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Sample records for jupiter mass planets

  1. Accretion of Jupiter-mass planets in the limit of vanishing viscosity

    SciTech Connect

    Szulágyi, J.; Morbidelli, A.; Crida, A.; Masset, F.

    2014-02-20

    In the core-accretion model, the nominal runaway gas-accretion phase brings most planets to multiple Jupiter masses. However, known giant planets are predominantly Jupiter mass bodies. Obtaining longer timescales for gas accretion may require using realistic equations of states, or accounting for the dynamics of the circumplanetary disk (CPD) in the low-viscosity regime, or both. Here we explore the second way by using global, three-dimensional isothermal hydrodynamical simulations with eight levels of nested grids around the planet. In our simulations, the vertical inflow from the circumstellar disk (CSD) to the CPD determines the shape of the CPD and its accretion rate. Even without a prescribed viscosity, Jupiter's mass-doubling time is ∼10{sup 4} yr, assuming the planet at 5.2 AU and a Minimum Mass Solar Nebula. However, we show that this high accretion rate is due to resolution-dependent numerical viscosity. Furthermore, we consider the scenario of a layered CSD, viscous only in its surface layer, and an inviscid CPD. We identify two planet-accretion mechanisms that are independent of the viscosity in the CPD: (1) the polar inflow—defined as a part of the vertical inflow with a centrifugal radius smaller than two Jupiter radii and (2) the torque exerted by the star on the CPD. In the limit of zero effective viscosity, these two mechanisms would produce an accretion rate 40 times smaller than in the simulation.

  2. Jupiter: As a planet. [its physical characteristics and radio waves emitted from Jupiter

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The planet Jupiter, its planetary mass and atmosphere, radio waves emitted from Jupiter, thermal radiation, internal structure of Jupiter, and the possibility of life on Jupiter are discussed. Educational study projects are included.

  3. Hydrodynamics of giant planet formation. II - Model equations and critical mass. III - Jupiter's nucleated instability

    SciTech Connect

    Wuchterl, G. )

    1991-05-01

    A spherically symmetric protoplanetary model with a growing rigid core and a gaseous envelope of solar composition is used to investigate the character and evolution of the nucleated instability; the model equations formulated are used to follow the static evolution of a protogiant planet in the 'Kyoto' solar nebula, lying at Jupiter's solar distance, to its critical core mass. Convective energy transfer has been formulated for inclusion in implicit radiation hydrodynamical computations. It is established that collapse need not occur at the critical mass, which in agreement with earlier investigations is found to be of the order of 13.1 earth masses. This model is then used as an initial condition for a radiation hydrodynamical calculation of the nucleated instability. It is found that nonlinear hydrodynamic waves are excited by a kappa mechanism, and that an outflow is driven. 56 refs.

  4. The SOPHIE search for northern extrasolar planets. III. A Jupiter-mass companion around HD 109246

    NASA Astrophysics Data System (ADS)

    Boisse, I.; Eggenberger, A.; Santos, N. C.; Lovis, C.; Bouchy, F.; Hébrard, G.; Arnold, L.; Bonfils, X.; Delfosse, X.; Desort, M.; Díaz, R. F.; Ehrenreich, D.; Forveille, T.; Gallenne, A.; Lagrange, A. M.; Moutou, C.; Udry, S.; Pepe, F.; Perrier, C.; Perruchot, S.; Pont, F.; Queloz, D.; Santerne, A.; Ségransan, D.; Vidal-Madjar, A.

    2010-11-01

    We report the detection of a Jupiter-mass planet discovered with the SOPHIE spectrograph mounted on the 1.93-m telescope at the Haute-Provence Observatory. The new planet orbits HD 109246, a G0V star slightly more metallic than the Sun. HD 109246b has a minimum mass of 0.77 MJup, an orbital period of 68 days, and an eccentricity of 0.12. It is placed in a sparsely populated region of the period distribution of extrasolar planets. We also present a correction method for the so-called seeing effect that affects the SOPHIE radial velocities. We complement this discovery announcement with a description of some calibrations that are implemented in the SOPHIE automatic reduction pipeline. These calibrations allow the derivation of the photon-noise radial velocity uncertainty and some useful stellar properties (v sin i, [Fe/H], log R’HK) directly from the SOPHIE data. Based on observations made with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS/OAMP), France (program 07A.PNP.CONS).RV tables (Tables C.1 and C.2) are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/523/A88

  5. Jupiter: Lord of the Planets.

    ERIC Educational Resources Information Center

    Kaufmann, William

    1984-01-01

    Presents a chapter from an introductory college-level astronomy textbook in which full-color photographs and numerous diagrams highlight an extensive description of the planet Jupiter. Topics include Jupiter's geology, rotation, magnetic field, atmosphere (including clouds and winds), and the Great Red Spot. (DH)

  6. There might be giants: unseen Jupiter-mass planets as sculptors of tightly packed planetary systems

    NASA Astrophysics Data System (ADS)

    Hands, T. O.; Alexander, R. D.

    2016-03-01

    The limited completeness of the Kepler sample for planets with orbital periods ≳1 yr leaves open the possibility that exoplanetary systems may host undetected giant planets. Should such planets exist, their dynamical interactions with the inner planets may prove vital in sculpting the final orbital configurations of these systems. Using an N-body code with additional forces to emulate the effects of a protoplanetary disc, we perform simulations of the assembly of compact systems of super-Earth-mass planets with unseen giant companions. The simulated systems are analogous to Kepler-11 or Kepler-32 in that they contain four or five inner super-Earths, but our systems also contain longer-period giant companions which are unlikely to have been detected by Kepler. We find that giant companions tend to break widely spaced first-order mean-motion resonances, allowing the inner planets to migrate into tighter resonances. This leads to more compact architectures and increases the occurrence rate of Laplace resonant chains.

  7. ECCENTRIC JUPITERS VIA DISK–PLANET INTERACTIONS

    SciTech Connect

    Duffell, Paul C.; Chiang, Eugene E-mail: echiang@astro.berkeley.edu

    2015-10-20

    Numerical hydrodynamics calculations are performed to determine the conditions under which giant planet eccentricities can be excited by parent gas disks. Unlike in other studies, Jupiter-mass planets are found to have their eccentricities amplified—provided their orbits start off as eccentric. We disentangle the web of co-rotation, co-orbital, and external resonances to show that this finite-amplitude instability is consistent with that predicted analytically. Ellipticities can grow until they reach of order of the disk's aspect ratio, beyond which the external Lindblad resonances that excite eccentricity are weakened by the planet's increasingly supersonic epicyclic motion. Forcing the planet to still larger eccentricities causes catastrophic eccentricity damping as the planet collides into gap walls. For standard parameters, the range of eccentricities for instability is modest; the threshold eccentricity for growth (∼0.04) is not much smaller than the final eccentricity to which orbits grow (∼0.07). If this threshold eccentricity can be lowered (perhaps by non-barotropic effects), and if the eccentricity driving documented here survives in 3D, it may robustly explain the low-to-moderate eccentricities ≲0.1 exhibited by many giant planets (including Jupiter and Saturn), especially those without planetary or stellar companions.

  8. KELT-10b and KELT-11b: Two Sub-Jupiter Mass Planets well-Suited for Atmospheric Characterization in the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Rodriguez, Joseph E.

    2015-12-01

    The Kilodegree Extremely Little Telescope (KELT) project is a photometric survey in both the northern and southern hemispheres for transiting planets around bright stars (8 < V < 11), and has discovered 15 planets to date. Of these, several possess unique characteristics that make them especially well suited for study of planet atmospheres. Here, I present the first two discoveries from the KELT-South survey. KELT-10b is an inflated transiting sub-Jupiter mass planet (0.68 MJ) around a V=10.7 early G-star. It has the 3rd deepest transit (1.4%) in the southern hemisphere for a star V < 12.5, making it a great target for transmission spectroscopy. KELT-11b is a highly inflated transiting Saturn mass planet (0.22 MJ) orbiting one of the brightest planet-hosting stars in the southern hemisphere. Interestingly, KELT-11b's host star is a clear sub-giant star (log(g) ~ 3.7). I will discuss their impact for atmospheric characterization. For example, the highly inflated nature of the KELT-11b planet provides the ability to study a sub-Jupiter atmosphere at very low planetary gravity, while the sub-giant nature of its host star allows us to study the effects of post main sequence evolution of a host star on a hot Jupiter.

  9. The observational case for Jupiter being a typical massive planet.

    PubMed

    Lineweaver, Charles H; Grether, Daniel

    2002-01-01

    We identify a subsample of the recently detected extrasolar planets that is minimally affected by the selection effects of the Doppler detection method. With a simple analysis we quantify trends in the surface density of this subsample in the period-Msin(i) plane. A modest extrapolation of these trends puts Jupiter in the most densely occupied region of this parameter space, thus indicating that Jupiter is a typical massive planet rather than an outlier. Our analysis suggests that Jupiter is more typical than indicated by previous analyses. For example, instead of MJup mass exoplanets being twice as common as 2 MJup exoplanets, we find they are three times as common.

  10. Kepler-423b: a half-Jupiter mass planet transiting a very old solar-like star

    NASA Astrophysics Data System (ADS)

    Gandolfi, D.; Parviainen, H.; Deeg, H. J.; Lanza, A. F.; Fridlund, M.; Prada Moroni, P. G.; Alonso, R.; Augusteijn, T.; Cabrera, J.; Evans, T.; Geier, S.; Hatzes, A. P.; Holczer, T.; Hoyer, S.; Kangas, T.; Mazeh, T.; Pagano, I.; Tal-Or, L.; Tingley, B.

    2015-04-01

    We report the spectroscopic confirmation of the Kepler object of interest KOI-183.01 (Kepler-423b), a half-Jupiter mass planet transiting an old solar-like star every 2.7 days. Our analysis is the first to combine the full Kepler photometry (quarters 1-17) with high-precision radial velocity measurements taken with the FIES spectrograph at the Nordic Optical Telescope. We simultaneously modelled the photometric and spectroscopic data-sets using Bayesian approach coupled with Markov chain Monte Carlo sampling. We found that the Kepler pre-search data conditioned light curve of Kepler-423 exhibits quarter-to-quarter systematic variations of the transit depth, with a peak-to-peak amplitude of ~4.3% and seasonal trends reoccurring every four quarters. We attributed these systematics to an incorrect assessment of the quarterly variation of the crowding metric. The host star Kepler-423 is a G4 dwarf with M⋆ = 0.85 ± 0.04 M⊙, R⋆ = 0.95 ± 0.04 R⊙, Teff= 5560 ± 80 K, [M/H] = - 0.10 ± 0.05 dex, and with an age of 11 ± 2 Gyr. The planet Kepler-423b has a mass of Mp= 0.595 ± 0.081MJup and a radius of Rp= 1.192 ± 0.052RJup, yielding a planetary bulk density of ρp = 0.459 ± 0.083 g cm-3. The radius of Kepler-423b is consistent with both theoretical models for irradiated coreless giant planets and expectations based on empirical laws. The inclination of the stellar spin axis suggests that the system is aligned along the line of sight. We detected a tentative secondary eclipse of the planet at a 2σ confidence level (ΔFec = 14.2 ± 6.6 ppm) and found that the orbit might have asmall non-zero eccentricity of 0.019+0.028-0.014. With a Bond albedo of AB = 0.037 ± 0.019, Kepler-423b is one of the gas-giant planets with the lowest albedo known so far. Based on observations obtained with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of

  11. Jupiter

    NASA Astrophysics Data System (ADS)

    Encrenaz, T.; Murdin, P.

    2002-10-01

    At 5.2 AU from the Sun (table 1), Jupiter is the closest and the most massive of the GIANT PLANETS, which extend in the outer solar system up to heliocentric distances of 30 AU. Its mass amounts to 318 terrestrial masses, and its diameter is 11 times the terrestrial one (table 2). Like the other giant planets, Jupiter has a low density (1.31 g cm-3) which reflects its chemical composition, mostly ...

  12. Kepler constraints on planets near hot Jupiters

    SciTech Connect

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; /Caltech /Harvard-Smithsonian Ctr. Astrophys.

    2012-05-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2:1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  13. Kepler constraints on planets near hot Jupiters

    PubMed Central

    Steffen, Jason H.; Ragozzine, Darin; Fabrycky, Daniel C.; Carter, Joshua A.; Ford, Eric B.; Holman, Matthew J.; Rowe, Jason F.; Welsh, William F.; Borucki, William J.; Boss, Alan P.; Ciardi, David R.; Quinn, Samuel N.

    2012-01-01

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 2∶1 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history. PMID:22566651

  14. Kepler constraints on planets near hot Jupiters.

    PubMed

    Steffen, Jason H; Ragozzine, Darin; Fabrycky, Daniel C; Carter, Joshua A; Ford, Eric B; Holman, Matthew J; Rowe, Jason F; Welsh, William F; Borucki, William J; Boss, Alan P; Ciardi, David R; Quinn, Samuel N

    2012-05-22

    We present the results of a search for planetary companions orbiting near hot Jupiter planet candidates (Jupiter-size candidates with orbital periods near 3 d) identified in the Kepler data through its sixth quarter of science operations. Special emphasis is given to companions between the 21 interior and exterior mean-motion resonances. A photometric transit search excludes companions with sizes ranging from roughly two-thirds to five times the size of the Earth, depending upon the noise properties of the target star. A search for dynamically induced deviations from a constant period (transit timing variations) also shows no significant signals. In contrast, comparison studies of warm Jupiters (with slightly larger orbits) and hot Neptune-size candidates do exhibit signatures of additional companions with these same tests. These differences between hot Jupiters and other planetary systems denote a distinctly different formation or dynamical history.

  15. Exploring the diversity of Jupiter-class planets.

    PubMed

    Fletcher, Leigh N; Irwin, Patrick G J; Barstow, Joanna K; de Kok, Remco J; Lee, Jae-Min; Aigrain, Suzanne

    2014-04-28

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term 'hot Jupiter' fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the

  16. High-Resolution Spectroscopic Follow-up of OGLE Planetary Transit Candidates in the Galactic Bulge: Two Possible Jupiter-Mass Planets and Two Blends

    NASA Astrophysics Data System (ADS)

    Konacki, Maciej; Torres, Guillermo; Sasselov, Dimitar D.; Jha, Saurabh

    2003-11-01

    We report the results of our campaign to follow up spectroscopically several candidate extrasolar transiting planets from the OGLE-III survey in the direction of the Galactic center, announced in 2001. All of these objects present shallow and periodic dips in brightness that may be due to planetary companions. Our Keck I/High Resolution Echelle Spectrometer (HIRES) observations have revealed two interesting cases (OGLE-TR-10 with a period of 3.1 days and OGLE-TR-58 with a period of 4.3 days) that show no radial velocity variations at the level of 100-200 m s-1. If orbited by companions, their masses would be similar to Jupiter. With the information in hand (including the light curves) we are not able to rule out that these candidates are instead the result of contamination from an eclipsing binary in the same line of sight (a ``blend''). We also discuss the case of OGLE-TR-56, which was recently reported by Konacki et al. to have a Jupiter-size companion, on the basis of an earlier analysis of our data and we present supporting information. Two other candidates, OGLE-TR-3 and OGLE-TR-33, show clear evidence that they are blends. We describe tests carried out to characterize the stability of the HIRES spectrograph and its impact on the determination of precise velocities for faint stars (V>=15 mag) using exposures of a thorium-argon lamp as the wavelength reference. Systematic effects are at the level of 100 m s-1 or smaller and tend to dominate the total error budget. We also evaluate the precision attainable using the iodine gas absorption cell as an alternative fiducial, and we propose a simplified version of the standard procedure employed for high-precision Doppler planet searches that is very promising. Results from both this method and the classical ThAr technique show the feasibility of spectroscopic follow-up for faint targets in the range V=14-17. We point out also that the high incidence of contamination from blends and other false positives in the OGLE

  17. Exploring the diversity of Jupiter-class planets

    PubMed Central

    Fletcher, Leigh N.; Irwin, Patrick G. J.; Barstow, Joanna K.; de Kok, Remco J.; Lee, Jae-Min; Aigrain, Suzanne

    2014-01-01

    Of the 900+ confirmed exoplanets discovered since 1995 for which we have constraints on their mass (i.e. not including Kepler candidates), 75% have masses larger than Saturn (0.3 MJ), 53% are more massive than Jupiter and 67% are within 1 AU of their host stars. When Kepler candidates are included, Neptune-sized giant planets could form the majority of the planetary population. And yet the term ‘hot Jupiter’ fails to account for the incredible diversity of this class of astrophysical object, which exists on a continuum of giant planets from the cool jovians of our own Solar System to the highly irradiated, tidally locked hot roasters. We review theoretical expectations for the temperatures, molecular composition and cloud properties of hydrogen-dominated Jupiter-class objects under a variety of different conditions. We discuss the classification schemes for these Jupiter-class planets proposed to date, including the implications for our own Solar System giant planets and the pitfalls associated with compositional classification at this early stage of exoplanetary spectroscopy. We discuss the range of planetary types described by previous authors, accounting for (i) thermochemical equilibrium expectations for cloud condensation and favoured chemical stability fields; (ii) the metallicity and formation mechanism for these giant planets; (iii) the importance of optical absorbers for energy partitioning and the generation of a temperature inversion; (iv) the favoured photochemical pathways and expectations for minor species (e.g. saturated hydrocarbons and nitriles); (v) the unexpected presence of molecules owing to vertical mixing of species above their quench levels; and (vi) methods for energy and material redistribution throughout the atmosphere (e.g. away from the highly irradiated daysides of close-in giants). Finally, we discuss the benefits and potential flaws of retrieval techniques for establishing a family of atmospheric solutions that reproduce the

  18. Study of Power Options for Jupiter and Outer Planet Missions

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Fincannon, James

    2015-01-01

    Power for missions to Jupiter and beyond presents a challenging goal for photovoltaic power systems, but NASA missions including Juno and the upcoming Europa Clipper mission have shown that it is possible to operate solar arrays at Jupiter. This work analyzes photovoltaic technologies for use in Jupiter and outer planet missions, including both conventional arrays, as well as analyzing the advantages of advanced solar cells, concentrator arrays, and thin film technologies. Index Terms - space exploration, spacecraft solar arrays, solar electric propulsion, photovoltaic cells, concentrator, Fresnel lens, Jupiter missions, outer planets.

  19. JUPITER WILL BECOME A HOT JUPITER: CONSEQUENCES OF POST-MAIN-SEQUENCE STELLAR EVOLUTION ON GAS GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Madhusudhan, Nikku E-mail: Nikku.Madhusudhan@yale.edu

    2012-09-10

    When the Sun ascends the red giant branch (RGB), its luminosity will increase and all the planets will receive much greater irradiation than they do now. Jupiter, in particular, might end up more highly irradiated than the hot Neptune GJ 436b and, hence, could appropriately be termed a 'hot Jupiter'. When their stars go through the RGB or asymptotic giant branch stages, many of the currently known Jupiter-mass planets in several-AU orbits will receive levels of irradiation comparable to the hot Jupiters, which will transiently increase their atmospheric temperatures to {approx}1000 K or more. Furthermore, massive planets around post-main-sequence stars could accrete a non-negligible amount of material from the enhanced stellar winds, thereby significantly altering their atmospheric chemistry as well as causing a significant accretion luminosity during the epochs of most intense stellar mass loss. Future generations of infrared observatories might be able to probe the thermal and chemical structure of such hot Jupiters' atmospheres. Finally, we argue that, unlike their main-sequence analogs (whose zonal winds are thought to be organized in only a few broad, planetary-scale jets), red-giant hot Jupiters should have multiple, narrow jets of zonal winds and efficient day-night redistribution.

  20. Pan-Planets: Searching for hot Jupiters around cool dwarfs

    NASA Astrophysics Data System (ADS)

    Obermeier, C.; Koppenhoefer, J.; Saglia, R. P.; Henning, Th.; Bender, R.; Kodric, M.; Deacon, N.; Riffeser, A.; Burgett, W.; Chambers, K. C.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Price, P. A.; Sweeney, W.; Wainscoat, R. J.; Waters, C.

