the properties of protoplanetary disks. Millimeter and radio observatories, in particular interferometers, allow us to investigate even the most deeply embedded and youngest protostars. Complementary to these observational achievements, novel multi-scale and multi-physics theoretical and numerical models have provided new insights into the physical and chemical processes that govern the birth of stars and their planetary systems. Sophisticated radiative transfer modeling is critical in order to better connect theories with observations. Since the last Protostars and Planets volume, more than 1000 new extrasolar planets have been identified and there are thousands more waiting to be verified. Such a large database allows for the first time a statistical assessment of the planetary properties as well as their evolution pathways. These investigations show the enormous diversity of the architecture of planetary systems and the properties of planets. High-contrast imaging at short and long wavelengths has resolved protoplanetary disks and associated planets, and transit spectroscopy is a new tool that allows us to study even the physical properties of extrasolar planetary atmospheres. The understanding of our own solar system has also progressed enormously since 2005. For instance, the sample-return Stardust mission has provided direct insight into the composition of comets and asteroids, and has demonstrated the importance of mixing processes in the early solar system. And much more is now known about the origin and role of short-lived nuclides at these stages of the solar system. For generations of astronomers, the Protostars and Planets volumes have served as an essential resource for our understanding of star and planet formation. They are used by students to dive into new topics, and

  14. FURTHER EVIDENCE OF THE PLANETARY NATURE OF HD 95086 b FROM GEMINI/NICI H-BAND DATA

    SciTech Connect

    Meshkat, T.; Kenworthy, M.; Bailey, V.; Su, K. Y. L.; Rameau, J.; Chauvin, G.; Lagrange, A.-M.; Boccaletti, A.; Mamajek, E. E.; Currie, T.

    2013-10-01

    We present our analysis of the Gemini/NICI H-band data of HD 95086, following the discovery of the planet HD 95086 b in L'. The H-band data reach a contrast of 12.7 mag relative to the host star at 5? levels in the location of HD 95086 b, and no point source is found. Our non-detection and H – L' color limit rules out the possibility that the object is a foreground L/T dwarf and that, if it is bound to HD 95086, it is a genuine planetary mass object. We estimate a new pre-main-sequence isochronal age for HD 95086 of 17 ± 4 Myr, which is commensurate with previous mean age estimates for the Lower Cen-Crux subgroup. Adopting an age of 17 Myr, the color limit is inconsistent with the COND model, marginally consistent with the BT-SETTL model, and consistent with the DUSTY model.

  15. Aqueous Gemini Surfactant Self-Assembly into Complex Lyotropic Phases

    NASA Astrophysics Data System (ADS)

    Mahanthappa, Mahesh; Sorenson, Gregory

    2012-02-01

    In spite of the potentially wide-ranging applications of aqueous bicontinuous lyotropic liquid crystals (LLCs), the discovery of amphiphiles that reliably form these non-constant mean curvature morphologies over large phase windows remains largely serendipitous. Recent work has established that cationic gemini surfactants exhibit a pronounced tendency to form bicontinuous cubic (e.g. gyroid) phases as compared to their parent single-tail amphiphiles. The universality of this phenomenon in other surfactant systems remains untested. In this paper, we will report the aqueous LLC phase behavior of a new class of anionic gemini surfactants derived from long chain carboxylic acids. Our studies show that these new surfactants favor the formation of non-constant mean curvature gyroid and primitive (``Plumber's Nightmare'') structures over amphiphile concentration windows up to 20 wt% wide. Based on these observations, we will discuss insights gained into the delicate force balance governing the self-assembly of these surfactants into aqueous bicontinuous LLCs.

  16. Simulating Planet-Hunting in a Lab

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Three simulated planets -- one as bright as Jupiter, one half as bright as Jupiter and one as faint as Earth -- stand out plainly in this image created from a sequence of 480 images captured by the High Contrast Imaging Testbed at JPL. A roll-subtraction technique, borrowed from space astronomy, was used to distinguish planets from background light. The asterisk marks the location of the system's simulated star.

  17. Precision Astrometry of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Unwin, Stephen C.; Traub, W. A.

    2010-05-01

    Exoplanets are now being discovered by a variety of observational techniques, including radial velocity, transits, microlensing and in a few examples, direct imaging. Each technique has distinct advantages and disadvantages, depending on the planet or system parameters of interest. The exoplanet parameter space is very large, and only partially explored. Precision astrometry has yet to contribute significantly, due to the difficulty of achieving the necessary precision from the ground. Space astrometry of exoplanets will begin with Gaia, which will explore Jupiter-mass planet populations. The Space Interferometry Mission (SIM Lite) will provide the precision needed to do a thorough survey of the local neighborhood for planets down to Earth mass, and measure their masses and orbits. In this poster we show how astrometry opens up a critical part of the exoplanet parameter space: low-mass planets around nearby stars. This is of particular significance because these are the planets for which direct imaging and spectroscopy will provide the most detailed understanding of planets that may have Earth-like characteristics.

  18. Gemini 3 prime crew receive instructions for egress during briefing

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronauts John W. Young (left) and Virgil I. Grissom (second from left) receive instructions for getting out of the Gemini spacecraft after a water landing during a briefing in the galley of the NASA Motor Vessel Retriever en route to the training site 15 miles South of Galveston, Texas. Giving the briefing were Harold E. Granger (second from right) and Peter Armitage (right), both from the Manned Spacecraft Center Landing and Recovery Division.

  19. Easier Phase IIs: Recent Improvements to the Gemini User Tools

    NASA Astrophysics Data System (ADS)

    Miller, Bryan; Nuñez, A.

    2013-01-01

    During 2011 and 2012 Gemini Observatory undertook a significant project to improve the software tools used by investigators to propose for and prepare observations. The main goal was to make the definition of observation details (the Phase II process) easier and faster. The main initiatives included rewriting the observing proposal tool (Phase I Tool) and making several major improvements to the Observing Tool, including automatic settings for arc and flat exposures, automatic guide star selection for all instruments and wavefront sensors, and more complete initial template observations with capabilities for simultaneous editing of many observations. This poster explains these major changes as well as outlines future development plans. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  20. On the Shoulders of Titans: A History of Project Gemini

    NASA Technical Reports Server (NTRS)

    Hacker, B. C.

    1977-01-01

    Gemini was the intermediate manned space flight program between America's first steps into space with Mercury and the manned lunar expeditions of Apollo. Because of its position between these two other efforts, Gemini is probably less remembered. Still, it more than had its place in man's progress into this new frontier. Gemini accomplishments were manyfold. They included many firsts: first astronaut-controlled maneuvering in space; first rendezvous in space of one spacecraft with another; first docking of one spacecraft with a propulsive stage and use of that stage to transfer man to high altitude; first traverse of man into the earth's radiation belts; first extended manned flights of a week or more in duration; first extended stays of man outside his spacecraft; first controlled reentry and precision landing; and many more. These achievements were significant in ways one cannot truly evaluate even today, but two things stand out: (1) it was the time when America caught up and surpassed the Soviet Union in manned space flight, and (2) these demonstrations of capability were an absolute prerequisite to the phenomenal Apollo accomplishments then yet to come.

  1. Validating Kepler Planet Candidates

    NASA Astrophysics Data System (ADS)

    Lissauer, Jack J.; Torres, G.; Marcy, G.; Brown, T.; Gilliland, R.; Gautier, T. N.; Isaacson, H.; Dupree, A.; Kepler Science Team

    2011-01-01

    The Kepler Science Team has identified more than 700 transit-like signatures in the first 43 days of data returned from the spacecraft (Borucki et al. 2010, arXiv1006.2799B). However, only 7 of these candidates have been confirmed as planets as of late September 2010. The number of true planets in this sample is clearly far larger than 7, but the sample is also 'contaminated' with false-positives, including many from eclipsing binary stars. Separating the wheat from the chaff requires a careful study of individual candidates using both Kepler photometry and spectroscopic and imaging data from the ground. Techniques that the Science Team is developing to address these issues, which include detailed analysis of the photometric data and follow-up observations with ground-based telescopes, will be presented. Kepler was selected as the 10th mission of the Discovery Program. Funding for this mission is provided by NASA, Science Mission Directorate.

  2. Determining the Narrow-Line Region Geometry of Mrk 3 with Gemini/NIFS

    NASA Astrophysics Data System (ADS)

    Pope, Crystal L.; Fischer, Travis C.; Crenshaw, D. Michael

    2015-01-01

    We present a study of the narrow-line region (NLR) and inner disk of the Seyfert 2 Mrk 3, based on observations from the Gemini Near-Infrared Integral Field Spectrometer (NIFS). Mrk 3 exhibits emission-line knots within the NLR that are in the shape of a backward S, which is likely due to dust/gas spirals in the galaxy's disk that have been illuminated by the AGN's ionizing bicone. With our NIFS observations, we determine the kinematics of Mrk 3 using an automated Bayesian model selection algorithm. Comparing the NLR kinematics measured with NIFS to those previously measured with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), we are able to test the accuracy of our previous kinematic outflow model.

  3. Synthesis of organic rectorite with novel Gemini surfactants for copper removal

    NASA Astrophysics Data System (ADS)

    Han, Guocheng; Han, Yang; Wang, Xiaoying; Liu, Shijie; Sun, Runcang

    2014-10-01

    Three novel Gemini surfactants were used to prepare organic rectorite (OREC) under microwave irradiation, in comparison with single-chain surfactant ester quaternary ammonium salt (EQAS) and cetyltrimethyl ammonium bromide (CTAB). The structure and morphology of OREC were characterized by XRD, BET, FT-IR, TEM and TGA. The removal of Cu2+ on OREC from aqueous solution was performed. The results reveal that Gemini surfactants modified REC had larger interlayer distance and higher surface area than single-chain surfactants EQAS and CTAB, and the increasing amount or chain length of Gemini surfactants led to larger layer spacing and higher adsorption capacities. The adsorption behavior of Gemini surfactant modified REC can be better described by Freundlich adsorption isotherm model, with a maximum adsorption capacity of 15.16 mg g-1. The desorption and regeneration experiments indicate good reuse property of Gemini modified REC adsorbent. Therefore, this study may widen the utilization of Gemini surfactants modified layered silicates.

  4. Gemini 7 prime crew during suiting up procedures at Launch Complex 16

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Astronaut James A. Lovell Jr. (left), Gemini 7 prime crew pilot, talks with NASA space suit technician Clyde Teague during suiting up procedures at Launch Complex 16, Kennedy Space Center. Lovell wears the new lightweight space suit planned for use during the Gemini 7 mission (61756); Astronaut Frank Borman, comand pilot of the Gemini 7 space flight, undergoes suiting up operations in Launch Complex 16 during prelaunch countdown. Medical biosensors are attached to his scalp (61757).

  5. Gemini 9-A spacecraft touches down in the Atlantic at end of mission

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Gemini 9-A space flight is concluded as the Gemini 9 spacecraft touches down in the Atlantic. In this view its parachute is still deployed as the spacecraft hits the water (34117); Astronauts Thomas Stafford (right) and Eugene Cernan wave to the crowd aboard the aircraft carrier U.S.S. Wasp as they emerge from their Gemini 9 capsule. John C. Stonesifer (far right), with the Manned Spacecraft Center's Landing and Recovery Division, was on board to greet the astronauts (34118).

  6. Line-by-line analysis of Neptune's near-IR spectrum observed with Gemini/NIFS and VLT/CRIRES

    NASA Astrophysics Data System (ADS)

    Irwin, P. G. J.; Lellouch, E.; de Bergh, C.; Courtin, R.; Bézard, B.; Fletcher, L. N.; Orton, G. S.; Teanby, N. A.; Calcutt, S. B.; Tice, D.; Hurley, J.; Davis, G. R.

    2014-01-01

    New line data describing the absorption of CH4 and CH3D from 1.26 to 1.71 ?m (WKMC-80K, Campargue, A., Wang, L., Mondelain, D., Kassi, S., Bézard, B., Lellouch, E., Coustenis, A., de Bergh, C., Hirtzig, M., Drossart, P. [2012]. Icarus 219, 110-128) have been applied to the analysis of Gemini-N/NIFS observations of Neptune made in 2009 and VLT/CRIRES observations made in 2010. The new line data are found to greatly improve the fit to the observed spectra and present a considerable advance over previous methane datasets. The improved fits lead to an empirically derived wavelength-dependent correction to the scattering properties of the main observable cloud deck at 2-3 bars that is very similar to the correction determined for Uranus' lower cloud using the same line dataset by Irwin et al. (Irwin, P.G.J., de Bergh, C., Courtin, R., Bézard, B., Teanby, N.A., Davis, G.R., Fletcher, L.N., Orton, G.S., Calcutt, S.B., Tice, D., Hurley, J. [2012]. Icarus 220, 369-382). By varying the abundance of CH3D in our simulations, analysis of the Gemini/NIFS observations leads to a new determination of the CH3D/CH4 ratio for Neptune of 3.0-0.9+1.0×10-4, which is smaller than previous determinations, but is identical (to within error) with the CH3D/CH4 ratio of 2.9-0.5+0.9×10-4 derived by a similar analysis of Gemini/NIFS observations of Uranus made in the same year. Thus it appears that the atmospheres of Uranus and Neptune have an almost identical D/H ratio, which suggests that the icy planetisimals forming these planets came from the same source reservoir, or a reservoir that was well-mixed at the locations of ice giant formation, assuming complete mixing between the atmosphere and interior of both these planets. VLT/CRIRES observations of Neptune have also been analysed with the WKMC-80K methane line database, yielding very good fits, with little evidence for missing absorption features. The CRIRES spectra indicate that the mole fraction of CO at the 2-3 bar level must be substantially less than its estimated stratospheric value of 1 × 10-6, which suggests that the predominant source of CO in Neptune's atmosphere is external, through the influx of micrometeorites and comets, although these data cannot rule out an additional internal source.

  7. Astrometry of Directly Imaged Exoplanets after PSF Subtraction using MCMC Forward Modeling

    NASA Astrophysics Data System (ADS)

    Wang, Jason; Graham, James R.; Pueyo, Laurent; Ruffio, Jean-Baptise; GPIES Collaboration

    2016-01-01

    Direct imaging allows for the characterization of the orbits of exoplanets. However, to remove the glare of the host star, we must use observing strategies (e.g., angular differential imaging and spectral differential imaging) and data reduction techniques (e.g., Karhunen-Loève Image Projection; KLIP) that distort the apparent position of an exoplanet. Using recent methods to forward model the point spread function of a planet after using KLIP to subtract out the stellar light (Pueyo 2015), we are able to account for these astrometric biases. With the forward models, we can use a Markov chain Monte Carlo (MCMC) algorithm to derive the posterior distribution on the position of an exoplanet. To test our methodology, we apply our technique to Gemini Planet Imager integral field spectroscopy (IFS) data of the newly discovered exoplanet around 51 Eri and the extensively studied exoplanet beta Pictoris b. In general, this technique is applicable to any broadband direct imaging data and IFS data where the spectrum is assumed to be known.

  8. The effect of a small heat source on PSF stability for high-contrast imaging.

    PubMed

    Evans, Julia W; Macintosh, Bruce; Norton, Andrew; Dillon, Daren; Gavel, Donald

    2009-07-01

    High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. The Laboratory for Adaptive Optics at UC Santa Cruz is investigating limits to high-contrast imaging in support of the Gemini Planet Imager (GPI). In this paper we examine the effect of heat sources in the testbed on point-spread-function (PSF) stability. Introducing a heat source primarily introduces image motion. The GPI error budget requires image motion to be less than 0.1 lambda /D. Systematic motion of the PSF core is typically 0.01 lambda /D rms and with a 20 watt heat source introduced near the pupil plane image motion is increased to 0.02 lambda /D rms. Therefore, even a heat source as large as 20 watts near the pupil plane causes errors below the GPI requirement, but the combination of the heat source and additional air turbulence on the system introduced by changes to the enclosure or the fan of other components can produce significantly more motion. Heat also can affect the speckle pattern in the high-contrast region, but in the final instrument other sources of error should be more significant. PMID:19582080

  9. The Dependence of Signal-To-Noise Ratio (S/N) Between Star Brightness and Background on the Filter Used in Images Taken by the Vulcan Photometric Planet Search Camera

    NASA Technical Reports Server (NTRS)

    Mena-Werth, Jose

    1998-01-01

    The Vulcan Photometric Planet Search is the ground-based counterpart of Kepler Mission Proposal. The Kepler Proposal calls for the launch of telescope to look intently at a small patch of sky for four year. The mission is designed to look for extra-solar planets that transit sun-like stars. The Kepler Mission should be able to detect Earth-size planets. This goal requires an instrument and software capable of detecting photometric changes of several parts per hundred thousand in the flux of a star. The goal also requires the continuous monitoring of about a hundred thousand stars. The Kepler Mission is a NASA Discovery Class proposal similar in cost to the Lunar Prospector. The Vulcan Search is also a NASA project but based at Lick Observatory. A small wide-field telescope monitors various star fields successively during the year. Dozens of images, each containing tens of thousands of stars, are taken any night that weather permits. The images are then monitored for photometric changes of the order of one part in a thousand. These changes would reveal the transit of an inner-orbit Jupiter-size planet similar to those discovered recently in spectroscopic searches. In order to achieve a one part in one thousand photometric precision even the choice of a filter used in taking an exposure can be critical. The ultimate purpose of an filter is to increase the signal-to-noise ratio (S/N) of one's observation. Ideally, filters reduce the sky glow cause by street lights and, thereby, make the star images more distinct. The higher the S/N, the higher is the chance to observe a transit signal that indicates the presence of a new planet. It is, therefore, important to select the filter that maximizes the S/N.

  10. Extrasolar planet detection

    NASA Technical Reports Server (NTRS)

    Korechoff, R. P.; Diner, D. J.; Tubbs, E. F.; Gaiser, S. L.

    1994-01-01

    This paper discusses the concept of extrasolar planet detection using a large-aperture infared imaging telescope. Coronagraphic stellar apodization techniques are less efficient at infrared wavelengths compared to the visible, as a result of practical limitations on aperture dimensions, thus necessitating additional starlight suppression to make planet detection feasible in this spectral domain. We have been investigating the use of rotational shearing interferometry to provide up to three orders of magnitude of starlight suppression over broad spectral bandwidths. We present a theoretical analysis of the system performance requirements needed to make this a viable instrument for planet detection, including specifications on the interferometer design and telescope aperture characteristics. The concept of using rotational shearing interferometry as a wavefront error detector, thus providing a signal that can be used to adaptively correct the wavefront, will be discussed. We also present the status of laboratory studies of on-axis source suppression using a recently constructed rotational shearing interferometer that currently operates in the visible.

  11. Planet Ocean

    NASA Astrophysics Data System (ADS)

    Afonso, Isabel

    2014-05-01

    A more adequate name for Planet Earth could be Planet Ocean, seeing that ocean water covers more than seventy percent of the planet's surface and plays a fundamental role in the survival of almost all living species. Actually, oceans are aqueous solutions of extraordinary importance due to its direct implications in the current living conditions of our planet and its potential role on the continuity of life as well, as long as we know how to respect the limits of its immense but finite capacities. We may therefore state that natural aqueous solutions are excellent contexts for the approach and further understanding of many important chemical concepts, whether they be of chemical equilibrium, acid-base reactions, solubility and oxidation-reduction reactions. The topic of the 2014 edition of GIFT ('Our Changing Planet') will explore some of the recent complex changes of our environment, subjects that have been lately included in Chemistry teaching programs. This is particularly relevant on high school programs, with themes such as 'Earth Atmosphere: radiation, matter and structure', 'From Atmosphere to the Ocean: solutions on Earth and to Earth', 'Spring Waters and Public Water Supply: Water acidity and alkalinity'. These are the subjects that I want to develop on my school project with my pupils. Geographically, our school is located near the sea in a region where a stream flows into the sea. Besides that, our school water comes from a borehole which shows that the quality of the water we use is of significant importance. This project will establish and implement several procedures that, supported by physical and chemical analysis, will monitor the quality of water - not only the water used in our school, but also the surrounding waters (stream and beach water). The samples will be collected in the borehole of the school, in the stream near the school and in the beach of Carcavelos. Several physical-chemical characteristics related to the quality of the water will be taken into consideration, for instance, the value of the pH, using universal indicator paper, color, through visual evaluation and the temperature with the help of a thermometer. There will be also registered some existent chemical parameters as chloride, alkalinity, total hardness (Ca2+ and Mg2+), nitrate, nitrite, ammonia and phosphate. Two methods will be used for analysis, the titration and the kit of semi-quantitative chemical analyses. This kit is composed by biocompatible substances, which means they are not harmful for the environment and can be disposed of by domestic sewage systems. The results will be subsequently analyzed bearing in mind the maximum and recommended standards values for each one of the parameters. After this, the results achieved will be discussed. I believe this project contains characteristics that will be of interest to our students, thus enabling them to participate actively and effectively develop their knowledge and enhance their scientific curiosity.

  12. A treatment procedure for Gemini North/NIFS data cubes: application to NGC 4151

    NASA Astrophysics Data System (ADS)

    Menezes, R. B.; Steiner, J. E.; Ricci, T. V.

    2014-03-01

    We present a detailed procedure for treating data cubes obtained with the Near-Infrared Integral Field Spectrograph (NIFS) of the Gemini North telescope. This process includes the following steps: correction of the differential atmospheric refraction, spatial re-sampling, Butterworth spatial filtering, `instrumental fingerprint' removal and Richardson-Lucy deconvolution. The clearer contours of the structures obtained with the spatial re-sampling, the high spatial-frequency noise removed with the Butterworth spatial filtering, the removed `instrumental fingerprints' (which take the form of vertical stripes along the images) and the improvement of the spatial resolution obtained with the Richardson-Lucy deconvolution result in images with a considerably higher quality. An image of the Br? emission line from the treated data cube of NGC 4151 allows the detection of individual ionized-gas clouds (almost undetectable without the treatment procedure) of the narrow-line region of this galaxy, which are also seen in an [O III] image obtained with the Hubble Space Telescope. The radial velocities determined for each one of these clouds seem to be compatible with models of biconical outflows proposed by previous studies. Considering the observed improvements, we believe that the procedure we describe in this work may result in more reliable analysis of data obtained with this instrument.

  13. Scientific and technical performance of GMOS: the Gemini Multi-Object Spectrograph

    NASA Astrophysics Data System (ADS)

    Crampton, David; Murowinski, Richard

    2004-09-01

    GMOS is the first telescope - spectrograph combination that acts as a complete system to deliver enhanced image quality and stability while simultaneously exploiting the large aperture of an 8m telescope. The entire system (optics, mechanics, software, detectors) was designed to take advantage of the best images that the Gemini telescopes produce while being extremely reliable and efficient. The built-in wavefront sensor allows the telescope to quickly point at an object, optimize its focus and then track it precisely for many hours (possibly over several nights) while maintaining perfect telescope and instrument focus and providing first order image compensation. As a result of the carefully-engineered design of its structure and mechanisms and its active flexure control system, GMOS offers unique scientific opportunities. A recent enhancement was the implementation of the "nod and shuffle" technique to give improved sky subtraction for very faint object spectroscopy. Some of the scientific highlights of GMOS' many modes (Imaging, MOS, IFU, precision velocities) are reviewed, and some of the "lessons-learned" during the first few years of operation are described.

  14. Spektral Fingerprint and UV environment of Habitable Planets

    NASA Astrophysics Data System (ADS)

    Kaltenegger, Lisa

    2015-12-01

    The fingerprint of a habitable planets changes with star type, stellar activity,and geological time. The changes determines if habitability can be detected on such planets, both in transmission and by direct imaging. We'll discuss the latest results and prioritization of planets for follow up observations with upcoming telescopes.

  15. Extrasolar planets Lecture 2: Planetary formation theory and

    E-print Network

    Parker, Quentin A.

    end up in close orbits ·These constitute the hot inner planets. #12;This near infrared HST image showsExtrasolar planets Lecture 2: Planetary formation theory and detection techniques Prof. Quentin A Parker ASTR178 - other worlds: planets and planetary systems 1 #12;Formation of a Star and proto

  16. The Microlensing Planet Finder: Completing the Census of Extrasolar Planets in the Milky Way

    E-print Network

    D. P. Bennett; I. Bond; E. Cheng; S. Friedman; P. Garnavich; B. Gaudi; R. Gilliland; A. Gould; M. Greenhouse; K. Griest; R. Kimble; J. Lunine; J. Mather; D. Minniti; M. Niedner; B. Paczynski; S. Peale; B. Rauscher; M. Rich; K. Sahu; D. Tenerelli; A. Udalski; N. Woolf; P. Yock

    2004-09-09

    The Microlensing Planet Finder (MPF) is a proposed Discovery mission that will complete the first census of extrasolar planets with sensitivity to planets like those in our own solar system. MPF will employ a 1.1m aperture telescope, which images a 1.3 sq. deg. field-of-view in the near-IR, in order to detect extrasolar planets with the gravitational microlensing effect. MPF's sensitivity extends down to planets of 0.1 Earth masses, and MPF can detect Earth-like planets at all separations from 0.7AU to infinity. MPF's extrasolar planet census will provide critical information needed to understand the formation and frequency of extra solar planetary systems similar to our own.

  17. High-contrast imaging of Sirius~A with VLT/SPHERE: Looking for giant planets down to one astronomical unit

    E-print Network

    Vigan, A; Salter, G; Mesa, D; Homeier, D; Moutou, C; Allard, F

    2015-01-01

    Sirius has always attracted a lot of scientific interest, especially after the discovery of a companion white dwarf at the end of the 19th century. Very early on, the existence of a potential third body was put forward to explain some of the observed properties of the system. We present new coronagraphic observations obtained with VLT/SPHERE that explore, for the very first time, the innermost regions of the system down to 0.2" (0.5 AU) from Sirius A. Our observations cover the near-infrared from 0.95 to 2.3 $\\mu$m and they offer the best on-sky contrast ever reached at these angular separations. After detailing the steps of our SPHERE/IRDIFS data analysis, we present a robust method to derive detection limits for multi-spectral data from high-contrast imagers and spectrographs. In terms of raw performance, we report contrasts of 14.3 mag at 0.2", ~16.3 mag in the 0.4-1.0" range and down to 19 mag at 3.7". In physical units, our observations are sensitive to giant planets down to 11 $M_{Jup}$ at 0.5 AU, 6-7 $...

  18. A bright future for direct planets & disks

    E-print Network

    Guyon, Olivier

    of Arizona SubaruTelescope #12;- understanding planetary systems formation & evolution - Planetary? phase function atmosphere variation ? Direct imaging dynamical model dynamical model Planet formation ... 2003-2006 Lossless apodization by aspheric optics. #12;PIAA optics - Diamond turning 13 #12

  19. Terrestrial Planet Geophysics

    NASA Astrophysics Data System (ADS)

    Phillips, R. J.

    2008-12-01

    Terrestrial planet geophysics beyond our home sphere had its start arguably in the early 1960s, with Keith Runcorn contending that the second-degree shape of the Moon is due to convection and Mariner 2 flying past Venus and detecting no planetary magnetic field. Within a decade, in situ surface geophysical measurements were carried out on the Moon with the Apollo program, portions of the lunar magnetic and gravity fields were mapped, and Jack Lorell and his colleagues at JPL were producing spherical harmonic gravity field models for Mars using tracking data from Mariner 9, the first spacecraft to orbit another planet. Moreover, Mariner 10 discovered a planetary magnetic field at Mercury, and a young Sean Solomon was using geological evidence of surface contraction to constrain the thermal evolution of the innermost planet. In situ geophysical experiments (such as seismic networks) were essentially never carried out after Apollo, although they were sometimes planned just beyond the believability horizon in planetary mission queues. Over the last three decades, the discipline of terrestrial planet geophysics has matured, making the most out of orbital magnetic and gravity field data, altimetric measurements of surface topography, and the integration of geochemical information. Powerful constraints are provided by tectonic and volcanic information gleaned from surface images, and the engagement of geologists in geophysical exercises is actually quite useful. Accompanying these endeavors, modeling techniques, largely adopted from the Earth Science community, have become increasingly sophisticated and have been greatly enhanced by the dramatic increase in computing power over the last two decades. The future looks bright with exciting new data sets emerging from the MESSENGER mission to Mercury, the promise of the GRAIL gravity mission to the Moon, and the re-emergence of Venus as a worthy target for exploration. Who knows? With the unflagging optimism and persistence of a few diehards, we may eventually have a seismic and heat flow network on Mars.

  20. Hubble Observes the Planet Uranus

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This NASA Hubble Space Telescope image of the planet Uranus reveals the planet's rings and bright clouds and a high altitude haze above the planet's south pole.

    Hubble's new view was obtained on August 14, 1994, when Uranus was 1.7 billion miles (2.8 billion kilometers) from Earth. These details, as imaged by the Wide Field Planetary Camera 2, were only previously seen by the Voyager 2 spacecraft, which flew by Uranus in 1986. Since then, none of these inner satellites has been further observed, and detailed observations of the rings have not been possible.

    Though Uranus' rings were discovered indirectly in 1977 (through stellar occultation observations), they have never before been seen in visible light through a ground-based telescope.

    Hubble resolves several of Uranus' rings, including the outermost Epsilon ring. The planet has a total of 11 concentric rings of dark dust. Uranus is tipped such that its rotation axis lies in the plane of its orbit, so the rings appear nearly face-on.

    Three of Uranus' inner moons each appear as a string of three dots at the bottom of the picture. This is because the picture is a composite of three images, taken about six minutes apart, and then combined to show the moons' orbital motions. The satellites are, from left to right, Cressida, Juliet, and Portia. The moons move much more rapidly than our own Moon does as it moves around the Earth, so they noticeably change position over only a few minutes.

    One of the four gas giant planets of our solar system, Uranus is largely featureless. HST does resolve a high altitude haze which appears as a bright 'cap' above the planet's south pole, along with clouds at southern latitudes (similar structures were observed by Voyager). Unlike Earth, Uranus' south pole points toward the Sun during part of the planet's 84-year orbit. Thanks to its high resolution and ability to make observations over many years, Hubble can follow seasonal changes in Uranus's atmosphere, which should be unusual given the planet's large tilt.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  1. Diamond Turned High Precision PIAA Optics and Four Mirror PIAA System for High Contrast Imaging of Exo-planets

    NASA Technical Reports Server (NTRS)

    Balasubramanian, Kunjithapatham; Cady, Eric; Pueyo, Laurent; Ana, Xin; Shaklan, Stuart; Guyon, Olivier; Belikov, Ruslan

    2011-01-01

    Off-axis, high-sag PIAA optics for high contrast imaging present challenges in manufacturing and testing. With smaller form factors and consequently smaller surface deformations (< 80 microns), diamond turned fabrication of these mirrors becomes feasible. Though such a design reduces the system throughput, it still provides 2(lambda)D inner working angle. We report on the design, fabrication, measurements, and initial assessment of the novel PIAA optics in a coronagraph testbed. We also describe, for the first time, a four mirror PIAA coronagraph that relaxes apodizer requirements and significantly improves throughput while preserving the low-cost benefits.

  2. The Gemini Instrument Program D. A. Simons, F. C. Gillett, J. M. Oschmann, C. M. Mountain, R. Nolan

    E-print Network

    The Gemini Instrument Program D. A. Simons, F. C. Gillett, J. M. Oschmann, C. M. Mountain, R. Nolan Instrument Program Douglas A. Simons, Fred Gillett, Jim Oschmann, Matt Mountain, Robert Nolan Gemini

  3. Extreme Exoplanet Direct Imaging: New Results with GPI and SCExAO and the Path to Imaging Another Earth

    NASA Astrophysics Data System (ADS)

    Currie, Thayne

    2015-12-01

    We describe the discovery of a bright, young Kuiper belt-like debris disk around HD 115600, a ˜ 1.4--1.5 M_{?}, ˜ 15 Myr old member of the Sco-Cen OB Association. Our H-band coronagraphy/integral field spectroscopy from the Gemini Planet Imager shows the ring has a (luminosity scaled) semi major axis of (˜ 22 AU) ˜ 48 AU, similar to the current Kuiper belt. The disk appears to have neutral scattering dust, is eccentric (e ˜ 0.1--0.2), and could be sculpted by analogues to the outer solar system planets. Spectroscopy of the disk ansae reveal a slightly blue to gray disk color, consistent with major Kuiper belt chemical constituents, where water-ice is a very plausible dominant constituent. Besides being the first object discovered with the next generation of extreme adaptive optics systems (i.e. SCExAO, GPI, SPHERE), HD 115600's debris ring and planetary system provides a key reference point for the early evolution of the solar system, the structure and composition of the Kuiper belt, and the interaction between debris disks and planets.

  4. THE DIRECTLY IMAGED PLANET AROUND THE YOUNG SOLAR ANALOG 1RXS J160929.1 - 210524: CONFIRMATION OF COMMON PROPER MOTION, TEMPERATURE, AND MASS

    SciTech Connect

    Lafreniere, David; Jayawardhana, Ray; Van Kerkwijk, Marten H.

    2010-08-10

    Giant planets are usually thought to form within a few tens of AU of their host stars, and hence it came as a surprise when we found what appeared to be a planetary mass ({approx}0.008 M {sub sun}) companion around the 5 Myr old solar mass star 1RXS J160929.1 - 210524 in the Upper Scorpius association. At the time, we took the object's membership in Upper Scorpius-established from near-infrared, H- and K-band spectroscopy-and its proximity (2.''2 or 330 AU) to the primary as strong evidence for companionship, but could not verify their common proper motion. Here, we present follow-up astrometric measurements that confirm that the companion is indeed comoving with the primary star, which we interpret as evidence that it is a truly bound planetary mass companion. We also present new J-band spectroscopy and 3.0-3.8 {mu}m photometry of the companion. Based on a comparison with model spectra, these new measurements are consistent with the previous estimate of the companion effective temperature of 1800 {+-} 200 K. We present a new estimate of the companion mass based on evolution models and the calculated bolometric luminosity of the companion; we obtain a value of 0.008{sup +0.003} {sub -0.002} M {sub sun}, again consistent with our previous result. Finally, we present angular differential imaging observations of the system allowing us to rule out additional planets in the system more massive than 1 M {sub Jup}, 2 M {sub Jup}, and 8 M {sub Jup} at projected separations larger than 3'' ({approx}440 AU), 0.''7 ({approx}100 AU), and 0.''35 ({approx}50 AU), respectively. This companion is the least massive known to date at such a large orbital distance; it shows that objects in the planetary mass range exist at orbital separations of several hundred AU, posing a serious challenge for current formation models.

  5. Characterizing Transiting Exoplanet Atmospheres with Gemini/GMOS: First Results

    NASA Astrophysics Data System (ADS)

    Huitson, Catherine; Desert, Jean-Michel; Bean, Jacob; Fortney, Jonathan J.; Stevenson, Kevin B.; Bergmann, Marcel

    2015-01-01

    We present the first results from a 4-year ground-based survey of nine transiting exoplanet atmospheres. The program uses the Multi-Object Spectrograph (GMOS) on both Gemini north and south to repetitively measure transit lightcurves of individual exoplanets at high spectrophotometric precision. I will present the first results from this program. We attain photometric precisions per spectral bin of 200-600 ppm. Such precision enables us to construct transmission spectra of hot Jupiters. These transmission spectra reveal the dominant upper-atmosphere absorbers in the optical bandpass. Our overarching goal is to understand the prevalence and formation of high altitude clouds and hazes, and other important atmospheric constituents.

  6. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS

    SciTech Connect

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2009-07-10

    We study the final architecture of planetary systems that evolve under the combined effects of planet-planet and planetesimal scattering. Using N-body simulations we investigate the dynamics of marginally unstable systems of gas and ice giants both in isolation and when the planets form interior to a planetesimal belt. The unstable isolated systems evolve under planet-planet scattering to yield an eccentricity distribution that matches that observed for extrasolar planets. When planetesimals are included the outcome depends upon the total mass of the planets. For M {sub tot} {approx}> 1 M{sub J} the final eccentricity distribution remains broad, whereas for M {sub tot} {approx}< 1 M{sub J} a combination of divergent orbital evolution and recircularization of scattered planets results in a preponderance of nearly circular final orbits. We also study the fate of marginally stable multiple planet systems in the presence of planetesimal disks, and find that for high planet masses the majority of such systems evolve into resonance. A significant fraction leads to resonant chains that are planetary analogs of Jupiter's Galilean satellites. We predict that a transition from eccentric to near-circular orbits will be observed once extrasolar planet surveys detect sub-Jovian mass planets at orbital radii of a {approx_equal} 5-10 AU.

  7. Gemini 8 spacecraft hoisted aboard the U.S.S. Leonard F. Mason

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The Gemini 8 spacecraft, with Astronauts Neil A. Armstrong and David R. Scott still aboard, is hoisted aboard the destroyer U.S.S. Leonard F. Mason. Trouble with the Gemini 8 Orbit Attitude and Maneuvering System (OAMS) forced an early termination of the mission.

  8. Design considerations of the AO module for the Gemini South multi-conjugate adaptive optics system

    E-print Network

    Design considerations of the AO module for the Gemini South multi-conjugate adaptive optics system Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 B. Optical Design Service, 8 S. Bella Vista Drive, Tucson optics system E. Jamesa , C. Boyera , R. A. Buchroederb , B.L. Ellerbroeka , M. Huntena a Gemini

  9. Gemini 10 spacecraft touches down in the Atlantic Ocean at end of mission

    NASA Technical Reports Server (NTRS)

    1966-01-01

    The Gemini 10 space flight is concluded as the Gemini 10 spacecraft, with Astronauts John Young and Michael Collins aboard, touches down in the Atlantic about 4 miles from the prime recovery ship, the U.S.S. Guadalcanal. In this view, the spacecrafts parachute is still deployed as it hits the water.

  10. Preliminary results of the 2001-2002 Gemini sodium monitoring campaign at Cerro Tololo, Chile

    E-print Network

    Preliminary results of the 2001-2002 Gemini sodium monitoring campaign at Cerro Tololo, Chile, SE-22100 Lund, Sweden D. Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile E. Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena, Chile #12;Preliminary

  11. The properties of the planet(s) around Beta Pictoris

    NASA Astrophysics Data System (ADS)

    Bonnefoy, M.

    2014-09-01

    Since the discovery of the Beta Pictoris dust system in the 80s, the detailed study of the disk and the discovery of the falling evaporating bodies phenomenon around this star provided a growing evidence that the system was hosting, at least, on gas giant planet. In 2009, Lagrange et al. identified in VLT/NaCo high resolution imaging data a candidate planet located at a projected separation of 9 AU in the disk of Beta Pictoris. Since then, follow-up images of the system obtained with various instruments from 0.98 m to 4.8 m enabled to confirm that Beta Pic b is circling the star on a low-eccentricity orbit, has a mass of ~7-13 MJup, and a hot (Teff 1700 K) dusty atmosphere. The determination of Beta Pic b's orbital motion and spectro-photometric properties, the radial velocity (RV) measurements of the star, and the detailed study of disk structures offer altogether a unique chance to characterize the chemical and physical properties of a directly imaged planet, and to understand in detail how it formed and influenced the system architecture. In this talk, I will review the past and ongoing efforts to characterize the properties of Beta Pictoris b, and to find additional planets in the system.

  12. Detecting companions to extrasolar planets using mutual events

    E-print Network

    J. Cabrera; J. Schneider

    2007-03-23

    We investigate a new approach to the detection of companions to extrasolar planets beyond the transit method. We discuss the possibility of the existence of binary planets. We develop a method based on the imaging of a planet-companion as an unresolved system (but resolved from its parent star). It makes use of planet-companion mutual phenomena, namely mutual transits and mutual shadows. We show that companions can be detected and their radius measured down to lunar sizes.

  13. Magellan Adaptive Optics first-light observations of the exoplanet beta Pic b. II. 3-5 micron direct imaging with MagAO+Clio, and the empirical bolometric luminosity of a self-luminous giant planet

    E-print Network

    Morzinski, Katie M; Skemer, Andy J; Close, Laird M; Hinz, Phil M; Rodigas, T J; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Bailey, Vanessa P; Follette, Katherine B; Kopon, Derek; Weinberger, Alycia J; Wu, Ya-Lin

    2015-01-01

    Young giant exoplanets are a unique laboratory for understanding cool, low-gravity atmospheres. A quintessential example is the massive extrasolar planet $\\beta$ Pic b, which is 9 AU from and embedded in the debris disk of the young nearby A6V star $\\beta$ Pictoris. We observed the system with first light of the Magellan Adaptive Optics (MagAO) system. In Paper I we presented the first CCD detection of this planet with MagAO+VisAO. Here we present four MagAO+Clio images of $\\beta$ Pic b at 3.1 $\\mu$m, 3.3 $\\mu$m, $L^\\prime$, and $M^\\prime$, including the first observation in the fundamental CH$_4$ band. To remove systematic errors from the spectral energy distribution (SED), we re-calibrate the literature photometry and combine it with our own data, for a total of 22 independent measurements at 16 passbands from 0.99--4.8 $\\mu$m. Atmosphere models demonstrate the planet is cloudy but are degenerate in effective temperature and radius. The measured SED now covers $>$80\\% of the planet's energy, so we approach ...

  14. HUBBLE OBSERVES THE PLANET URANUS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This NASA Hubble Space Telescope image of the planet Uranus reveals the planet's rings and bright clouds and a high altitude haze above the planet's south pole. Hubble's new view was obtained on August 14, 1994, when Uranus was 1.7 billion miles (2.8 billion kilometers) from Earth. These details, as imaged by the Wide Field Planetary Camera 2, were only previously seen by the Voyager 2 spacecraft, which flew by Uranus in 1986. Since then, none of these inner satellites has been further observed, and detailed observations of the rings have not been possible. Though Uranus' rings were discovered indirectly in 1977 (through stellar occultation observations), they have never before been seen in visible light through a ground-based telescope. Hubble resolves several of Uranus' rings, including the outermost Epsilon ring. The planet has a total of 11 concentric rings of dark dust. Uranus is tipped such that its rotation axis lies in the plane of its orbit, so the rings appear nearly face-on. Three of Uranus' inner moons each appear as a string of three dots at the bottom of the picture. This is because the picture is a composite of three images, taken about six minutes apart, and then combined to show the moons' orbital motions. The satellites are, from left to right, Cressida, Juliet, and Portia. The moons move much more rapidly than our own Moon does as it moves around the Earth, so they noticeably change position over only a few minutes. One of the four gas giant planets of our solar system, Uranus is largely featureless. HST does resolve a high altitude haze which appears as a bright 'cap' above the planet's south pole, along with clouds at southern latitudes (similar structures were observed by Voyager). Unlike Earth, Uranus' south pole points toward the Sun during part of the planet's 84-year orbit. Thanks to its high resolution and ability to make observations over many years, Hubble can follow seasonal changes in Uranus's atmosphere, which should be unusual given the planet's large tilt. Credit: Kenneth Seidelmann, U.S. Naval Observatory, and NASA These observations were conducted by a team led by Dr. Ken Seidelmann of the U.S. Naval Observatory as Principal Investigator. These images have been processed by Professor Douglas Currie and Mr. Dan Dowling in the Department of Physics at the University of Maryland. Other team members are Dr. Ben Zellner at Georgia Southern University, Dr. Dan Pascu and Mr. Jim Rhode at the U.S. Naval Observatory, and Dr. Ed Wells, Mr. Charles Kowal (Computer Science Corporation) and Dr. Alex Storrs of the Space Telescope Science Institute.

  15. OBSERVATIONS OF BINARY STARS WITH THE DIFFERENTIAL SPECKLE SURVEY INSTRUMENT. IV. OBSERVATIONS OF KEPLER, CoRoT, AND HIPPARCOS STARS FROM THE GEMINI NORTH TELESCOPE

    SciTech Connect

    Horch, Elliott P.; Howell, Steve B.; Everett, Mark E.; Ciardi, David R. E-mail: steve.b.howell@nasa.gov E-mail: ciardi@ipac.caltech.edu

    2012-12-01

    We present the results of 71 speckle observations of binary and unresolved stars, most of which were observed with the DSSI speckle camera at the Gemini North Telescope in 2012 July. The main purpose of the run was to obtain diffraction-limited images of high-priority targets for the Kepler and CoRoT missions, but in addition, we observed a number of close binary stars where the resolution limit of Gemini was used to better determine orbital parameters and/or confirm results obtained at or below the diffraction limit of smaller telescopes. Five new binaries and one triple system were discovered, and first orbits are calculated for other two systems. Several systems are discussed in detail.

  16. High-Contrast 3.8 Micron Imaging Of The Brown Dwarf/Planet-Mass Companion to GJ 758

    E-print Network

    Currie, Thayne; Fabrycky, Daniel; Murray-Clay, Ruth; Rodigas, Timothy; Hinz, Phil

    2010-01-01

    We present L' band (3.8 $\\mu m$) MMT/Clio high-contrast imaging data for the nearby star GJ 758, which was recently reported by Thalmann et al. (2009) to have one -- possibly two-- faint comoving companions (GJ 758B and ``C", respectively). GJ 758B is detected in two distinct datasets. Additionally, we report a \\textit{possible} detection of the object identified by Thalmann et al as ``GJ 758C" in our more sensitive dataset, though it is likely a residual speckle. However, if it is the same object as that reported by Thalmann et al. it cannot be a companion in a bound orbit. GJ 758B has a H-L' color redder than nearly all known L--T8 dwarfs. Based on comparisons with the COND evolutionary models, GJ 758B has T$_{e}$ $\\sim$ 560 K$^{^{+150 K}_{-90K}}$ and a mass ranging from $\\sim$ 10--20 M$_{J}$ if it is $\\sim$ 1 Gyr old to $\\sim$ 25--40 M$_{J}$ if it is 8.7 Gyr old. GJ 758B is likely in a highly eccentric orbit, e $\\sim$ 0.73$^{^{+0.12}_{-0.21}}$, with a semimajor axis of $\\sim$ 44 AU$^{^{+32 AU}_{-14 AU}}$. ...