    2016-03-01

    The Pan-Planets survey observed an area of 42 sq deg. in the galactic disk for about 165 h. The main scientific goal of the project is the detection of transiting planets around M dwarfs. We establish an efficient procedure for determining the stellar parameters Teff and log g of all sources using a method based on SED fitting, utilizing a three-dimensional dust map and proper motion information. In this way we identify more than 60 000 M dwarfs, which is by far the largest sample of low-mass stars observed in a transit survey to date. We present several planet candidates around M dwarfs and hotter stars that are currently being followed up. Using Monte Carlo simulations we calculate the detection efficiency of the Pan-Planets survey for different stellar and planetary populations. We expect to find 3.0+3.3-1.6 hot Jupiters around F, G, and K dwarfs with periods lower than 10 days based on the planet occurrence rates derived in previous surveys. For M dwarfs, the percentage of stars with a hot Jupiter is under debate. Theoretical models expect a lower occurrence rate than for larger main sequence stars. However, radial velocity surveys find upper limits of about 1% due to their small sample, while the Kepler survey finds a occurrence rate that we estimate to be at least 0.17b(+0.67-0.04) %, making it even higher than the determined fraction from OGLE-III for F, G and K stellar types, 0.14 (+0.15-0.076) %. With the large sample size of Pan-Planets, we are able to determine an occurrence rate of 0.11 (+0.37-0.02) % in case one of our candidates turns out to be a real detection. If, however, none of our candidates turn out to be true planets, we are able to put an upper limit of 0.34% with a 95% confidence on the hot Jupiter occurrence rate of M dwarfs. This limit is a significant improvement over previous estimates where the lowest limit published so far is 1.1% found in the WFCAM Transit Survey. Therefore we cannot yet confirm the theoretical prediction of a lower

  1. Scientists Revise Thinking on Comets, Planet Jupiter

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses scientific information obtained from Pioneer 10's Jupiter flyby and the comet Kohoutek's first trip around the sun, including the high hydrogen emission of Jupiter's principal moon, Io. (CC)

  2. Investigation of hydrogen and helium pumping by sputter ion pumps for Jupiter and outer planets mass spectrometer

    NASA Technical Reports Server (NTRS)

    Scott, B. W.

    1977-01-01

    The phenomena of ion pumping is reviewed with emphasis on the pumping mechanism for hydrogen and helium. The experimental tests measure the performance of a small, flight proven ion pump which has a nominal four liter/second pumping speed for air. The speed of this pump for hydrogen and helium, and for hydrogen/helium mixes, is presented with particular detail regarding the time dependence. Pump test results are related to anticipated performance of the mass spectrometer by the pumping speeds for the gases to the partial pressure in the ion source. From this analysis, the pump specifications are quantified in terms of mission goals and in terms of observed pumping speeds for the various gases, load levels, and time periods.

  3. Three newly discovered sub-Jupiter-mass planets: WASP-69b and WASP-84b transit active K dwarfs and WASP-70Ab transits the evolved primary of a G4+K3 binary

    NASA Astrophysics Data System (ADS)

    Anderson, D. R.; Collier Cameron, A.; Delrez, L.; Doyle, A. P.; Faedi, F.; Fumel, A.; Gillon, M.; Gómez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Lendl, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Skillen, I.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.; West, R. G.

    2014-12-01

    We report the discovery of the transiting exoplanets WASP-69b, WASP-70Ab and WASP-84b, each of which orbits a bright star (V ˜ 10). WASP-69b is a bloated Saturn-mass planet (0.26 MJup, 1.06 RJup) in a 3.868-d period around an active, ˜1-Gyr, mid-K dwarf. ROSAT detected X-rays 60±27 arcsec from WASP-69. If the star is the source then the planet could be undergoing mass-loss at a rate of ˜1012 g s-1. This is one to two orders of magnitude higher than the evaporation rate estimated for HD 209458b and HD 189733b, both of which have exhibited anomalously large Lyman α absorption during transit. WASP-70Ab is a sub-Jupiter-mass planet (0.59 MJup, 1.16 RJup) in a 3.713-d orbit around the primary of a spatially resolved, 9-10-Gyr, G4+K3 binary, with a separation of 3.3 arcsec (≥800 au). WASP-84b is a sub-Jupiter-mass planet (0.69 MJup, 0.94 RJup) in an 8.523-d orbit around an active, ˜1-Gyr, early-K dwarf. Of the transiting planets discovered from the ground to date, WASP-84b has the third-longest period. For the active stars WASP-69 and WASP-84, we pre-whitened the radial velocities using a low-order harmonic series. We found that this reduced the residual scatter more than did the oft-used method of pre-whitening with a fit between residual radial velocity and bisector span. The system parameters were essentially unaffected by pre-whitening.

  4. Discovering Habitable Earths, Hot Jupiters, and Other Close Planets with Microlensing

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.

    2012-06-01

    Searches for planets via gravitational lensing have focused on cases in which the projected separation, a, between planet and star is comparable to the Einstein radius, RE . This paper considers smaller orbital separations and demonstrates that evidence of close-orbit planets can be found in the low-magnification portion of the light curves generated by the central star. We develop a protocol for discovering hot Jupiters as well as Neptune-mass and Earth-mass planets in the stellar habitable zone. When planets are not discovered, our method can be used to quantify the probability that the lens star does not have planets within specified ranges of the orbital separation and mass ratio. Nearby close-orbit planets discovered by lensing can be subject to follow-up observations to study the newly discovered planets or to discover other planets orbiting the same star. Careful study of the low-magnification portions of lensing light curves should produce, in addition to the discoveries of close-orbit planets, definite detections of wide-orbit planets through the discovery of "repeating" lensing events. We show that events exhibiting extremely high magnification can effectively be probed for planets in close, intermediate, and wide distance regimes simply by adding several-time-per-night monitoring in the low-magnification wings, possibly leading to gravitational lensing discoveries of multiple planets occupying a broad range of orbits, from close to wide, in a single planetary system.

  5. DISCOVERING HABITABLE EARTHS, HOT JUPITERS, AND OTHER CLOSE PLANETS WITH MICROLENSING

    SciTech Connect

    Di Stefano, R.

    2012-06-20

    Searches for planets via gravitational lensing have focused on cases in which the projected separation, a, between planet and star is comparable to the Einstein radius, R{sub E} . This paper considers smaller orbital separations and demonstrates that evidence of close-orbit planets can be found in the low-magnification portion of the light curves generated by the central star. We develop a protocol for discovering hot Jupiters as well as Neptune-mass and Earth-mass planets in the stellar habitable zone. When planets are not discovered, our method can be used to quantify the probability that the lens star does not have planets within specified ranges of the orbital separation and mass ratio. Nearby close-orbit planets discovered by lensing can be subject to follow-up observations to study the newly discovered planets or to discover other planets orbiting the same star. Careful study of the low-magnification portions of lensing light curves should produce, in addition to the discoveries of close-orbit planets, definite detections of wide-orbit planets through the discovery of 'repeating' lensing events. We show that events exhibiting extremely high magnification can effectively be probed for planets in close, intermediate, and wide distance regimes simply by adding several-time-per-night monitoring in the low-magnification wings, possibly leading to gravitational lensing discoveries of multiple planets occupying a broad range of orbits, from close to wide, in a single planetary system.

  6. Jupiter

    NASA Astrophysics Data System (ADS)

    Simon, Seymour

    Describes the characteristics of the planet Jupiter and its moons as revealed by photographs sent back by two unmanned Voyager spaceships which took one-and-one half years to reach this distant giant.

  7. WASP-47: A Hot Jupiter System with Two Additional Planets Discovered by K2

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Vanderburg, Andrew; Adams, Fred C.; Rappaport, Saul A.; Schwengeler, Hans Martin

    2015-10-01

    Using new data from the K2 mission, we show that WASP-47, a previously known hot Jupiter host, also hosts two additional transiting planets: a Neptune-sized outer planet and a super-Earth inner companion. We measure planetary properties from the K2 light curve and detect transit timing variations (TTVs), confirming the planetary nature of the outer planet. We performed a large number of numerical simulations to study the dynamical stability of the system and to find the theoretically expected TTVs. The theoretically predicted TTVs are in good agreement with those observed, and we use the TTVs to determine the masses of two planets, and place a limit on the third. The WASP-47 planetary system is important because companion planets can both be inferred by TTVs and are also detected directly through transit observations. The depth of the hot Jupiter's transits make ground-based TTV measurements possible, and the brightness of the host star makes it amenable for precise radial velocity measurements. The system serves as a Rosetta Stone for understanding TTVs as a planet detection technique.

  8. N-body simulations of terrestrial planet formation under the influence of a hot Jupiter

    SciTech Connect

    Ogihara, Masahiro; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro E-mail: ogihara@nagoya-u.jp

    2014-06-01

    We investigate the formation of multiple-planet systems in the presence of a hot Jupiter (HJ) using extended N-body simulations that are performed simultaneously with semianalytic calculations. Our primary aims are to describe the planet formation process starting from planetesimals using high-resolution simulations, and to examine the dependences of the architecture of planetary systems on input parameters (e.g., disk mass, disk viscosity). We observe that protoplanets that arise from oligarchic growth and undergo type I migration stop migrating when they join a chain of resonant planets outside the orbit of an HJ. The formation of a resonant chain is almost independent of our model parameters, and is thus a robust process. At the end of our simulations, several terrestrial planets remain at around 0.1 AU. The formed planets are not equal mass; the largest planet constitutes more than 50% of the total mass in the close-in region, which is also less dependent on parameters. In the previous work of this paper, we have found a new physical mechanism of induced migration of the HJ, which is called a crowding-out. If the HJ opens up a wide gap in the disk (e.g., owing to low disk viscosity), crowding-out becomes less efficient and the HJ remains. We also discuss angular momentum transfer between the planets and disk.

  9. An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b.

    PubMed

    Hellier, Coel; Anderson, D R; Cameron, A Collier; Gillon, M; Hebb, L; Maxted, P F L; Queloz, D; Smalley, B; Triaud, A H M J; West, R G; Wilson, D M; Bentley, S J; Enoch, B; Horne, K; Irwin, J; Lister, T A; Mayor, M; Parley, N; Pepe, F; Pollacco, D L; Segransan, D; Udry, S; Wheatley, P J

    2009-08-27

    The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M(Jup)), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10(6), as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.

  10. THE HEAVY-ELEMENT MASSES OF EXTRASOLAR GIANT PLANETS, REVEALED

    SciTech Connect

    Miller, Neil; Fortney, Jonathan J.

    2011-08-01

    We investigate a population of transiting planets that receive relatively modest stellar insolation, indicating equilibrium temperatures <1000 K, and for which the heating mechanism that inflates hot Jupiters does not appear to be significantly active. We use structural evolution models to infer the amount of heavy elements within each of these planets. There is a correlation between the stellar metallicity and the mass of heavy elements in its transiting planet(s). It appears that all giant planets possess a minimum of {approx}10-15 Earth masses of heavy elements, with planets around metal-rich stars having larger heavy-element masses. There is also an inverse relationship between the mass of the planet and the metal enrichment (Z{sub pl}/Z{sub star}), which appears to have little dependency on the metallicity of the star. Saturn- and Jupiter-like enrichments above solar composition are a hallmark of all the gas giants in the sample, even planets of several Jupiter masses. These relationships provide an important constraint on planet formation and suggest large amounts of heavy elements within planetary H/He envelopes. We suggest that the observed correlation can soon also be applied to inflated planets, such that the interior heavy-element abundance of these planets could be estimated, yielding better constraints on their interior energy sources. We point to future directions for planetary population synthesis models and suggest future correlations. This appears to be the first evidence that extrasolar giant planets, as a class, are enhanced in heavy elements.

  11. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. II. A SATURN-JUPITER CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-08-10

    We carry out a series of high-resolution (1024 x 1024) hydrodynamic simulations to investigate the orbital evolution of a Saturn-Jupiter pair embedded in a gaseous disk. This work extends the results of our previous work by exploring a different orbital configuration-Jupiter lies outside Saturn (q < 1, where q {identical_to} M{sub i} /M{sub o} is the mass ratio of the inner planet and the outer one). We focus on the effects of different initial separations (d) between the two planets and the various surface density profiles of the disk, where {sigma} {proportional_to} r {sup -}{alpha}. We also compare the results of different orbital configurations of the planet pair. Our results show that (1) when the initial separation is relatively large (d>d {sub iLr}, where d {sub iLr} is the distance between Jupiter and its first inner Lindblad resonance), the two planets undergo divergent migration. However, the inward migration of Saturn could be halted when Jupiter compresses the inner disk in which Saturn is embedded. (2) Convergent migration occurs when the initial separation is smaller (d < d {sub iLr}) and the density slope of the disk is nearly flat ({alpha} < 1/2). Saturn is then forced by Jupiter to migrate inward where the two planets are trapped into mean motion resonances (MMRs), and Saturn may get very close to the central star. (3) In the case of q < 1, the eccentricity of Saturn could be excited to a very high value (e{sub S} {approx} 0.4-0.5) by the MMRs and the system could maintain stability. These results explain the formation of MMRs in the exoplanet systems where the outer planet is more massive than the inner one. It also helps us to understand the origin of the 'hot Jupiter/Saturn' with a highly eccentric orbit.

  12. On the Frequency of Additional Planets in Short Period Hot Jupiter Systems from Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Dittmann, Jason; Close, L.; Scuderi, L.

    2011-05-01

    The large number of hot Jupiter planets allows one to probe these systems for additional unseen planets via transit timing variations (TTVs). Even relatively small terrestrial planets, when placed in an energetically favorable mean motion resonance (MMR), can cause detectable TTVs with an amplitude of several minutes (Holman and Murray 2005, Agol et al. 2005). In an effort to discover and characterize such companions, we have embarked on a systematic study of known transiting hot Jupiters, utilizing the 1.55 meter Kuiper telescope on Mt. Bigelow to measure multiple individual transits in an observing season to within 30 second precision, and constrain the nature of any planetary companions. Here, we present current and preliminary results on this study, and show that the systems HAT-P-5, HAT- P-6, HAT-P-8, HAT-P-9, WASP-11/HAT-P-10, HAT-P-11, TrES-2, and WASP-10 do not contain small mass companions in MMRs, or moderate mass companions in close enough proximity to induce TTVs on the order of 1.5 minutes.

  13. On the Final Mass of Giant Planets

    NASA Technical Reports Server (NTRS)

    Estrada, P. R.; Mosqueira, I.

    2004-01-01

    In the core accretion model of giant planet formation, when the core reaches critical mass, hydrostatic equilibrium is no longer possible and gas accretion ensues. If the envelope is radiative, the critical core mass is nearly independent of the boundary conditions and is roughly M(sub crit) 10Mass of the Earth (with weak dependence on the rate of planetesimal accretion M(sub core) and the disk opacity k). Given that such a core may form at the present location of Jupiter in a time comparable to its Type I migration time (10(exp 5) - 10(exp 6) years) provided that the nebula was significantly enhanced in solids with respect to the MMSN and stall at this location in a weakly turbulent (alpha approximately less than 10(exp -4) disk, it may be appropriate to assume that such objects inevitably form and drive the evolution of late-phase T Tauri star disks. Here we investigate the final masses of giant planets in disks with one or more than one such cores. Although the presence of several planets would lead to Type II migration (due to the effective viscosity resulting from the planetary tidal torques), we ignore this complication for now and simply assume that each core has stalled at its location in the disk. Once a core has achieved critical mass, its gaseous accretion is governed by the given Kelvin-Helmholtz timescale.

  14. AN INTERPRETATION OF THE ORBITAL PERIOD DIFFERENCE BETWEEN HOT JUPITERS AND GIANT PLANETS ON LONG-PERIOD ORBITS

    SciTech Connect

    Jin Liping

    2010-09-10

    It is believed that a hot Jupiter (giant planet with a short period less than 10 days) forms in the outer region of a protoplanetary disk, then migrates inward to an orbit with a short period around 3 days, and stops there by a final stopping mechanism. The prominent problem is why hot Jupiters migrate inward to short-period orbits, while other extrasolar giant planets and Jovian planets in our solar system exist on long-period orbits. Here we show that this difference in orbital periods is caused by two populations of protoplanetary disks. One population experiences gravitational instability during some periods of their lifetime (GI disks), while the other does not (No-GI disks). In GI disks, planets can quickly migrate inward to short-period orbits to become hot Jupiters. In No-GI disks, the migration is so slow that planets can exist on long-period orbits. Protoplanetary disks are classified into the two populations because of the differences in properties of molecular cloud cores, from which disks from. We specifically compare our theory with observations. Our theory is supported by observations of extrasolar planets. We analyze the current status of our solar system and find that our solar nebula belongs to the population with a low migration rate. This is consistent with the observation that Jupiter and Saturn are indeed on long-period orbits. Our results further suggest that, in the future observations, a hot Jupiter cannot be found around a star with mass below a critical mass (0.14-0.28 M {sub sun}).

  15. Nonuniform viscosity in the solar nebula and large masses of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Jin, L.

    2004-08-01

    I report a novel theory that nonuniform viscous frictional force in the solar nebula accounts for the largest mass of Jupiter and Saturn and their largest amount of H and He among the planets, two outstanding facts that are unsolved puzzles in our understanding of origin of the Solar System. It is shown that the nebula model of uniform viscosity does not match the present planet masses. By studying current known viscosity mechanisms, I show that viscosity is more efficient in the inner region inside Mercury and the outer region outside Jupiter-Saturn than the intermediate region. The more efficient viscosity drives faster radial inflow of material during the nebula evolution. Because the inflow in the outer region is faster than the intermediate region, the material tends to accumulate in Jupiter-Saturn region which is between the outer and intermediate region. It is demonstrated that the gas trapping time of Jovian planets is longer than the inflow time in the outer region. Therefore the gas already flows to Jupiter-Saturn region before Uranus and Neptune can capture significant gas. But the inflow in the Jupiter-Saturn region is so slow that they can capture large amount of gas before the gas can flow further inward. Hence they have larger masses with larger H and He content than Uranus and Neptune. I also extend the discussion to the masses of the terrestrial planets, especially low mass of Mercury. The advantages of this theory are discussed.

  16. Hot Jupiters with relatives: discovery of additional planets in orbit around WASP-41 and WASP-47

    NASA Astrophysics Data System (ADS)

    Neveu-VanMalle, M.; Queloz, D.; Anderson, D. R.; Brown, D. J. A.; Collier Cameron, A.; Delrez, L.; Díaz, R. F.; Gillon, M.; Hellier, C.; Jehin, E.; Lister, T.; Pepe, F.; Rojo, P.; Ségransan, D.; Triaud, A. H. M. J.; Turner, O. D.; Udry, S.

    2016-02-01

    We report the discovery of two additional planetary companions to WASP-41 and WASP-47. WASP-41 c is a planet of minimum mass 3.18 ± 0.20 MJup and eccentricity 0.29 ± 0.02, and it orbits in 421 ± 2 days. WASP-47 c is a planet of minimum mass 1.24 ± 0.22 MJup and eccentricity 0.13 ± 0.10, and it orbits in 572 ± 7 days. Unlike most of the planetary systems that include a hot Jupiter, these two systems with a hot Jupiter have a long-period planet located at only ~1 au from their host star. WASP-41 is a rather young star known to be chromospherically active. To differentiate its magnetic cycle from the radial velocity effect induced by the second planet, we used the emission in the Hα line and find this indicator well suited to detecting the stellar activity pattern and the magnetic cycle. The analysis of the Rossiter-McLaughlin effect induced by WASP-41 b suggests that the planet could be misaligned, though an aligned orbit cannot be excluded. WASP-47 has recently been found to host two additional transiting super Earths. With such an unprecedented architecture, the WASP-47 system will be very important for understanding planetary migration. Using data collected at ESO's La Silla Observatory, Chile: HARPS on the ESO 3.6 m (Prog ID 087.C-0649 & 089.C-0151), the Swiss Euler Telescope, TRAPPIST, the 1.54-m Danish telescope (Prog CN2013A-159), and at the LCOGT's Faulkes Telescope South.Photometric lightcurve and RV tables 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/586/A93

  17. The Occurrence of Additional Giant Planets Inside the Water-Ice Line in Systems with Hot Jupiters: Evidence Against High-Eccentricity Migration

    NASA Astrophysics Data System (ADS)

    Schlaufman, Kevin C.; Winn, Joshua N.

    2016-07-01

    The origin of Jupiter-mass planets with orbital periods of only a few days is still uncertain. It is widely believed that these planets formed near the water-ice line of the protoplanetary disk, and subsequently migrated into much smaller orbits. Most of the proposed migration mechanisms can be classified either as disk-driven migration, or as excitation of a very high eccentricity followed by tidal circularization. In the latter scenario, the giant planet that is destined to become a hot Jupiter spends billions of years on a highly eccentric orbit, with apastron near the water-ice line. Eventually, tidal dissipation at periastron shrinks and circularizes the orbit. If this is correct, then it should be especially rare for hot Jupiters to be accompanied by another giant planet interior to the water-ice line. Using the current sample of giant planets discovered with the Doppler technique, we find that hot Jupiters with P orb < 10 days are no more or less likely to have exterior Jupiter-mass companions than longer-period giant planets with P orb ≥ 10 days. This result holds for exterior companions both inside and outside of the approximate location of the water-ice line. These results are difficult to reconcile with the high-eccentricity migration scenario for hot Jupiter formation.

  18. 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 (mass) using a combination of analytic and numerical calculations, and I will show that all low-mass planets obey a kind of universal mass-radius relationship: an expansion whose first term is M approx. R(sup 3).

  19. ON THE FUNDAMENTAL MASS-PERIOD FUNCTIONS OF EXTRASOLAR PLANETS

    SciTech Connect

    Jiang, I.-G.; Yeh, L.-C.; Chang, Y.-C.; Hung, W.-L.