  17. VR-Planets : a 3D immersive application for real-time flythrough images of planetary surfaces

    NASA Astrophysics Data System (ADS)

    Civet, François; Le Mouélic, Stéphane

    2015-04-01

    During the last two decades, a fleet of planetary probes has acquired several hundred gigabytes of images of planetary surfaces. Mars has been particularly well covered thanks to the Mars Global Surveyor, Mars Express and Mars Reconnaissance Orbiter spacecrafts. HRSC, CTX, HiRISE instruments allowed the computation of Digital Elevation Models with a resolution from hundreds of meters up to 1 meter per pixel, and corresponding orthoimages with a resolution from few hundred of meters up to 25 centimeters per pixel. The integration of such huge data sets into a system allowing user-friendly manipulation either for scientific investigation or for public outreach can represent a real challenge. We are investigating how innovative tools can be used to freely fly over reconstructed landscapes in real time, using technologies derived from the game industry and virtual reality. We have developed an application based on a game engine, using planetary data, to immerse users in real martian landscapes. The user can freely navigate in each scene at full spatial resolution using a game controller. The actual rendering is compatible with several visualization devices such as 3D active screen, virtual reality headsets (Oculus Rift), and android devices.

  18. Integral field spectroscopy with the GEMINI multi-object spectrographs

    NASA Astrophysics Data System (ADS)

    Allington-Smith, Jeremy R.; Content, Robert; Dodsworth, George N.; Murray, Graham J.; Ren, Deqing; Robertson, David J.; Turner, James E.; Webster, John

    2000-08-01

    The GEMINI Multiobject Spectrograph (GMOS), due for delivery in late 2000, will include a powerful integral field spectroscopic capability. The instrument scan switch to this mode by the remote insertion of an integral field unit (IFU) into the focal plane in place of multiobject masks. The initial implementation of the GMOS IFU will cover a field in excess of 50 square arcsec with a sampling of 0.2 arcsec via 1500 spatial elements with spectra covering up to 3000 pixels. The spectrum length may also be doubled by halving the field. A separate field is provided at fixed offset to facilitate accurate background subtraction. The system employs a fiber-lenslet technique that provides significant benefits over unlensed fiber reformatters and fiberless lenslet arrays. The specific advantages are unit filling factor, high throughput and long spectra. The IFU has been designed in the light of our experience with two other successful devices of this type. We summarize the design of the device and discuss how the IFU will be operated within the context of GMOS and the GEMINI telescopes. Finally, we present options for implementing IFUs with finer spatial resolution on GMOS.

  19. Polycontinuous Lyotropic Liquid Crystalline Network Phases from Gemini Dicarboxylate Surfactants

    NASA Astrophysics Data System (ADS)

    Mahanthappa, Mahesh; Sorenson, Gregory; Schmitt, Adam

    2015-03-01

    Arising from the water concentration-dependent self-assembly of amphiphilic molecules, lyotropic liquid crystals (LLCs) form a wide variety of structurally periodic nanoscale morphologies including discontinuous micellar phases (I), hexagonally-packed cylinders (C), and lamellar (L) phases. In intermediate amphiphile concentration windows between the L and C phases, one typically observes three bicontinuous cubic network phases: gyroid (G), diamond (D), and primitive (P). Recent theoretical work has suggested the possible stability of a variety of non-cubic network phase LLCs, yet none of these phases have been previously observed. In this presentation, we describe the experimental discovery of the first triply periodic network phase LLC with 3D-hexagonal symmetry (space group #193) in binary mixtures of water with a simple gemini dicarboxylate surfactant based on dodecanoic acid. Using a combination of SAXS and rheological methods, we structurally characterize this new phase and show that it is comprised of three interpenetrating lipidic networks of 3-fold connectors in a matrix of water. This finding highlights the unusual aqueous phase behavior of gemini surfactants and suggests new methods for discovering and stabilizing new network phase LLCs beyond the gyroid.

  20. The Gemini MCAO bench: system overview and lab integration

    NASA Astrophysics Data System (ADS)

    Bec, Matthieu; Rigaut, Francois J.; Galvez, Ramon; Arriagada, Gustavo; Boccas, Maxime; Gausachs, Gaston; Gratadour, Damien; James, Eric; Rojas, Roberto; Rogers, Rolando; Sheehan, Michael P.; Trancho, Gelys; Vucina, Tomislav

    2008-07-01

    We present Canopus, the AO bench for Gemini's Multi Conjugate Adaptive Optics System (GEMS), a unique facility for the Gemini South telescope located at Cerro Pachon in Chile. The MCAO system uses five laser beacons in conjunction with different natural guide stars configurations. A deployable fold mirror located in the telescope Acquisition and Guiding Unit (A&G) sends the telescope beam to the entrance of the bench. The beam is split within Canopus into three main components: two sensing paths and the output corrected science beam. Light from the laser constellation (589nm) is directed to five Shack-Hartman wave front sensors (E2V-39 CCDs read at 800Hz). Visible light from natural guide stars is sent to three independent sensors arrays (SCPM AQ4C Avalanche Photodiodes modules in quad cell arrangement) via optical fibers mounted on independent stages and a slow focus sensor (E2V-57 back-illuminated CCD). The infrared corrected beam exits Canopus and goes to instrumentation for science. The Real Time Controller (RTC) analyses wavefront signals and correct distortions using a fast tip-tilt mirror and three deformable mirrors conjugated at different altitudes. The RTC also adjusts positioning of the laser beacon (Beam Transfer Optics fast steering array), and handles miscellaneous offloads (M1 figure, M2 tip/tilt, LGS zoom and magnification corrections, NGS probes adjustments etc.). Background optimizations run on a separate dedicated server to feed new parameters into the RTC.

  1. Dance of the Planets

    ERIC Educational Resources Information Center

    Riddle, Bob

    2005-01-01

    As students continue their monthly plotting of the planets along the ecliptic they should start to notice differences between inner and outer planet orbital motions, and their relative position or separation from the Sun. Both inner and outer planets have direct eastward motion, as well as retrograde motion. Inner planets Mercury and Venus,…

  2. Characterizing K2 Planet Discoveries

    NASA Astrophysics Data System (ADS)

    Vanderburg, Andrew; Montet, Benjamin; Johnson, John; Buchhave, Lars A.; Zeng, Li; Bieryla, Allyson; Latham, David W.; Charbonneau, David; Harps-N Collaboration, The Robo-Ao Team

    2015-01-01

    We present an effort to confirm the first planet discovered by the two-wheeled Kepler mission. We analyzed K2 photometry, correcting for nonuniform detector response as a function of the spacecraft's pointing, and detected a transiting planet candidate. We describe our multi-telescope followup observing campaign, consisting of photometric, spectroscopic, and high resolution imaging observations, including over 40 HARPS-N radial velocity measurements. The new planet is a super-Earth orbiting a bright star amenable to followup observations. HARPS-N was funded by the Swiss Space Office, the Harvard Origin of Life Initiative, the Scottish Universities Physics Alliance, the University of Geneva, the Smithsonian Astrophysical Observatory, the Italian National Astrophysical Institute, the University of St. Andrews, Queens University Belfast, and the University of Edinburgh.

  3. An Optical/UV Space Coronagraph Concept for the Terrestrial Planet Finder

    E-print Network

    Vanderbei, Robert J.

    ), by the middle of the next decade; it will search for terrestrial planets in the habitable zone of roughly 150 observatory with the ability to image extrasolar earthlike planets, that is, planets within the habitable survey 150 F, G, and K stars for the existence of terrestrial planets within the habitable zones

  4. Seeing the Universe in 3D: First Demonstration Science Results from CIRPASS and GMOS on Gemini Integral Field Spectrographs

    NASA Astrophysics Data System (ADS)

    Bunker, A. J.; Smith, J. K.; Bower, R. G.; Cambridge CIRPASS Team; Durham/Gemini-Observatory GMOS Team

    2002-12-01

    Area spectroscopy has significant advantages over both traditional imaging and long-slit spectroscopy: it is more efficient in observing time, and yields substantially more information. Through Integral Field Units, area spectroscopy is becoming an essential part of new facility instruments on the latest large telescopes. We have recently carried out the first integral field spectroscopy of high redshift galaxies with an 8-m telescope. These observations were part of an international demonstration science program with Gemini Observatory lead by the Institute of Astronomy, Cambridge, and the University of Durham. In June 2002 we used the optical Gemini Multi-Object Spectrograph (GMOS) on Gemini-North in IFU mode (Allington-Smith et al. 2002, PASP 114, 892). GMOS has a fibre-fed IFU with a 1000 lenslet array covering an area of 5"x7" with 0.2"-diameter lenslets and with a wavelength range of 0.4-1 microns. In August 2002 we commissioned the new near-infrared IFU CIRPASS (Cambridge IR Panoramic Survey Spectrograph, Parry et al. 2000, SPIE 4008, 1193) on Gemini-South. CIRPASS is a fibre-fed spectrograph with a 490 lenslet array covering an area of up to 5"x12" with the 0.36" lenslet scale. CIRPASS operates in the J- and H-bands (1-1.7microns). For both CIRPASS and GMOS we used high resolution gratings with a resolving power of R=4000 (75 km/s FWHM) enabling us to work efficiently between the sky lines: the redshifts of our targets were chosen to have emission lines in "clean" regions of the night sky spectrum. We covered a wide range of targets and science goals, including the nature of high-redshift damped Lyman-alpha absorption systems (see Bunker et al. 2001, astro-ph/0011421) and the star formation and kinematics of high-redshift galaxies. Here we focus on some preliminary results from "3D" spectroscopy of z? 1 objects, mapping the emission lines in a 3CR radio galaxy and in a gravitationally lensed arc.

  5. Anybody out there ?Anybody out there ? Imaging exoplanetsImaging exoplanets

    E-print Network

    Guyon, Olivier

    habitable planet First potentially habitable planets now identified #12;#12;Directly imaging planet is necessary to find life We need to take spectra of habitable planets Spectra of Earth (taken by looking opportunities Next generation of large telescopes on the ground will be able to image habitable planets around

  6. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    NASA Astrophysics Data System (ADS)

    Marcy, Geoffrey W.; Isaacson, Howard; Howard, Andrew W.; Rowe, Jason F.; Jenkins, Jon M.; Bryson, Stephen T.; Latham, David W.; Howell, Steve B.; Gautier, Thomas N., III; Batalha, Natalie M.; Rogers, Leslie; Ciardi, David; Fischer, Debra A.; Gilliland, Ronald L.; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen; Huber, Daniel; Chaplin, William J.; Basu, Sarbani; Buchhave, Lars A.; Quinn, Samuel N.; Borucki, William J.; Koch, David G.; Hunter, Roger; Caldwell, Douglas A.; Van Cleve, Jeffrey; Kolbl, Rea; Weiss, Lauren M.; Petigura, Erik; Seager, Sara; Morton, Timothy; Johnson, John Asher; Ballard, Sarah; Burke, Chris; Cochran, William D.; Endl, Michael; MacQueen, Phillip; Everett, Mark E.; Lissauer, Jack J.; Ford, Eric B.; Torres, Guillermo; Fressin, Francois; Brown, Timothy M.; Steffen, Jason H.; Charbonneau, David; Basri, Gibor S.; Sasselov, Dimitar D.; Winn, Joshua; Sanchis-Ojeda, Roberto; Christiansen, Jessie; Adams, Elisabeth; Henze, Christopher; Dupree, Andrea; Fabrycky, Daniel C.; Fortney, Jonathan J.; Tarter, Jill; Holman, Matthew J.; Tenenbaum, Peter; Shporer, Avi; Lucas, Philip W.; Welsh, William F.; Orosz, Jerome A.; Bedding, T. R.; Campante, T. L.; Davies, G. R.; Elsworth, Y.; Handberg, R.; Hekker, S.; Karoff, C.; Kawaler, S. D.; Lund, M. N.; Lundkvist, M.; Metcalfe, T. S.; Miglio, A.; Silva Aguirre, V.; Stello, D.; White, T. R.; Boss, Alan; Devore, Edna; Gould, Alan; Prsa, Andrej; Agol, Eric; Barclay, Thomas; Coughlin, Jeff; Brugamyer, Erik; Mullally, Fergal; Quintana, Elisa V.; Still, Martin; Thompson, Susan E.; Morrison, David; Twicken, Joseph D.; Désert, Jean-Michel; Carter, Josh; Crepp, Justin R.; Hébrard, Guillaume; Santerne, Alexandre; Moutou, Claire; Sobeck, Charlie; Hudgins, Douglas; Haas, Michael R.; Robertson, Paul; Lillo-Box, Jorge; Barrado, David

    2014-02-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm-3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R ?. Larger planets evidently contain a larger fraction of low-density material (H, He, and H2O). Based in part on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology.

  7. The Gemini Science User Support Department: A community-centered approach to user support

    NASA Astrophysics Data System (ADS)

    Chené, André-Nicolas; Thomas-Osip, Joanna

    2016-01-01

    The Gemini Science User Support Department (SUSD) was formed a little more than a year ago to create a collaborative community of users and staff and to consolidate existing post-observing support throughout the observatory for more efficient use of resources as well as better visibility amongst our user community. This poster is an opportunity to exchange ideas about how Gemini can improve your experience while working with the Observatory and present details about new avenues of post-observing support coming soon. We encourage your feedback at any time.Shortly after its creation, the SUSD conducted a complete revision of the communication cycle between Gemini and its community of researchers. The cycle was then revisited from the perspective of an astronomer interested in using Gemini for their research. This exercise led to a series of proposed changes that are currently under development, and the implementation of a sub-selection is expected in 2016, including the following. (1) Email notifications: Gemini users will receive new forms of email communications that are more instructive and tailored to their program. The objective is to direct the users more efficiently toward the useful links and documentation all along the lifecycle of the program, from phaseII to after the data are completely reduced. (2) HelpDesk system: The HelpDesk will become more user-friendly and transparent. (3) Webpages: The organization of the Gemini webpages will be redesigned to optimize navigation; especially for anything regarding more critical periods likes phaseIs and phaseIIs. (4) Data Reduction User Forum: Following recommendations from Gemini users, new capabilities were added to the forum, like email notifications, and a voting system, in order to make it more practical. This forum's objective is to bring the Gemini community together to exchange their ideas, thoughts, questions and solutions about data reduction, a sort of Reddit, StackOverflow or Slashdot for Gemini data.

  8. Exo-planet Direct Imaging with On-Axis and/or Segmented Apertures in Space: Adaptive Compensation of Aperture Discontinuities

    NASA Astrophysics Data System (ADS)

    Soummer, Remi

    Capitalizing on a recent breakthrough in wavefront control theory for obscured apertures made by our group, we propose to demonstrate a method to achieve high contrast exoplanet imaging with on-axis obscured apertures. Our new algorithm, which we named Adaptive Compensation of Aperture Discontinuities (ACAD), provides the ability to compensate for aperture discontinuities (segment gaps and/or secondary mirror supports) by controlling deformable mirrors in a nonlinear wavefront control regime not utilized before but conceptually similar to the beam reshaping used in PIAA coronagraphy. We propose here an in-air demonstration at 1E- 7 contrast, enabled by adding a second deformable mirror to our current test-bed. This expansion of the scope of our current efforts in exoplanet imaging technologies will enabling us to demonstrate an integrated solution for wavefront control and starlight suppression on complex aperture geometries. It is directly applicable at scales from moderate-cost exoplanet probe missions to the 2.4 m AFTA telescopes to future flagship UVOIR observatories with apertures potentially 16-20 m. Searching for nearby habitable worlds with direct imaging is one of the top scientific priorities established by the Astro2010 Decadal Survey. Achieving this ambitious goal will require 1e-10 contrast on a telescope large enough to provide angular resolution and sensitivity to planets around a significant sample of nearby stars. Such a mission must of course also be realized at an achievable cost. Lightweight segmented mirror technology allows larger diameter optics to fit in any given launch vehicle as compared to monolithic mirrors, and lowers total life-cycle costs from construction through integration & test, making it a compelling option for future large space telescopes. At smaller scales, on-axis designs with secondary obscurations and supports are less challenging to fabricate and thus more affordable than the off-axis unobscured primary mirror designs envisioned in many past mission concept studies. But until recently, it was believed that internal coronagraphs were incapable of yielding very high contrast on segmented or obscured telescopes. Recent developments now show that there is in fact a clear path to high contrast coronagraphy on such apertures. For the past several years we have been pursuing high contrast imaging development for segmented telescopes, supported in part by APRA (award NNX12AG05G, ROSES 2011). The ACAD algorithm, developed in the course of our current APRA, in principle appears to enable high contrast coronagraphy on obscured apertures as we set out to achieve. The practical laboratory demonstration of this new algorithm now requires additional resources not foreseen at the time of our prior proposal. Chief of these is the need for a second Boston Micromachines deformable mirror. The ACAD algorithm relies on the conversion of phase to amplitude as light propagates between two deformable mirrors at differing optical conjugates; a second DM is absolutely essential to its laboratory demonstration and validation. We propose now to demonstrate the ACAD algorithm in air at a contrast of ~1e-7 in narrow spectral bands, and extend that performance through development of broad band ~ 20%) optimization methods. Note that this proposal is a proper subset of an alternative proposal submitted to SAT-TDEM by our team that would also include additional higher TRL demonstrations.

  9. Extrasolar Carbon Planets

    E-print Network

    Marc J. Kuchner; S. Seager

    2005-05-02

    We suggest that some extrasolar planets planets and low-mass white dwarf planets are especially good candidate members of this new class of planets, but these objects could also conceivably form around stars like the Sun. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk's C/O ratio above solar, a condition that pileups of carbonaceous grains may create in ordinary protoplanetary disks. Hot, Neptune-mass carbon planets should show a significant paucity of water vapor in their spectra compared to hot planets with solar abundances. Cooler, less massive carbon planets may show hydrocarbon-rich spectra and tar-covered surfaces. The high sublimation temperatures of diamond, SiC, and other carbon compounds could protect these planets from carbon depletion at high temperatures.

  10. High gene delivery efficiency of alkylated low-molecular-weight polyethylenimine through gemini surfactant-like effect

    PubMed Central

    Liu, Shan; Huang, Wei; Jin, Ming-Ji; Wang, Qi-Ming; Zhang, Gan-Lin; Wang, Xiao-Min; Shao, Shuai; Gao, Zhong-Gao

    2014-01-01

    To our knowledge, the mechanism underlying the high transfection efficiency of alkylated low-molecular-weight polyethylenimine (PEI) is not yet well understood. In this work, we grafted branched PEI (molecular weight of 1,800 Da; bPEI1800) with lauryl chains (C12), and found that bPEI1800-C12 was structurally similar to gemini surfactant and could similarly assemble into micelle-like particles. Stability, cellular uptake, and lysosome escape ability of bPEI1800-C12/DNA polyplexes were all greatly enhanced after C12 grafting. bPEI1800-C12/DNA polyplexes exhibited significantly higher transfection efficiency than Lipofectamine™ 2000 in the presence of serum. Bioluminescence imaging showed that systemic injection of bPEI1800-C12/DNA polyplexes resulted in intensive luciferase expression in vivo and bioluminescence signals that could be detected even in the head. Altogether, the high transfection efficacy of bPEI1800-C12 was because bPEI1800-C12, being an analog of gemini surfactant, facilitated lysosome escape and induced the coil–globule transition of DNA to assemble into a highly organized micelle-like structure that showed high stability. PMID:25114526

  11. A two deformable-mirror concept to improve the laser efficiency of Gemini South MCAO (GeMS)

    NASA Astrophysics Data System (ADS)

    Béchet, Clémentine; Guesalaga, Andrés; Neichel, Benoit; Fesquet, Vincent; Guzman, Dani

    2013-12-01

    Gem's is the first laser-based multi-conjugate adaptive optics offeredto the astronomical community. Its asterism of 5 laser guide stars hasrecently proved to provide very uniform turbulence correction over the85''x85'' observation field, opening the new era of wide-field highangular resolution studies from the ground. Good AO performance requireshowever good wavefront sensing measurements from the laser guide stars,which directly depends on the quality of the laser spot image. Theoptimization of the lasers launched out of the telescope requires tofollow frequent and constraining calibrations and alignments procedures(quasi-static aberrations), in order to guarantee satisfying amplitudeand phase of the beam. These complex and time-consuming procedures willstrongly penalize the availability of Gem's.A laser beam shaping concept has been recently suggested to overcomesuch issues. It consists in applying, in the beam transfer optics, afield-conjugation thanks to 2 deformable mirrors. We review thisconcept. In particular, we discuss the criterion to be optimized and thedesired amplitude and phase shapes at the output of the Gemini beamtransfer optics. We deduce the control to be applied to the mirrors fromthe optimization of the signal-to-noise ratio of the wavefront sensingin Gem's. An iterative algorithm is used to estimate the phases, with aweighted least-squares unwrapper to avoid branch points. This algorithmefficiency is demonstrated with adequate beam shaping simulations.Discussion is made about how to implement such concept at Gemini.

  12. Fan-In Communications On A Cray Gemini Interconnect

    SciTech Connect

    Jones, Terry R; Settlemyer, Bradley W

    2014-01-01

    Using the Cray Gemini interconnect as our platform, we present a study of an important class of communication operations the fan-in communication pattern. By its nature, fan-in communications form hot spots that present significant challenges for any interconnect fabric and communication software stack. Yet despite the inherent challenges, these communication patterns are common in both applications (which often perform reductions and other collective operations that include fan-in communication such as barriers) and system software (where they assume an important role within parallel file systems and other components requiring high-bandwidth or low-latency I/O). Our study determines the effectiveness of differing clientserver fan-in strategies. We describe fan-in performance in terms of aggregate bandwidth in the presence of varying degrees of congestion, as well as several other key attributes. Comparison numbers are presented for the Cray Aries interconnect. Finally, we provide recommended communication strategies based on our findings.

  13. Gemini 8.2-m primary mirror no. 1 polishing

    NASA Astrophysics Data System (ADS)

    Cayrel, Marc; Beraud, P.; Paseri, Jacques; Dromas, E.