    2010-01-01

    Employing a catalog of 175 extrasolar planets (exoplanets) detected by the Doppler-shift method, we constructed the independent and coupled mass-period functions. It is the first time in this field that the selection effect is considered in the coupled mass-period functions. Our results are consistent with those of Tabachnik and Tremaine in 2002, with the major difference that we obtain a flatter mass function but a steeper period function. Moreover, our coupled mass-period functions show that about 2.5% of stars would have a planet with mass between Earth Mass and Neptune Mass, and about 3% of stars would have a planet with mass between Neptune Mass and Jupiter Mass.

  20. Helping students understand planet categories using "sensing" personification: Jupiter as want-to-be star, Earth as want-to-be Jupiter, etc.

    NASA Astrophysics Data System (ADS)

    Tabor-Morris, Anne

    2015-11-01

    Students often, in learning about the classification of planets, consider the planets to be in strict categories (such as gas giants and terrestrial planets) and assume that these categories are drastically different in nature. This is not the case. Small objects such as asteroids have a weak gravitational pull such that they cannot hold an atmosphere, while terrestrial planets are capable of holding a gaseous (often transparent) atmosphere according to their larger mass. However, asteroids and terrestrial planets are very similar in composition (though not necessarily in homogeneity due to varying presence of collisional heating during formation). Meanwhile, gas giant planets (also often referred to as Jovian planets) such as Jupiter have been theorized to contain super-sized rocky terrestrial-like planets interior to their dense cloud covering. Hence, due then to their similar natures, the categorization of the terrestrial and gas giant planets is made not due to fundamental differences in the nature of the planets, a concept often ill-understood by students. Examining this further, the gas giants are planets whose masses, and hence gravitational ability to condense their gases, especially those close to their core, is less than those of stars wherein thermonuclear fusion initiates. This implies that stars also have terrestrial cores (albeit likely extremely densely packed), but the gaseous environments of hydrogen are dense enough to start and sustain this process of thermonuclear fusion. It is proposed here that seeing planets as fundamentally related to each other in composition though differing in size allows students to better understand the variety of planet types AND describing these as want-to-be (or wanna-be) in terms of ranking and according to a “sensing” personification that eschews anthropomorphism, animism, or teleology [see A. E. Tabor-Morris, “Thinking in terms of sensors: personification of self as an object in physics problem solving

  1. Jupiter and Planet Earth. [planetary and biological evolution and natural satellites

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The evolution of Jupiter and Earth are discussed along with their atmospheres, the radiation belts around both planets, natural satellites, the evolution of life, and the Pioneer 10. Educational study projects are also included.

  2. A hot Jupiter orbiting a 2-million-year-old solar-mass T Tauri star

    NASA Astrophysics Data System (ADS)

    Donati, J. F.; Moutou, C.; Malo, L.; Baruteau, C.; Yu, L.; Hébrard, E.; Hussain, G.; Alencar, S.; Ménard, F.; Bouvier, J.; Petit, P.; Takami, M.; Doyon, R.; Cameron, A. Collier

    2016-06-01

    Hot Jupiters are giant Jupiter-like exoplanets that orbit their host stars 100 times more closely than Jupiter orbits the Sun. These planets presumably form in the outer part of the primordial disk from which both the central star and surrounding planets are born, then migrate inwards and yet avoid falling into their host star. It is, however, unclear whether this occurs early in the lives of hot Jupiters, when they are still embedded within protoplanetary disks, or later, once multiple planets are formed and interact. Although numerous hot Jupiters have been detected around mature Sun-like stars, their existence has not yet been firmly demonstrated for young stars, whose magnetic activity is so intense that it overshadows the radial velocity signal that close-in giant planets can induce. Here we report that the radial velocities of the young star V830 Tau exhibit a sine wave of period 4.93 days and semi-amplitude 75 metres per second, detected with a false-alarm probability of less than 0.03 per cent, after filtering out the magnetic activity plaguing the spectra. We find that this signal is unrelated to the 2.741-day rotation period of V830 Tau and we attribute it to the presence of a planet of mass 0.77 times that of Jupiter, orbiting at a distance of 0.057 astronomical units from the host star. Our result demonstrates that hot Jupiters can migrate inwards in less than two million years, probably as a result of planet-disk interactions.

  3. The Dynamics of the WASP-47 Planetary System: A Hot Jupiter, Two Additional Planets, and Observable Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.; Becker, Juliette C.; Vanderburg, Andrew; Rappaport, Saul; Schwengeler, Hans Martin

    2015-12-01

    New data from the K2 mission indicate that WASP-47, a previously known Hot Jupiter host, also hosts two additional transiting planets: a Neptune-sized outer planet and a super-Earth inner companion. The measured period ratios and size ratios for these planets are unusual (extreme) for Hot Jupiter systems. We measure the planetary properties from the K2 light curve and detect transit timing variations, thereby confirming the planetary nature of the outer planet. We performed a large ensemble of numerical simulations to study the dynamical stability of the system and to find the theoretically expected transit timing variations (TTVs). The system is stable provided that the orbital eccentricities are small. The theoretically predicted TTVs are in good agreement with those observed, and we use the TTVs to determine the masses of two planets, and place a limit on the third. The WASP-47 planetary system is important because the companion planets can both be inferred by TTVs and are also detected directly through transit observations. The depth of the Hot Jupiter’s transits make ground-based TTV measurements possible, and the brightness of the host star makes it amenable for precise radial velocity measurements. The system thus serves as a Rosetta Stone for understanding TTVs as a planet detection technique. Moreover, this compact set of planets in nearly circular, coplanar orbits demonstrates that at least a subset of Jupiter-size planets can migrate in close to their host star in a dynamically quiet manner. As final curiosity, WASP-47 hosts one of few extrasolar planetary systems that can observe Earth in transit.

  4. Jupiter Observation Campaign: Citizen Science at the Outer Planets

    NASA Astrophysics Data System (ADS)

    Jones, J. Houston.; Wessen, A.; Pappalardo, Robert; Perry, Jason, Vance, Steve; Beisser, Kerri; Dyches, Preston

    2010-12-01

    NASA Solar System Education and Public Outreach (E/PO) will coordinate and disseminate a consistent process for receiving Jupiter observation data from citizen scientists. This may include a public repository or network matching scientists with citizen scientists who want to provide needed observations in a standard and consistent format. This will be a good Outer Planet mission contribution to the science community. Solar System Thematic E/PO will design a repository, or connect people with a process, and manage the process of defining the formatting and other needs of the data contributions from: 1) Regular observers: who right now do not have a consistent imaging of photography process or file naming convention for their data, etc. 2) Experienced observers, who currently send data on occasion to a network which includes appreciative scientists. record the start and end times of video they view each night, 3) Regional associations (ALPO, ALPO-Japan, BAA etc.) might be able to collect this info, disseminate the ground rules, etc.

  5. A common mass scaling for satellite systems of gaseous planets.

    PubMed

    Canup, Robin M; Ward, William R

    2006-06-15

    The Solar System's outer planets that contain hydrogen gas all host systems of multiple moons, which notably each contain a similar fraction of their respective planet's mass (approximately 10(-4)). This mass fraction is two to three orders of magnitude smaller than that of the largest satellites of the solid planets (such as the Earth's Moon), and its common value for gas planets has been puzzling. Here we model satellite growth and loss as a forming giant planet accumulates gas and rock-ice solids from solar orbit. We find that the mass fraction of its satellite system is regulated to approximately 10(-4) by a balance of two competing processes: the supply of inflowing material to the satellites, and satellite loss through orbital decay driven by the gas. We show that the overall properties of the satellite systems of Jupiter, Saturn and Uranus arise naturally, and suggest that similar processes could limit the largest moons of extrasolar Jupiter-mass planets to Moon-to-Mars size.

  6. A Low Mass for Mars from Jupiter's Early Gas-Driven Migration

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin J.; Morbidelli, Alessandro; Raymond, Sean N.; O'Brien, David P.; Mandell, Avi M.

    2011-01-01

    Jupiter and Saturn formed in a few million years from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only approximately 100,000 years. Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 AU is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 AU, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 AU; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 AU and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.

  7. The anglo-australian planet search. XXIII. Two new Jupiter analogs

    SciTech Connect

    Wittenmyer, Robert A.; Horner, Jonathan; Tinney, C. G.; Salter, G. S.; Bailey, J.; Wright, D.; Butler, R. P.; Jones, H. R. A.; Tuomi, Mikko; Carter, B. D.; Koch, F. Elliott; O'Toole, S. J.

    2014-03-10

    We report the discovery of two long-period giant planets from the Anglo-Australian Planet Search. HD 154857c is in a multiple-planet system, while HD 114613b appears to be solitary. HD 114613b has an orbital period P = 10.5 yr, and a minimum mass msin i of 0.48 M {sub Jup}; HD 154857c has P = 9.5 yr and msin i = 2.6 M {sub Jup}. These new data confirm the planetary nature of the previously unconstrained long-period object in the HD 154857 system. We have performed detailed dynamical stability simulations which show that the HD 154857 two-planet system is stable on timescales of at least 10{sup 8} yr. These results highlight the continued importance of 'legacy' surveys with long observational baselines; these ongoing campaigns are critical for determining the population of Jupiter analogs, and hence of those planetary systems with architectures most like our own solar system.

  8. A hot Jupiter orbiting a 2-million-year-old solar-mass T Tauri star.

    PubMed

    Donati, J F; Moutou, C; Malo, L; Baruteau, C; Yu, L; Hébrard, E; Hussain, G; Alencar, S; Ménard, F; Bouvier, J; Petit, P; Takami, M; Doyon, R; Collier Cameron, A

    2016-06-30

    Hot Jupiters are giant Jupiter-like exoplanets that orbit their host stars 100 times more closely than Jupiter orbits the Sun. These planets presumably form in the outer part of the primordial disk from which both the central star and surrounding planets are born, then migrate inwards and yet avoid falling into their host star. It is, however, unclear whether this occurs early in the lives of hot Jupiters, when they are still embedded within protoplanetary disks, or later, once multiple planets are formed and interact. Although numerous hot Jupiters have been detected around mature Sun-like stars, their existence has not yet been firmly demonstrated for young stars, whose magnetic activity is so intense that it overshadows the radial velocity signal that close-in giant planets can induce. Here we report that the radial velocities of the young star V830 Tau exhibit a sine wave of period 4.93 days and semi-amplitude 75 metres per second, detected with a false-alarm probability of less than 0.03 per cent, after filtering out the magnetic activity plaguing the spectra. We find that this signal is unrelated to the 2.741-day rotation period of V830 Tau and we attribute it to the presence of a planet of mass 0.77 times that of Jupiter, orbiting at a distance of 0.057 astronomical units from the host star. Our result demonstrates that hot Jupiters can migrate inwards in less than two million years, probably as a result of planet–disk interactions.

  9. The Now Frontier. Pioneer to Jupiter. Man Links Earth and Planets. Issue No. 1-5.

    ERIC Educational Resources Information Center

    1973

    This packet of space science instructional materials includes five issues related to the planet Jupiter. Each issue presents factual material about the planet, diagramatic representations of its movements and positions relative to bright stars or the earth, actual photographs and/or tables of data collected relevant to Pioneer 10, the spacecraft…

  10. Orbital migration of giant planets induced by gravitationally unstable gaps: the effect of planet mass

    NASA Astrophysics Data System (ADS)

    Cloutier, Ryan; Lin, Min-Kai

    2013-09-01

    It has been established that self-gravitating disc-satellite interaction can lead to the formation of a gravitationally unstable gap. Such an instability may significantly affect the orbital migration of gap-opening perturbers in self-gravitating discs. In this paper, we extend the two-dimensional hydrodynamic simulations of Lin & Papaloizou to investigate the role of the perturber or planet mass on the gravitational stability of gaps and its impact on orbital migration. We consider giant planets with planet-to-star mass ratio q ≡ Mp/M* ∈ [0.3, 3.0] × 10-3 (so that q = 10-3 corresponds to a Jupiter mass planet if M* = M⊙), in a self-gravitating disc with disc-to-star mass ratio Md/M* = 0.08, aspect ratio h = 0.05 and Keplerian Toomre parameter Qk0 = 1.5 at 2.5 times the planet's initial orbital radius. These planet masses correspond to tilde{q}in [0.9, 1.7], where tilde{q} is the ratio of the planet Hill radius to the local disc scale-height. Fixed-orbit simulations show that all planet masses we consider open gravitationally unstable gaps, but the instability is stronger and develops sooner with increasing planet mass. The disc-on-planet torques typically become more positive with increasing planet mass. In freely migrating simulations, we observe faster outward migration with increasing planet mass, but only for planet masses capable of opening unstable gaps early on. For q = 0.0003 (tilde{q}=0.9), the planet undergoes rapid inward type III migration before it can open a gap. For q = 0.0013 (tilde{q}=1.5) we find it is possible to balance the tendency for inward migration by the positive torques due to an unstable gap, but only for a few 10 s of orbital periods. We find the unstable outer gap edge can trigger outward type III migration, sending the planet to twice its initial orbital radius on dynamical time-scales. We briefly discuss the importance of our results in the context of giant planet formation on wide orbits through disc fragmentation.

  11. Bayesian thermal evolution models for giant planets: Helium rain and double-diffusive convection in Jupiter

    NASA Astrophysics Data System (ADS)

    Mankovich, Christopher; Fortney, Jonathan J.; Nettelmann, Nadine; Moore, Kevin

    2016-10-01

    Hydrogen and helium unmix when sufficiently cool, and this bears on the thermal evolution of all cool giant planets at or below one Jupiter mass. Over the past few years, ab initio simulations have put us in the era of quantitative predictions for this H-He immiscibility at megabar pressures. We present models for the thermal evolution of Jupiter, including its evolving helium distribution following one such ab initio H-He phase diagram. After 4 Gyr of homogeneous evolution, differentiation establishes a helium gradient between 1 and 2 Mbar that dynamically stabilizes the fluid to overturning convection. The result is a region undergoing overstable double-diffusive convection (ODDC), whose relatively weak vertical heat transport maintains a superadiabatic temperature gradient. With a general parameterization for the ODDC efficiency, the models can reconcile Jupiter's intrinsic flux, atmospheric helium content, and mean radius at the age of the solar system if the H-He phase diagram is translated to cooler temperatures.We cast our nonadiabatic thermal evolution models in a Markov chain Monte Carlo parameter estimation framework, retrieving the total heavy element mass, the superadiabaticity of the deep temperature gradient, and the phase diagram temperature offset. Models using the interpolated Saumon, Chabrier and van Horn (1995) equation of state (SCvH-I) favor very inefficient ODDC such that the deep temperature gradient is strongly superadiabatic, forming a thermal boundary layer that allows the molecular envelope to cool quickly while the deeper interior (most of the planet's mass) actually heats up over time. If we modulate the overall cooling time with an additional free parameter, mimicking the effect of a colder or warmer EOS, the models favor those that are colder than SCvH-I; this class of EOS is also favored by shock experiments. The models in this scenario have more modest deep superadiabaticities such that the envelope cools more gradually and the deep

  12. Search for giant planets in M67. III. Excess of hot Jupiters in dense open clusters

    NASA Astrophysics Data System (ADS)

    Brucalassi, A.; Pasquini, L.; Saglia, R.; Ruiz, M. T.; Bonifacio, P.; Leão, I.; Canto Martins, B. L.; de Medeiros, J. R.; Bedin, L. R.; Biazzo, K.; Melo, C.; Lovis, C.; Randich, S.

    2016-07-01

    Since 2008 we used high-precision radial velocity (RV) measurements obtained with different telescopes to detect signatures of massive planets around main-sequence and evolved stars of the open cluster (OC) M67. We aimed to perform a long-term study on giant planet formation in open clusters and determine how this formation depends on stellar mass and chemical composition. A new hot Jupiter (HJ) around the main-sequence star YBP401 is reported in this work. An update of the RV measurements for the two HJ host-stars YBP1194 and YBP1514 is also discussed. Our sample of 66 main-sequence and turnoff stars includes 3 HJs, which indicates a high rate of HJs in this cluster (5.6% for single stars and 4.5%% for the full sample). This rate is much higher than what has been discovered in the field, either with RV surveys or by transits. High metallicity is not a cause for the excess of HJs in M67, nor can the excess be attributed to high stellar masses. When combining this rate with the non-zero eccentricity of the orbits, our results are qualitatively consistent with a HJ formation scenario dominated by strong encounters with other stars or binary companions and subsequent planet-planet scattering, as predicted by N-body simulations. Based on observations collected at the ESO 3.6 m telescope (La Silla), at the 1.93 m telescope of the Observatoire de Haute-Provence (OHP), at the Hobby Eberly Telescope (HET), at the Telescopio Nazionale Galileo (TNG, La Palma) and at the Euler Swiss Telescope.

  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. CROWDING-OUT OF GIANTS BY DWARFS: AN ORIGIN FOR THE LACK OF COMPANION PLANETS IN HOT JUPITER SYSTEMS

    SciTech Connect

    Ogihara, Masahiro; Inutsuka, Shu-ichiro; Kobayashi, Hiroshi

    2013-11-20

    We investigate the formation of close-in terrestrial planets from planetary embryos under the influence of a hot Jupiter (HJ) using gravitational N-body simulations that include gravitational interactions between the gas disk and the terrestrial planet (e.g., type I migration). Our simulations show that several terrestrial planets efficiently form outside the orbit of the HJ, making a chain of planets, and all of them gravitationally interact directly or indirectly with the HJ through resonance, which leads to inward migration of the HJ. We call this mechanism of induced migration of the HJ ''crowding-out''. The HJ is eventually lost through collision with the central star, and only several terrestrial planets remain. We also find that the efficiency of the crowding-out effect depends on the model parameters; for example, the heavier the disk is, the more efficient the crowding-out is. When planet formation occurs in a massive disk, the HJ can be lost to the central star and is never observed. On the other hand, for a less massive disk, the HJ and terrestrial planets can coexist; however, the companion planets may be below the detection limit of current observations. In both cases, systems with a HJ and terrestrial planets have little chance of detection. Therefore, our model naturally explains the lack of companion planets in HJ systems regardless of the disk mass. In effect, our model provides a theoretical prediction for future observations; additional planets can be discovered just outside the HJ, and their masses should generally be small.

  15. A SHORT-PERIOD CENSOR OF SUB-JUPITER MASS EXOPLANETS WITH LOW DENSITY

    SciTech Connect

    Szabo, Gy. M.; Kiss, L. L.

    2011-02-01

    Despite the existence of many short-period hot Jupiters, there is not one hot Neptune with an orbital period less than 2.5 days. Here, we discuss a cluster analysis of the currently known 106 transiting exoplanets to investigate a possible explanation for this observation. We find two distinct clusters in the mass-density space, one with hot Jupiters with a wide range of orbital periods (0.8-114 days) and a narrow range of planet radii (1.2 {+-} 0.2 R{sub J} ) and another one with a mixture of super-Earths, hot Neptunes, and hot Jupiters, exhibiting a surprisingly narrow period distribution (3.7 {+-} 0.8 days). These two clusters follow strikingly different distributions in the period-radius parameter plane. The branch of sub-Jupiter mass exoplanets is censored by the orbital period at the large-radius end: no planets with mass between 0.02 and 0.8 M{sub J} or with radius between 0.25 and 1.0 R{sub J} are known with P{sub orb} < 2.5 days. This clustering is not predicted by current theories of planet formation and evolution, which we also review briefly.

  16. From Dust to Dust: Protoplanetary Disk Accretion, Hot Jupiter Climates, and the Evaporation of Rocky Planets

    NASA Astrophysics Data System (ADS)

    Perez-Becker, Daniel Alonso

    2013-12-01

    This dissertation is composed of three independent projects in astrophysics concerning phenomena that are concurrent with the birth, life, and death of planets. In Chapters 1 & 2, we study surface layer accretion in protoplanetary disks driven stellar X-ray and far-ultraviolet (FUV) radiation. In Chapter 3, we identify the dynamical mechanisms that control atmospheric heat redistribution on hot Jupiters. Finally, in Chapter 4, we characterize the death of low-mass, short-period rocky planets by their evaporation into a dusty wind. Chapters 1 & 2: Whether protoplanetary disks accrete at observationally significant rates by the magnetorotational instability (MRI) depends on how well ionized they are. We find that disk surface layers ionized by stellar X-rays are susceptible to charge neutralization by condensates---ranging from mum-sized dust to angstrom-sized polycyclic aromatic hydrocarbons (PAHs). Ion densities in X-ray-irradiated surfaces are so low that ambipolar diffusion weakens the MRI. In contrast, ionization by stellar FUV radiation enables full-blown MRI turbulence in disk surface layers. Far-UV ionization of atomic carbon and sulfur produces a plasma so dense that it is immune to ion recombination on grains and PAHs. Even though the FUV-ionized layer is ˜10--100 times more turbulent than the X-ray-ionized layer, mass accretion rates of both layers are comparable because FUV photons penetrate to lower surface densities than do X-rays. We conclude that surface layer accretion occurs at observationally significant rates at radii ≳ 1--10 AU. At smaller radii, both X-ray- and FUV-ionized surface layers cannot sustain the accretion rates generated at larger distance and an additional means of transport is needed. In the case of transitional disks, it could be provided by planets. Chapter 3: Infrared light curves of transiting hot Jupiters present a trend in which the atmospheres of the hottest planets are less efficient at redistributing the stellar energy

  17. Mass-loss evolution of close-in exoplanets: Evaporation of hot Jupiters and the effect on population

    SciTech Connect

    Kurokawa, H.; Nakamoto, T.

    2014-03-01

    During their evolution, short-period exoplanets may lose envelope mass through atmospheric escape owing to intense X-ray and extreme ultraviolet (XUV) radiation from their host stars. Roche-lobe overflow induced by orbital evolution or intense atmospheric escape can also contribute to mass loss. To study the effects of mass loss on inner planet populations, we calculate the evolution of hot Jupiters considering mass loss of their envelopes and thermal contraction. Mass loss is assumed to occur through XUV-driven atmospheric escape and the following Roche-lobe overflow. The runaway effect of mass loss results in a dichotomy of populations: hot Jupiters that retain their envelopes and super Earths whose envelopes are completely lost. Evolution primarily depends on the core masses of planets and only slightly on migration history. In hot Jupiters with small cores (≅ 10 Earth masses), runaway atmospheric escape followed by Roche-lobe overflow may create sub-Jupiter deserts, as observed in both mass and radius distributions of planetary populations. Comparing our results with formation scenarios and observed exoplanets populations, we propose that populations of closely orbiting exoplanets are formed by capturing planets at/inside the inner edges of protoplanetary disks and subsequent evaporation of sub-Jupiters.

  18. Planets of the solar system. [Jupiter and Venus

    NASA Technical Reports Server (NTRS)

    Kondratyev, K. Y.; Moskalenko, N. I.

    1978-01-01

    Venera and Mariner spacecraft and ground based radio astronomy and spectroscopic observations of the atmosphere and surface of venus are examined. The composition and structural parameters of the atmosphere are discussed as the basis for development of models and theories of the vertical structure of the atmosphere, the greenhouse effect, atmospheric circulation and cloud cover. Recommendations for further meteorological studies are given. Ground based and Pioneer satellite observation data on Jupiter are explored as well as calculations and models of the cloud structure, atmospheric circulation and thermal emission field of Jupiter.

  19. Optical Ground-Based Spectra of Jupiter and Saturn: An Exploration of Giant Planet Chromophores

    NASA Astrophysics Data System (ADS)

    Chanover, Nancy J.; Simon-Miller, A. A.; Hudson, R. L.; Loeffler, M. J.

    2013-10-01

    We present and interpret ground-based optical spectra of Jupiter and Saturn recently acquired in an effort to characterize candidate coloring agents, or chromophores, in the atmospheres of the gas giant planets of our solar system. Surprisingly, despite hundreds of years of observations, we still do not know the identity of the trace chemical compounds that color the atmospheres of the giant planets. Previous analyses have attempted to identify a specific chemical that is responsible for the colors, but none has yet been conclusively proven. We acquired spatially resolved optical spectra of various regions in the atmospheres of both Jupiter and Saturn in February 2013 using the Dual Imaging Spectrograph (DIS) on the Astrophysical Research Consortium's 3.5-meter telescope at Apache Point Observatory. The spectra cover the range of 300-1000 nm, with a spectral resolution of R ~ 1200. For the observations of both Jupiter and Saturn, we used DIS with the 6 arcminute long slit aligned with the planets' latitudinal bands and stepped the slit north-south to build up a spectral image cube with spectra at all locations on the planet. This enables the extraction of subapertures within the slit corresponding to specific locations, e.g. the Great Red Spot on Jupiter, during the data reduction process. We compare the optical spectra of various colored regions in the giant planet atmospheres to laboratory data of candidate chromophores. The characterization of chromophore materials will provide insight into the upper tropospheric dynamics and circulation patterns on Jupiter and Saturn that provide a stable environment for the creation and/or sustenance of chromophores. This will help further our understanding of the different evolutionary pathways of the gas giant planets of our solar system, providing a process-oriented view of their variations in cloud colors.

  20. Characterizing Low-Mass Planets in Kepler's Multi-Planet Systems with Transit Timing

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Lissauer, Jack; Rowe, Jason; Fabrycky, Daniel

    2014-11-01

    The Kepler mission has revealed an abundance of planets in a regime of mass and size that is absent from the Solar System. This includes systems of high multiplicity within 1 AU, where low-mass volatile-rich planets have been observed in compact orbital configurations. Smaller, rocky planets have also been observed in such systems. The existing sample of characterized planets on the mass-radius diagram shows no abrupt transition from rocky planets to those that must be volatile-rich, but characteristic trends are beginning to emerge. More precise characterizations of planets by mass, radius, and incident flux will aid in revealing fundamental properties of a common class of exoplanets. There is a small sample of exoplanets with known masses and radii, mostly hot jupiters whose radii are known from transit depths, and whose masses are determined from radial velocity spectroscopy (RV). In the absence of mass determinations via RV observations, transit timing variations (TTVs) offer a chance to probe perturbations between planets that pass close to one another or are near resonance, and hence dynamical fits to observed transit times can be used to measure planetary masses and orbital parameters. Such modelling with Kepler data probes planetary masses over orbital periods ranging from ~5-100 days, complementing the sample of RV detections. Furthermore, in select cases, dynamical fits to observed TTVs can tightly constrain the orbital eccentricity vectors, which can, alongside the transit light curve, tightly constrain the density and radius of the host star, and hence reduce the uncertainty on planetary radius. TTV studies have revealed a class of low-mass low-density objects with a substantial mass fraction in the form of a voluminous H-rich atmosphere. To these we add precise mass measurements of the outer planets of Kepler-33, a compact system with five known transiting planets, three of which show detectable transit timing variations. These results will be placed

  1. Limits on the Core Mass of Jupiter

    NASA Astrophysics Data System (ADS)

    Stevenson, D. J.

    2015-12-01

    The core is here defined as the central concentration of elements heavier than hydrogen and helium (it need not be solid and it need not be purely heavy elements and it will not have a sharp boundary). Its determination is a major goal of the Juno mission (2016-17) and it will be difficult to determine because it is expected to be only a few percent of the total mass. It has long been known that there is no prospect of determining the nature of this core (e.g., its density) from gravity measurements, even though the mass can be estimated. By consideration of simple models that are nonetheless faithful to the essential physics, it is further shown that should the core be contaminated with light elements (hydrogen and helium) then the gravity data can tell us the core mass as defined (with some caveats about the fuzziness of its boundary) but not the total mass within some small radius (which could include any light elements mixed in). This is both good and bad news: Good in that the core is thought to be diagnostic of the conditions under which the planet formed but bad in that the admixture also tells us more about both formation process and core erosion. Further, a linear perturbation theory has been developed that provides an easy approximate way of determining how errors in the equation of state (EOS) propagate into errors in the estimated core mass or envelope enrichment in heavies in models that nonetheless satisfy all observables. This theory does not require detailed models of the planet but provides an integral mapping from changes in the EOS into approximate changes in radius at fixed mass, and low degree gravity (or moment of inertia, MOI). This procedure also shows that there exist perturbations that leave the radius, mass and MOI unchanged but cause a change in J2, though in practice the non-uniqueness of structure by this consideration (~0.2% or less in MOI for example) is less than the non-uniqueness arising from likely EOS uncertainties (~1% in total

  2. A historical interpretation of the study of the visible cloud morphology on the planet Jupiter: 1610-1878

    NASA Astrophysics Data System (ADS)

    Hockey, Thomas Arnold

    The majority of the literature discussing the perceived physical appearance of Jupiter published prior to 1878 was examined in order to determine to what extent observations were biased by technical limitations and preconceptions of their day and, in lieu of these, how useful this body of work is in characterizing the behavior of the Jovian upper atmosphere over the last three hundred years. The biographies of the historical observers; their instrumentation, available viewing conditions, and observational techniques; their means of communication with their fellows; and the primary interpretive references available to their libraries were investigated in order to attempt to explain discrepancies and agreement between what was reported in pre-photographic times and what is presently seen. It was found that nearly all of the prominent feature-types found on Jupiter today existed during the nineteenth century and, in some cases, earlier. The longevity and frequency of the appearance of features can not be accurately determined from the time before objective surveys of the planet were organized. This is because, during each apparition of Jupiter, nonprofessional part-time observers, working independently chose to use their finite time and resources to follow the progress of specific discoveries on its disk to the exclusion of the rest of the planet. Interpretation of Jovian features were subject to three major impediments: the belief in and search for a solid surface of Jupiter at moderate depth below the clouds; a lack of appreciation for the two or more orders of magnitude differences of scale between the dimensions of Jupiter's area, mass, and properties of its atmosphere compared to those of the Earth; and an inability to differentiate between real and phantom features watched through seeing-limited telescopes.

  3. The Photoeccentric Effect and Proto-hot Jupiters. I. Measuring Photometric Eccentricities of Individual Transiting Planets

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, John Asher

    2012-09-01

    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the "cold" Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations—part of the "photoeccentric" light curve signature of a planet's eccentricity—even with long-cadence Kepler photometry and loosely constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71+0.16 - 0.09, in good agreement with the discovery value e = 0.67 ± 0.08 based on 33 radial-velocity measurements. We present two additional tests using Kepler data. In each case, the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto-hot Jupiters predicted by Socrates et al.

  4. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. I. MEASURING PHOTOMETRIC ECCENTRICITIES OF INDIVIDUAL TRANSITING PLANETS

    SciTech Connect

    Dawson, Rebekah I.; Johnson, John Asher

    2012-09-10

    Exoplanet orbital eccentricities offer valuable clues about the history of planetary systems. Eccentric, Jupiter-sized planets are particularly interesting: they may link the 'cold' Jupiters beyond the ice line to close-in hot Jupiters, which are unlikely to have formed in situ. To date, eccentricities of individual transiting planets primarily come from radial-velocity measurements. Kepler has discovered hundreds of transiting Jupiters spanning a range of periods, but the faintness of the host stars precludes radial-velocity follow-up of most. Here, we demonstrate a Bayesian method of measuring an individual planet's eccentricity solely from its transit light curve using prior knowledge of its host star's density. We show that eccentric Jupiters are readily identified by their short ingress/egress/total transit durations-part of the 'photoeccentric' light curve signature of a planet's eccentricity-even with long-cadence Kepler photometry and loosely constrained stellar parameters. A Markov Chain Monte Carlo exploration of parameter posteriors naturally marginalizes over the periapse angle and automatically accounts for the transit probability. To demonstrate, we use three published transit light curves of HD 17156 b to measure an eccentricity of e = 0.71{sup +0.16}{sub -0.09}, in good agreement with the discovery value e = 0.67 {+-} 0.08 based on 33 radial-velocity measurements. We present two additional tests using Kepler data. In each case, the technique proves to be a viable method of measuring exoplanet eccentricities and their confidence intervals. Finally, we argue that this method is the most efficient, effective means of identifying the extremely eccentric, proto-hot Jupiters predicted by Socrates et al.

  5. Scorched Planets: Understanding the Structure and Climate of Hot Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Colón, Knicole; Martioli, Eder; Angerhausen, Daniel; Rodriguez, Joseph E.; Zhou, George; Pepper, Joshua; Stassun, Keivan; Gaudi, B. Scott; James, David; Eastman, Jason; Beatty, Thomas G.; Bayliss, Daniel

    2015-12-01

    Radial velocity and transit surveys have revealed that hot Jupiters are intrinsically rare in the Galaxy. These extreme examples of extrasolar planets have been the subject of many studies to date, but their formation and evolution are still shrouded in mystery. I will present results from a large ground-based survey to study the atmospheres of hot Jupiters via their secondary eclipses in the near-infrared. Such observations provide us with a direct measurement of thermal emission from a planet’s day-side, allowing us to probe the connection between the atmospheric structure and climate deep in their atmospheres, as well as the irradiation from their host star. I will present results obtained for several hot Jupiters using the wide-field camera WIRCam on the 3.6m Canada-France-Hawaii-Telescope (CFHT). The sample of hot Jupiters observed to date in the CFHT survey spans a range of planetary parameters (e.g. temperatures and densities) and also includes several new exotic discoveries from the KELT transit survey, such as a planet in a hierarchical triple stellar system as well as a planet with a very rapidly rotating host star. Results from the CFHT survey will be combined with those from an ongoing survey of hot Jupiter eclipses in the southern hemisphere using the 3.9m Anglo-Australian Telescope as well as an upcoming survey using the 4m Mayall Telescope at Kitt Peak National Observatory. The combined survey will be the largest homogeneous study of this kind to date, and it will provide us with the congruent observations of a significant number of unique planets in eclipse. These observations will ultimately allow a comprehensive statistical analysis of the diversity of hot Jupiter atmospheres via their near-infrared eclipses. In addition, this project will identify legacy targets for comparative exoplanetology using next-generation facilities such as the James Webb Space Telescope.

  6. A Venus-mass Planet Orbiting a Brown Dwarf: A Missing Link between Planets and Moons

    NASA Astrophysics Data System (ADS)

    Udalski, A.; Jung, Y. K.; Han, C.; Gould, A.; Kozłowski, S.; Skowron, J.; Poleski, R.; Soszyński, I.; Pietrukowicz, P.; Mróz, P.; Szymański, M. K.; Wyrzykowski, Ł.; Ulaczyk, K.; Pietrzyński, G.; Shvartzvald, Y.; Maoz, D.; Kaspi, S.; Gaudi, B. S.; Hwang, K.-H.; Choi, J.-Y.; Shin, I.-G.; Park, H.; Bozza, V.

    2015-10-01

    The co-planarity of solar system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hundreds of co-planar planetary systems by the Kepler satellite demonstrate that this formation mechanism is extremely widespread. Many moons in the solar system, such as the Galilean moons of Jupiter, also formed out of the accretion disks that coalesced into the giant planets. Here we report the discovery of an intermediate system, OGLE-2013-BLG-0723LB/Bb, composed of a Venus-mass planet orbiting a brown dwarf, which may be viewed either as a scaled-down version of a planet plus a star or as a scaled-up version of a moon plus a planet orbiting a star. The latter analogy can be further extended since they orbit in the potential of a larger, stellar body. For ice-rock companions formed in the outer parts of accretion disks, like Uranus and Callisto, the scaled masses and separations of the three types of systems are similar, leading us to suggest that the formation processes of companions within accretion disks around stars, brown dwarfs, and planets are similar.

  7. Mass Spectrometry in Jupiter's Atmosphere: Vertical Variation of Volatile Vapors

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; Atreya, Sushil K.; Mahaffy, Paul R.

    2014-05-01

    The Galileo Probe made the first and only in situ measurements of composition in Jupiter's atmosphere, led by the Galileo Probe Mass Spectrometer, or GPMS [1]. The major contribution from this instrument was the measurement of abundances and isotope ratios of the noble gases, as well as the volatile gases CH4, NH3, H2O, and H2S [2,3]. These initial results were further refined by detailed laboratory calibrations for the noble gases [4] and the volatiles [5]. The probe measurements resulted in the first determination of the heavy element abundances (except carbon that was known previously) and He/H ratio, which provide critical constraints to models of the formation of Jupiter and the origin of its atmosphere [6,7]. The condensable volatiles, or CVs (ammonia, H2S, and water), increased with depth in the probe entry site. This vertical variation was observed at levels much deeper than the modeled cloud bases, as predicted by one-dimensional chemical equilibrium models. The discrepancy is due to the probe's entry into a dry region known as a 5-μm hot spot. The 5-μm hot spots are part of an atmospheric wave system that encircles Jupiter just north of the equator. Despite the anomalous meteorology, the bulk abundances of NH3 and H2S were measured by the probe, and found to be enriched with respect to solar composition (similarly to the non-condensable volatile CH4). The deepest water mixing ratio, however, was observed to be depleted relative to solar composition. We review an updated context for the CV vertical profiles measured by the GPMS, based on the latest results from remote sensing, simulation, and reinterpretation of Galileo Probe measurements. In particular, we find that (1) the bulk abundance of water in Jupiter's atmosphere must be greater than the subsolar abundance derived from the deepest GPMS measurements [8], and that (2) CV mixing ratios are controlled by a range of processes in addition to condensation of the ices NH3, NH4SH, and H2O [5-9]. Both

  8. Minor planets and comets in libration about the 2:1 resonance with Jupiter

    NASA Technical Reports Server (NTRS)

    Franklin, F. A.; Marsden, B. G.; Williams, J. G.; Bardwell, C. M.

    1975-01-01

    We examine the orbits of minor planets in a search for objects librating about the 2:1 mean-motion resonance with Jupiter. Some 30 candidates are found among the Palomar-Leiden Survey and other unnumbered minor planets. Although almost all the orbits are very uncertain, there does seem to be an indication that librators of low orbital eccentricity do exist, contrary to the hypothesis by Giffen. We also tabulate data describing 12 comets that are temporarily librating about the 2:1 resonance. Finally, we present a discussion of what are apparently 'apocentric' librations. This type of libration, of which we find seven representatives among the numbered minor planets, can occur only for sufficiently small eccentricity. For such bodies, the role of Jupiter's eccentricity is vital; it is associated with a continuing alternation between apocentric libration and an oscillation of the line of apsides.

  9. Migrating Planets

    NASA Astrophysics Data System (ADS)

    Murray, N.; Hansen, B.; Holman, M.; Tremaine, S.

    1998-01-01

    A planet orbiting in a disk of planetesimals can experience an instability in which it migrates to smaller orbital radii. Resonant interactions between the planet and planetesimals remove angular momentum from the planetesimals, increasing their eccentricities. Subsequently, the planetesimals either collide with or are ejected by the planet, reducing the semimajor axis of the planet. If the surface density of planetesimals exceeds a critical value, corresponding to 0.03 solar masses of gas inside the orbit of Jupiter, the planet will migrate inward a large distance. This instability may explain the presence of Jupiter-mass objects in small orbits around nearby stars.

  10. Galileo to Jupiter: Probing the Planet and Mapping Its Moons

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The first project to use the space shuttle as an interplanetary launch vehicle, the Galileo mission is designed to obtain information about the origin and evolution of the solar system by studying large-scale phenomena on Jupiter and its satellites. Aimed towards Mars to obtain gravity assist, the orbiting spacecraft will deploy a probe, which penetrating the Jovian atmosphere, will transmit data for approximately an hour. The spacecraft itself will inspect the atmospheres, ionospheres, and surfaces of Ganymede, Io, Europa, and Callisto, as well as determine their magnetic and gravitational properties. The experiments to be conducted and their scientific objectives are described. Known facts about the Jovian system are reviewed.

  11. PLANET HUNTERS. V. A CONFIRMED JUPITER-SIZE PLANET IN THE HABITABLE ZONE AND 42 PLANET CANDIDATES FROM THE KEPLER ARCHIVE DATA

    SciTech Connect

    Wang, Ji; Fischer, Debra A.; Boyajian, Tabetha S.; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M.; Barclay, Thomas; Schwamb, Megan E.; Lintott, Chris; Simpson, Robert; Jek, Kian J.; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Smith, Arfon M.; Parrish, Michael; Lynn, Stuart; Schawinski, Kevin; and others

    2013-10-10

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R{sub PL} = 10.12 ± 0.56 R{sub ⊕}) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false-positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least 3 transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between those of Neptune and Jupiter. These detections nearly double the number of gas-giant planet candidates orbiting at habitable-zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events.

  12. Planet Hunters. V. A Confirmed Jupiter-size Planet in the Habitable Zone and 42 Planet Candidates from the Kepler Archive Data

    NASA Astrophysics Data System (ADS)

    Wang, Ji; Fischer, Debra A.; Barclay, Thomas; Boyajian, Tabetha S.; Crepp, Justin R.; Schwamb, Megan E.; Lintott, Chris; Jek, Kian J.; Smith, Arfon M.; Parrish, Michael; Schawinski, Kevin; Schmitt, Joseph R.; Giguere, Matthew J.; Brewer, John M.; Lynn, Stuart; Simpson, Robert; Hoekstra, Abe J.; Jacobs, Thomas Lee; LaCourse, Daryll; Schwengeler, Hans Martin; Chopin, Mike; Herszkowicz, Rafal

    2013-10-01

    We report the latest Planet Hunter results, including PH2 b, a Jupiter-size (R PL = 10.12 ± 0.56 R ⊕) planet orbiting in the habitable zone of a solar-type star. PH2 b was elevated from candidate status when a series of false-positive tests yielded a 99.9% confidence level that transit events detected around the star KIC 12735740 had a planetary origin. Planet Hunter volunteers have also discovered 42 new planet candidates in the Kepler public archive data, of which 33 have at least 3 transits recorded. Most of these transit candidates have orbital periods longer than 100 days and 20 are potentially located in the habitable zones of their host stars. Nine candidates were detected with only two transit events and the prospective periods are longer than 400 days. The photometric models suggest that these objects have radii that range between those of Neptune and Jupiter. These detections nearly double the number of gas-giant planet candidates orbiting at habitable-zone distances. We conducted spectroscopic observations for nine of the brighter targets to improve the stellar parameters and we obtained adaptive optics imaging for four of the stars to search for blended background or foreground stars that could confuse our photometric modeling. We present an iterative analysis method to derive the stellar and planet properties and uncertainties by combining the available spectroscopic parameters, stellar evolution models, and transiting light curve parameters, weighted by the measurement errors. Planet Hunters is a citizen science project that crowd sources the assessment of NASA Kepler light curves. The discovery of these 43 planet candidates demonstrates the success of citizen scientists at identifying planet candidates, even in longer period orbits with only two or three transit events. .