    1998-08-01

    The 8-m class primary mirrors of the GEMINI Telescopes are thin ULE menisci actively supported. The two mirror blanks are produced by CORNING, the optical figuring, manufacturing and assembling of interfaces are done by REOSC. REOSC is as well in charge of the transportation of the mirror blanks from CORNING to REOSC, and of the shipment of the finished optics to Hawaii and to Chile. The mirror assembly requirements are summarized, the manufacturing and testing methods are addressed. REOSC had to design and manufacture a dedicated active supporting system, representative of the one used at the telescope level. Its design and performance are presented. The manufacturing steps undertaken at REOSC and the results achieved are then detailed: mirror blank surface generating and grinding, polishing, testing. The current status of the mirrors is finally presented.

  14. Gemini Surfactants Based on Bis-Imidazolium Alkoxy Derivatives as Effective Agents for Delivery of Nucleic Acids: A Structural and Spectroscopic Study

    PubMed Central

    Pietralik, Zuzanna; Ko?odziejska, ?aneta; Weiss, Marek; Kozak, Maciej

    2015-01-01

    The success rate of gene therapy depends on the efficient transfection of genetic material into cells. The golden mean between harmlessness and high effectiveness can be provided by synthetic lipid-like molecules that are similar to the components of biological membranes. Cationic gemini surfactants are one such moiety and because of their favourable physicochemical properties (double positive electric charge, reduced toxicity, low values of critical micelle concentration), they show great potential as delivery system components for genetic material in gene therapy. The aim of this study was to investigate the process of the complexation of cationic gemini surfactants with nucleic acids: double-stranded DNA of different sizes (21 bp, ~185 bp, ~20 kbp) and siRNA (21 bp). The tested series of dicationic surfactants consists of bis-imidazolium quaternary salts with varying lengths of hydrophobic side chains (m = 5, 6, 7, 8, 9, 11, 12, 14, 16). On the basis of the data obtained by circular dichroism spectroscopy and electrophoresis, we concluded that the studied gemini surfactants with long side chains effectively bind nucleic acids at low concentrations, which leads to the formation of stable lipoplexes. Images obtained by atomic force microscopy also confirmed the formation of vesicular structures, i.e., complexes between DNA and surfactants. The cytotoxicity of selected surfactants was also tested on HeLa cells. The surfactant toxicity significantly depends on surfactant geometry (the length of hydrophobic chain). PMID:26641889

  15. SN 1987A after 18 Years: Mid-Infrared GEMINI and SPITZER Observations of the Remnant

    NASA Technical Reports Server (NTRS)

    Bouchet, Patrice; Dwek, Eli; Danziger, John; Arendt, Richard G.; DeBuizer, James M.; Park, Sangwook; Suntzeff, Nicholas B.; Kirshner, Robert P.; Challis, Peter

    2007-01-01

    We present high resolution 11.7 and 18.3 micron mid-IR images of SN 1987A obtained on day 6526 since the explosion with the Thermal-Region Camera and Spectrograph (T-ReCS) attached to the Gemini South 8m telescope. The 11.7 micron flux has increased significantly since our last observations on day 6067. The images clearly show that all the emission arises from the equatorial ring (ER). Nearly contemporaneous spectra obtained on day 6184 with the MIPS at 24 micron, on day 6130 with the IRAC in 3.6- 8 micron region, and on day 6190 with the IRS in the 12-37 micron instruments on board the Spitzer Space Telescope's show that the emission consists of thermal emission from silicate dust that condensed out in the red giant wind of the progenitor star. The dust temperature is 1662(sup +18) (sub -12) K, and the emitting dust mass is (2.6(sup +2.0 (sub -1.4)) x 10 (exp -6) M(solar). Lines of [Ne II] 12.82 micron and [Ne III] 15.56 pm are clearly present in the Spitzer spectrum, as well as a weak [Si II] 3 34.8 micron line. We also detect two lines near 26 micron which we tentatively ascribe to [Fe II] 25.99 pm and [0 IV] 25.91 micron. Comparison of the mid-IR Gemini 11.7 micron image with X-ray images obtained by Chandra, UV-optical images obtained by HST, and radio synchrotron images obtained by the ATCA show generally good correlation of the images across all wavelengths. Because of the limited resolution of the mid-IR images we cannot uniquely determine the location. or heating mechanism of the dust giving rise to the emission. The dust could be collisionally heated by the X-ray emitting plasma, providing a unique diagnostic of plasma conditions. Alternatively, the dust could be radiatively heated in the dense UV-optical knots that are overrun by the advancing supernova blast wave. In either case the dust-to-gas mass ratio in the circumstellar medium around the supernova is significantly lower than that in the general interstellar medium of the LMC, suggesting either a low condensation efficiency in the wind of the progenitor star, or the efficient destruction of the dust by the SN blast wave. Overall, we are witnessing the interaction of the SN blast wave with its surrounding medium, creating an environment that is rapidly evolving at all wavelengths. Continuous multiwavelength observations of SN 1987A such as these provide unique snapshots of the very early evolution of supernova remnants.

  16. Radial velocities of stars with multiple co-orbital planets

    NASA Astrophysics Data System (ADS)

    Dobrovolskis, Anthony R.

    2015-04-01

    To date, well over a thousand planets have been discovered orbiting other stars, hundreds of them in multi-planet systems. Most of these exoplanets have been detected by either the transit method or the radial velocity method, rather than by other methods such as astrometry or direct imaging. Both the radial velocity and astrometric methods rely upon the reflex motion of the parent star induced by the gravitational attraction of its planets. However, this reflex motion is subject to misinterpretation when a star has two or more planets with the same orbital period. Such co-orbital planets may effectively "hide" from detection by current algorithms.

  17. Characterizing Transiting Planet Atmospheres through 2025

    NASA Astrophysics Data System (ADS)

    Cowan, N. B.; Greene, T.; Angerhausen, D.; Batalha, N. E.; Clampin, M.; Colón, K.; Crossfield, I. J. M.; Fortney, J. J.; Gaudi, B. S.; Harrington, J.; Iro, N.; Lillie, C. F.; Linsky, J. L.; Lopez-Morales, M.; Mandell, A. M.; Stevenson, K. B.; ExoPAG SAG-10

    2015-03-01

    The discovery of planets around other stars is revolutionizing our notions of planet formation and is poised to do the same for planetary climate. Studying transiting planets is complementary to eventual studies of directly imaged planets: (1) we can readily measure the mass and radius of transiting planets, linking atmospheric properties to bulk composition and formation, (2) many transiting planets are strongly irradiated and exhibit novel atmospheric physics, and (3) the most common temperate terrestrial planets orbit close to red dwarf stars and are difficult to image directly. We have only been able to comprehensively characterize the atmospheres of a handful of transiting planets, because most orbit faint stars. The Transiting Exoplanet Survey Satellite (TESS) will discover transiting planets orbiting the brightest stars, enabling, in principle, an atmospheric survey of 102-103 bright hot Jupiters and warm sub-Neptunes. Uniform observations of such a statistically significant sample would provide leverage to understand - and learn from - the diversity of short-period planets, and would identify the minority of truly special planets worthy of more intensive follow-up. We argue that the best way to maximize the scientific returns of TESS is to adopt a triage approach. A space mission consisting of a ˜1 m telescope with an optical-NIR spectrograph could measure molecular absorption for nonterrestrial planets discovered by TESS, as well as eclipses and phase variations for the hottest jovians. Such a mission could observe up to 103 transits per year, thus enabling it to survey a large fraction of the bright (J < 11) hot-Jupiters and warm sub-Neptunes TESS is expected to find. The James Webb Space Telescope (JWST) could be used to perform detailed atmospheric characterization of the most interesting transiting targets (transit, eclipse, and - when possible - phase-resolved spectroscopy). TESS is also expected to discover a few temperate terrestrial planets transiting nearby M-Dwarfs. Characterizing these worlds will be time-intensive: JWST will need months to provide tantalizing constraints on the presence of an atmosphere, planetary rotational state, clouds, and greenhouse gases. Future flagship missions should be designed to provide better constraints on the habitability of M-Dwarf temperate terrestrial planets.

  18. Watching How Planets Form

    NASA Astrophysics Data System (ADS)

    2006-09-01

    Anatomy of a Planet-Forming Disc around a Star More Massive than the Sun With the VISIR instrument on ESO's Very Large Telescope, astronomers have mapped the disc around a star more massive than the Sun. The very extended and flared disc most likely contains enough gas and dust to spawn planets. It appears as a precursor of debris discs such as the one around Vega-like stars and thus provides the rare opportunity to witness the conditions prevailing prior to or during planet formation. "Planets form in massive, gaseous and dusty proto-planetary discs that surround nascent stars. This process must be rather ubiquitous as more than 200 planets have now been found around stars other than the Sun," said Pierre-Olivier Lagage, from CEA Saclay (France) and leader of the team that carried out the observations. "However, very little is known about these discs, especially those around stars more massive than the Sun. Such stars are much more luminous and could have a large influence on their disc, possibly quickly destroying the inner part." The astronomers used the VISIR instrument [1] on ESO's Very Large Telescope to map in the infrared the disc surrounding the young star HD 97048. With an age of a few million years [2], HD 97048 belongs to the Chameleon I dark cloud, a stellar nursery 600 light-years away. The star is 40 times more luminous than our Sun and is 2.5 times as massive. The astronomers could only have achieved such a detailed view due to the high angular resolution offered by an 8-metre size telescope in the infrared, reaching a resolution of 0.33 arcsecond. They discovered a very large disc, at least 12 times more extended than the orbit of the farthest planet in the Solar System, Neptune. The observations suggest the disc to be flared. "This is the first time such a structure, predicted by some theoretical models, is imaged around a massive star," said Lagage. ESO PR Photo 36/06 ESO PR Photo 36/06 A Flared Proto-Planetary Disc Such a geometry can only be explained if the disc contains a large amount of gas, in this case, at least as much as 10 times the mass of Jupiter. It should also contain more than 50 Earth masses in dust. The dust mass derived here is more than thousand times larger than what is observed in debris discs and Kuiper belt-like structures found around older, 'Vega-like' stars, such as Beta Pictoris, Vega, Fomalhaut and HR 4796. The dust around these stars is thought to be produced by collisions of larger bodies. The dust mass observed around HD 97048 is similar to the mass invoked for the (undetected) parent bodies in the more evolved systems. HD 97048's disc is thus most likely a precursor of debris discs observed around older stars. "From the structure of the disc, we infer that planetary embryos may be present in the inner part of the disc," said Lagage. "We are planning follow-up observations at higher angular resolution with ESO's VLT interferometer in order to probe these regions." A video, made by the CEA, is also available. More Information The scientists report their discovery in the 28 September issue of Science Express, the rapid online publication service of the journal Science: "Anatomy of a flaring proto-planetary disc around a young intermediate-mass star", by P.-O. Lagage et al. The team is composed of Pierre-Olivier Lagage, Coralie Doucet, and Eric Pantin, (CEA Saclay, France), Sébastien Charnoz (Paris 7 Denis Diderot University), Emilie Habart (Institut d'Astrophysique Spatiale, Orsay, France), Gaspard Duchêne, François Ménard, and Christophe Pinte (Laboratoire d'Astrophysique de Grenoble, France), and Jan-Willem Pel (Groningen University, The Netherlands).

  19. Planet Parameters in Microlensing Events

    E-print Network

    B. Scott Gaudi; Andrew Gould

    1996-10-16

    A planetary microlensing event occurs when a planet perturbs one of the two images created in a point-mass microlensing event, causing a deviation from the standard Paczy\\'nski curve. Determination of the two physical parameters that can be extracted from a planetary microlensing event, the planet/star mass ratio q, and the planet/star separation in units of the stellar Einstein ring, $y_p$, is hampered by several types of degeneracies. There are two distinct and qualitatively different classes of planetary events: major and minor image perturbations. For major image perturbations, there is a potentially crippling continuous degeneracy in q which is of order $\\delta_d^{-1}$, where $\\delta_d$ is the maximum fractional deviation of the planetary perturbation. Since the threshold of detection is expected to be $\\delta_d \\sim 5%$, this degeneracy in q can be a factor of $\\sim 20$. For minor image perturbations, the continuous degeneracy in q is considerably less severe, and is typically less than a factor 4. We show that these degeneracies can be resolved by observations from dedicated telescopes on several continents together with optical/infrared photometry from one of these sites. There also exists a class of discrete degeneracies. These are typically easy to resolve given good temporal coverage of the planetary event. Unambiguous interpretation of planetary microlensing events requires the resolution of both types of degeneracy. We describe the degeneracies in detail and specify the situations in which they are problematic. We also describe how individual planet masses and physical projected separations can be measured.

  20. Direct Imaging and Spectroscopy of a Young Extrasolar Kuiper Belt in the Nearest OB Association

    NASA Astrophysics Data System (ADS)

    Currie, Thayne; Lisse, Carey M.; Kuchner, Marc; Madhusudhan, Nikku; Kenyon, Scott J.; Thalmann, Christian; Carson, Joseph; Debes, John

    2015-07-01

    We describe the discovery of a bright, young Kuiper belt-like debris disk around HD 115600, a ˜1.4-1.5 M?, ˜15 Myr old member of the Sco-Cen OB Association. Our H-band coronagraphy/integral field spectroscopy from the Gemini Planet Imager shows the ring has a (luminosity-scaled) semimajor axis of (˜22 AU) ˜ 48 AU, similar to the current Kuiper belt. The disk appears to have neutral-scattering dust, is eccentric (e ˜ 0.1-0.2), and could be sculpted by analogs to the outer solar system planets. Spectroscopy of the disk ansae reveal a slightly blue to gray disk color, consistent with major Kuiper belt chemical constituents, where water ice is a very plausible dominant constituent. Besides being the first object discovered with the next generation of extreme adaptive optics systems (i.e., SCExAO, GPI, SPHERE), HD 115600's debris ring and planetary system provide a key reference point for the early evolution of the solar system, the structure, and composition of the Kuiper belt and the interaction between debris disks and planets.

  1. Planet - Disk Symbiosis

    E-print Network

    Sari, R; Sari, Re'em; Goldreich, Peter

    2004-01-01

    Planets form in disks around young stars. Interactions with these disks cause them to migrate and thus affect their final orbital periods. We suggest that the connection between planets and disks may be deeper and involve a symbiotic evolution. By contributing to the outward transport of angular momentum, planets promote disk accretion. Here we demonstrate that planets sufficiently massive to open gaps could be the primary agents driving disk accretion. Those having masses below the gap opening threshold drift inward more rapidly than the disk material and can only play a minor role in its accretion. Eccentricity growth during gap formation may involve an even more intimate symbiosis. Given a small initial eccentricity, just a fraction of a percent, the orbital eccentricity of a massive planet may grow rapidly once a mass in excess of the planet's mass has been repelled to form a gap around the planet's orbit. Then, as the planet's radial excursions approach the gap's width, subsequent eccentricity growth slo...

  2. Fisheye view of Gemini 4 prime crew during simulated exercises at Pad 19

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Fisheye view of Astronauts James A. McDivitt and Edward H. White II inside the Gemini 4 spacecraft during simulated exercises at pad 19, Cape Kennedy, Florida. NASA Headquarters alternative photo number is 65-H-274.

  3. Gemini 12 crew receive Official welcome aboard U.S.S. Wasp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts James A. Lovell Jr. (left), command pilot, and Edwin E. Aldrin Jr., pilot, receive Official welcome as they arrive aboard the aircraft carrier U.S.S. Wasp after their splashdown at the end of the Gemini 12 mission.

  4. Gemini North and South Laser Guide Star Systems Requirements and Preliminary Designs

    E-print Network

    to produce one laser guide star at Mauna Kea, Hawaii, whereas the Gemini South AO System will use up to five-optimized 8-m telescopes respectively located at the summit of Mauna Kea, Hawaii, and Cerro Pachon, Chile

  5. Magellan Adaptive Optics First-light Observations of the Exoplanet ? Pic b. II. 3-5 ?m Direct Imaging with MagAO+Clio, and the Empirical Bolometric Luminosity of a Self-luminous Giant Planet

    NASA Astrophysics Data System (ADS)

    Morzinski, Katie M.; Males, Jared R.; Skemer, Andy J.; Close, Laird M.; Hinz, Phil M.; Rodigas, T. J.; Puglisi, Alfio; Esposito, Simone; Riccardi, Armando; Pinna, Enrico; Xompero, Marco; Briguglio, Runa; Bailey, Vanessa P.; Follette, Katherine B.; Kopon, Derek; Weinberger, Alycia J.; Wu, Ya-Lin

    2015-12-01

    Young giant exoplanets are a unique laboratory for understanding cool, low-gravity atmospheres. A quintessential example is the massive extrasolar planet ? Pic b, which is 9 AU from and embedded in the debris disk of the young nearby A6V star ? Pictoris. We observed the system with first light of the Magellan Adaptive Optics (MagAO) system. In Paper I we presented the first CCD detection of this planet with MagAO+VisAO. Here we present four MagAO+Clio images of ? Pic b at 3.1 ?m, 3.3 ?m, L?, and {M}\\prime , including the first observation in the fundamental CH4 band. To remove systematic errors from the spectral energy distribution (SED), we re-calibrate the literature photometry and combine it with our own data, for a total of 22 independent measurements at 16 passbands from 0.99 to 4.8 ?m. Atmosphere models demonstrate the planet is cloudy but are degenerate in effective temperature and radius. The measured SED now covers >80% of the planet's energy, so we approach the bolometric luminosity empirically. We calculate the luminosity by extending the measured SED with a blackbody and integrating to find log({{L}}{bol}/{{L}}? ) \\=\\-3.78+/- 0.03. From our bolometric luminosity and an age of 23 ± 3 Myr, hot-start evolutionary tracks give a mass of 12.7 ± 0.3 {{M}}{Jup}, radius of 1.45 ± 0.02 {{R}}{Jup}, and Teff of 1708 ± 23 K (model-dependent errors not included). Our empirically determined luminosity is in agreement with values from atmospheric models (typically -3.8 dex), but brighter than values from the field-dwarf bolometric correction (typically -3.9 dex), illustrating the limitations in comparing young exoplanets to old brown dwarfs.

  6. Releve de planetes geantes autour d'etoiles proches par imagerie directe et optimisation d'une technique d'imagerie multibande

    NASA Astrophysics Data System (ADS)

    Lafreniere, David

    The primary goal of this thesis is the search for exoplanets using direct imaging. Given the small angular separation and the very large luminosity ratio between a planet and its star this task is very difficult. The approach adopted for the present work is differential imaging, which consists in obtaining a reference image of the point-spread function (PSF) of the star, and subtracting this reference image from a target image to remove the stellar signal. Initially, two tools aimed at improving the quality of this subtraction are developed. The first is a new instrumental concept that makes it possible to increase the correlation of images obtained at different wavelengths in simultaneous spectral differential imaging. This concept consists in placing a holographic diffuser at the entrance focal plane of a multi-channel camera in order to break the coherence of the wavefront entering the camera; this largely reduces the effect of optical aberrations in the camera on the structure of the PSF recorded in each channel. A prototype based on this concept provided an attenuation of the PSF by a factor 12-15, an improvement by a factor ˜5 compared to the attenuation obtained without a diffuser. The second tool developed is a new algorithm allowing to combine several reference images of the stellar PSF together to form a reference image more faithful to the target image. The application of this algorithm to an angular differential imaging sequence of observations yielded an improvement in sensitivity by a factor of up to 3. Finally, the results of a search for giant planets around 85 nearby young stars are presented; this search was done with the Gemini North telescope. The sensitivity of the observations, expressed in difference of magnitudes at 1.6 mum between a planet and its star, is typically 9.5 at 0.5 ?, 12.9 at 1?, 15 at 2?, and 16.5 at 5?. For a typical target star, a 100 million year old K0 star located at 22 pc from the Sun, these sensitivities allow the detection of planets more massive than 2 MJup with a projected separation between 40 and 200 UA. Overall, more than 300 candidate exoplanets were identified around 54 of the stars observed; a follow-up of 48 of these stars has confirmed that their candidates are all unrelated background stars. A statistical analysis of the results indicates that, by assuming a mass function dn/dm ? m-1.1 and a semi-major axis distribution d n/da ? a-1 the upper limits on the fraction of stars with at least one planet of mass 0.5--13 MJup are 28% for the interval 10--25 AU, 13% for 25--50 AU, and 9.3% for 50--200 AU, with a 95% credibility. Keywords: exoplanets, high-contrast imaging, image processing, astronomical instrumentation

  7. Kepler Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2015-01-01

    Kepler has vastly increased our knowledge of planets and planetary systems located close to stars. The new data shows surprising results for planetary abundances, planetary spacings and the distribution of planets on a mass-radius diagram. The implications of these results for theories of planet formation will be discussed.

  8. Terrestrial Planets: Comparative Planetology

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Papers were presented at the 47th Annual Meteoritical Society Meeting on the Comparative planetology of Terrestrial Planets. Subject matter explored concerning terrestrial planets includes: interrelationships among planets; plaentary evolution; planetary structure; planetary composition; planetary Atmospheres; noble gases in meteorites; and planetary magnetic fields.

  9. Peeking at the Planets.

    ERIC Educational Resources Information Center

    Riddle, Bob

    2002-01-01

    Provides information about each of the planets in our solar system. Focuses on information related to the space missions that have visited or flown near each planet, and includes a summary of what is known about some of the features of each planet. (DDR)

  10. Evaporation of extrasolar planets

    E-print Network

    David Ehrenreich

    2008-07-11

    Atomic hydrogen escaping from the extrasolar giant planet HD209458b provides the largest observational signature ever detected for an extrasolar planet atmosphere. In fact, the upper atmosphere of this planet is evaporating. Observational evidences and interpretations coming from various models are reviewed. Implications for exoplanetology are discussed.

  11. Microlensing Searches for Extrasolar Planets

    E-print Network

    Gaudi, B. Scott

    Microlensing Searches for Extrasolar Planets Microlensing Searches for Extrasolar Planets I for Extrasolar Planets, B. Scott Gaudi, IAS #12;The Search for Extrasolar PlanetsThe Search for Extrasolar Planets Why Search for Extrasolar Planets ? Frequency of Life Clues to Star Formation Low End

  12. Gemini NIFS Observations Of The Galactic UCHII Region K3-50a

    NASA Astrophysics Data System (ADS)

    Blum, Robert D.; MCGregor, P. J.

    2009-01-01

    Gemini North adaptive optics imaging spectroscopy is presented for the Galactic UCHII region K3-50A. Data were obtained in the K-band using the Near infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A kinematic flow (+/- 25 \\kms) is evident in the Br gamma line map which may be related to the larger scale ionized flow detailed in earlier investigations. Though clearly resolved from the nebula, the central source itself remains buried, and the NIFS spectrum shows no evidence of photospheric lines.