  13. PHOTO ILLUSTRATION OF COMET P/SHOEMAKER-LEVY 9 and PLANET JUPITER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a composite photo, assembled from separate images of Jupiter and comet P/Shoemaker-Levy 9, as imaged by the Wide Field and Planetary Camera-2 (WFPC-2), aboard NASA's Hubble Space Telescope (HST). Jupiter was imaged on May 18, 1994, when the giant planet was at a distance of 420 million miles (670 million km) from Earth. This 'true-color' picture was assembled from separate HST exposures in red, blue, and green light. Jupiter's rotation between exposures creates the blue and red fringe on either side of the disk. HST can resolve details in Jupiter's magnificent cloud belts and zones as small as 200 miles (320 km) across (wide field mode). This detailed view is only surpassed by images from spacecraft that have traveled to Jupiter. The dark spot on the disk of Jupiter is the shadow of the inner moon Io. This volcanic moon appears as an orange and yellow disk just to the upper right of the shadow. Though Io is approximately the size of Earth's Moon (but 2,000 times farther away), HST can resolve surface details. When the comet was observed on May 17, its train of 21 icy fragments stretched across 710 thousand miles (1.1 million km) of space, or 3 times the distance between Earth and the Moon. This required six WFPC exposures along the comet train to include all the nuclei. The image was taken in red light. The apparent angular size of Jupiter relative to the comet, and its angular separation from the comet when the images were taken, have been modified for illustration purposes. Credit: H.A. Weaver, T.E. Smith (Space Telescope Science Institute) and J.T. Trauger, R.W. Evans (Jet Propulsion Laboratory), and NASA

  14. Terrestrial planet and asteroid formation in the presence of giant planets. I. Relative velocities of planetesimals subject to Jupiter and Saturn perturbations.

    PubMed

    Kortenkamp, S J; Wetherill, G W

    2000-01-01

    We investigate the orbital evolution of 10(13)- to 10(25) -g planetesimals near 1 AU and in the asteroid belt (near 2.6 AU) prior to the stage of evolution when the mutual perturbations between the planetesimals become important. We include nebular gas drag and the effects of Jupiter and Saturn at their present masses and in their present orbits. Gas drag introduces a size-dependent phasing of the secular perturbations, which leads to a pronounced dip in encounter velocities (Venc) between bodies of similar mass. Plantesimals of identical mass have Venc approximately 1 and approximately 10 m s-1 (near 1 and 2.6 AU, respectively) while bodies differing by approximately 10 in mass have Venc approximately 10 and approximately 100 m s-1 (near 1 and 2.6 AU, respectively). Under these conditions, growth, rather than erosion, will occur only by collisions of bodies of nearly the same mass. There will be essentially no gravitational focusing between bodies less than 10(22) to 10(25) g, allowing growth of planetary embryos in the terrestrial planet region to proceed in a slower nonrunaway fashion. The environment in the asteroid belt will be even more forbidding and it is uncertain whether even the severely depleted present asteroid belt could form under these conditions. The perturbations of Jupiter and Saturn are quite sensitive to their semi-major axes and decrease when the planets' heliocentric distances are increased to allow for protoplanet migration. It is possible, though not clearly demonstrated, that this could produce a depleted asteroid belt but permit formation of a system of terrestrial planet embryos on a approximately 10(6)-year timescale, initially by nonrunaway growth and transitioning to runaway growth after approximately 10(5) years. The calculations reported here are valid under the condition that the relative velocities of the bodies are determined only by Jupiter and Saturn perturbations and by gas drag, with no mutual perturbations between

  15. Terrestrial planet and asteroid formation in the presence of giant planets. I. Relative velocities of planetesimals subject to Jupiter and Saturn perturbations

    NASA Technical Reports Server (NTRS)

    Kortenkamp, S. J.; Wetherill, G. W.

    2000-01-01

    We investigate the orbital evolution of 10(13)- to 10(25) -g planetesimals near 1 AU and in the asteroid belt (near 2.6 AU) prior to the stage of evolution when the mutual perturbations between the planetesimals become important. We include nebular gas drag and the effects of Jupiter and Saturn at their present masses and in their present orbits. Gas drag introduces a size-dependent phasing of the secular perturbations, which leads to a pronounced dip in encounter velocities (Venc) between bodies of similar mass. Plantesimals of identical mass have Venc approximately 1 and approximately 10 m s-1 (near 1 and 2.6 AU, respectively) while bodies differing by approximately 10 in mass have Venc approximately 10 and approximately 100 m s-1 (near 1 and 2.6 AU, respectively). Under these conditions, growth, rather than erosion, will occur only by collisions of bodies of nearly the same mass. There will be essentially no gravitational focusing between bodies less than 10(22) to 10(25) g, allowing growth of planetary embryos in the terrestrial planet region to proceed in a slower nonrunaway fashion. The environment in the asteroid belt will be even more forbidding and it is uncertain whether even the severely depleted present asteroid belt could form under these conditions. The perturbations of Jupiter and Saturn are quite sensitive to their semi-major axes and decrease when the planets' heliocentric distances are increased to allow for protoplanet migration. It is possible, though not clearly demonstrated, that this could produce a depleted asteroid belt but permit formation of a system of terrestrial planet embryos on a approximately 10(6)-year timescale, initially by nonrunaway growth and transitioning to runaway growth after approximately 10(5) years. The calculations reported here are valid under the condition that the relative velocities of the bodies are determined only by Jupiter and Saturn perturbations and by gas drag, with no mutual perturbations between

  16. Red worlds: Spitzer exploration of a compact system of temperate terrestrial planets transiting a nearby Jupiter-sized star

    NASA Astrophysics Data System (ADS)

    Gillon, Michael; Burdanov, Artem; Delrez, Laetitia; Jehin, Emmanuel; Magain, Pierre; Van Grootel, Valerie; Bolmont, Emeline; Leconte, Jeremy; Raymond, Sean; Selsis, Franck; Demory, Brice-Olivier; Queloz, Didier; Triaud, Amaury; de Wit, Julien; Burgasser, Adam; Carey, Sean; Ingalls, Jim; Lederer, Sue; Agol, Eric; Deck, Katherine

    2016-08-01

    The recently detected TRAPPIST-1 planetary system represents a unique opportunity to extend the nascent field of comparative exoplanetology into the realm of temperate terrestrial worlds. It is composed of at least three Earth-sized planets similar in sizes and irradiations to Earth and Venus transiting an ultra-cool dwarf star only 39 light-years away. Thanks to the Jupiter-size and infrared brightness of their host star, the planets are amenable for detailed atmospheric characterization with JWST, including for biosignatures detection. Our Spitzer Exploration Science Program aims to prepare and optimize the detailed study of this fascinating planetary system through the two following complementary sub-programs: (1) a 480 hrs continuous monitoring of the star to explore its full inner system up to its ice line in a search for any other transiting object(s) (planet, moon, Trojan) with a sensitivity high enough to detect any body as small as Ganymede, and (2) the observation of ~130 transits of the planets (520 hrs). This second part has two goals. First, to measure precisely the planets' masses and eccentricities through the Transit Timing Variations method, to constrain strongly their compositions and energy budgets. Secondly, to measure with an extremely high precision the planets' effective radii at 4.5 microns to assess, when combined with future HST/WFC3 observations, the presence of an atmosphere around them. The two complementary parts of this program will make it a long-lasting legacy of Spitzer to the fields of comparative exoplanetology and astrobiology, by providing the necessary measurements on the inner system of TRAPPIST-1 (complete census, masses, eccentricities, first insights on atmospheres) required to initiate and optimize the detailed atmospheric characterization of its different components with JWST and other future facilities.

  17. Coupled Evolutions of the Stellar Obliquity, Orbital Distance, and Planet's Radius due to the Ohmic Dissipation Induced in a Diamagnetic Hot Jupiter around a Magnetic T Tauri Star

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Ling; Bodenheimer, Peter H.; Gu, Pin-Gao

    2012-10-01

    We revisit the calculation of the ohmic dissipation in a hot Jupiter presented by Laine et al. by considering more realistic interior structures, stellar obliquity, and the resulting orbital evolution. In this simplified approach, the young hot Jupiter of one Jupiter mass is modeled as a diamagnetic sphere with a finite resistivity, orbiting across tilted stellar magnetic dipole fields in vacuum. Since the induced ohmic dissipation occurs mostly near the planet's surface, we find that the dissipation is unable to significantly expand the young hot Jupiter. Nevertheless, the planet inside a small corotation orbital radius can undergo orbital decay by the dissipation torque and finally overfill its Roche lobe during the T Tauri star phase. The stellar obliquity can evolve significantly if the magnetic dipole is parallel/antiparallel to the stellar spin. Our results are validated by the general torque-dissipation relation in the presence of the stellar obliquity. We also run the fiducial model of Laine et al. and find that the planet's radius is sustained at a nearly constant value by the ohmic heating, rather than being thermally expanded to the Roche radius as suggested by the authors.

  18. COUPLED EVOLUTIONS OF THE STELLAR OBLIQUITY, ORBITAL DISTANCE, AND PLANET'S RADIUS DUE TO THE OHMIC DISSIPATION INDUCED IN A DIAMAGNETIC HOT JUPITER AROUND A MAGNETIC T TAURI STAR

    SciTech Connect

    Chang, Yu-Ling; Gu, Pin-Gao; Bodenheimer, Peter H.

    2012-10-01

    We revisit the calculation of the ohmic dissipation in a hot Jupiter presented by Laine et al. by considering more realistic interior structures, stellar obliquity, and the resulting orbital evolution. In this simplified approach, the young hot Jupiter of one Jupiter mass is modeled as a diamagnetic sphere with a finite resistivity, orbiting across tilted stellar magnetic dipole fields in vacuum. Since the induced ohmic dissipation occurs mostly near the planet's surface, we find that the dissipation is unable to significantly expand the young hot Jupiter. Nevertheless, the planet inside a small corotation orbital radius can undergo orbital decay by the dissipation torque and finally overfill its Roche lobe during the T Tauri star phase. The stellar obliquity can evolve significantly if the magnetic dipole is parallel/antiparallel to the stellar spin. Our results are validated by the general torque-dissipation relation in the presence of the stellar obliquity. We also run the fiducial model of Laine et al. and find that the planet's radius is sustained at a nearly constant value by the ohmic heating, rather than being thermally expanded to the Roche radius as suggested by the authors.

  19. THE MASS DISTRIBUTION OF SUBGIANT PLANET HOSTS

    SciTech Connect

    Lloyd, James P.

    2013-09-01

    High mass stars are hostile to Doppler measurements due to rotation and activity on the main-sequence, so RV searches for planets around massive stars have relied on evolved stars. A large number of planets have been found around evolved stars with M > 1.5 M{sub Sun }. To test the robustness of mass determinations, Lloyd compared mass distributions of planet hosting subgiants with distributions from integrating isochrones and concluded that it is unlikely the subgiant planet hosts are this massive, but rather that the mass inferences are systematically in error. The conclusions of Lloyd have been called in to question by Johnson et al., who show TRILEGAL-based mass distributions that disagree with the mass distributions in Lloyd, which they attribute to Malmquist bias. Johnson et al. argue that the very small spectroscopic observational uncertainties favor high masses, and there are a large number of high mass sub giants in RV surveys. However, in this Letter, it is shown that Malmquist bias does not impact the mass distributions, but the mass distribution is sensitive to Galaxy model. The relationship needed to reconcile the subgiant planet host masses with any model of the Galactic stellar population is implausible, and the conclusion of Lloyd that spectroscopic mass determinations of subgiants are likely to have been overestimated is robust.

  20. A search for the infrared spectroscopic signature of hot Jupiter planets

    NASA Astrophysics Data System (ADS)

    Lucas, P. W.; Roche, P. F.

    2002-10-01

    We present the results of an attempt to detect the hottest `hot Jupiter' planets directly in the thermal infrared. A simple method based upon high signal-to-noise ratio spectroscopy of the central star at low spectral resolution is described. In the 2-4 μm region the contrast ratio between planet and star is expected to be relatively low and the planetary spectrum should appear as a faint signal on top of the stellar spectrum, distinguished by edges of H2O absorption. No water edges were found to 3σ limits of one part in a few hundred in each case. These upper limits are compared with the irradiated planetary atmosphere models of Barman, Hauschildt & Allard to derive upper limits on the size of the hot Jupiters, which are expected to be somewhat larger than Jupiter. If reasonably strong H2O absorption occurs in these objects then typical upper limits of R < 3 RJup are derived, the precision being limited by the stability of telluric transmission. Only a modest improvement in precision is needed (e.g. with space-based instruments) to reach the range of greatest interest (1 < R < 2 RJup).

  1. Delay of planet formation at large radius and the outward decrease in mass and gas content of Jovian planets

    NASA Astrophysics Data System (ADS)

    Jin, Li-Ping; Liu, Chun-Jian; Zhang, Yu

    2015-09-01

    A prominent observation of the solar system is that the mass and gas content of Jovian planets decrease outward with orbital radius, except that, in terms of these properties, Neptune is almost the same as Uranus. In previous studies, the solar nebula was assumed to preexist and the formation process of the solar nebula was not considered. It was therefore assumed that planet formation at different radii started at the same time in the solar nebula. We show that planet formation at different radii does not start at the same time and is delayed at large radii. We suggest that this delay might be one of the factors that causes the outward decrease in the masses of Jovian planets. The nebula starts to form from its inner part because of the inside-out collapse of its progenitorial molecular cloud core. The nebula then expands outward due to viscosity. Material first reaches a small radius and then reaches a larger radius, so planet formation is delayed at the large radius. The later the material reaches a planet's location, the less time it has to gain mass and gas content. Hence, the delay tends to cause the outward decrease in mass and gas content of Jovian planets. Our nebula model shows that the material reaches Jupiter, Saturn, Uranus and Neptune at t = 0.40, 0.57, 1.50 and 6.29 × 106 yr, respectively. We discuss the effects of time delay on the masses of Jovian planets in the framework of the core accretion model of planet formation. Saturn's formation is not delayed by much time relative to Jupiter so that they both reach the rapid gas accretion phase and become gas giants. However, the delay in formation of Uranus and Neptune is long and might be one of the factors that cause them not to reach the rapid gas accretion phase before the gas nebula is dispersed. Saturn has less time to go through the rapid gas accretion, so Saturn's mass and gas content are significantly less than those of Jupiter.

  2. EMBRYO IMPACTS AND GAS GIANT MERGERS. I. DICHOTOMY OF JUPITER AND SATURN's CORE MASS

    SciTech Connect

    Li Shulin; Agnor, C.B.; Lin, D. N. C.

    2010-09-10

    Interior to the gaseous envelopes of Saturn, Uranus, and Neptune, there are high-density cores with masses larger than 10 Earth masses. According to the conventional sequential accretion hypothesis, such massive cores are needed for the onset of efficient accretion of their gaseous envelopes. However, Jupiter's gaseous envelope is more massive and its core may be less massive than those of Saturn. In order to account for this structural diversity and the super-solar metallicity in the envelope of Jupiter and Saturn, we investigate the possibility that they may have either merged with other gas giants or consumed several Earth-mass protoplanetary embryos during or after the rapid accretion of their envelope. In general, impinging sub-Earth-mass planetesimals disintegrate in gas giants' envelopes, deposit heavy elements well outside the cores, and locally suppress the convection. Consequently, their fragments sediment to promote the growth of cores. Through a series of numerical simulations, we show that it is possible for colliding super-Earth-mass embryos to reach the cores of gas giants. Direct parabolic collisions also lead to the coalescence of gas giants and merging of their cores. In these cases, the energy released from the impact leads to vigorous convective motion throughout the envelope and the erosion of the cores. This dichotomy contributes to the observed dispersion in the internal structure and atmospheric composition between Jupiter and Saturn and other gas giant planets and elsewhere.

  3. Spin-orbit angle measurements for six southern transiting planets. New insights into the dynamical origins of hot Jupiters

    NASA Astrophysics Data System (ADS)

    Triaud, A. H. M. J.; Collier Cameron, A.; Queloz, D.; Anderson, D. R.; Gillon, M.; Hebb, L.; Hellier, C.; Loeillet, B.; Maxted, P. F. L.; Mayor, M.; Pepe, F.; Pollacco, D.; Ségransan, D.; Smalley, B.; Udry, S.; West, R. G.; Wheatley, P. J.

    2010-12-01

    Context. Several competing scenarios for planetary-system formation and evolution seek to explain how hot Jupiters came to be so close to their parent stars. Most planetary parameters evolve with time, making it hard to distinguish between models. The obliquity of an orbit with respect to the stellar rotation axis is thought to be more stable than other parameters such as eccentricity. Most planets, to date, appear aligned with the stellar rotation axis; the few misaligned planets so far detected are massive (> 2 MJ). Aims: Our goal is to measure the degree of alignment between planetary orbits and stellar spin axes, to search for potential correlations with eccentricity or other planetary parameters and to measure long term radial velocity variability indicating the presence of other bodies in the system. Methods: For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle β between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We used a combined analysis of photometry and radial velocities, fitting model parameters with the Markov Chain Monte Carlo method. After obtaining β we attempt to statistically determine the distribution of the real spin-orbit angle ψ. Results: We found that three of our targets have β above 90°: WASP-2b: β = 153°+11-15, WASP-15b: β = 139.6°+5.2-4.3 and WASP-17b: β = 148.5°+5.1-4.2; the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0°. We find no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All six orbits are close to circular, with only one firm detection of eccentricity e = 0.00848+0.00085-0.00095 in WASP-18b. No long-term radial acceleration was detected for any of the targets

  4. Extrasolar planets around intermediate mass stars

    NASA Astrophysics Data System (ADS)

    Hatzes, A. P.

    2008-08-01

    One of the earliest hints for extrasolar planets came with the discovery almost 15 years ago of low amplitude, long period radial velocity (RV) variations in several K giant stars, β Gem, α Tau (Aldebaran) and α Boo. Since then it has been confirmed that for β Gem (stellar mass =1.7 Modot) these RV variations are due to a planetary companion. Aldebaran is another K giant star showing long-lived (>26 years) and coherent RV variations. These are most likely due to a planetary companion having a mass of 9 MJup using an estimated mass of 2.5 Modot for the star. Giant stars like α Tau and β Gem offer us the possibility of studying the process of planet formation around stars more massive than the sun. The main sequence stars with masses >1.2 Modot are ill-suited for RV surveys as there are few spectral lines for measuring the RV and these are often broadened by high rates of stellar rotation. Currently over 20 intermediate mass giant stars are known to host extrasolar planets. This sample is sufficiently large that we can begin to look at the overall properties of planets around intermediate mass stars. These suggest that more massive stars may have more massive planets that the orbital eccentricities for their extrasolar planets show the wide range of eccentricities seen for main sequence, solar mass stars, and that unlike for main sequence stars there seems to be no preference for metal rich intermediate mass stars to host extrasolar planets.

  5. Solar nebula constraints derived from the masses and formation times of Earth, Mars, Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Mosqueira, Ignacio; Lichtig, Ryan

    2014-11-01

    Terrestrial planets accreted from the late-stage collisional evolution of planetary embryos (roughly Mars-sized) and leftover planetesimals (Chambers 2013). Since the timescale to produce Earth-like analogues is on the order of ~ 100 My, the solar nebula gas would have dissipated by then. On the other hand, Hf-W chronology yields a short accretion timescale for Mars ~9 My (Dauphas and Pourmand 2011), which is similar to the gas dissipation time (Haisch et al. 2011). The Grand-Tack model proposes that Jupiter and Saturn migrated inward until Saturn was caught in a 2:3 mean motion resonance then migrated outward, truncating the disk in the process and accounting for Mars’ orbit, accretion timescale, and small mass (Walsh et al. 2011). However, in order to power the migration of the giant planets this model assumes the presence of a massive (compared to Jupiter) viscously evolving gas disk. This means that the giant planets themselves would not have completed their growth. Thus, the Grand-Tack model provides an explanation for the small mass of Mars at the cost of ignoring the resulting problematic large mass of Saturn. Here we fix the locations and masses of Jupiter and Saturn and develop a model in which the depleted region is due to three key mechanisms: one, removal of collisional fragments by gas drag; two, coalescence of planetary embryos by sweeping secular resonances during gas disk dispersal; three, removal of planetary embryos by Type I tidal interaction with the gas disk. We use analytical and numerical N-body results to evaluate the consequences of the above processes for the disk of solids. We focus on the variables controlling the extent of the depleted region. We stress that the static giant planets nevertheless play a determining role: first, by filtering-out outer disk planetesimal fragments that would otherwise replenish the inner disk; second, by increasing the (phased) eccentricities of planetary embryos thereby allowing larger objects to form

  6. Using Dynamical Models to Predict the Terrestrial-Mass Free-Floating Planet Population

    NASA Astrophysics Data System (ADS)

    Barclay, Thomas; Quintana, Elisa V.

    2016-10-01

    In the classical picture of planet formation, planets form within circumstellar disks as a product of star formation. The material in the disk either forms into a planet, remains bound to the star, falls into the star, or is ejected from the system. We explore the properties of this ejected material using N-body simulations of the late stages of terrestrial planet formation. We find that in planetary systems like ours (with Jupiter and Saturn) about half the ejected material is in bodies less massive than the Moon and half is in bodies more massive than Mars. No planets more massive than half an Earth-mass, however, were ejected, primarily because most of the ejections occur before the timescales needed to grow an Earth-mass body. Without giant planets present in the system, very little material is ever ejected. We predict that future space-borne microlensing searches for free-floating terrestrial-mass planets, such as WFIRST, will discover large numbers of Mars-mass planets but will not make significant detections of Earth-mass planets.

  7. Earth, Jupiter and Saturn as guides for extrasolar planets and brown dwarfs: a lightning climatology study

    NASA Astrophysics Data System (ADS)

    Hodosán, Gabriella; Asensio Torres, Rubén; Helling, Christiane; Vorgul, Irena

    2015-04-01

    Large-scale electrostatic discharges (i.e. lightning) have been observed in the Solar System. Apart from Earth there are direct detections from Jupiter and Saturn and indirect (only radio) detection from Uranus and Neptune. Recent observations made by the Venus Explorer revealed radio signals that may be related to lightning. Observations indicate that clouds form on extrasolar planets and brown dwarfs. The conditions in these clouds may be good for lightning to occur, which can be a main ionization process in these atmospheres (lightning in mineral clouds e.g.: Bailey et al. 2014, ApJ, 784, 43; Helling at al. 2013, ApJ, 767, 136; Helling et al. 2013, P&SS, 77, 152). In this study our aim is to compare lightning climatology from Earth, Jupiter and Saturn and use these statistics as a guide to study potential lightning on extrasolar planetary objects. Earth is a fair analogy for rocky or ocean planets while Jupiter and Saturn resemble giant planets and brown dwarfs. To give an estimate on the total lightning energy (or power) that can reach us from a particular extrasolar body, we need to know how much lightning can occur on the object globally. We will show the possibilities in the number and quality of the giant planet data sets, which may give a fine comparison of future observations of extrasolar giant gas planets and even brown dwarfs. Data were obtained from Lightning Imaging Sensor (LIS)/Optical Transient Detector (OTD) (e.g.: Cecil et al. 2014, Atmospheric Research, 135, 404), Sferics Timing and Ranging Network (STARNET) (e.g.: Morales Rodrigues et al. 2011, 2014, XIV and XV International Conference on Atmospheric Electricity) and World Wide Lightning Location Network (WWLLN) (e.g.: Hutchins et al. 2012, Radio Science, 47, RS6005), four major lightning detecting networks, which monitor lightning occurrence in the optical or radio range on Earth. We compare flash/stroke rates in space and time and use the data to refer to Earth as a transiting exoplanet. We

  8. The mass disruption of Jupiter Family comets

    NASA Astrophysics Data System (ADS)

    Belton, Michael J. S.

    2015-01-01

    I show that the size-distribution of small scattered-disk trans-neptunian objects when derived from the observed size-distribution of Jupiter Family comets (JFCs) and other observational constraints implies that a large percentage (94-97%) of newly arrived active comets within a range of 0.2-15.4 km effective radius must physically disrupt, i.e., macroscopically disintegrate, within their median dynamical lifetime. Additional observational constraints include the numbers of dormant and active nuclei in the near-Earth object (NEO) population and the slope of their size distributions. I show that the cumulative power-law slope (-2.86 to -3.15) of the scattered-disk TNO hot population between 0.2 and 15.4 km effective radius is only weakly dependent on the size-dependence of the otherwise unknown disruption mechanism. Evidently, as JFC nuclei from the scattered disk evolve into the inner Solar System only a fraction achieve dormancy while the vast majority of small nuclei (e.g., primarily those with effective radius <2 km) break-up. The percentage disruption rate appears to be comparable with that of the dynamically distinct Oort cloud and Halley type comets (Levison, H.F., Morbidelli, A., Dones, L., Jedicke, R., Wiegert, P.A., Bottke Jr., W.F. [2002]. Science 296, 2212-2215) suggesting that all types of comet nuclei may have similar structural characteristics even though they may have different source regions and thermal histories. The typical disruption rate for a 1 km radius active nucleus is ∼5 × 10-5 disruptions/year and the dormancy rate is typically 3 times less. We also estimate that average fragmentation rates range from 0.01 to 0.04 events/year/comet, somewhat above the lower limit of 0.01 events/year/comet observed by Chen and Jewitt (Chen, J., Jewitt, D.C. [1994]. Icarus 108, 265-271).

  9. Extrasolar planet population synthesis . IV. Correlations with disk metallicity, mass, and lifetime

    NASA Astrophysics Data System (ADS)

    Mordasini, C.; Alibert, Y.; Benz, W.; Klahr, H.; Henning, T.

    2012-05-01

    semimajor axis distribution of giant planets exists because in low-metallicity disks, planets start farther out, but migrate more, while the contrary applies to high metallicities. The final semimajor axis distribution contains an imprint of the ice line. Close-in low mass planets have a lower mean metallicity than hot Jupiters. The frequency of giant planets varies approximately as Mdisk1.2 and τdisk2. Conclusions: The properties of protoplanetary disks - the initial and boundary conditions for planet formation - are decisive for the properties of planets, and leave many imprints on the population.

  10. Viscoelastic tidal dissipation in giant planets and formation of hot Jupiters through high-eccentricity migration

    NASA Astrophysics Data System (ADS)

    Storch, Natalia I.; Lai, Dong

    2014-02-01

    We study the possibility of tidal dissipation in the solid cores of giant planets and its implication for the formation of hot Jupiters through high-eccentricity migration. We present a general framework by which the tidal evolution of planetary systems can be computed for any form of tidal dissipation, characterized by the imaginary part of the complex tidal Love number, Im[{tilde{k}}_2(ω )], as a function of the forcing frequency ω. Using the simplest viscoelastic dissipation model (the Maxwell model) for the rocky core and including the effect of a non-dissipative fluid envelope, we show that with reasonable (but uncertain) physical parameters for the core (size, viscosity and shear modulus), tidal dissipation in the core can accommodate the tidal-Q constraint of the Solar system gas giants and at the same time allows exoplanetary hot Jupiters to form via tidal circularization in the high-e migration scenario. By contrast, the often-used weak friction theory of equilibrium tide would lead to a discrepancy between the Solar system constraint and the amount of dissipation necessary for high-e migration. We also show that tidal heating in the rocky core can lead to modest radius inflation of the planets, particularly when the planets are in the high-eccentricity phase (e ˜ 0.6) during their high-e migration. Finally, as an interesting by-product of our study, we note that for a generic tidal response function Im[{tilde{k}}_2(ω )], it is possible that spin equilibrium (zero torque) can be achieved for multiple spin frequencies (at a given e), and the actual pseudo-synchronized spin rate depends on the evolutionary history of the system.

  11. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    SciTech Connect

    Batygin, Konstantin; Stevenson, David J.

    2013-05-20

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M{sub Circled-Plus }, multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  12. Effects of mass loss for highly-irradiated giant planets

    NASA Astrophysics Data System (ADS)

    Hubbard, W. B.; Hattori, M. F.; Burrows, A.; Hubeny, I.; Sudarsky, D.

    2007-04-01

    We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres differ by two orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Baraffe et al. [Baraffe, I., Selsis, F., Chabrier, G., Barman, T.S., Allard, F., Hauschildt, P.H., Lammer, H., 2004. Astron. Astrophys. 419, L13-L16] predict the highest rate, based on the theory of Lammer et al. [Lammer, H., Selsis, F., Ribas, I., Guinan, E.F., Bauer, S.J., Weiss, W.W., 2003. Astrophys. J. 598, L121-L124]. Scaling the theory of Watson et al. [Watson, A.J., Donahue, T.M., Walker, J.C.G., 1981. Icarus 48, 150-166] to parameters for a highly-irradiated exoplanet, we find an escape rate ˜10 lower than Baraffe's. With the scaled Watson theory we find modest mass loss, occurring early in the history of a hot EGP. In this theory, mass loss including the effect of Roche-lobe overflow becomes significant primarily for masses below a Saturn mass, for semimajor axes ⩾0.023 AU. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present.

  13. HAT-P-34b-HAT-P-37b: FOUR TRANSITING PLANETS MORE MASSIVE THAN JUPITER ORBITING MODERATELY BRIGHT STARS

    SciTech Connect

    Bakos, G. A.; Hartman, J. D.; Csubry, Z.; Penev, K.; Torres, G.; Beky, B.; Latham, D. W.; Bieryla, A.; Quinn, S.; Szklenar, T.; Esquerdo, G. A.; Noyes, R. W.; Buchhave, L. A.; Kovacs, G.; Shporer, A.; Fischer, D. A.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Sato, B.; and others

    2012-07-15

    We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33 M{sub J} and periods from 1.33 to 5.45 days. These planets orbit relatively bright F and G dwarf stars (from V = 10.16 to V = 13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33 M{sub J}), has a high eccentricity of e = 0.441 {+-} 0.032 at a period of P = 5.452654 {+-} 0.000016 days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters.

  14. ON THE MIGRATION OF JUPITER AND SATURN: CONSTRAINTS FROM LINEAR MODELS OF SECULAR RESONANT COUPLING WITH THE TERRESTRIAL PLANETS

    SciTech Connect

    Agnor, Craig B.; Lin, D. N. C.

    2012-02-01

    We examine how the late divergent migration of Jupiter and Saturn may have perturbed the terrestrial planets. Using a modified secular model we have identified six secular resonances between the {nu}{sub 5} frequency of Jupiter and Saturn and the four apsidal eigenfrequencies of the terrestrial planets (g{sub 1-4}). We derive analytic upper limits on the eccentricity and orbital migration timescale of Jupiter and Saturn when these resonances were encountered to avoid perturbing the eccentricities of the terrestrial planets to values larger than the observed ones. Because of the small amplitudes of the j = 2, 3 terrestrial eigenmodes the g{sub 2} - {nu}{sub 5} and g{sub 3} - {nu}{sub 5} resonances provide the strongest constraints on giant planet migration. If Jupiter and Saturn migrated with eccentricities comparable to their present-day values, smooth migration with exponential timescales characteristic of planetesimal-driven migration ({tau} {approx} 5-10 Myr) would have perturbed the eccentricities of the terrestrial planets to values greatly exceeding the observed ones. This excitation may be mitigated if the eccentricity of Jupiter was small during the migration epoch, migration was very rapid (e.g., {tau} {approx}< 0.5 Myr perhaps via planet-planet scattering or instability-driven migration) or the observed small eccentricity amplitudes of the j = 2, 3 terrestrial modes result from low probability cancellation of several large amplitude contributions. Results of orbital integrations show that very short migration timescales ({tau} < 0.5 Myr), characteristic of instability-driven migration, may also perturb the terrestrial planets' eccentricities by amounts comparable to their observed values. We discuss the implications of these constraints for the relative timing of terrestrial planet formation, giant planet migration, and the origin of the so-called Late Heavy Bombardment of the Moon 3.9 {+-} 0.1 Ga ago. We suggest that the simplest way to satisfy these

  15. The Low Mass of Mars: First Evidence of Early Gas-Driven Migration by Jupiter

    NASA Astrophysics Data System (ADS)

    Walsh, K. J.; Morbidelli, A.; Raymond, S. N.; O'Brien, D. P.; Mandell, A. M.

    2010-12-01

    Numerical simulations of planetary accretion have succeeded in matching most of the physical and orbital properties of the terrestrial planets with one glaring exception: they categorically form Mars analogs that are roughly an order of magnitude too massive (Raymond et al. 2009). The initial conditions that best reproduce the mass of Mars require that the inner planetesimal disk had an outer edge at 1 Astronomical Unit (AU) (Hansen 2009). To date, no mechanism has been shown to create this edge and remain compatible with the current-day solar system, in particular the existence of the asteroid belt. Here we show that a substantial gas-driven radial migration of the giant planets is the needed mechanism. Hydrodynamical simulations show that the evolution of Jupiter and Saturn in a gas-disk generically leads to a two-stage, inward-then-outward, migration where the extent of each stage of migration depends on a priori unconstrained disk parameters (Masset & Snellgrove 2001, Morbidelli et al. 2007, Pierens & Nelson 2008). We demonstrate with numerical simulations that, if Jupiter migrated inwards to 1.5 AU before migrating out towards its current location, its gravitational influence would truncate the inner planetesimal disk at 1 AU. The resulting disk naturally reproduces all the terrestrial planets including Mars. During the giant planets' migration, the asteroid belt is emptied and later re-populated from two distinct parent populations. This provides the first dynamical explanation for the current dichotomy of physical properties of the main asteroid belt, with anhydrous asteroids (S-type) in the inner part and primitive asteroids (C-type) in the outer part (Gradie & Tedesco 1982). Our model links the origin of the inner solar system -- explaining the mass of Mars and the properties of the asteroid belt -- to a realistic evolution of the giant planets. Thus Mars and the asteroid belt provide the first evidence for an early solar system evolution characterized by

  16. The effects of the formation of a giant planet on the evolution of the protoplanetary disk: the case of Jupiter in the Solar System

    NASA Astrophysics Data System (ADS)

    Turrini, Diego

    2015-11-01

    The formation of a giant planet is one of the milestones in the life of a planetary system, as it plays a leading role in shaping its subsequent evolution. Once the core of the forming giant planet reaches the critical mass needed to trigger the hydrodynamical instability in the surrounding nebular gas and start the rapid phase of gas accretion, the planetary system in which the planet is embedded suddenly experience the appearance of a strong gravitational perturber. Even in absence of migration, this event will trigger a 0.5-1 Myr-long phase of violent remixing and enhanced collisional evolution of the planetary bodies in the protoplanetary disk. For what it concerns the giant planet itself, this primordial bombardment will result in the capture of high-Z material from a wide orbital range, including the inner regions of the planetary system. For what it concerns the other bodies of the protoplanetary disk, this phase of remixing and bombardment will result in the collisional erosion of the smallest planetesimals in the dynamically-excited orbital regions and in the delivery of water and volatile elements to the inner regions of the planetary system. While the mass growth of the giant planet is necessary and sufficient condition to trigger this primordial bombardment, planetary migration plays a major role in determining its intensity. Using the formation of Jupiter in the Solar System as our case study, we will illustrate how this event affects the Jovian system and the asteroid belt. Concerning the latter, we will also discuss how the composition of asteroid Vesta, whose formation and differentiation predate the formation of Jupiter, supplies information on the primordial dynamical evolution of the giant planet.

  17. Extrasolar Planets and Prospects for Terrestrial Planets

    NASA Astrophysics Data System (ADS)

    Marcy, Geoffrey W.; Butler, R. Paul; Vogt, Steven S.; Fischer, Debra A.

    2004-06-01

    Examination of ˜2000 sun--like stars has revealed 97 planets (as of 2002 Nov), all residing within our Milky Way Galaxy and within ˜200 light years of our Solar System. They have masses between 0.1 and 10 times that of Jupiter, and orbital sizes of 0.05--5 AU. Thus planets occupy the entire detectable domain of mass and orbits. News &summaries about extrasolar planets are provided at: http://exoplanets.org. These planets were all discovered by the wobble of the host stars, induced gravitationally by the planets, causing a periodicity in the measured Doppler effect of the starlight. Earth--mass planets remain undetectable, but space--based missions such as Kepler, COROT and SIM may provide detections of terrestrial planets within the next decade. The number of planets increases with decreasing planet mass, indicating that nature makes more small planets than jupiter--mass planets. Extrapolation, though speculative, bodes well for an even larger number of earth--mass planets. These observations and the theory of planet formation suggests that single sun--like stars commonly harbor earth--sized rocky planets, as yet undetectable. The number of planets increases with increasing orbital distance from the host star, and most known planets reside in non--circular orbits. Many known planets reside in the habitable zone (albeit being gas giants) and most newly discovered planets orbit beyond 1 AU from their star. A population of Jupiter--like planets may reside at 5--10 AU from stars, not easily detectable at present. The sun--like star 55 Cancri harbors a planet of 4--10 Jupiter masses orbiting at 5.5 AU in a low eccentricity orbit, the first analog of our Jupiter, albeit with two large planets orbiting inward. To date, 10 multiple--planet systems have been discovered, with four revealing gravitational interactions between the planets in the form of resonances. GJ 876 has two planets with periods of 1 and 2 months. Other planetary systems are ``hierarchical'', consisting

  18. Determination of the Minimum Masses of Heavy Elements in the Envelopes of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Mousis, Olivier; Marboeuf, Ulysse; Lunine, Jonathan I.; Alibert, Yann; Fletcher, Leigh N.; Orton, Glenn S.; Pauzat, Françoise; Ellinger, Yves

    2009-05-01

    decreases from ~ 16.7 to 15.6 M ⊕, including a mass of water diminishing from 8.6 to 7.7 M ⊕. The accretion of planetesimals with ices to rocks ratios ~ 1 in the envelope of Jupiter, namely a value derived from the bulk densities of Ganymede and Callisto, remains compatible with the mass of heavy elements predicted by interior models. On the other hand, the accretion of planetesimals with similar ice-to-rock in the envelope of Saturn implies a mass of heavy elements greater than the one predicted by interior models, unless a substantial fraction of the accreted rock and water sedimented onto the core of the planet during its evolution.

  19. Orbital circularization of a planet accreting disk gas: the formation of distant jupiters in circular orbits based on a core accretion model

    SciTech Connect

    Kikuchi, Akihiro; Higuchi, Arika; Ida, Shigeru E-mail: higuchia@geo.titech.ac.jp

    2014-12-10

    Recently, gas giant planets in nearly circular orbits with large semimajor axes (a ∼ 30-1000 AU) have been detected by direct imaging. We have investigated orbital evolution in a formation scenario for such planets, based on a core accretion model. (1) Icy cores accrete from planetesimals at ≲ 30 AU, (2) they are scattered outward by an emerging nearby gas giant to acquire highly eccentric orbits, and (3) their orbits are circularized through the accretion of disk gas in outer regions, where they spend most of their time. We analytically derived equations to describe the orbital circularization through gas accretion. Numerical integrations of these equations show that the eccentricity decreases by a factor of more than 5 while the planetary mass increases by a factor of 10. Because runaway gas accretion increases planetary mass by ∼10-300, the orbits are sufficiently circularized. On the other hand, a is reduced at most only by a factor of two, leaving the planets in the outer regions. If the relative velocity damping by shock is considered, the circularization slows down, but is still efficient enough. Therefore, this scenario potentially accounts for the formation of observed distant jupiters in nearly circular orbits. If the apocenter distances of the scattered cores are larger than the disk sizes, their a shrink to a quarter of the disk sizes; the a-distribution of distant giants could reflect the outer edges of the disks in a similar way that those of hot jupiters may reflect inner edges.

  20. Obtaining the Mass and Radius of Extra-Solar Giant Planets

    NASA Technical Reports Server (NTRS)

    Castellano, Tim; Mead, Susan (Technical Monitor)

    1998-01-01

    The scientific utility and feasibility of detecting transits of the 9 known extrasolar planets is explored. A transit of a solar-like star by a Jupiter mass planet produces a 1% decrease in the amount of light received from the star. Transit observation will remove the ambiguity in the measurement of the planetary mass inherent in the radial velocity method and confirm the planet's existence. The 9 known planets have a 33% chance of producing at least one observable transit. Additional extrasolar planet detections from the radial velocity surveys will increase this probability to greater than 90%. The radius of the planet can be determined by the fractional decrease in light received during transit. The mass and radius may distinguish rocky or gas giant planets from brown dwarfs. The probability of detection, the transit signal size and duration, and predictions of the transit times (including errors) are calculated for circular and elliptical orbits. Observational limits are investigated and it is shown that small telescopes and existing detectors are adequate enough to achieve the 0.1% photometry necessary to detect transits of the known extrasolar planets.