  13. The dusty nuclear torus in NGC4151: constraints from Gemini NIFS observations

    E-print Network

    Riffel, Rogemar A; Mcgregor, Peter J

    2009-01-01

    We have used a near-infrared nuclear spectrum (covering the Z, J, H and K bands) of the nucleus of NGC 4151 obtained with the Gemini Near-infrared Integral Field Spectrograph (NIFS) and adaptive optics, to isolate and constrain the properties of a near-IR unresolved nuclear source whose spectral signature is clearly present in our data. The near-IR spectrum was combined with an optical spectrum obtained with the Space Telescope Imaging Spectrograph which was used to constrain the contribution of a power-law component. After subtraction of the power-law component, the near-IR continuum is well fitted by a blackbody function, with $T=1285\\pm50 $K, which dominates the nuclear spectrum -- within an aperture of radius 0$\\farcs$3 -- in the near-IR. We attribute the blackbody component to emission by a dusty structure, with hot dust mass $M_{\\rm HD}=(6.9\\pm 1.5) \\times10^{-4} {\\rm M_\\odot}$, not resolved by our observations, which provide only an upper limit for its distance from the nucleus of 4 pc. If the reddenin...

  14. Near Infrared Observations of GQ Lup b Using the Gemini Integral Field Spectrograph NIFS

    E-print Network

    Lavigne, Jean-Francois; Lafreniere, David; Marois, Christian; Barman, Travis

    2009-01-01

    We present new JHK spectroscopy (R ~ 5000) of GQ Lup b, acquired with the near-infrared integral field spectrograph NIFS and the adaptive optics system ALTAIR at the Gemini North telescope. Angular differential imaging was used in the J and H bands to suppress the speckle noise from GQ Lup A; we show that this approach can provide improvements in signal-to-noise ratio (S/N) by a factor of 2 - 6 for companions located at subarcsecond separations. Based on high quality observations and GAIA synthetic spectra, we estimate the companion effective temperature to Teff = 2400 +/- 100 K, its gravity to log g = 4.0 +/- 0.5, and its luminosity to log(L/L_s) = -2.47 +/- 0.28. Comparisons with the predictions of the DUSTY evolutionary tracks allow us to constrain the mass of GQ Lup b to 8 - 60 MJup, most likely in the brown dwarf regime. Compared with the spectra published by Seifahrt and collaborators, our spectra of GQ Lup b are significantly redder (by 15 - 50%) and do not show important Pa\\beta emission. Our spectra ...

  15. Radio Galaxy 3C 230 Observed with Gemini Laser-Adaptive-Optics Integral-Field Spectroscopy

    E-print Network

    Steinbring, Eric

    2011-01-01

    The Altair laser-guide-star adaptive optics facility combined with the Near-Infrared Integral Field Spectrometer (NIFS) on Gemini North have been employed to study the morphology and kinematics of 3C 230 at z=1.5, the first such observations of a high-redshift radio galaxy. These suggest a bi-polar outflow spanning 0"9 (~16 kpc projected distance for a standard lambda-CDM cosmology) reaching a mean relative velocity of 235 km/s in redshifted H-alpha + [NII] and [SII] emission. Structure is resolved to 0"1 (0.8 kpc), well correlated with optical images from the Hubble Space Telescope and Very Large Array radio maps obtained at similar spatial resolution. Line diagnostics suggest that over the 10^7 yr to 10^8 yr duration of its AGN activity, gas has been ejected into bright turbulent lobes at rates comparable to star formation, although constituting perhaps only 1 percent of the baryonic mass in the galaxy.

  16. Photometry and Dynamics of the Minor Merger AM 1219-430 with Gemini GMOS-S

    NASA Astrophysics Data System (ADS)

    Hernandez-Jimenez, J. A.; Pastoriza, M. G.; Rodrigues, I.; Krabbe, A. C.; Winge, C.; Bonatto, C.

    2014-10-01

    This work is based on r' and g' images and long-slit spectra obtained with the GMOS at the Gemini South Telescope. We detected a tidal tail in the main galaxy (AM 1219A) and a bridge of material connecting the galaxies. The surface brightness profile of AM 1219A was decomposed into bulge and disc components. The profile shows a light excess of ˜ 53 % due to the contribution of star-forming regions. On the other hand, the surface brightness profile of the secondary galaxy shows a lens structure in addition to the bulge and disc. The rotation curve of AM 1219A is quite asymmetric, suggesting a gas perturbed by interaction. The overall best-fitting solution for the mass distribution of AM 1219A was found with M/L for bulge and disc of ?_{b}=2.8_{-0.4}^{+0.4} and ?_{d}=2.4_{-0.2}^{+0.3}, respectively, and a NFW profile of M_{200}=2.0_{-0.4}^{+0.5}× 10^{12} M_{odot } and c=16.0_{-1.1}^{+1.2}.

  17. NEAR-INFRARED OBSERVATIONS OF GQ LUP b USING THE GEMINI INTEGRAL FIELD SPECTROGRAPH NIFS

    SciTech Connect

    Lavigne, Jean-Francois; Doyon, Rene; Lafreniere, David; Marois, Christian; Barman, Travis

    2009-10-20

    We present new JHK spectroscopy (R approx 5000) of GQ Lup b, acquired with the Near-Infrared Integral Field Spectrograph and the adaptive optics system ALTAIR at the Gemini North telescope. Angular differential imaging was used in the J and H bands to suppress the speckle noise from GQ Lup A; we show that this approach can provide improvements in signal-to-noise ratio (S/N) by a factor of 2-6 for companions located at subarcsecond separations. Based on high-quality observations and Global Astrometric lnterferometer for Astrophysics synthetic spectra, we estimate the companion effective temperature to T {sub eff} = 2400 +- 100 K, its gravity to log g = 4.0 +- 0.5, and its luminosity to log(L/L {sub sun}) = -2.47 +- 0.28. Comparisons with the predictions of the DUSTY evolutionary tracks allow us to constrain the mass of GQ Lup b to 8-60 M {sub Jup}, most likely in the brown dwarf regime. Compared with the spectra published by Seifahrt and collaborators, our spectra of GQ Lup b are significantly redder (by 15%-50%) and do not show important Pabeta emission. Our spectra are in excellent agreement with the lower S/N spectra previously published by McElwain and collaborators.

  18. A giant planet around HD95086 ?

    NASA Astrophysics Data System (ADS)

    Rameau, Julien; Chauvin, Gaël; Lagrange, Anne-Marie; Meshkat, Tiffany; Boccaletti, Anthony; Quanz, Sascha P.; Bonnefoy, Mickaël; Bailey, Vanessa; Kenworthy, Matthew; Currie, Thayne; Girard, Julien H.; Delorme, Philippe; Desidera, Silvano; Dumas, Christophe; Mordasini, Christoph; Klahr, Hubert; Bonavita, Mariangela

    2013-07-01

    Understanding planetary systems formation and evolution has become one of the challenges in as- tronomy, since the discovery of the first exoplanet around the solar-type star 51 Peg in the 90's. While more than 800 planets (mostly giants) closer than a few AU have been identified with radial velocity and transit techniques, very few have been imaged and definitely confirmed around stars, at separations below a hundred of astronomical units. Direct imaging detection of exoplanet is indeed a major frontier in planetary astrophysics. It surveys a region of semi-major axes (> 5 AU) that is almost inaccessible to other methods. Moreover, the planets imaged so far orbit young stars; indeed the young planets are still hot and the planet-star contrasts are compatible with the detection limits currently achievable, in contrast with similar planets in older systems. Noticeably, the stars are of early-types, and surrounded by debris disks, i.e. disks populated at least by small grains with lifetimes so short that they must be permanently produced, probably by destruction (evaporation, collisions) of larger solid bodies. Consequently, every single discovery has a tremendous impact on the understanding of the formation, the dynamical evolution, and the physics of giant planets. In this context, I will present our recent discovery of one faint companion to a nearby, dusty, and young A-type star (at 56 AU projected separation). Background contaminants are rejected with high confidence level based on both astrometry and photometry with three dataset at more than a year-time-laps and two different wavelength regimes. From the system age (10 to 17 Myr) and from model-dependent luminosity estimates, we derive mass of 4 to 5 Jupiter mass. This planet is therefore the one with the lowest mass ever imaged around a star. Given its orbital and physical properties, I will discuss the implication on its atmosphere with respect to other imaged companions but also on its formation.

  19. The detectability of extrasolar planet surroundings - I. Reflected-light photometry of unresolved rings

    E-print Network

    Luc Arnold; Jean Schneider

    2004-06-09

    It is expected that the next generation of high-contrast imaging instruments will deliver the first unresolved image of an extrasolar planet. The emitted thermal infrared light from the planet should show no phase effect assuming the planet is in thermal equilibrium. But the reflected visible light will vary versus the phase angle. Here, we study the photometric variation of the reflected light versus the orbital phase of a ringed extrasolar planet. We show that a ring around an extrasolar planet, both obviously unresolved, can be detected by its specific photometric signature. A simple quantitative model is discussed, taking into account the basic optical and geometrical properties of the ringed planet.

  20. Detectability of planetary rings around an extrasolar planet from reflected-light photometry

    E-print Network

    L. Arnold; J. Schneider

    2005-10-19

    The next generation of high-contrast imaging instruments will provide the first unresolved image of an extrasolar planet. While the emitted infrared light from the planet in thermal equilibrium should show almost no phase effect, the reflected visible light will vary with the orbital phase angle. We study the photometric variation of the reflected light with orbital phase of a ringed extrasolar planet. We show that a ring around an extrasolar planet, both obviously unresolved, can be detected by its specific photometric signature. Keywords: Stars: planetary systems -- Planets: rings -- Extrasolar planet characterization

  1. Journey to a Star Rich with Planets

    NASA Technical Reports Server (NTRS)

    2007-01-01

    [figure removed for brevity, see original site] Click on the image for movie of Journey to a Star Rich with Planets

    This artist's animation takes us on a journey to 55 Cancri, a star with a family of five known planets - the most planets discovered so far around a star besides our own.

    The animation begins on Earth, with a view of the night sky and 55 Cancri (flashing dot), located 41 light-years away in the constellation Cancer. It then zooms through our solar system, passing our asteroids and planets, until finally arriving at the outskirts of 55 Cancri.

    The first planet to appear is the farthest out from the star -- a giant planet, probably made of gas, with a mass four times that of Jupiter. This planet orbits its star every 14 years, similar to Jupiter's 11.9-year orbit.

    As the movie continues, the three inner planets are shown, the closest of which is about 10 to 13 times the mass of Earth with an orbital period of less than three days.

    Zooming out, the animation highlights the newest member of the 55 Cancri family - a massive planet, likely made of gas, water and rock, about 45 times the mass of Earth and orbiting the star every 260 days. This planet is the fourth out from the star, and lies in the system's habitable zone (green). A habitable zone is the place around a star where liquid water would persist. Though the newest planet probably has a thick gaseous envelope, astronomers speculate that it could have one or more moons. In our own solar system, moons are common, so it seems likely that they also orbit planets in other solar systems. If such moons do exist, and if they are as large as Mars or Earth, astronomers speculate that they would retain atmospheres and surface liquid water that might make interesting environments for the development of life.

    The animation ends with a comparison between 55 Cancri and our solar system.

    The colors of the illustrated planets were chosen to resemble those of our own solar system. Astronomers do not know what the planets look like.

  2. Planet Demographics from Transits

    NASA Astrophysics Data System (ADS)

    Howard, Andrew

    2015-08-01

    From the demographics of planets detected by the Kepler mission, we have learned that there exists approximately one planet per star for planets larger than Earth orbiting inside of 1 AU. We have also learned the relative occurrence of these planets as a function of their orbital periods, sizes, and host star masses and metallicities. In this talk I will review the key statistical findings that the planet size distribution peaks in the range 1-3 times Earth-size, the orbital period distribution is characterized by a power-law cut off at short periods, small planets are more prevalent around small stars, and that approximately 20% of Sun-like stars hosts a planet 1-2 times Earth-size in a habitable zone. Looking forward, I will describe analysis of photometry from the K2 mission that is yielding initial planet discoveries and offering the opportunity to measure planet occurrence in widely separated regions of the galaxy. Finally, I will also discuss recent techniques to discover transiting planets in space-based photometry and to infer planet population properties from the ensemble of detected and non-detected transit signals.

  3. The Radiometric Bode's Law and Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Lazio, T. Joseph, W.; Farrell, W. M.; Dietrick, Jill; Greenlees, Elizabeth; Hogan, Emily; Jones, Christopher; Hennig, L. A.

    2004-09-01

    We predict the radio flux densities of the extrasolar planets in the current census, making use of an empirical relation-the radiometric Bode's law-determined from the five ``magnetic'' planets in the solar system (the Earth and the four gas giants). Radio emission from these planets results from solar wind-powered electron currents depositing energy in the magnetic polar regions. We find that most of the known extrasolar planets should emit in the frequency range 10-1000 MHz and, under favorable circumstances, have typical flux densities as large as 1 mJy. We also describe an initial, systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array (VLA). The limits set by the VLA images (~300 mJy) are consistent with, but do not provide strong constraints on, the predictions of the model. Future radio telescopes, such as the Low Frequency Array and the Square Kilometer Array, should be able to detect the known extrasolar planets or place austere limits on their radio emission. Planets with masses much lower than those in the current census will probably radiate below 10 MHz and will require a space-based array.

  4. The Radiometric Bode's Law and Extrasolar Planets

    E-print Network

    Joseph Lazio; W. M. Farrell; Jill Dietrick; Elizabeth Greenlees; Emily Hogan; Christopher Jones; L. A. Hennig

    2004-05-18

    We predict the radio flux densities of the extrasolar planets in the current census, making use of an empirical relation--the radiometric Bode's Law--determined from the five ``magnetic'' planets in the solar system (Earth and the four gas giants). Radio emission from these planets results from solar-wind powered electron currents depositing energy in the magnetic polar regions. We find that most of the known extrasolar planets should emit in the frequency range 10--1000 MHz and, under favorable circumstances, have typical flux densities as large as 1 mJy. We also describe an initial, systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array. The limits set by the VLA images (~ 300 mJy) are consistent with, but do not provide strong constraints on, the predictions of the model. Future radio telescopes, such as the Low Frequency Array (LOFAR) and the Square Kilometer Array (SKA), should be able to detect the known extrasolar planets or place austere limits on their radio emission. Planets with masses much lower than those in the current census will probably radiate below 10 MHz and will require a space-based array.

  5. Gemini optical observations of binary millisecond-pulsars

    E-print Network

    Testa, V; Pallanca, C; Corongiu, A; Ferraro, F R

    2015-01-01

    Milli-second pulsars (MSPs) are rapidly spinning neutron stars, with spin periods P_s star. In this work we present the results of the search for the companion stars of four binary milli-second pulsars, carried out with archival data from the Gemini South telescope. Based upon a very good positional coincidence with the pulsar radio coordinates, we likely identified the companion stars to three MSPs, namely PSRJ0614-3329 (g=21.95 +- 0.05), J1231-1411 (g=25.40 +-0.23), and J2017+0603 (g=24.72 +- 0.28). For the last pulsar (PSRJ0613-0200) the identification was hampered by the presence of a bright star (g=16 +- 0.03) at \\sim 2" from the pulsar radio coordinates and we could only set 3-sigma upper limits of g=25.0, r= 24.3, and i= 24.2 on the magnitudes of its companion star. The candidate companion stars to PSRJ0614-3329, J1231-1411, and J2017+0603 can be tentatively identified as He white dwarfs (WDs) on the bas...

  6. Cellular uptake of polyurethane nanocarriers mediated by gemini quaternary ammonium.

    PubMed

    Ding, Mingming; He, Xueling; Wang, Zhigao; Li, Jiehua; Tan, Hong; Deng, Hua; Fu, Qiang; Gu, Qun

    2011-12-01

    The effective passage of drug formulations into tumor cells is a key factor in the development of nanoscale delivery systems. However, rapid cellular uptake with reduced toxicity remains a great challenge for efficient and safe delivery. In this study, we first use gemini quaternary ammonium (GQA) as a cell internalization promoter to enhance the cellular uptake of drug nanocarriers. It is found that a twenty times faster cell internalization could be achieved by introducing GQA into biodegradable multiblock polyurethane nanomicelles, as confirmed by flow cytometry and confocal laser scanning microscopy (CLSM) studies. Meanwhile, an added methoxyl-poly(ethylene glycol) (mPEG) outer corona could protect these cationic micelles from cytotoxicity at high concentrations, as verified by methyl tetrazolium (MTT) assay. Moreover, GQA not only acts as an enhancer for rapid cellular entry, but also plays an important role in controlled self-assembly and high drug loading capacity. Our work offers a new understanding on the role of cationic surfactants; and provides a facile and economical approach for the design of versatile drug nanocarriers to achieve efficient delivery and good biocompatibility. PMID:21907404

  7. Exploring Planetary System Evolution Through High-Contrast Imaging

    NASA Astrophysics Data System (ADS)

    Esposito, Thomas; Fitzgerald, Michael P.; Kalas, Paul; Graham, James R.; Millar-Blanchaer, Max; Gpies Team

    2015-01-01

    Direct imaging of circumstellar disks provides unique information about planetary system construction and evolution. Several hundred nearby main-sequence stars are known to host debris disks, which are produced by mutual collisions of orbiting planetesimals during a phase thought to coincide with terrestrial planet formation. Therefore, detection of the dust in such systems through scattered near-infrared starlight offers a view of the circumstellar environment during the epoch of planet assembly. We have used ground-based coronagraphic angular differential imaging (ADI) with Keck NIRC2 and Gemini Planet Imager (GPI) to investigate disk structures that may act as signposts of planets. ADI and its associated image processing algorithms (e.g., LOCI) are powerful tools for suppressing the stellar PSF and quasistatic speckles that can contaminate disk signal. However, ADI PSF-subtraction also attenuates disk surface brightness in a spatially- and parameter-dependent manner, thereby biasing photometry and compromising inferences regarding the physical processes responsible for the dust distribution. To account for this disk "self-subtraction," we developed a novel technique to forward model the disk structure and compute a self-subtraction map for a given ADI-processed image. Applying this method to NIRC2 near-IR imaging of the HD 32297 debris disk, we combined the high signal-to-noise ratio (S/N) of ADI data with unbiased photometry to measure midplane curvature in the edge-on disk and a break in the disk's radial brightness profile. Such a break may indicate the location of a planetesimal ring that is a source of the light-scattering micron-sized grains. For the HD 61005 debris disk, we examined similar data together with GPI 1.6-micron polarization data and detected the dust ring's swept-back morphology, brightness asymmetry, stellocentric offset, and inner clearing. To study the physical mechanism behind these features, we explored how eccentricity and mutual inclination affect disk morphology by constructing self-subtracted scattered-light models (using our forward-modeling technique) and comparing them with complementary NIRC2 (several-arcsecond scales) and GPI (high S/N close to the star) observations.

  8. Which Ringed Planet...!?

    NASA Astrophysics Data System (ADS)

    2002-12-01

    Don't worry - you are not the only one who thought this was a nice amateur photo of planet Saturn, Lord of the Rings in our Solar System! But then the relative brightness and positions of the moons may appear somewhat unfamiliar... and the ring system does look unusually bright when compared to the planetary disk...?? Well, it is not Saturn, but Uranus , the next giant planet further out, located at a distance of about 3,000 million km, or 20 times the distance between the Sun and the Earth. The photo shows Uranus surrounded by its rings and some of the moons, as they appear on a near-infrared image that was obtained in the K s -band (at wavelength 2.2 µm) with the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory (Chile) . The exposure was made on November 19, 2002 (03:00 hrs UT) during a planetary research programme. The observing conditions were excellent (seeing 0.5 arcsec) and the exposure lasted 5 min. The angular diameter of Uranus is about 3.5 arcsec. The observers at ISAAC were Emmanuel Lellouch and Thérése Encrenaz of the Observatoire de Paris (France) and Jean-Gabriel Cuby and Andreas Jaunsen (both ESO-Chile). The rings The rings of Uranus were discovered in 1977, from observations during a stellar occultation event by astronomer teams at the Kuiper Airborne Observatory (KAO) and the Perth Observatory (Australia). Just before and after the planet moved in front of the (occulted) star, the surrounding rings caused the starlight to dim for short intervals of time. Photos obtained from the Voyager-2 spacecraft in 1986 showed a multitude of very tenuous rings. These rings are almost undetectable from the Earth in visible light. However, on the present VLT near-infrared picture, the contrast between the rings and the planet is strongly enhanced. At the particular wavelength at which this observation was made, the infalling sunlight is almost completely absorbed by gaseous methane present in the planetary atmosphere and the disk of Uranus therefore appears unsually dark. At the same time, the icy material in the rings reflects the sunlight and appears comparatively bright. Uranus is unique among the planets of the solar system in having a tilted rotation axis that is close to the main solar system plane in which most planets move (the "Ecliptic"). At the time of the Voyager-2 encounter (1986), the southern pole was oriented toward the Earth. Now, sixteen years later (corresponding to about one-fifth of Uranus' 84-year period of revolution), we observe the Uranian ring system at an angle that is comparable to the one under which we see Saturn when its ring system is most "open". The moons ESO PR Photo 31b/02 ESO PR Photo 31b/02 [Preview - JPEG: 400 x 526 pix - 76k] [Full-Res - JPEG: 1460 x 1919 pix - 1.1M] Caption : PR Photo 31b/02 provides identifications of the Uranian moons present in PR Photo 31a/02 . The unidentified, round object to the left is a background star. The image scale in indicated by the bar. Seven of the moons of Uranus have been identified in PR Photo 31b/02 [1]. Of these, Titania and Oberon are the brightest (visual magnitude about 14). They were first seen in 1787 by the discoverer of Uranus, William Herschel (1738-1822), working at Bath in England. Ariel and Umbriel were found in 1851 by William Lassell (1799-1880) at Liverpool in the same country. Miranda was discovered in 1948 by Gerard Kuiper (1905-1973) at the 5-m Palomar telescope in California (USA). The much smaller and fainter Puck and Portia (visual magnitude about 21 and barely visible in the photo) were first found in 1985-86 by Stephen P. Synnott of the Jet Propulsion Laboratory (USA), during a study of Voyager-2 photos obtained soon before this NASA spacecraft flew by Uranus in January 1986. Other VLT images If you now want to see a fine VLT photo of Saturn, please look at PR Photo 04a/02 , obtained in late 2001. It was made with the NAOS-CONICA (NACO) Adaptive Optics facility and is therefore much less influenced by atmospheric turbulence and hence correspondingly shar

  9. On planet formation in HL Tau

    NASA Astrophysics Data System (ADS)

    Dipierro, Giovanni; Price, Daniel; Laibe, Guillaume; Hirsh, Kieran; Cerioli, Alice; Lodato, Giuseppe

    2015-10-01

    We explain the axisymmetric gaps seen in recent long-baseline observations of the HL Tau protoplanetary disc with the Atacama Large Millimetre/Submillimetre Array (ALMA) as being due to the different response of gas and dust to embedded planets in protoplanetary discs. We perform global, three-dimensional dusty smoothed particle hydrodynamics calculations of multiple planets embedded in dust/gas discs which successfully reproduce most of the structures seen in the ALMA image. We find a best match to the observations using three embedded planets with masses of 0.2, 0.27 and 0.55 MJ in the three main gaps observed by ALMA, though there remain uncertainties in the exact planet masses from the disc model.