  1. FRIENDS OF HOT JUPITERS. III. AN INFRARED SPECTROSCOPIC SEARCH FOR LOW-MASS STELLAR COMPANIONS

    SciTech Connect

    Piskorz, Danielle; Knutson, Heather A.; Ngo, Henry; Batygin, Konstantin; Muirhead, Philip S.; Crepp, Justin R.; Hinkley, Sasha; Morton, Timothy D.

    2015-12-01

    Surveys of nearby field stars indicate that stellar binaries are common, yet little is known about the effects that these companions may have on planet formation and evolution. The Friends of Hot Jupiters project uses three complementary techniques to search for stellar companions to known planet-hosting stars: radial velocity monitoring, adaptive optics imaging, and near-infrared spectroscopy. In this paper, we examine high-resolution K band infrared spectra of fifty stars hosting gas giant planets on short-period orbits. We use spectral fitting to search for blended lines due to the presence of cool stellar companions in the spectra of our target stars, where we are sensitive to companions with temperatures between 3500 and 5000 K and projected separations less than 100 AU in most systems. We identify eight systems with candidate low-mass companions, including one companion that was independently detected in our AO imaging survey. For systems with radial velocity accelerations, a spectroscopic non-detection rules out scenarios involving a stellar companion in a high inclination orbit. We use these data to place an upper limit on the stellar binary fraction at small projected separations, and show that the observed population of candidate companions is consistent with that of field stars and also with the population of wide-separation companions detected in our previous AO survey. We find no evidence that spectroscopic stellar companions are preferentially located in systems with short-period gas giant planets on eccentric and/or misaligned orbits.

  2. Jupiter

    NASA Astrophysics Data System (ADS)

    Bagenal, Fran; Dowling, Timothy E.; McKinnon, William B.

    2007-03-01

    Preface; 1. Introduction F. Bagenal, T. E. Dowling and W. B. McKinnon; 2. The origin of Jupiter J. I. Lunine, A. Corandini, D. Gautier, T. C. Owen and G. Wuchterl; 3. The interior of Jupiter T. Guillot, D. J. Stevenson, W. B. Hubbard and D. Saumon; 4. The composition of the atmosphere of Jupiter F. W. Taylor, S. K. Atreya, Th. Encrenaz, D. M. Hunten, P. G. J. Irwin and T. C. Owen; 5. Jovian clouds and haze R. A. West, K. H. Baines, A. J. Friedson, D. Banfield, B. Ragent and F. W. Taylor; 6. Dynamics of Jupiter's atmosphere A. P. Ingersoll, T. E. Dowling, P. J. Gierasch, G. S. Orton, P. L. Read, A. Sánchez-Lavega, A. P. Showman, A. A. Simon-Miller and A. R. Vasavada; 7. The stratosphere of Jupiter J. I. Moses, T. Fouchet, R. V. Yelle, A. J. Friedson, G. S. Orton, B. Bézard, P. Drossart, G. R. Gladstone, T. Kostiuk and T. A. Livengood; 8. Lessons from Shoemaker-Levy 9 about Jupiter and planetary impacts J. Harrington, I. de Pater, S. H. Brecht, D. Deming, V. Meadows, K. Zahnle and P. D. Nicholson; 9. Jupiter's thermosphere and ionosphere R. V. Yelle and S. Miller; 10. Jovian dust: streams, clouds and rings H. Krüger, M. Horányi, A. V. Krivov and A. L. Graps; 11. Jupiter's ring-moon system J. A. Burns, D. P. Simonelli, M. R. Showalter, D. P. Hamilton, C. C. Porco, H. Throop and L. W. Esposito; 12. Jupiter's outer satellites and trojans D. C. Jewitt, S. Sheppard and C. Porco; 13. Interior composition, structure and dynamics of the Galilean satellites G. Schubert, J. D. Anderson, T. Spohn and W. B. McKinnon; 14. The lithosphere and surface of Io A. S. McEwen, L. P. Keszthelyi, R. Lopes, P. M. Schenk and J. R. Spencer; 15. Geology of Europa R. Greeley, C. F. Chyba, J. W. Head III, T. B. McCord, W. B. McKinnon, R. T. Pappalardo and P. Figueredo; 16. Geology of Ganymede R. T. Pappalardo, G. C. Collins, J. W. Head III, P. Helfenstein, T. B. McCord, J. M. Moore, L. M. Procktor, P. M. Shenk and J. R. Spencer; 17. Callisto J. M. Moore, C. R. Chapman. E. B. Bierhaus, R

  3. Transiting planets from WASP-South, Euler, and TRAPPIST. WASP-68 b, WASP-73 b, and WASP-88 b, three hot Jupiters transiting evolved solar-type stars

    NASA Astrophysics Data System (ADS)

    Delrez, L.; Van Grootel, V.; Anderson, D. R.; Collier-Cameron, A.; Doyle, A. P.; Fumel, A.; Gillon, M.; Hellier, C.; Jehin, E.; Lendl, M.; Neveu-VanMalle, M.; Maxted, P. F. L.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B.; Smith, A. M. S.; Southworth, J.; Triaud, A. H. M. J.; Udry, S.; West, R. G.

    2014-03-01

    Using the WASP transit survey, we report the discovery of three new hot Jupiters, WASP-68 b, WASP-73 b and WASP-88 b. The planet WASP-68 bhas a mass of 0.95 ± 0.03 MJup, a radius of 1.24-0.06+0.10 RJup, and orbits a V = 10.7 G0-type star (1.24 ± 0.03 M⊙ 1.69-0.06+0.11 R⊙, Teff = 5911 ± 60 K) with a period of 5.084298 ± 0.000015 days. Its size is typical of hot Jupiters with similar masses. The planet WASP-73 bis significantly more massive (1.88-0.06+0.07 MJup) and slightly larger (1.16-0.08+0.12 RJup) than Jupiter. It orbits a V = 10.5 F9-type star (1.34-0.04+0.05 M⊙, 2.07-0.08+0.19 R⊙, Teff = 6036 ± 120 K) every 4.08722 ± 0.00022 days. Despite its high irradiation (~2.3 × 109 erg s-1 cm-2), WASP-73 b has a high mean density (1.20-0.30+0.26 ρJup) that suggests an enrichment of the planet in heavy elements. The planet WASP-88 bis a 0.56 ± 0.08 MJuphot Jupiter orbiting a V = 11.4 F6-type star (1.45 ± 0.05 M⊙, 2.08-0.06+0.12 R⊙, Teff = 6431 ± 130 K) with a period of 4.954000 ± 0.000019 days. With a radius of 1.70-0.07+0.13 RJup, it joins the handful of planets with super-inflated radii. The ranges of ages we determine through stellar evolution modeling are 4.5-7.0 Gyr for WASP-68, 2.8-5.7 Gyr for WASP-73 and 1.8-4.3 Gyr for WASP-88. The star WASP-73 appears to be significantly evolved, close to or already in the subgiant phase. The stars WASP-68 and WASP-88 are less evolved, although in an advanced stage of core H-burning. Tables 1-3 are available in electronic form at http://www.aanda.orgThe photometric time-series used in this work 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/563/A143

  4. WASP-16b: A NEW JUPITER-LIKE PLANET TRANSITING A SOUTHERN SOLAR ANALOG

    SciTech Connect

    Lister, T. A.; Anderson, D. R.; Smalley, B. S.; Wilson, D. M.; Bentley, S. J.; Hellier, C.; Maxted, P. F. L.; Gillon, M.; Triaud, A. H. M. J.; Mayor, M.; Hebb, L.; Collier Cameron, A.; Enoch, R.; Horne, K.; West, R. G.; Christian, D. J.; Joshi, Y. C.; Haswell, C. A.; Irwin, J.; Kane, S. R.

    2009-09-20

    We report the discovery from WASP-South of a new Jupiter-like extrasolar planet, WASP-16b, which transits its solar analog host star every 3.12 days. Analysis of the transit photometry and radial velocity spectroscopic data leads to a planet with R{sub p} = 1.008 +- 0.071 R{sub Jup} and M{sub p} = 0.855 +- 0.059 M{sub Jup}, orbiting a host star with R {sub *} = 0.946 +- 0.054 R{sub sun} and M{sub *} = 1.022 +- 0.101 M{sub sun}. Comparison of the high resolution stellar spectrum with synthetic spectra and stellar evolution models indicates the host star is a near-solar metallicity ([Fe/H] =0.01 +- 0.10) solar analog (T{sub eff} = 5700 +- 150 K and log g = 4.5 +- 0.2) of intermediate age (tau = 2.3{sup +5.8}{sub -2.2} Gyr).

  5. SALT observations of the chromospheric activity of transiting planet hosts: mass-loss and star-planet interactions★

    NASA Astrophysics Data System (ADS)

    Staab, D.; Haswell, C. A.; Smith, Gareth D.; Fossati, L.; Barnes, J. R.; Busuttil, R.; Jenkins, J. S.

    2017-04-01

    We measured the chromospheric activity of the four hot Jupiter hosts WASP-43, WASP-51/HAT-P-30, WASP-72 and WASP-103 to search for anomalous values caused by the close-in companions. The Mount Wilson Ca II H & K S-index was calculated for each star using observations taken with the Robert Stobie Spectrograph at the Southern African Large Telescope. The activity level of WASP-43 is anomalously high relative to its age and falls among the highest values of all known main-sequence stars. We found marginal evidence that the activity of WASP-103 is also higher than expected from the system age. We suggest that for WASP-43 and WASP-103 star-planet interactions (SPI) may enhance the Ca II H & K core emission. The activity levels of WASP-51/HAT-P-30 and WASP-72 are anomalously low, with the latter falling below the basal envelope for both main-sequence and evolved stars. This can be attributed to circumstellar absorption due to planetary mass-loss, though absorption in the interstellar medium may contribute. A quarter of known short-period planet hosts exhibit anomalously low activity levels, including systems with hot Jupiters and low-mass companions. Since SPI can elevate and absorption can suppress the observed chromospheric activity of stars with close-in planets, their Ca II H & K activity levels are an unreliable age indicator. Systems where the activity is depressed by absorption from planetary mass-loss are key targets for examining planet compositions through transmission spectroscopy.

  6. Magnitudes of selected stellar occultation candidates for Pluto and other planets, with new predictions for Mars and Jupiter

    NASA Technical Reports Server (NTRS)

    Sybert, C. B.; Bosh, A. S.; Sauter, L. M.; Elliot, J. L.; Wasserman, L. H.

    1992-01-01

    Occultation predictions for the planets Mars and Jupiter are presented along with BVRI magnitudes of 45 occultation candidates for Mars, Jupiter, Saturn, Uranus, and Pluto. Observers can use these magnitudes to plan observations of occultation events. The optical depth of the Jovian ring can be probed by a nearly central occultation on 1992 July 8. Mars occults an unusually red star in early 1993, and the occultations for Pluto involving the brightest candidates would possibly occur in the spring of 1992 and the fall of 1993.

  7. HAT-P-44b, HAT-P-45b, and HAT-P-46b: Three Transiting Hot Jupiters in Possible Multi-planet Systems

    NASA Astrophysics Data System (ADS)

    Hartman, J. D.; Bakos, G. Á.; Torres, G.; Kovács, G.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Latham, D. W.; Bieryla, A.; Buchhave, L. A.; Bhatti, W.; Béky, B.; Csubry, Z.; Penev, K.; de Val-Borro, M.; Noyes, R. W.; Fischer, D. A.; Esquerdo, G. A.; Everett, M.; Szklenár, T.; Zhou, G.; Bayliss, D.; Shporer, A.; Fulton, B. J.; Sanchis-Ojeda, R.; Falco, E.; Lázár, J.; Papp, I.; Sári, P.

    2014-06-01

    We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V = 13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49 M J, and radii of 1.24, 1.43, and 1.28 R J. The stellar hosts have masses of 0.94, 1.26, and 1.28 M ⊙. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, including the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494 ± 0.081, and a minimum mass of 4.0 M J. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5 ± 6.3 m s-1 is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0 M J, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters. 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. Keck

  8. HAT-P-44b, HAT-P-45b, AND HAT-P-46b: Three transiting hot Jupiters in possible multi-planet systems

    SciTech Connect

    Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Csubry, Z.; Penev, K.; De Val-Borro, M.; Torres, G.; Latham, D. W.; Bieryla, A.; Béky, B.; Noyes, R. W.; Esquerdo, G. A.; Kovács, G.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Buchhave, L. A.; Fischer, D. A.; Everett, M.; Szklenár, T.; and others

    2014-06-01

    We report the discovery by the HATNet survey of three new transiting extrasolar planets orbiting moderately bright (V = 13.2, 12.8, and 11.9) stars. The planets have orbital periods of 4.3012, 3.1290, and 4.4631 days, masses of 0.35, 0.89, and 0.49 M {sub J}, and radii of 1.24, 1.43, and 1.28 R {sub J}. The stellar hosts have masses of 0.94, 1.26, and 1.28 M {sub ☉}. Each system shows significant systematic variations in its residual radial velocities, indicating the possible presence of additional components. Based on its Bayesian evidence, the preferred model for HAT-P-44 consists of two planets, including the transiting component, with the outer planet having a period of 872 days, eccentricity of 0.494 ± 0.081, and a minimum mass of 4.0 M {sub J}. Due to aliasing we cannot rule out alternative solutions for the outer planet having a period of 220 days or 438 days. For HAT-P-45, at present there is not enough data to justify the additional free parameters included in a multi-planet model; in this case a single-planet solution is preferred, but the required jitter of 22.5 ± 6.3 m s{sup –1} is relatively high for a star of this type. For HAT-P-46 the preferred solution includes a second planet having a period of 78 days and a minimum mass of 2.0 M {sub J}, however the preference for this model over a single-planet model is not very strong. While substantial uncertainties remain as to the presence and/or properties of the outer planetary companions in these systems, the inner transiting planets are well characterized with measured properties that are fairly robust against changes in the assumed models for the outer planets. Continued radial velocity monitoring is necessary to fully characterize these three planetary systems, the properties of which may have important implications for understanding the formation of hot Jupiters.

  9. A COLD NEPTUNE-MASS PLANET OGLE-2007-BLG-368Lb: COLD NEPTUNES ARE COMMON

    SciTech Connect

    Sumi, T.; Abe, F.; Fukui, A. E-mail: abe@stelab.nagoya-u.ac.j

    2010-02-20

    We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q = [9.5 +- 2.1] x 10{sup -5} via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the Microlensing Observations in Astrophysics survey, real-time light-curve monitoring and intensive follow-up observations. A Bayesian analysis returns the stellar mass and distance at M{sub l} = 0.64{sup +0.21}{sub -0.26} M{sub sun} and D{sub l} = 5.9{sup +0.9}{sub -1.4} kpc, respectively, so the mass and separation of the planet are M{sub p} = 20{sup +7}{sub -8} M{sub +} and a = 3.3{sup +1.4}{sub -0.8} AU, respectively. This discovery adds another cold Neptune-mass planet to the planetary sample discovered by microlensing, which now comprises four cold Neptune/super-Earths, five gas giant planets, and another sub-Saturn mass planet whose nature is unclear. The discovery of these 10 cold exoplanets by the microlensing method implies that the mass ratio function of cold exoplanets scales as dN{sub pl}/dlog q {proportional_to} q {sup -0.7+}-{sup 0.2} with a 95% confidence level upper limit of n < -0.35 (where dN{sub pl}/dlog q {proportional_to} q{sup n} ). As microlensing is most sensitive to planets beyond the snow-line, this implies that Neptune-mass planets are at least three times more common than Jupiters in this region at the 95% confidence level.

  10. PARASITIC INTERFERENCE IN LONG BASELINE OPTICAL INTERFEROMETRY: REQUIREMENTS FOR HOT JUPITER-LIKE PLANET DETECTION

    SciTech Connect

    Matter, A.; Lopez, B.; Lagarde, S.; Danchi, W. C.; Navarro, R.

    2009-12-01

    The observable quantities in optical interferometry, which are the modulus and the phase of the complex visibility, may be corrupted by parasitic fringes superimposed on the genuine fringe pattern. These fringes are due to an interference phenomenon occurring from stray light effects inside an interferometric instrument. We developed an analytical approach to better understand this phenomenon when stray light causes cross talk between beams. We deduced that the parasitic interference significantly affects the interferometric phase and thus the associated observables including the differential phase and the closure phase. The amount of parasitic flux coupled to the piston between beams appears to be very influential in this degradation. For instance, considering a point-like source and a piston ranging from lambda/500 to lambda/5 in the L band (lambda = 3.5 mum), a parasitic flux of about 1% of the total flux produces a parasitic phase reaching at most one-third of the intrinsic phase. The piston, which can have different origins (instrumental stability, atmospheric perturbations, etc.), thus amplifies the effect of parasitic interference. According to the specifications of piston correction in space or at ground level (respectively lambda/500 approx 2 nm and lambda/30 approx 100 nm), the detection of hot Jupiter-like planets, one of the most challenging aims for current ground-based interferometers, limits parasitic radiation to about 5% of the incident intensity. This was evaluated by considering different types of hot Jupiter synthetic spectra. Otherwise, if no fringe tracking is used, the detection of a typical hot Jupiter-like system with a solar-like star would admit a maximum level of parasitic intensity of 0.01% for piston errors equal to lambda/15. If the fringe tracking specifications are not precisely observed, it thus appears that the allowed level of parasitic intensity dramatically decreases and may prevent the detection. In parallel, the calibration

  11. Motions in the interiors and atmospheres of Jupiter and Saturn. II - Barotropic instabilities and normal modes of an adiabatic planet

    NASA Technical Reports Server (NTRS)

    Ingersoll, A. P.; Miller, R. L.

    1986-01-01

    A rotating and adiabatic inviscid fluid planet possesses low frequency motions that are barotropic, quasi-geostrophic and quasi-columnar. The limiting curvature at which flow becomes unstable upon projection onto the planetary surface is negative, with an amplitude that is 3-4 times that for thin atmospheres, in planets in which density linearly decreases to zero at the surface. This result is shown to hold for all quasi-columnar perturbations. Both the phase speed of the normal mode oscillations and the barotropic stability criterion have features in common with Saturn and Jupiter oscillations.

  12. Close-in planets around giant stars. Lack of hot-Jupiters and prevalence of multiplanetary systems

    NASA Astrophysics Data System (ADS)

    Lillo-Box, J.; Barrado, D.; Correia, A. C. M.

    2016-05-01

    Extrasolar planets abound in almost any possible configuration. However, until five years ago, there was a lack of planets orbiting closer than 0.5 au to giant or subgiant stars. Since then, recent detections have started to populated this regime by confirming 13 planetary systems. We discuss the properties of these systems in terms of their formation and evolution off the main sequence. Interestingly, we find that 70.0 ± 6.6% of the planets in this regime are inner components of multiplanetary systems. This value is 4.2σ higher than for main-sequence hosts, which we find to be 42.4 ± 0.1%. The properties of the known planets seem to indicate that the closest-in planets (a< 0.06 au) to main-sequence stars are massive (i.e., hot Jupiters) and isolated and that they are subsequently engulfed by their host as it evolves to the red giant branch, leaving only the predominant population of multiplanetary systems in orbits 0.06 Jupiters.

  13. Ogle-2012-blg-0724lb: A Saturn Mass Planet Around an M-dwarf

    NASA Technical Reports Server (NTRS)

    Hirao, Y.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Rattenbury, N.; Suzuki, D.; Koshimoto, N.; Abe, F.; Asakura, Y.; Bhattacharya, A.

    2016-01-01

    We report the discovery of a planet by the microlensing method, OGLE-2012-BLG-0724Lb. Although the duration of the planetary signal for this event was one of the shortest seen for a planetary event, the anomaly was well covered thanks to high-cadence observations taken by the survey groups OGLE and MOA. By analyzing the light curve, this planetary system is found to have a mass ratio q = (1.58 +/- 0.15) x 10(exp -3). By conducting a Bayesian analysis, we estimate that the host star is an M dwarf with a mass of M(sub L) = 0.29(+0.33/-0.16) solar mass located at D(sub L) = 6.7(+1.1/-1.2) kpc away from the Earth and the companion's mass is m(sub P) = 0.47(+0.54/-0.26) M(Jup). The projected planet- host separation is a falsum = 1.6(+0.4/-0.3) AU. Because the lens-source relative proper motion is relatively high, future highresolution images would detect the lens host star and determine the lens properties uniquely. This system is likely a Saturn-mass exoplanet around an M dwarf, and such systems are commonly detected by gravitational microlensing. This adds another example of a possible pileup of sub-Jupiters (0.2 less than m(sub P)/M(sub Jup) less than 1) in contrast to a lack of Jupiters (approximately 1-2 M(sub Jup)) around M dwarfs, supporting the prediction by core accretion models that Jupiter-mass or more massive planets are unlikely to form around M dwarfs.