  10. Planet-crossing asteroid survey

    NASA Technical Reports Server (NTRS)

    Wilder, P. D.

    1984-01-01

    The planet-crossing asteroid survey was begun in 1973 in order to study those asteroids which may intersect the orbits of the inner planets. Throughout the history of the survey, many of the various classes of asteroids were investigated. The near-Earth objects including the Apollo, Amor, and Aten families were studied in addition to asteroids whose orbits cross that of Mars, and some objects which are generally confined to the main belt. Observing was done on the 18 inch Schmidt telescope at the Palomar Mtn. Observatory. Typically, two consecutive photographs of a favorable field are taken. The exposure times of the films are usually twenty minutes and ten minutes, respectively. The telescope is guided at sidereal rate, so that asteroids will leave short trailed images. The films are then scanned for trails. By comparing the two films, the direction and approximate rate of motion of an asteroid may be determined.

  11. ExtraSolar Planets How did we find the planets?

    E-print Network

    Walter, Frederick M.

    ExtraSolar Planets #12;How did we find the planets? · Mercury, Venus, Mars, Jupiter, Saturn: orbital motions · KBOs: motions #12;How do we find ExtraSolar Planets? #12;How do we find ExtraSolar Planets? · Back to Astronomy... #12;Finding Extrasolar Planets. I Direct Searches Direct searches

  12. Masses, Radii, and Orbits of Small Kepler Planets: The Transition from Gaseous to Rocky Planets

    E-print Network

    Marcy, Geoffrey W; Howard, Andrew W; Rowe, Jason F; Jenkins, Jon M; Bryson, Stephen T; Latham, David W; Howell, Steve B; Gautier, Thomas N; Batalha, Natalie M; Rogers, Leslie A; Ciardi, David; Fischer, Debra A; Gilliland, Ronald L; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen; Huber, Daniel; Chaplin, William J; Basu, Sarbani; Buchhave, Lars A; Quinn, Samuel N; Borucki, William J; Koch, David G; Hunter, Roger; Caldwell, Douglas A; Van Cleve, Jeffrey; Kolbl, Rea; Weiss, Lauren M; Petigura, Erik; Seager, Sara; Morton, Timothy; Johnson, John Asher; Ballard, Sarah; Burke, Chris; Cochran, William D; Endl, Michael; MacQueen, Phillip; Everett, Mark E; Lissauer, Jack J; Ford, Eric B; Torres, Guillermo; Fressin, Francois; Brown, Timothy M; Steffen, Jason H; Charbonneau, David; Basri, Gibor S; Sasselov, Dimitar D; Winn, Joshua; Sanchis-Ojeda, Roberto; Christiansen, Jessie; Adams, Elisabeth; Henze, Christopher; Dupree, Andrea; Fabrycky, Daniel C; Fortney, Jonathan J; Tarter, Jill; Holman, Matthew J; Tenenbaum, Peter; Shporer, Avi; Lucas, Philip W; Welsh, William F; Orosz, Jerome A; Bedding, T R; Campante, T L; Davies, G R; Elsworth, Y; Handberg, R; Hekker, S; Karoff, C; Kawaler, S D; Lund, M N; Lundkvist, M; Metcalfe, T S; Miglio, A; Aguirre, V Silva; Stello, D; White, T R; Boss, Alan; Devore, Edna; Gould, Alan; Prsa, Andrej; Agol, Eric; Barclay, Thomas; Coughlin, Jeff; Brugamyer, Erik; Mullally, Fergal; Quintana, Elisa V; Still, Martin; hompson, Susan E; Morrison, David; Twicken, Joseph D; Désert, Jean-Michel; Carter, Josh; Crepp, Justin R; Hébrard, Guillaume; Santerne, Alexandre; Moutou, Claire; Sobeck, Charlie; Hudgins, Douglas; Haas, Michael R; Robertson, Paul; Lillo-Box, Jorge; Barrado, David

    2014-01-01

    We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities for all of the transiting planets (41 of 42 have a false-positive probability under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than 3X the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify 6 planets with densities above 5 g/cc, suggesting a mostly rocky interior f...

  13. A Gemini/GMOS study of the physical conditions and kinematics of the blue compact dwarf galaxy Mrk 996

    NASA Astrophysics Data System (ADS)

    Telles, Eduardo; Thuan, Trinh X.; Izotov, Yuri I.; Carrasco, Eleazar R.

    2014-01-01

    Aims: We present an integral field spectroscopic study with the Gemini Multi-Object Spectrograph (GMOS) of the unusual blue compact dwarf (BCD) galaxy Mrk 996. Methods: We show through velocity and dispersion maps, emission-line intensity and ratio maps, and by a new technique of electron density limit imaging that the ionization properties of different regions in Mrk 996 are correlated with their kinematic properties. Results: From the maps, we can spatially distinguish a very dense high-ionization zone with broad lines in the nuclear region, and a less dense low-ionization zone with narrow lines in the circumnuclear region. Four kinematically distinct systems of lines are identified in the integrated spectrum of Mrk 996, suggesting stellar wind outflows from a population of Wolf-Rayet (WR) stars in the nuclear region, superposed on an underlying rotation pattern. From the intensities of the blue and red bumps, we derive a population of ~473 late nitrogen (WNL) stars and ~98 early carbon (WCE) stars in the nucleus of Mrk 996, resulting in a high N(WR)/N(O+WR) of 0.19. We derive, for the outer narrow-line region, an oxygen abundance 12 + log (O/H) = 7.94 ± 0.30 (~0.2 Z?) by using the direct Te method derived from the detected narrow [O iii]?4363 line. The nucleus of Mrk 996 is, however, nitrogen-enhanced by a factor of ~20, in agreement with previous CLOUDY modeling. This nitrogen enhancement is probably due to nitrogen-enriched WR ejecta, but also to enhanced nitrogen line emission in a high-density environment. Although we have made use here of two new methods - principal component analysis (PCA) tomography and a method for mapping low- and high-density clouds - to analyze our data, new methodology is needed to further exploit the wealth of information provided by integral field spectroscopy. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and SECYT (Argentina).Reduced and calibrated data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/561/A64

  14. Seismology of Giant Planets

    E-print Network

    Gaulme, Patrick; Schmider, Francois-Xavier; Guillot, Tristan

    2014-01-01

    Seismology applied to giant planets could drastically change our understanding of their deep interiors, as it has happened with the Earth, the Sun, and many main-sequence and evolved stars. The study of giant planets' composition is important for understanding both the mechanisms enabling their formation and the origins of planetary systems, in particular our own. Unfortunately, its determination is complicated by the fact that their interior is thought not to be homogeneous, so that spectroscopic determinations of atmospheric abundances are probably not representative of the planet as a whole. Instead, the determination of their composition and structure must rely on indirect measurements and interior models. Giant planets are mostly fluid and convective, which makes their seismology much closer to that of solar-like stars than that of terrestrial planets. Hence, helioseismology techniques naturally transfer to giant planets. In addition, two alternative methods can be used: photometry of the solar light ref...

  15. The planet Pluto

    NASA Astrophysics Data System (ADS)

    Whyte, A. J.

    The search for a planet exterior to Neptune and the discovery of Pluto are discussed, and current knowledge of the planet Pluto is reviewed. Following a review of the discovery of the outer planets Uranus and Neptune, the 80-year search for a body which would account for the observed residuals in the motions of Uranus and Neptune is considered, with particular attention given to the work of Percival Lowell in calculating likely positions of the planet. The discovery of a planet in the position predicted by Lowell at Lowell Observatory in 1930 is then described, and the naming of the body Pluto is discussed. Consideration is then given to information concerning the orbit, mass, dimensions, density, composition and surface properties of Pluto acquired by photography, spectroscopy, photometry and polarimetry in the nearly 50 years following its discovery, with particular emphasis given to the discovery of the Pluto satellite designated Charon. Planned space-borne observations of the planet Pluto are indicated.

  16. The Terrestrial Planet Finder coronagraph dynamics error budget

    NASA Technical Reports Server (NTRS)

    Shaklan, Stuart B.; Marchen, Luis; Green, Joseph J.; Lay, Oliver P.

    2005-01-01

    The Terrestrial Planet Finder Coronagraph (TPF-C) demands extreme wave front control and stability to achieve its goal of detecting earth-like planets around nearby stars. We describe the performance models and error budget used to evaluate image plane contrast and derive engineering requirements for this challenging optical system.

  17. Formation of Giant Planets

    NASA Astrophysics Data System (ADS)

    Lissauer, J. J.; Stevenson, D. J.

    The observed properties of giant planets, models of their evolution, and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our solar system contain considerable quantities of hydrogen and helium; these gases could not have condensed into solid planetesimals within the protoplanetary disk. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. The transiting extrasolar planet HD149026b, which is slightly more massive than Saturn, appears to have comparable amounts of light gases and heavy elements. The other observed transiting exoplanets are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our solar system, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus, and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of these planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the giant planet cores grow massive enough to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary question regarding the core nucleated growth model is under what conditions can planets develop cores sufficiently massive to accrete gas envelopes within the lifetimes of gaseous protoplanetary disks.

  18. Antibacterial Activity, in Vitro Cytotoxicity, and Cell Cycle Arrest of Gemini Quaternary Ammonium Surfactants.

    PubMed

    Zhang, Shanshan; Ding, Shiping; Yu, Jing; Chen, Xuerui; Lei, Qunfang; Fang, Wenjun

    2015-11-10

    Twelve gemini quaternary ammonium surfactants have been employed to evaluate the antibacterial activity and in vitro cytotoxicity. The antibacterial effects of the gemini surfactants are performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with minimum inhibitory concentrations (MIC) ranging from 2.8 to 167.7 ?M. Scanning electron microscopy (SEM) analysis results show that these surfactants interact with the bacterial cell membrane, disrupt the integrity of the membrane, and consequently kill the bacteria. The data recorded on C6 glioma and HEK293 human kidney cell lines using an MTT assay exhibit low half inhibitory concentrations (IC50). The influences of the gemini surfactants on the cell morphology, the cell migration ability, and the cell cycle are observed through hematoxylin-eosin (HE) staining, cell wound healing assay, and flow cytometric analyses, respectively. Both the values of MIC and IC50 decrease against the growth of the alkyl chain length of the gemini surfactants with the same spacer group. In the case of surfactants 12-s-12, the MICs and IC50s are found to decrease slightly with the spacer chain length changing from 2 to 8 and again to increase at higher spacer length (s = 10-12). All of the gemini surfactants show great antibacterial activity and cytotoxicity, and they might exhibit potential applications in medical fields. PMID:26474336

  19. What makes a planet habitable ?

    E-print Network

    Guyon, Olivier

    What makes a planet habitable ? #12;#12;How to detect planets ? #12;Radial velocity #12;Transits storms · Gl 581 b,c,d,e [RV]: habitable planets ? Only 20 light year away, 4 planets. Gl 581 e (closest, but WILL "freeze away" with time When is a planet habitable ? #12;Water... Mars & Venus lost their oceans H2O

  20. Constraints on the frequency of circumbinary planets in wide orbits

    NASA Astrophysics Data System (ADS)

    Bonavita, Mariangela; Thalmann, Christian; Desidera, Silvano; Vigan, Arthur; Chauvin, Gael; Biller, Beth

    2015-12-01

    In the past decade, an increasing amount of effort has been spent on studying the formation and evolution of planets in the environment of binary host star systems (see e.g. the book “Planets in Binaries”, Haghighipour 2010). The Exoplanets.org database (Wright et al. 2011) lists several confirmed planets that have been found in binary systems to date. All of these discoveries have been made with indirect detection methods such as Doppler spectroscopy or transit photometry methods, which are heavily biased towards planets with short orbital periods and, therefore, favor circumstellar (‘s-type’) configurations around individual components of wide binary systems. Despite this bias, the Kepler spacecraft has discovered seven planets in circumbinary (‘p-type’) orbits encompassing tight binary systems, hinting at the existence of an extensive unseen population of circumbinary planets.Direct imaging, on the other hand, is a powerful planet detection technique particularly well suited to planets on wide orbits, which complements the limited parameter space of the indirect detection methods. However, such surveys have typically rejected binary systems from their target sample, leaving the population of wide-orbit planets in such systems largely unexplored. To address this, the SPOTS project (Search for Planets Orbiting Two Stars; Thalmann et al. 2014) is conducting the first dedicated direct imaging survey for circumbinary planets.In this talk I will present the results of a statistical analysis of the combined body of existing high contrast imaging constraints on circumbinary planets carried on to complement the results of our ongoing survey.

  1. Terrestrial planet formation

    PubMed Central

    Righter, K.; O’Brien, D. P.

    2011-01-01

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (?106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  2. Planet Formation - Overview

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2005-01-01

    Modern theories of star and planet formation are based upon observations of planets and smaller bodies within our own Solar System, exoplanets &round normal stars and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path.

  3. Terrestrial planet formation.

    PubMed

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  4. Planet - Disk Symbiosis

    E-print Network

    Re'em Sari; Peter Goldreich

    2003-07-05

    Planets form in disks around young stars. Interactions with these disks cause them to migrate and thus affect their final orbital periods. We suggest that the connection between planets and disks may be deeper and involve a symbiotic evolution. By contributing to the outward transport of angular momentum, planets promote disk accretion. Here we demonstrate that planets sufficiently massive to open gaps could be the primary agents driving disk accretion. Those having masses below the gap opening threshold drift inward more rapidly than the disk material and can only play a minor role in its accretion. Eccentricity growth during gap formation may involve an even more intimate symbiosis. Given a small initial eccentricity, just a fraction of a percent, the orbital eccentricity of a massive planet may grow rapidly once a mass in excess of the planet's mass has been repelled to form a gap around the planet's orbit. Then, as the planet's radial excursions approach the gap's width, subsequent eccentricity growth slows so that the planet's orbit continues to be confined within the gap.

  5. The Direct Imaging Search of Exoplanets from Ground and Space

    NASA Astrophysics Data System (ADS)

    Dou, Jiangpei; Ren, Deqing; Zhu, Yongtian

    2015-08-01

    Exoplanets search is one of the hottest topics in both modern astronomy and public domain. Until now over 1990 exoplanets have been confirmed mostly by the indirect radial velocity and transiting approaches, yielding several important physical information such as masses and radius. The study of the physics of planet formation and evolution will focus on giant planets through the direct imaging.However, the direct imaging of exoplanets remains challenging, due to the large flux ratio difference and the nearby angular distance. In recent years, the extreme adaptive optics (Ex-AO) coronagraphic instrumentation has been proposed and developed on 8-meter class telescopes, which is optimized for the high-contrast imaging observation from ground, for the giant exoplanets and other faint stellar companions. Gemini Planet Imager (GPI) has recently come to its first light, with a development period over 10 years. The contrast level has been pushed to 10-6. Due to the space limitation or this or other reasons, none professional adaptive optics is available for most of current 3~4 meter class telescopes, which will limit its observation power to some extent, especially in the research of high-contrast imaging of exoplanets.In this presentation, we will report the latest observation results by using our Extreme Adaptive Optics (Ex-AO) as a visiting instrument for high-contrast imaging on ESO’s 3.58-meter NTT telescope at LSO, and on 3.5-meter ARC telescope at Apache Point Observatory, respectively. It has demonstrated the Ex-AO can be used for the scientific research of exoplanets and brown dwarfs. With a update of the currect configuration with critical hardware, the dedicated instrument called as EDICT for imaging research of young giant exoplanets will be presented. Meanwhile, we have fully demonstrated in the lab a contrast on the order of 10-9 in a large detection area, which is a critical technique for future Earth-like exoplanets imaging space missions. And a space program of JEEEDIS will also be presented in this talk.

  6. Photoinduced demulsification of emulsions using a photoresponsive gemini surfactant.

    PubMed

    Takahashi, Yutaka; Fukuyasu, Kengo; Horiuchi, Tatsuya; Kondo, Yukishige; Stroeve, Pieter

    2014-01-14

    This Article reports on the influence of light irradiation on the stability of emulsions prepared using a photoresponsive gemini surfactant (C7-azo-C7) having an azobenzene skeleton as a spacer. When mixtures of trans C7-azo-C7 aqueous solution and n-octane are homogenized, stable emulsions are obtained in a specific region of weight fraction and surfactant concentration. Fluorescence microscopy observations using a small amount of fluorescent probes show that the stable emulsions are oil-in-water (O/W)-type. UV irradiation of stable O/W emulsions promotes the cis isomerization of trans C7-azo-C7 and leads to the coalescence of the oil (octane) droplets in the emulsions, that is, demulsification. While the equilibrated interfacial tension (IFT) between aqueous trans C7-azo-C7 solution and octane is almost the same as that between aqueous cis C7-azo-C7 and octane, the occupied area per molecule for C7-azo-C7 at octane/water interface decreases with the cis photoisomerization of trans isomer. Dynamic IFT measurement shows that UV irradiation to the interface between aqueous trans C7-azo-C7 solution and octane brings about an increase in the interfacial tension, indicating that the Gibbs free energy at the interface increases. From these results, the cis isomerization of trans C7-azo-C7 molecules at the O/W interface due to UV irradiation leads to direct contact between the water and octane phases, because of the reduction of molecular area at the interface, and subsequently makes the emulsions demulsified. PMID:24354334

  7. Influence of stellar multiplicity on planet formation. I. Evidence of suppressed planet formation due to stellar companions within 20 au and validation of four planets from the Kepler multiple planet candidates

    SciTech Connect

    Wang, Ji; Fischer, Debra A.; Xie, Ji-Wei; Barclay, Thomas

    2014-03-01

    The planet occurrence rate for multiple stars is important in two aspects. First, almost half of stellar systems in the solar neighborhood are multiple systems. Second, the comparison of the planet occurrence rate for multiple stars to that for single stars sheds light on the influence of stellar multiplicity on planet formation and evolution. We developed a method of distinguishing planet occurrence rates for single and multiple stars. From a sample of 138 bright (K{sub P} < 13.5) Kepler multi-planet candidate systems, we compared the stellar multiplicity rate of these planet host stars to that of field stars. Using dynamical stability analyses and archival Doppler measurements, we find that the stellar multiplicity rate of planet host stars is significantly lower than field stars for semimajor axes less than 20 AU, suggesting that planet formation and evolution are suppressed by the presence of a close-in companion star at these separations. The influence of stellar multiplicity at larger separations is uncertain because of search incompleteness due to a limited Doppler observation time baseline and a lack of high-resolution imaging observation. We calculated the planet confidence for the sample of multi-planet candidates and find that the planet confidences for KOI 82.01, KOI 115.01, KOI 282.01, and KOI 1781.02 are higher than 99.7% and thus validate the planetary nature of these four planet candidates. This sample of bright Kepler multi-planet candidates with refined stellar and orbital parameters, planet confidence estimation, and nearby stellar companion identification offers a well-characterized sample for future theoretical and observational study.

  8. Reading the Signatures of Extrasolar Planets in Debris Disks

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc J.

    2009-01-01

    An extrasolar planet sculpts the famous debris dish around Fomalhaut; probably ma ny other debris disks contain planets that we could locate if only we could better recognize their signatures in the dust that surrounds them. But the interaction between planets and debris disks involves both orbital resonances and collisions among grains and rocks in the disks --- difficult processes to model simultanemus]y. I will describe new 3-D models of debris disk dynamics that incorporate both collisions and resonant trapping of dust for the first time, allowing us to decode debris disk images and read the signatures of the planets they contain.

  9. Giant Planet Observations with the James Webb Space Telescope

    E-print Network

    Norwood, James; Fletcher, Leigh N; Orton, Glenn; Irwin, Patrick G J; Atreya, Sushil; Rages, Kathy; Cavalié, Thibault; Sánchez-Lavega, Agustin; Hueso, Ricardo; Chanover, Nancy

    2015-01-01

    This white paper examines the benefit of the upcoming James Webb Space Telescope for studies of the Solar System's four giant planets: Jupiter, Saturn, Uranus, and Neptune. JWST's superior sensitivity, combined with high spatial and spectral resolution, will enable near- and mid-infrared imaging and spectroscopy of these objects with unprecedented quality. In this paper we discuss some of the myriad scientific investigations possible with JWST regarding the giant planets. This discussion is preceded by the specifics of JWST instrumentation most relevant to giant planet observations. We conclude with identification of desired pre-launch testing and operational aspects of JWST that would greatly benefit future studies of the giant planets.

  10. Origins of Eccentric Extrasolar Planets: Testing the Planet-Planet Scattering Model

    E-print Network

    Eric B. Ford; Frederic A. Rasio

    2008-06-06

    (Abridged) In planetary systems with two or more giant planets, dynamical instabilities can lead to collisions or ejections through strong planet--planet scattering. Previous studies for simple initial configurations with two equal-mass planets revealed some discrepancies between the results of numerical simulations and the observed orbital elements of extrasolar planets. Here, we show that simulations with two unequal mass planets starting on nearly circular orbits predict a reduced frequency of collisions and a broader range of final eccentricities. The two-planet scattering model can easily reproduce the observed eccentricities with a plausible distribution of planet mass ratios. Further, the two-planet scattering model predicts a maximum eccentricity of about 0.8, independent of the distribution of planet mass ratios, provided that both planets are initially place on nearly circular orbits. This compares favorably with current observations and will be tested by future planet discoveries. The combination of planet--planet scattering and tidal circularization may be able to explain the existence of some giant planets with very short period orbits. Orbital migration due to planet scattering could play an important role in explaining the increased rate of giant planets with very short period orbits. We also re-examine and discuss various possible correlations between eccentricities and other properties of observed extrasolar planets. We demonstrate that the observed distribution of planet masses, orbital periods, and eccentricities can provide constraints for models of planet formation and evolution.

  11. Large-scale, low-cost synthesis of monodispersed gold nanorods using a gemini surfactant

    NASA Astrophysics Data System (ADS)

    Xu, Yong; Zhao, Yang; Chen, Lei; Wang, Xuchun; Sun, Jianxia; Wu, Haihua; Bao, Feng; Fan, Jian; Zhang, Qiao

    2015-04-01

    In this work, we demonstrate that monodispersed gold nanorods (AuNRs) can be obtained in a large-scale and cost-effective way. By using an industrial grade gemini surfactant (P16-8-16), the cost of the synthesis of high-quality AuNRs can be significantly reduced by 90%. The synthesis can be scaled up to over 4 L. The aspect ratio of AuNRs can be well tuned from ~2.4 to ~6.3, resulting in a wide tunability of the SPR properties. Systematic studies reveal that P16-8-16 could have a dual function: it can not only act as a capping ligand to stabilize AuNRs but also it can pre-reduce Au3+ to Au+ by the unsaturated C&z.dbd;C bond. Furthermore, the shape of AuNRs can be tailored from straight nanorods to ``dog-bones'' by simply varying the concentration of the surfactant. A mechanistic study shows that the shape change can be attributed to the presence of excess bromide ions because of the complex effect between bromide ions and gold ions. This work will not only help to achieve the industrial production of AuNRs, but also promote research into practical applications of various nanomaterials.In this work, we demonstrate that monodispersed gold nanorods (AuNRs) can be obtained in a large-scale and cost-effective way. By using an industrial grade gemini surfactant (P16-8-16), the cost of the synthesis of high-quality AuNRs can be significantly reduced by 90%. The synthesis can be scaled up to over 4 L. The aspect ratio of AuNRs can be well tuned from ~2.4 to ~6.3, resulting in a wide tunability of the SPR properties. Systematic studies reveal that P16-8-16 could have a dual function: it can not only act as a capping ligand to stabilize AuNRs but also it can pre-reduce Au3+ to Au+ by the unsaturated C&z.dbd;C bond. Furthermore, the shape of AuNRs can be tailored from straight nanorods to ``dog-bones'' by simply varying the concentration of the surfactant. A mechanistic study shows that the shape change can be attributed to the presence of excess bromide ions because of the complex effect between bromide ions and gold ions. This work will not only help to achieve the industrial production of AuNRs, but also promote research into practical applications of various nanomaterials. Electronic supplementary information (ESI) available: Digital pictures during the growth process of AuNRs, TEM images of nanoparticles obtained without P16-8-16 or silver, and HRTEM image and SAED patterns of quadrupeds. See DOI: 10.1039/c5nr00343a

  12. Synthesis, characterization and comparative evaluation of phenoxy ring containing long chain gemini imidazolium and pyridinium amphiphiles.

    PubMed

    Bhadani, Avinash; Kataria, Hardeep; Singh, Sukhprit

    2011-09-01

    Two series of phenoxy ring containing long chain imidazolium and pyridinium based gemini amphiphiles have been synthesized from renewable cardanol oil having different spacers (i. e. -S-(CH(2))(n)-S-, where n is 2, 3, 4 & 6). Critical micelle concentration (cmc) of these new gemini amphiphiles has been determined by conductivity method. Further, these new cationic amphiphiles have been evaluated for their DNA binding capability by agarose gel electrophoresis, ethidium bromide exclusion experiments and transmission electron microscopy (TEM). The cytotoxicity of these new amphiphiles have been evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Comparative studies of these phenoxy ring containing long chain gemini imidazolium amphiphiles and their pyridinium analogues depicted low cmc values of the later but greater DNA interaction capability and low cytotoxicity of the former series of amphiphiles. PMID:21676409

  13. Adsorption and Aggregation behaviors of tetrasiloxane-tailed gemini surfactants with (EO)m spacers.

    PubMed

    Guoyong, Wang; Wenshan, Qu; Zhiping, Du; Wanxu, Wang; Qiuxiao, Li

    2013-03-21

    Adsorption and aggregation behaviors of novel tetrasiloxane-tailed gemini surfactants N,N'-ditetrasiloxane-N,N'-digluconamide oligo ethylene glycol diglycidyl (Si-m-Si, where m is the number of ethylene glycol of 1, 2, and 3) were investigasted using surface tension, bromophenol blue encapsulation, dynamic light scattering (DLS), and transmission electron microscope (TEM) methods. The static surface tension of the aqueous Si-m-Si solutions measured at the critical aggregate concentration (CAC) was observed to be lower than that of traditional hydrocarbon gemini surfactants. This suggests that these newly synthesized gemini surfactants are capable of forming a closely packed monolayer film at the air/aqueous solution interface. With a combination of DLS data, TEM measurements, and bromophenol blue entrapment studies, formations of vesicles in Si-m-Si solutions appear to occur at a concentration well above the CAC. Moreover, the size of vesicles depended on their m values. PMID:23438340

  14. Detecting Extrasolar Planets with Integral Field Spectroscopy

    E-print Network

    A. Berton; R. G. Gratton; M. Feldt; T. Henning; S. Desidera; M. Turatto; H. M. Schmid; R. Waters

    2006-05-11

    Observations of extrasolar planets using Integral Field Spectroscopy (IFS), if coupled with an extreme Adaptive Optics system and analyzed with a Simultaneous Differential Imaging technique (SDI), are a powerful tool to detect and characterize extrasolar planets directly; they enhance the signal of the planet and, at the same time, reduces the impact of stellar light and consequently important noise sources like speckles. In order to verify the efficiency of such a technique, we developed a simulation code able to test the capabilities of this IFS-SDI technique for different kinds of planets and telescopes, modelling the atmospheric and instrumental noise sources. The first results obtained by the simulations show that many significant extrasolar planet detections are indeed possible using the present 8m-class telescopes within a few hours of exposure time. The procedure adopted to simulate IFS observations is presented here in detail, explaining in particular how we obtain estimates of the speckle noise, Adaptive Optics corrections, specific instrumental features, and how we test the efficiency of the SDI technique to increase the signal-to-noise ratio of the planet detection. The most important results achieved by simulations of various objects, from 1 M_J to brown dwarfs of 30 M_J, for observations with an 8 meter telescope, are then presented and discussed.

  15. Giant Planet and Brown Dwarf Formation

    NASA Astrophysics Data System (ADS)

    Chabrier, G.; Johansen, A.; Janson, M.; Rafikov, R.

    Understanding the dominant brown dwarf and giant planet formation processes, and finding out whether these processes rely on completely different mechanisms or share common channels, represents one of the major challenges of astronomy and remains the subject of heated debate. It is the aim of this review to summarize the latest developments in this field and to address the issue of origin by comparing different brown dwarf and giant planet formation scenarios with presently available observational constraints. As examined in the review, if objects are classified as "brown dwarfs" or "giant planets" on the basis of their formation mechanism, it has now become clear that their mass domains overlap and that there is no mass limit between these two distinct populations. Furthermore, while there is increasing observational evidence for the existence of non-deuterium (D)-burning brown dwarfs, some giant planets, characterized by a significantly metal-enriched composition, might be massive enough to ignite D burning in their core. Deuterium burning (or lack thereof) thus plays no role in either brown dwarf or giant planet formation. Consequently, we argue that the International Astronomical Union (IAU) definition for distinguishing these two populations has no physical justification and results in scientific confusion. In contrast, brown dwarfs and giant planets might bear some imprints of their formation mechanism, notably in their mean density and the physical properties of their atmosphere. Future direct imaging surveys will undoubtedly provide crucial information and perhaps provide some clear observational diagnostics to unambiguously distinguish these different astrophysical objects.

  16. Identifying wide, cold planets within 8pc

    NASA Astrophysics Data System (ADS)

    Deacon, Niall; Kraus, Adam; Crossfield, Ian

    2014-12-01

    Direct imaging exoplanet studies have recently unveiled a previously-unexpected population of massive planets (up to 15 M_Jup) in wide orbits (>100AU). Although most of these discoveries have been around younger stars and have been of similar temperatures to field brown dwarfs, one object (WD 0806-661B), is the coldest planet known outside our solar system. We propose a survey of all stars and brown dwarfs within 8pc to identify massive planetary companions in the 150-1500AU separation range. We will 1) Measure the fraction of wide planetary mass companions to stars in the Solar neighbourhood. 2) Identify all planets within 8 parsecs with masses above 8 Jupiter masses in our chosen projected separation range with lower mass limits for closer and younger stars. 3) Identify approximately 8 planets, four of which will have temperatures below 300K making them ideal targets to study water clouds in cold atmospheres with both JWST and the next generation of ground-based extremely large telescopes. Our survey will be the most complete survey for wide planets to-date and will provide both a measurement of the wide planet population and a legacy of cold, well constrained targets for future observatories.

  17. Draft: to appear in Optics Express Fainter and closer: finding planets by symmetry breaking

    E-print Network

    Ribak, Erez

    on Earth-like planet detection with extremely large telescopes," Astron. Astrophys. 447, 397-403 (2006). 7Draft: to appear in Optics Express Fainter and closer: finding planets by symmetry breaking Erez N *Corresponding author: eribak@physics.technion.ac.il Abstract: Imaging of planets is very difficult, due

  18. Theoretical Spectra and Atmospheres of Extrasolar Giant Planets

    E-print Network

    David Sudarsky; Adam Burrows; Ivan Hubeny

    2003-02-19

    We present a comprehensive theory of the spectra and atmospheres of irradiated extrasolar giant planets. We explore the dependences on stellar type, orbital distance, cloud characteristics, planet mass, and surface gravity. Phase-averaged spectra for specific known extrasolar giant planets that span a wide range of the relevant parameters are calculated, plotted, and discussed. The connection between atmospheric composition and emergent spectrum is explored in detail. Furthermore, we calculate the effect of stellar insolation on brown dwarfs. We review a variety of representative observational techniques and programs for their potential for direct detection, in light of our theoretical expectations, and we calculate planet-to-star flux ratios as a function of wavelength. Our results suggest which spectral features are most diagnostic of giant planet atmospheres and reveal the best bands in which to image planets of whatever physical or orbital characteristics.

  19. Shocks and star formation in Stephan's Quintet. I. Gemini spectroscopy of H?-bright knots

    SciTech Connect

    Konstantopoulos, I. S.; Cluver, M. E.; Appleton, P. N.; Guillard, P.; Trancho, G.; Bastian, N.; Charlton, J. C.; Fedotov, K.; Gallagher, S. C.; Smith, L. J.; Struck, C. J.

    2014-03-20

    We present a Gemini-GMOS spectroscopic study of Hubble Space Telescope (HST)-selected H?-emitting regions in Stephan's Quintet (HCG 92), a nearby compact galaxy group, with the aim of disentangling the processes of shock-induced heating and star formation in its intra-group medium. The ?40 sources are distributed across the system, but most densely concentrated in the ?kiloparsec-long shock region. Their spectra neatly divide them into narrow- and broad-line emitters, and we decompose the latter into three or more emission peaks corresponding to spatial elements discernible in HST imaging. The emission-line ratios of the two populations of H?-emitters confirm their nature as H II regions (90% of the sample) or molecular gas heated by a shock front propagating at ?300 km s{sup –1}. Their redshift distribution reveals interesting three-dimensional structure with respect to gas-phase baryons, with no H II regions associated with shocked gas, no shocked regions in the intruder galaxy NGC 7318B, and a sharp boundary between shocks and star formation. We conclude that star formation is inhibited substantially, if not entirely, in the shock region. Attributing those H II regions projected against the shock to the intruder, we find a lopsided distribution of star formation in this galaxy, reminiscent of pileup regions in models of interacting galaxies. The H? luminosities imply mass outputs, star formation rates, and efficiencies similar to nearby star-forming regions. Two large knots are an exception to this, being comparable in stellar output to the prolific 30 Doradus region. We also examine Stephan's Quintet in the context of compact galaxy group evolution, as a paradigm for intermittent star formation histories in the presence of a rich, X-ray-emitting intra-group medium. All spectra are provided as supplemental materials.

  20. Structural and transfection properties of amine-substituted gemini surfactant-based nanoparticles

    SciTech Connect

    Wettig,S.; Badea, I.; Donkuru, M.; Verrall, R.; Foldvari, M.

    2007-01-01

    Increases in DNA transfection efficiencies for non-viral vectors can be achieved through rational design of novel cationic building blocks. Based on previous results examining DNA condensation by polyamines, novel gemini surfactants have been designed that incorporate aza or imino substituents within the spacer group in order to increase interactions with DNA and potentially improve their DNA transfection ability. Transfection efficiencies and cell toxicity of gemini nanoparticles constructed from plasmid DNA, gemini surfactant, and a neutral lipid were measured in COS7 cells using a luciferase assay. Structural properties of nanoparticles were examined by using circular dichroism, particle size, zeta potential, and small-angle X-ray scattering (SAXS) measurements. The incorporation of aza and imino substituents within the spacer group was observed to enhance the transfection ability of gemini surfactants. Incorporation of an imino group in the structure of the 1,9-bis(dodecyl)-1,1,9,9-tetramethyl-5-imino-1,9-nonanediammonium dibromide surfactant (12-7NH-12) resulted in a statistically significant (p < 0.01) 9-fold increase in transfection compared to an unsubstituted gemini surfactant and a 3-fold increase compared to the corresponding aza-substituted compound. A pH-dependent transition in size and zeta potential was observed to occur at pH 5.5 for complexes formed from the 12-7NH-12 compound. SAXS results show weakly ordered structures and the presence of multiple phases. The incorporation of a pH-active imino group within the spacer of the gemini surfactant results in a significant increase in transfection efficiency that can be related to both pH-induced changes in nanoparticle structure and the formation of multiple phases that more readily allow for membrane fusion that may facilitate DNA release.

  1. Future Missions to Study Signposts of Planets

    NASA Technical Reports Server (NTRS)

    Traub, Wesley A.

    2011-01-01

    This talk will focus on debris disks, will compare ground and space and will discuss 2 proposed missions, Exoplanetary Circumstellar Environments And Disk Explorer (EXCEDE) and Zodiac II. At least 2 missions have been proposed for disk imaging. The technology is largely in hand today. A small mission would do excellent disk science, and would test technology for a future large mission for planets.

  2. Name That Planet!

    ERIC Educational Resources Information Center

    Beck, Judy; Rust, Cindy

    2002-01-01

    Presents an activity in which students in groups explore one planet in the solar system and present their findings to the whole class. Focuses on the planet's location in the solar system, geological features, rate of revolutions, and calendar year. (YDS)

  3. March of the Planets

    ERIC Educational Resources Information Center

    Thompson, Bruce

    2007-01-01

    The motion of the planets in their orbits can be demonstrated to students by using planetarium software programs. These allow time to be sped up so that the relative motions are readily observed. However, it is also valuable to have the students understand the real speed of the planets in their orbits. This paper describes an exercise that gives…

  4. Planets in Motion

    ERIC Educational Resources Information Center

    Riddle, Bob

    2005-01-01

    All the planets in the solar system revolve around the Sun in the same direction, clockwise when viewed from above the North Pole. This is referred to as direct motion. From the perspective on the Earth's surface, the planets travel east across the sky in relation to the background of stars. The Sun also moves eastward daily, but this is an…

  5. Planet Earth: Plate Tectonics

    E-print Network

    Watts, A. B. "Tony"

    Planet Earth: Plate Tectonics Recommended Books: An Introduction to Our Dynamic Planet (ODP), 2007, ice and sediment for long periods of geological time (>105 a). · Controlled and passive (e, Problem sets etc Lecture 1: Plate Mechanics and Kinematics The Earth comprises 7 major plates and a number

  6. A lopsided planet Photolibrary

    E-print Network

    Nimmo, Francis

    by an asteroid. Nothing surprising in that: one look at the Red Planet's crater- pocked surface is enough planet. the IDea that the northern lowlands might be a humongous impact crater isn't new. American right. Craters are usually circular. The basin isn't. Partly that's because a group of gigantic

  7. First light of the VLT planet finder SPHERE - II. The physical properties and the architecture of the young systems PZ Tel and HD 1160 revisited

    E-print Network

    Maire, A -L; Ginski, C; Vigan, A; Messina, S; Mesa, D; Galicher, R; Gratton, R; Desidera, S; Kopytova, T G; Millward, M; Thalmann, C; Claudi, R U; Ehrenreich, D; Zurlo, A; Chauvin, G; Antichi, J>; Baruffolo, A; Bazzon, A; Beuzit, J -L; Blanchard, P; Boccaletti, A; de Boer, J; Carle, M; Cascone, E; Costille, A; De Caprio, V; Delboulbe, A; Dohlen, K; Dominik, C; Feldt, M; Fusco, T; Girard, J H; Giro, E; Gisler, D; Gluck, L; Gry, C; Henning, T; Hubin, N; Hugot, E; Jaquet, M; Kasper, M; Lagrange, A -M; Langlois, M; Mignant, D Le; Llored, M; Madec, F; Martinez, P; Mawet, D; Milli, J; Moeller-Nilsson, O; Mouillet, D; Moulin, T; Moutou, C; Origne, A; Pavlov, A; Petit, C; Pragt, J; Puget, P; Ramos, J; Rochat, S; Roelfsema, R; Salasnich, B; Sauvage, J -F; Schmid, H M; Turatto, M; Udry, S; Vakili, F; Wahhaj, Z; Weber, L; Wildi, F

    2015-01-01

    [Abridged] Context. The young systems PZ Tel and HD 1160, hosting known low-mass companions, were observed during the commissioning of the new planet finder SPHERE with several imaging and spectroscopic modes. Aims. We aim to refine the physical properties and architecture of both systems. Methods. We use SPHERE commissioning data and REM observations, as well as literature and unpublished data from VLT/SINFONI, VLT/NaCo, Gemini/NICI, and Keck/NIRC2. Results. We derive new photometry and confirm the nearly daily photometric variability of PZ Tel A. Using literature data spanning 38 yr, we show that the star also exhibits a long-term variability trend. The 0.63-3.8 mic SED of PZ Tel B allows us to revise its properties: spectral type M7+/-1, Teff=2700+/-100 K, log(g)0.66) of PZ Tel B. For e4 MJ) outside 0.5" for the PZ Tel system. We also show that K1-K2 color can be used with YJH low-resolution spectra to identify young L-type companions, provided high photometric accuracy (<0.05 mag) is achieved. Conclusi...

  8. Formation of Planets Around the Sun and Other Stars.

    SciTech Connect

    Lin, Doug

    2005-11-14

    Formation of Planets around the Sun and other stars. The quest to understand the formation of planets and planetary systems has entered an era of renaissance. Driven by observational discoveries in solar system exploration, protostellar disks, and extra solar planets, we have established a rich data bank which contains not only relic clues around mature stars, including the Sun, but also direct image of ongoing processes around young stars. For the first time in this scientific endeavor, we have adequate information to construct quantitative models to account for the ubiquity of planets and diversity of planetary systems. Some of the most intriguing theoretical questions facing us today include: a) how did the planets in the solar system form with their present-day mass, composition, and orbital elements, b) is planet formation a deterministic or chaotic process, and c) what are the observable signatures of planet formation and evolution around nearby young and mature stars? I will present a comprehensive scenario which suggests a) gas giant planets formed through coagulation of planetsimals and gas accretion onto earth-like cores; b) the final assemblage of the terrestrial planets in the solar system occurred through the propagation of Jupiter's secular resonance 4-30 Myrs after the emergence of the gas giant; and c) although they are yet to be discovered, Earth-like planets are expected to be common around nearby stars.

  9. Planets X and Pluto

    NASA Astrophysics Data System (ADS)

    Hoyt, W. G.

    It is pointed out that man has discovered some fundamental truths about the universe through mathematics. The 'X' in the title of the reported study refers to the trans-Neptunian planet postulated by Percival Lowell. Attention is given to Uranus and the asteroids, Neptune, the first search for planet X, the second search for planet X, the consideration of a trans-Neptunian planet, Lowell's legacies, the third search for planet X, the investigations performed by Clyde William Tombaugh, the early controversies regarding Pluto, and the ultimate resolution of the controversies. It was finally recognized that Pluto cannot have caused the perturbations in the motion of Uranus that Lowell, Pickering, Kourganoff and others found over the years.

  10. Influence of statistical sequential decay on isoscaling and symmetry energy coefficient in a GEMINI simulation

    E-print Network

    P. Zhou; W. D. Tian; Y. G. Ma; X. Z. Cai; D. Q. Fang; H. W. Wang

    2011-11-17

    Extensive calculations on isoscaling behavior with the sequential-decay model gemini are performed for the medium-to-heavy nuclei in the mass range A = 60-120 at excitation energies up to 3 MeV/nucleon. The comparison between the products after the first-step decay and the ones after the entire-steps decay demonstrates that there exists a strong sequential decay effect on the final isoscaling parameters and the apparent temperature. Results show that the apparent symmetry energy coefficient $\\gamma_{app}$ does not reflect the initial symmetry energy coefficient $C_{sym}$ embedded in the mass calculation in the present GEMINI model.

  11. Modern Gemini-Approach to Technology Development for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    White, Harold

    2010-01-01

    In NASA's plan to put men on the moon, there were three sequential programs: Mercury, Gemini, and Apollo. The Gemini program was used to develop and integrate the technologies that would be necessary for the Apollo program to successfully put men on the moon. We would like to present an analogous modern approach that leverages legacy ISS hardware designs, and integrates developing new technologies into a flexible architecture This new architecture is scalable, sustainable, and can be used to establish human exploration infrastructure beyond low earth orbit and into deep space.

  12. Discovery of a Companion Candidate in the HD 169142 Transition Disk and the Possibility of Multiple Planet Formation

    NASA Astrophysics Data System (ADS)

    Reggiani, Maddalena; Quanz, Sascha P.; Meyer, Michael R.; Pueyo, Laurent; Absil, Olivier; Amara, Adam; Anglada, Guillem; Avenhaus, Henning; Girard, Julien H.; Carrasco Gonzalez, Carlos; Graham, James; Mawet, Dimitri; Meru, Farzana; Milli, Julien; Osorio, Mayra; Wolff, Schuyler; Torrelles, Jose-Maria

    2014-09-01

    We present L'- and J-band high-contrast observations of HD 169142, obtained with the Very Large Telescope/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source located at 0.''156 ± 0.''032 north of the host star (P.A. = 7.°4 ± 11.°3) appears in the final reduced L' image. At the distance of the star (~145 pc), this angular separation corresponds to a physical separation of 22.7 ± 4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. The source has a brightness of L' = 12.2 ± 0.5 mag, whereas it is not detected in the J band (J >13.8 mag). If its L' brightness arose solely from the photosphere of a companion and given the J - L' color constraints, it would correspond to a 28-32 M Jupiter object at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas is left in the inner disk cavity from which the companion could also be accreting. In this case, the object could be lower in mass and its luminosity enhanced by the accretion process and by a circumplanetary disk. A lower-mass object is more consistent with the observed cavity width. Finally, the observations enable us to place an upper limit on the L'-band flux of a second companion candidate orbiting in the disk annular gap at ~50 AU, as suggested by millimeter observations. If the second companion is also confirmed, HD 169142 might be forming a planetary system, with at least two companions opening gaps and possibly interacting with each other.

  13. DISCOVERY OF A COMPANION CANDIDATE IN THE HD 169142 TRANSITION DISK AND THE POSSIBILITY OF MULTIPLE PLANET FORMATION

    SciTech Connect

    Reggiani, Maddalena; Quanz, Sascha P.; Meyer, Michael R.; Amara, Adam; Avenhaus, Henning; Meru, Farzana; Pueyo, Laurent; Wolff, Schuyler; Absil, Olivier; Anglada, Guillem; Osorio, Mayra; Gonzalez, Carlos Carrasco; Graham, James; Torrelles, Jose-Maria

    2014-09-01

    We present L'- and J-band high-contrast observations of HD 169142, obtained with the Very Large Telescope/NACO AGPM vector vortex coronagraph and the Gemini Planet Imager, respectively. A source located at 0.''156 ± 0.''032 north of the host star (P.A. = 7.°4 ± 11.°3) appears in the final reduced L' image. At the distance of the star (?145 pc), this angular separation corresponds to a physical separation of 22.7 ± 4.7 AU, locating the source within the recently resolved inner cavity of the transition disk. The source has a brightness of L' = 12.2 ± 0.5 mag, whereas it is not detected in the J band (J >13.8 mag). If its L' brightness arose solely from the photosphere of a companion and given the J – L' color constraints, it would correspond to a 28-32 M {sub Jupiter} object at the age of the star, according to the COND models. Ongoing accretion activity of the star suggests, however, that gas is left in the inner disk cavity from which the companion could also be accreting. In this case, the object could be lower in mass and its luminosity enhanced by the accretion process and by a circumplanetary disk. A lower-mass object is more consistent with the observed cavity width. Finally, the observations enable us to place an upper limit on the L'-band flux of a second companion candidate orbiting in the disk annular gap at ?50 AU, as suggested by millimeter observations. If the second companion is also confirmed, HD 169142 might be forming a planetary system, with at least two companions opening gaps and possibly interacting with each other.

  14. Nonviral gene delivery: gemini bispyridinium surfactant-based DNA nanoparticles.

    PubMed

    Fisicaro, Emilia; Compari, Carlotta; Bacciottini, Franco; Contardi, Laura; Barbero, Nadia; Viscardi, Guido; Quagliotto, Pierluigi; Donofrio, Gaetano; Ró?ycka-Roszak, Bo?enna; Misiak, Pawe?; Wo?niak, Edyta; Sansone, Francesco

    2014-11-20

    The interaction with a model membrane, the formation of DNA nanoparticles, and the transfection ability of a homologous series of bispyridinium dihexadecyl cationic gemini surfactants, differing in the length of the alkyl spacer bridging the two pyridinium polar heads in the 1 and 1' positions (P16-n with n = 3, 4, 8, 12), have been studied by means of differential scanning calorimetry (DSC), atomic force microscopy, electrophoresis mobility shift assay, and transient transfection assay measurements. The results presented here show that their performance in gene delivery is strictly related to their structure in solution. For the first time the different transfection activities of the compounds can be explained by referring to their thermodynamic properties in solution, previously studied. The compound with a spacer formed by four carbon atoms, showing unexpected enthalpic properties vs concentration in solution, is the only one giving rise to a transfection activity comparable to that of the commercial reagent, when formulated with L-?-dioleoylphosphatidylethanolamine. We suggest that P16-4 behaves like molecular tongs able to grip basic groups near each other, allowing the formation of compact and nearly spherical DNA particles. The compound with the longest spacer gives rise to loosely condensed structures by forming a sort of bow, not able to give rise to transfection notwithstanding the double positive charge of the molecule. On the other hand, DSC measurements on synthetic membranes show that the compounds with the shortest spacers (three and four methylene groups) practically do not interact with the 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine membrane, while compounds P16-8 and, particularly, P16-12 induce the formation of surfactant-rich and surfactant-poor domains in the membrane, without showing any peculiarity for compound P16-4. This could suggest that the mechanisms involved in the interaction with the model membrane and in gene delivery are substantially different and could strike a blow for an endocytosis mechanism for the internalization in the cell of the DNA nanoparticles. PMID:25340646

  15. PLANETS & LIFE HUMAN & PLANETARY PERSPECTIVES PLANETS AND LIFE

    E-print Network

    Rothman, Daniel

    but are interesting literature linked to the ideas that we will be investigating. Evolution of a habitable planet: 1PLANETS & LIFE ­ HUMAN & PLANETARY PERSPECTIVES #12; 2 PLANETS AND LIFE HUMAN AND PLANETARY and our theoretical understanding of planet evolution. We will study processes between the deep interior

  16. ExtraSolar Planets Finding Extrasolar Planets. I

    E-print Network

    Walter, Frederick M.

    ExtraSolar Planets #12;Finding Extrasolar Planets. I Direct Searches Direct searches are difficult #12;Finding Extrasolar Planets. II Transits #12;Transits Transits requires an edge-on orbit. ·Jupiter;How Transits Work #12;Finding Extrasolar Planets. III Astrometric Wobble #12;Finding Extrasolar

  17. DetectingDetecting Planets in thePlanets in the

    E-print Network

    Gaudi, B. Scott

    is the planet- star mass ratio. The inner contour indicates the (d,q) for which the fraction of lensesDetectingDetecting Planets in thePlanets in the Galactic BulgeGalactic Bulge B. Scott Gaudi Institute for Advanced Study #12;Abstract Determination of the frequency of planets in environments

  18. From Disks to Planets

    NASA Astrophysics Data System (ADS)

    Youdin, Andrew N.; Kenyon, Scott J.

    This pedagogical chapter covers the theory of planet formation, with an emphasis on the physical processes relevant to current research. After summarizing empirical constraints from astronomical and geophysical data, we describe the structure and evolution of protoplanetary disks. We consider the growth of planetesimals and of larger solid protoplanets, followed by the accretion of planetary atmospheres, including the core accretion instability. We also examine the possibility that gas disks fragment directly into giant planets and/or brown dwarfs. We defer a detailed description of planet migration and dynamical evolution to other work, such as the complementary chapter in this series by Morbidelli.

  19. The planets and life.

    NASA Technical Reports Server (NTRS)

    Young, R. S.

    1971-01-01

    It is pointed out that planetary exploration is not simply a program designed to detect life on another planet. A planet similar to earth, such as Mars, when studied for evidence as to why life did not arise, may turn out to be scientifically more important than a planet which has already produced a living system. Of particular interest after Mars are Venus and Jupiter. Jupiter has a primitive atmosphere which may well be synthesizing organic molecules today. Speculations have been made concerning the possibility of a bio-zone in the upper atmosphere of Venus.

  20. Direct Imaging and Spectroscopy of a Young Extrasolar Kuiper Belt in the Nearest OB Association

    E-print Network

    Currie, Thayne; Kuchner, Marc J; Madhusudhan, Nikku; Kenyon, Scott J; Thalmann, Christian; Carson, Joseph; Debes, John H

    2015-01-01

    We describe the discovery of a bright, young Kuiper belt-like debris disk around HD 115600, a $\\sim$ 1.4--1.5 M$_\\mathrm{\\odot}$, $\\sim$ 15 Myr old member of the Sco-Cen OB Association. Our H-band coronagraphy/integral field spectroscopy from the \\textit{Gemini Planet Imager} shows the ring has a (luminosity scaled) semi major axis of ($\\sim$ 22 AU) $\\sim$ 48 AU, similar to the current Kuiper belt. The disk appears to have neutral scattering dust, is eccentric (e $\\sim$ 0.1--0.2), and could be sculpted by analogues to the outer solar system planets. Spectroscopy of the disk ansae reveal a slightly blue to gray disk color, consistent with major Kuiper belt chemical constituents, where water-ice is a very plausible dominant constituent. Besides being the first object discovered with the next generation of extreme adaptive optics systems (i.e. SCExAO, GPI, SPHERE), HD 115600's debris ring and planetary system provides a key reference point for the early evolution of the solar system, the structure and compositio...

  1. Wind buffeting effects on the Gemini 8m primary mirrors M. K. Cho1,2

    E-print Network

    Wind buffeting effects on the Gemini 8m primary mirrors M. K. Cho1,2 , L. Stepp1 , and S. Kim3 and Mechanical Engineering, University of Arizona, 1130 N. Mountain, Tucson, AZ 85721 #12;Wind buffeting effects mirror distortion caused by wind pressure variations. To quantify telescope wind loading effects

  2. Gemini 4 prime crew with Official medical nurse for Astronaut crew members

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Gemini 4 prime crew, Astronauts Edward H. White II, (left), and James A. McDivitt (right) are shown with Lt. Dolores (Dee) O'Hare, US Air Force, Center Medical Office, Flight Medicine Branch, Manned Spaceflight Center (MSC). Lieutenant O'Hare has served during several space flights as Official medical nurse for the astronaut crew members on the missions.

  3. Salt Effect on Microstructures in Cationic Gemini Surfactant Solutions as Studied by Dynamic Light Scattering

    E-print Network

    Huang, Jianbin

    Salt Effect on Microstructures in Cationic Gemini Surfactant Solutions as Studied by Dynamic Light, C12C12C12(Et) underwent a typical "ordinary-to-extraordinary (o-e) transition" with decreasing salt concentration to zero. At higher salt concentration, a single relaxation mode, corresponding to the diffusion

  4. Crewmen of the U.S.S. Wasp watching recovery of Gemini 6 spacecraft

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Crewmen of the aircraft carrier U.S.S. Wasp gather on deck to watch the recovery of the Gemini 6 spacecraft and astronauts. Note the signs hanging from the railings which say 'Seasons Greetings from WASP' and 'Spirit of 76'.

  5. Gemini 12 crew cut cake aboard U.S.S. Wasp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    A happy Gemini 12 prime crew slice a cake made aboard the aircraft carrier, U.S.S. Wasp. Astronauts James A. Lovell Jr. (left), command pilot, and Edwin E. Aldrin Jr., pilot, had just been picked up from the splashdown area by helicopter.

  6. Crewmen of the U.S.S. Wasp watching recovery of Gemini 7 spacecraft

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Crewmen of the aircraft carrier U.S.S. Wasp gather on deck to watch the recovery of the Gemini 7 spacecraft and astronauts. Note the signs hanging from the railings which say 'Seasons Greetings from WASP' and 'Spirit of 76'.

  7. Gemini 9-A astronauts welcomed aboard U.S.S. Wasp

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Astronauts Thomas Stafford and Eugene Cernan (right) receive a warm welcome as they arrive aboard the prime recovery ship, the aircraft carrier U.S.S. Wasp. John C. Stonesifer, with the Manned Spacecraft Center's Landing and Recovery Division, stands next to microphone at left. The Gemini 9 spacecraft can be seen in the right background of the view.

  8. The Gemini 8m Telescopes C.M. Mountain, F.C. Gillett, J. Oschmann

    E-print Network

    conditions of our sites on Mauna Kea and Cerro Pachon, we have taken an end­to­end systems approach are now under construction at both Mauna Kea and Cerro Pachon (Figure 1). On Mauna Kea, the enclosure, construction and operations of the Gemini telescopes. We report on the progress of the telescopes on both Mauna

  9. Is Pluto a Planet? And what is a planet, anyways?

    E-print Network

    Walter, Frederick M.

    Is Pluto a Planet? And what is a planet, anyways? N = N* fs fp AST 248 #12;What is a star? A star is that we need to know precisely what we mean when we use the word planet. Is Pluto a Planet? #12;Is Pluto a Planet? A body that: ·Orbits a star ·Is large enough for its gravity to make it round ·Is

  10. The Evryscope and extrasolar planets

    NASA Astrophysics Data System (ADS)

    Fors, Octavi; Law, Nicholas Michael; Ratzloff, Jeffrey; del Ser, Daniel; Wulfken, Philip J.; Kavanaugh, Dustin

    2015-08-01

    The Evryscope (Law et al. 2015) is a 24-camera hemispherical all-sky gigapixel telescope (8,000 sq.deg. FoV) with rapid cadence (2mins exposure, 4sec readout) installed at CTIO. Ground-based single-station transiting surveys typically suffer from light curve sparsity and suboptimal efficiency because of their limited field of view (FoV), resulting in incomplete and biased detections. In contrast, the Evryscope offers 97% survey efficiency and one of the single-station most continuous and simultaneous monitoring of millions of stars (only limited by the day-night window).This unique facility is capable of addressing new and more extensive planetary populations, including: 1) for the first time, continuously monitor every 2mins a set of ~1000 bright white dwarfs (WDs). This will allow us to put constraints on the habitable planet fraction of Ceres-size planetesimals at the level of 30%, only in a survey timescales of a few weeks, as well as first-time testing planetary evolution models beyond the AGB phase. 2) search for rocky planets in the habitable zone around ~5,000 bright, nearby M-dwarfs. 3) synergies between Evryscope and upcoming exoplanets missions (e.g. TESS, PLATO) are also promising for target pre-imaging characterization, and increasing the giant planet yield by recovering multiple transits from planets seen as single transit events from space. 4) all-sky 2-min cadence of rare microlensing events of nearby stars. 5) all-sky continuous survey of microlensing events of nearby stars at 2mins cadence. 6) increase the census of giant planets around ~70,000 nearby, bright (g<10) solar-type stars, whose atmospheres can be characterized by follow-up observations. We are developing new data analysis algorithms to address the above scientific goals: from detecting the extremely short and faint transits around WDs, to disentangle planetary signals from very bright stars, and to combine space-based light curves with the Evryscope's ones. We will present the first results from the Evryscope, which achieved first light in 2015.

  11. The Atmospheres of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Richardson, L. J.; Seager, S.

    2007-01-01

    In this chapter we examine what can be learned about extrasolar planet atmospheres by concentrating on a class of planets that transit their parent stars. As discussed in the previous chapter, one way of detecting an extrasolar planet is by observing the drop in stellar intensity as the planet passes in front of the star. A transit represents a special case in which the geometry of the planetary system is such that the planet s orbit is nearly edge-on as seen from Earth. As we will explore, the transiting planets provide opportunities for detailed follow-up observations that allow physical characterization of extrasolar planets, probing their bulk compositions and atmospheres.

  12. Near Infrared Surface Properties of the Two Intrinsically Brightest Minor Planets (90377) Sedna and (90482) Orcus

    E-print Network

    Chadwick A. Trujillo; Michael E. Brown; David L. Rabinowitz; Thomas R. Geballe

    2005-04-12

    We present low resolution K band spectra taken at the Gemini 8 meter telescope of (90377) Sedna and (90482) Orcus (provisional designations 2003 VB12 and 2004 DW, respectively), currently the two minor planets with the greatest absolute magnitudes (i.e. the two most reflective minor planets). We place crude limits on the surface composition of these two bodies using a Hapke model for a wide variety of assumed albedos. The unusual minor planet (90377) Sedna was discovered on November 14, 2003 UT at roughly 90 AU with 1.6 times the heliocentric distance and perihelion distance of any other bound minor planet. It is the first solar system object discovered between the Kuiper Belt and the Oort Cloud, and may represent a transition population between the two. The reflectance spectrum of (90377) Sedna appears largely featureless at the current signal-to-noise ratio, suggesting a surface likely to be highly processed by cosmic rays. For large grain models (100 micron to 1 cm) we find that (90377) Sedna must have less than 70% surface fraction of water ice and less than 60% surface fraction of methane ice to 3 sigma confidence. Minor planet (90482) Orcus shows strong water ice absorption corresponding to less than 50% surface fraction for grain models 25 micron and larger. Orcus cannot have more than 30% of its surface covered by large (100 mm to 1 cm) methane grains to 3 sigma confidence.

  13. Limits on stellar companions to exoplanet host stars with eccentric planets

    SciTech Connect

    Kane, Stephen R.; Hinkel, Natalie R.; Howell, Steve B.; Horch, Elliott P.; Feng, Ying; Wright, Jason T.; Ciardi, David R.; Everett, Mark E.; Howard, Andrew W.

    2014-04-20

    Though there are now many hundreds of confirmed exoplanets known, the binarity of exoplanet host stars is not well understood. This is particularly true of host stars that harbor a giant planet in a highly eccentric orbit since these are more likely to have had a dramatic dynamical history that transferred angular momentum to the planet. Here we present observations of four exoplanet host stars that utilize the excellent resolving power of the Differential Speckle Survey Instrument on the Gemini North telescope. Two of the stars are giants and two are dwarfs. Each star is host to a giant planet with an orbital eccentricity >0.5 and whose radial velocity (RV) data contain a trend in the residuals to the Keplerian orbit fit. These observations rule out stellar companions 4-8 mag fainter than the host star at passbands of 692 nm and 880 nm. The resolution and field of view of the instrument result in exclusion radii of 0.''05-1.''4, which excludes stellar companions within several AU of the host star in most cases. We further provide new RVs for the HD 4203 system that confirm that the linear trend previously observed in the residuals is due to an additional planet. These results place dynamical constraints on the source of the planet's eccentricities, place constraints on additional planetary companions, and inform the known distribution of multiplicity amongst exoplanet host stars.

  14. The radial velocity search for extrasolar planets

    NASA Technical Reports Server (NTRS)

    Mcmillen, Robert S.

    1988-01-01

    Researchers are measuring small changes in the line-of-sight velocities of stars to detect the oscillating reflex acceleration induced by large planets. The intention is to observe enough stars for a long enough time to be able to make a statement of the probability of planets in a certain range of masses even if no planetary perturbations are detected. To make these measurements of Doppler shift with the required sensitivity, a new instrument was specifically designed, built and tested for this campaign of ground-based planet detection. The instrument is an optical spectrometer for which wavelengths are first calibrated by transmission through a tunable Fabry-Perot etalon interferometer. The intrinsic stability of the etalon and an image-scrambling fiber optic light feed provide great sensitivity to line-of-sight accelerations and immunity to systematic errors.

  15. The Kepler Mission: Search for Habitable Planets

    NASA Technical Reports Server (NTRS)

    Borucki, William; Likins, B.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    Detecting extrasolar terrestrial planets orbiting main-sequence stars is of great interest and importance. Current ground-based methods are only capable of detecting objects about the size or mass of Jupiter or larger. The difficulties encountered with direct imaging of Earth-size planets from space are expected to be resolved in the next twenty years. Spacebased photometry of planetary transits is currently the only viable method for detection of terrestrial planets (30-600 times less massive than Jupiter). This method searches the extended solar neighborhood, providing a statistically large sample and the detailed characteristics of each individual case. A robust concept has been developed and proposed as a Discovery-class mission. Its capabilities and strengths are presented.

  16. Why 400 Years to Discover Countless Planets?

    NASA Astrophysics Data System (ADS)

    Carr, Paul H.

    2011-04-01

    In 1584, Dominican monk Giordano Bruno envisioned the stars as "countless suns with countless earths, all rotating around their suns." Searching for intellectual freedom, he fled his native Italy to Protestant Switzerland and Germany, but in 1600 the Roman Inquisition condemned him for heresy. He was burned at the stake. Fast-forwarding to 1995, the Swiss astronomers Michel Mayor and Didier Queloz announced the discovery of a planet orbiting a star similar to our sun (51 Pegasi). In 2010, 500 planets had been found orbiting 421 stars. On Feb 2, 2011, NASA announced 1200 planet candidates. It took 400 years for telescope technology to advance and for Copernicus, Galileo, Newton, Bradley, and Foucault to make major contributions, culminating in today's astrophysics with digital imaging and processing. Contrasting with Bruno, in 2010 Dominican Francisco Ayala, who had been president of the Sigma Xi and AAAS, won the 1.6M Templeton Prize for affirming life's spiritual dimension.

  17. The Triaxial Ellipsoid Diameters and Rotational Pole of Asteroid (9) Metis from AO at Gemini and Keck

    NASA Astrophysics Data System (ADS)

    Drummond, Jack D.; Merline, W. J.; Conrad, A.; Dumas, C.; Tamblyn, P.; Christou, J.; Carry, B.; Chapman, C.

    2012-10-01

    From Adaptive Optics (AO) images of (9) Metis at 14 epochs over 2008 December 8 and 9 at Gemini North, triaxial ellipsoid diameters of 218x175x112 km are derived with fitting uncertainties of 3x3x47 km. However, by including just two more AO images from Keck-II in June and August of 2003 in a global fit, the fitting uncertainty of the small axis drops by more than a third because of the lower sub-Earth latitude afforded in 2003 (-28°) compared to 2008 (+47°), and the triaxial ellipsoid diameters become 218x175x129 km with fitting uncertainties of 3x3x14 km. We have estimated the systematic uncertainty of our method to be 4.1, 2.7, and 3.8%, respectively, for the three diameters. These values were recently derived (Drummond et al., in prep) from a comparison of KOALA (Carry et al, Planetary and Space Science 66, 200-212) and our triaxial ellipsoid analysis of four asteroids. Quadratically adding this systematic error with the fitting error, the total uncertainty for Metis becomes 9x5x15 km. Concurrently, we find an EQJ2000 rotational pole at [RA; Dec]=[185° +19°] or in ecliptic coordinates, [? ; ? ]=[176° +20°] (ECJ2000).

  18. Formation of Planets Around the Sun and Other Stars

    SciTech Connect

    Lin, Doug

    2005-11-14

    The quest to understand the formation of planets and planetary systems has entered an era of renaissance. Driven by observational discoveries in solar system exploration, protostellar disks, and extra solar planets, we have established a rich data bank which contains not only relic clues around mature stars, including the Sun, but also direct image of ongoing processes around young stars. For the first time in this scientific endeavor, we have adequate information to construct quantitative models to account for the ubiquity of planets and diversity of planetary systems. Some of the most intriguing theoretical questions facing us today include: (a) how did the planets in the solar system form with their present-day mass, composition, and orbital elements, (b) is planet formation a deterministic or chaotic process, and (c) what are the observable signatures of planet formation and evolution around nearby young and mature stars? I will present a comprehensive scenario which suggests (a) gas giant planets formed through coagulation of planetsimals and gas accretion onto earth-like cores; (b) the final assemblage of the terrestrial planets in the solar system occurred through the propagation of Jupiter's secular resonance 4-30 Myrs after the emergence of the gas giant; and (c) although they are yet to be discovered, Earth-like planets are expected to be common around nearby stars.

  19. Kepler's Multiple Planet Systems

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2012-01-01

    Among the 1800 Kepler targets that have candidate planets, 20% have two or more candidate planets. While most of these objects have not yet been confirmed as true planets, several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Virtually all candidate systems are stable, as tested by numerical integrations (assuming a nominal mass-radius relationship). Statistical studies performed on these candidates reveal a great deal about the architecture of planetary systems, including the typical spacing of orbits and flatness of planetary systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. The characteristics of the confirmed Kepler multi-planet systems will also be discussed.

  20. Evaporation of extrasolar planets

    E-print Network

    Etangs, A Lecavelier des

    2012-01-01

    This article presents a review on the observations and theoretical modeling of the evaporation of extrasolar planets. The observations and the resulting constraints on the upper atmosphere (thermosphere and exosphere) of the "hot-Jupiters". are described. The early observations of the first discovered transiting extrasolar planet, HD209458b, allowed the discovery that this planet has an extended atmosphere of escaping hydrogen. Subsequent observations showed the presence of oxygen and carbon at very high altitude. These observations give unique constraints on the escape rate and mechanism in the atmosphere of hot-Jupiters. The most recent Lyman-alpha HST observations of HD189733b and MgII observations of Wasp-12b allow for the first time comparison of the evaporation from different planets in different environments. Models to quantify the escape rate from the measured occultation depths, and an energy diagram to describe the evaporation state of hot-Jupiters are presented. Using this diagram, it is shown that...