  14. Enhancement of the Accretion of Jupiters Core by a Voluminous Low-Mass Envelope

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; D'angelo, Gennaro; Weidenschilling, Stuart John; Bodenheimer, Peter; Hubickyj, Olenka

    2013-01-01

    We present calculations of the early stages of the formation of Jupiter via core nucleated accretion and gas capture. The core begins as a seed body of about 350 kilometers in radius and orbits in a swarm of planetesimals whose initial radii range from 15 meters to 100 kilometers. We follow the evolution of the swarm by accounting for growth and fragmentation, viscous and gravitational stirring, and for drag-induced migration and velocity damping. Gas capture by the core substantially enhances the cross-section of the planet for accretion of small planetesimals. The dust opacity within the atmosphere surrounding the planetary core is computed self-consistently, accounting for coagulation and sedimentation of dust particles released in the envelope as passing planetesimals are ablated. The calculation is carried out at an orbital semi-major axis of 5.2 AU and an initial solids' surface density of 10/g/cm^2 at that distance. The results give a core mass of 7 Earth masses and an envelope mass of approximately 0.1 Earth mass after 500,000 years, at which point the envelope growth rate surpasses that of the core. The same calculation without the envelope gives a core mass of only 4 Earth masses.

  15. The SOPHIE search for northern extrasolar planets. VI. Three new hot Jupiters in multi-planet extrasolar systems

    NASA Astrophysics Data System (ADS)

    Moutou, C.; Hébrard, G.; Bouchy, F.; Arnold, L.; Santos, N. C.; Astudillo-Defru, N.; Boisse, I.; Bonfils, X.; Borgniet, S.; Delfosse, X.; Díaz, R. F.; Ehrenreich, D.; Forveille, T.; Gregorio, J.; Labrevoir, O.; Lagrange, A.-M.; Montagnier, G.; Montalto, M.; Pepe, F.; Sahlmann, J.; Santerne, A.; Ségransan, D.; Udry, S.; Vanhuysse, M.

    2014-03-01

    We present high-precision radial-velocity measurements of three solar-type stars: HD 13908, HD 159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD 13908 b is a planet with a minimum mass of 0.865 ± 0.035MJup on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25MJup . The star HD 159243 also has two detected companions with respective masses, periods, and eccentricities of Mp= 1.13 ± 0.05 and 1.9 ± 0.13MJup , P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258 has a planetary companion with a minimum mass of 1.068 ± 0.038MJup , an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD 13908, HD 159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258 is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets. Tables 5-8 are 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/563/A22Tables 5-7 are also available in electronic form at http://www.aanda.orgBased on observations collected with the SOPHIE spectrograph on the 1.93 m telescope at the Observatoire de Haute-Provence (CNRS), France, by the SOPHIE RPE Consortium (program PNP.CONS).

  16. On the mass and orbit of the ninth planet

    NASA Astrophysics Data System (ADS)

    Ugwoke, Azubike Christian

    2016-07-01

    ON THE MASS AND ORBIT OF THE NINTH PLANET A new planet is currently being proposed in the literature.This yet to be observed planet has its mass and orbit yet to be determined. However, if this planet is to escape being labelled a plutinoid, it must posses all the characteristics of a planet as currently set by the IAU. In addition it must be massive enough to enable it couple into the gravitational potential of the sun. Our earlier paper on this issue has suggested that no new planets are expected beyond Neptune , due to the vanishing gravitational potential of the sun within that orbit.Any new planet must be indeed very massive to be gravitationally linked sufficiently to the sun. In the current paper we have obtained estimates for planet 9 orbit and mass using this method.

  17. The mass of dwarf planet Eris.

    PubMed

    Brown, Michael E; Schaller, Emily L

    2007-06-15

    The discovery of dwarf planet Eris was followed shortly by the discovery of its satellite, Dysnomia, but the satellite orbit, and thus the system mass, was not known. New observations with the Keck Observatory and the Hubble Space Telescopes show that Dysnomia has a circular orbit with a radius of 37,350 +/- 140 (1-sigma) kilometers and a 15.774 +/- 0.002 day orbital period around Eris. These orbital parameters agree with expectations for a satellite formed out of the orbiting debris left from a giant impact. The mass of Eris from these orbital parameters is 1.67 x 10(22) +/- 0.02 x 10(22) kilograms, or 1.27 +/- 0.02 that of Pluto.

  18. OGLE-2012-BLG-0724Lb: A Saturn-mass Planet around an M Dwarf

    NASA Astrophysics Data System (ADS)

    Hirao, Y.; Udalski, A.; Sumi, T.; Bennett, D. P.; Bond, I. A.; Rattenbury, N.; Suzuki, D.; Koshimoto, N.; Abe, F.; Asakura, Y.; Bhattacharya, A.; Freeman, M.; Fukui, A.; Itow, Y.; Li, M. C. A.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Matsuo, T.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Oyokawa, H.; Saito, To.; Sharan, A.; Shibai, H.; Sullivan, D. J.; Tristram, P. J.; Yonehara, A.; MOA Collaboration; Poleski, R.; Skowron, J.; Mróz, P.; Szymański, M. K.; Kozłowski, S.; Pietrukowicz, P.; Soszyński, I.; Wyrzykowski, Ł.; Ulaczyk, K.; OGLE Collaboration

    2016-06-01

    We report the discovery of a planet by the microlensing method, OGLE-2012-BLG-0724Lb. Although the duration of the planetary signal for this event was one of the shortest seen for a planetary event, the anomaly was well covered thanks to high-cadence observations taken by the survey groups OGLE and MOA. By analyzing the light curve, this planetary system is found to have a mass ratio q=(1.58+/- 0.15)× {10}-3. By conducting a Bayesian analysis, we estimate that the host star is an M dwarf with a mass of {M}{{L}}={0.29}-0.16+0.33 {M}⊙ located at {D}{{L}}={6.7}-1.2+1.1 {{kpc}} away from the Earth and the companion’s mass is {m}{{P}}={0.47}-0.26+0.54 {M}{{Jup}}. The projected planet-host separation is {a}\\perp ={1.6}-0.3+0.4 {{AU}}. Because the lens-source relative proper motion is relatively high, future high-resolution images would detect the lens host star and determine the lens properties uniquely. This system is likely a Saturn-mass exoplanet around an M dwarf, and such systems are commonly detected by gravitational microlensing. This adds another example of a possible pileup of sub-Jupiters (0.2\\lt {m}{{P}}/{M}{{Jup}}\\lt 1) in contrast to a lack of Jupiters (˜ 1{--}2 {M}{{Jup}}) around M dwarfs, supporting the prediction by core accretion models that Jupiter-mass or more massive planets are unlikely to form around M dwarfs.

  19. On the Orbital Evolution of a Giant Planet Pair Embedded in a Gaseous Disk. I. Jupiter-Saturn Configuration

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Zhou, Ji-Lin

    2010-05-01

    We carry out a series of high-resolution (1024 × 1024) hydrodynamical simulations to investigate the orbital evolution of Jupiter and Saturn embedded in a gaseous protostellar disk. Our work extends the results in the classical papers of Masset & Snellgrove and Morbidelli & Crida by exploring various surface density profiles (σ), where σ vprop r -α. The stability of the mean motion resonances (MMRs) caused by the convergent migration of the two planets is studied as well. Our results show that (1) the gap formation process of Saturn is greatly delayed by the tidal perturbation of Jupiter. These perturbations cause inward or outward runaway migration of Saturn, depending on the density profiles on the disk. (2) The convergent migration rate increases as α increases and the type of MMRs depends on α as well. When 0 < α < 1, the convergent migration speed of Jupiter and Saturn is relatively slow, thus they are trapped into 2:1 MMR. When α>4/3, Saturn passes through the 2:1 MMR with Jupiter and is captured into the 3:2 MMR. (3) The 3:2 MMR turns out to be unstable when the eccentricity of Saturn (es ) increases too high. The critical value above which instability will set in is es ~ 0.15. We also observe that the two planets are trapped into 2:1 MMR after the break of 3:2 MMR. This process may provide useful information for the formation of orbital configuration between Jupiter and Saturn in the solar system.

  20. ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. I. JUPITER-SATURN CONFIGURATION

    SciTech Connect

    Zhang Hui; Zhou Jilin

    2010-05-01

    We carry out a series of high-resolution (1024 x 1024) hydrodynamical simulations to investigate the orbital evolution of Jupiter and Saturn embedded in a gaseous protostellar disk. Our work extends the results in the classical papers of Masset and Snellgrove and Morbidelli and Crida by exploring various surface density profiles ({sigma}), where {sigma} {proportional_to} r {sup -{alpha}}. The stability of the mean motion resonances (MMRs) caused by the convergent migration of the two planets is studied as well. Our results show that (1) the gap formation process of Saturn is greatly delayed by the tidal perturbation of Jupiter. These perturbations cause inward or outward runaway migration of Saturn, depending on the density profiles on the disk. (2) The convergent migration rate increases as {alpha} increases and the type of MMRs depends on {alpha} as well. When 0 < {alpha} < 1, the convergent migration speed of Jupiter and Saturn is relatively slow, thus they are trapped into 2:1 MMR. When {alpha}>4/3, Saturn passes through the 2:1 MMR with Jupiter and is captured into the 3:2 MMR. (3) The 3:2 MMR turns out to be unstable when the eccentricity of Saturn (e{sub s} ) increases too high. The critical value above which instability will set in is e{sub s} {approx} 0.15. We also observe that the two planets are trapped into 2:1 MMR after the break of 3:2 MMR. This process may provide useful information for the formation of orbital configuration between Jupiter and Saturn in the solar system.

  1. Exceptional Stars Origins, Companions, Masses and Planets

    NASA Technical Reports Server (NTRS)

    Kulkarni, Shrinivas R.; Hansen, Bradley M. S.; Phinney, Sterl; vanKerkwijk, Martin H.; Vasisht, Gautam

    2004-01-01

    As SIM Interdisciplinary Scientist, we will study the formation, nature and planetary companions of the exotic endpoints of stellar evolution. Our science begins with stars evolving from asymptotic branch giants into white dwarfs. We will determine the parallax and orbital inclination of several iron-deficient post-AGB stars, who peculiar abundances and infrared excesses are evidence that they are accreting gas depleted of dust from a circumbinary disk. Measurement of the orbital inclination, companion mass arid parallax will provide critical constraints. One of these stars is a prime candidate for trying nulling observations, which should reveal light reflected from both the circumbinary and Roche disks. The circumbinary disks seem favorable sites for planet formation. Next, we will search for planets around white dwarfs, both survivors froni the main-sequence stage, and ones newly formed from the circumbinary disks of post-AGB binaries or in white dwarf mergers. Moving up in mass, we will measure the orbital reflex of OB/Be companions to pulsars, determine natal kicks and presupernova orbits, and expand the sample of well-determined neutron star masses. We will obtain the parallax of a transient X-ray binary, whose quiescent emission may be thermal emission from the neutron star, aiming for precise measurement of the neutron star radius. Finally, black holes. We will measure the reflex motions of the companion of what appear to be the most massive stellar black holes. The visual orbits will determine natal kicks, and test the assumptions underlying mass estimates made from the radial velocity curves, projected rotation, and ellipsoidal variations. In addition, we will attempt to observe the visual orbit of SS 433, as well as the proper motion of the emission line clumps in its relativistic jets. Additional information is included in the original document.

  2. 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.

  3. A historical interpretation of the study of the visible cloud morphology on the planet Jupiter: 1610-1878

    SciTech Connect

    Hockey, T.A.

    1988-01-01

    The majority of the literature discussing the perceived physical appearance of Jupiter published prior to 1878 has been examined in order to determine to what extent observations were biased by technical limitations and preconceptions of their day and, in lieu of these, how useful this body of work is in characterizing the behavior of the Jovian upper atmosphere over the last three hundred years. The biographies of the historical observers; their instrumentation, available viewing conditions, and observational techniques; their means of communication with their fellows; and the primary interpretive references available to their libraries have been investigated in order to attempt to explain discrepancies and agreement between what was reported in pre-photographic times and what is presently seen. It has been found that nearly all of the prominent feature-types found on Jupiter today existed during the nineteenth century and, in some cases, earlier. The longevity and frequency of the appearance of features can not be accurately determined from the time before objective surveys of the planet were organized. This is because, during each apparition of Jupiter, nonprofessional part-time observers, working independently chose to use their finite time and resources to follow the progress of specific discoveries on its disk to the exclusion of the rest of the planet.

  4. A Spitzer five-band analysis of the Jupiter-sized planet TrES-1

    SciTech Connect

    Cubillos, Patricio; Harrington, Joseph; Foster, Andrew S. D.; Lust, Nate B.; Hardy, Ryan A.; Bowman, M. Oliver; Madhusudhan, Nikku

    2014-12-10

    With an equilibrium temperature of 1200 K, TrES-1 is one of the coolest hot Jupiters observed by Spitzer. It was also the first planet discovered by any transit survey and one of the first exoplanets from which thermal emission was directly observed. We analyzed all Spitzer eclipse and transit data for TrES-1 and obtained its eclipse depths and brightness temperatures in the 3.6 μm (0.083% ± 0.024%, 1270 ± 110 K), 4.5 μm (0.094% ± 0.024%, 1126 ± 90 K), 5.8 μm (0.162% ± 0.042%, 1205 ± 130 K), 8.0 μm (0.213% ± 0.042%, 1190 ± 130 K), and 16 μm (0.33% ± 0.12%, 1270 ± 310 K) bands. The eclipse depths can be explained, within 1σ errors, by a standard atmospheric model with solar abundance composition in chemical equilibrium, with or without a thermal inversion. The combined analysis of the transit, eclipse, and radial-velocity ephemerides gives an eccentricity of e=0.033{sub −0.031}{sup +0.015}, consistent with a circular orbit. Since TrES-1's eclipses have low signal-to-noise ratios, we implemented optimal photometry and differential-evolution Markov Chain Monte Carlo (MCMC) algorithms in our Photometry for Orbits, Eclipses, and Transits pipeline. Benefits include higher photometric precision and ∼10 times faster MCMC convergence, with better exploration of the phase space and no manual parameter tuning.

  5. Voyager 2 Jupiter Eruption Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie records an eruptive event in the southern hemisphere of Jupiter over a period of 8 Jupiter days. Prior to the event, an undistinguished oval cloud mass cruised through the turbulent atmosphere. The eruption occurs over avery short time at the very center of the cloud. The white eruptive material is swirled about by the internal wind patterns of the cloud. As a result of the eruption, the cloud then becomes a type of feature seen elsewhere on Jupiter known as 'spaghetti bowls'.

    As Voyager 2 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 8 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Violet filter around May 6, 1979. The spacecraft was about 50 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  6. WASP-22 b: A TRANSITING 'HOT JUPITER' PLANET IN A HIERARCHICAL TRIPLE SYSTEM

    SciTech Connect

    Maxted, P. F. L.; Anderson, D. R.; Hellier, C.; Smalley, B.; Wilson, D. M.; Bentley, S. J.; Cegla, H.; Gillon, M.; Queloz, D.; Triaud, A. H. M. J.; Mayor, M.; Pepe, F.; West, R. G.; Collier Cameron, A.; Enoch, B.; Hebb, L.; Horne, K.; Parley, N.; Irwin, J.; Lister, T. A.

    2010-12-15

    We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star, WASP-22, is a moderately bright (V = 12.0) solar-type star (T{sub eff} = 6000 {+-} 100 K, [Fe/H] = -0.05 {+-} 0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical main-sequence star we estimate that the planet has a mass M{sub p} = 0.56 {+-} 0.02M{sub Jup} and a radius R{sub p} = 1.12 {+-} 0.04R{sub Jup}. In addition, there is a linear trend of 40 m s{sup -1} yr{sup -1} in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.

  7. Jupiter-like planets as dynamical barriers to inward-migrating super-Earths: a new understanding of the origin of Uranus and Neptune and predictions for extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Morbidelli, Alessandro; Izidoro Da Costa, Andre'; Raymond, Sean

    2014-11-01

    Planets of 1-4 times Earth's size on orbits shorter than 100 days exist around 30-50% of all Sun-like stars. These ``hot super-Earths'' (or ``mini-Neptunes''), or their building blocks, might have formed on wider orbits and migrated inward due to interactions with the gaseous protoplanetary disk. The Solar System is statistically unusual in its lack of hot super-Earths. Here, we use a suite of dynamical simulations to show that gas-giant planets act as barriers to the inward migration of super-Earths initially placed on more distant orbits. Jupiter's early formation may have prevented Uranus and Neptune (and perhaps Saturn's core) from becoming hot super-Earths. It may actually have been crucial to the very formation of Uranus and Neptune. In fact, the large spin obliquities of these two planets argue that they experienced a stage of giant impacts from multi-Earth mass planetary embryos. We show that the dynamical barrier offered by Jupiter favors the mutual accretion of multiple migrating planetary embryos, favoring the formation of a few massive objects like Uranus and Neptune. Our model predicts that the populations of hot super-Earth systems and Jupiter-like planets should be anti-correlated: gas giants (especially if they form early) should be rare in systems with many hot super-Earths. Testing this prediction will constitute a crucial assessment of the validity of the migration hypothesis for the origin of close-in super-Earths.

  8. Advanced Ion Mass Spectrometer for Giant Planet Ionospheres, Magnetospheres and Moons

    NASA Astrophysics Data System (ADS)

    Sittler, EC; Cooper, JF; Paschalidis, N.; Jones, SL; Rodriguez, M.; Ali, A.; Coplan, MA; Chornay, DJ; Sturner; Bateman, FB; Andre, N.; Fedorov, A.; Wurz, P.

    2015-10-01

    The Advanced Ion Composition Spectrometer (AIMS) has been under development from various NASA sources (NASA LWSID, NASA ASTID, NASA Goddard IRADs) to measure elemental, isotopic, and simple molecular composition abundances of 1 eV/e to 25 keV/e hot ions with wide field-of-view (FOV) in the 1 - 60 amu mass range at mass resolution M/ΔM ≤ 60 over a wide dynamic range of intensities and penetrating radiation background from the inner magnetospheres of Jupiter and Saturn to the outer magnetospheric boundary regions and the upstream solar wind. This instrument will work for both spinning spacecraft and 3-axis stabilized spacecraft with wide field-of-view capability in both cases. It will measure the ion velocity distribution functions (IVDF) for the individual ion species; ion velocity moments of the IVDF will give the fluid parameters (density, flow velocity and temperature) of the individual ion species. Outer planet mission applications are Io Observer, Jupiter Europa Orbiter/Europa Clipper, Enceladus Orbiter, and Uranus Orbiter as described in the decadal survey, but would also be valuable for inclusion on other missions to outer planet destinations such as Saturn- Titan and Neptune-Triton and for future missions to terrestrial planets, Venus and Mars, the Moon, asteroids, and comets, and of course for geospace applications to the Earth.

  9. Possible Outcomes of Coplanar High-eccentricity Migration: Hot Jupiters, Close-in Super-Earths, and Counter-orbiting Planets

    NASA Astrophysics Data System (ADS)

    Xue, Yuxin; Masuda, Kento; Suto, Yasushi

    2017-02-01

    We investigate the formation of close-in planets in near-coplanar eccentric hierarchical triple systems via the secular interaction between an inner planet and an outer perturber (Coplanar High-eccentricity Migration; CHEM). We generalize the previous work on the analytical condition for successful CHEM for point masses interacting only through gravity by taking into account the finite mass effect of the inner planet. We find that efficient CHEM requires that the systems should have m1 ≪ m0 and m1 ≪ m2. In addition to the gravity for point masses, we examine the importance of the short-range forces, and provide an analytical estimate of the migration timescale. We perform a series of numerical simulations in CHEM for systems consisting of a Sun-like central star, giant gas inner planet, and planetary outer perturber, including the short-range forces and stellar and planetary dissipative tides. We find that most of such systems end up with a tidal disruption; a small fraction of the systems produce prograde hot Jupiters (HJs), but no retrograde HJ. In addition, we extend CHEM to super-Earth mass range, and show that the formation of close-in super-Earths in prograde orbits is also possible. Finally, we carry out CHEM simulation for the observed hierarchical triple and counter-orbiting HJ systems. We find that CHEM can explain a part of the former systems, but it is generally very difficult to reproduce counter-orbiting HJ systems.

  10. Transiting exoplanets from the CoRoT space mission. VII. The ``hot-Jupiter''-type planet CoRoT-5b

    NASA Astrophysics Data System (ADS)

    Rauer, H.; Queloz, D.; Csizmadia, Sz.; Deleuil, M.; Alonso, R.; Aigrain, S.; Almenara, J. M.; Auvergne, M.; Baglin, A.; Barge, P.; Bordé, P.; Bouchy, F.; Bruntt, H.; Cabrera, J.; Carone, L.; Carpano, S.; de La Reza, R.; Deeg, H. J.; Dvorak, R.; Erikson, A.; Fridlund, M.; Gandolfi, D.; Gillon, M.; Guillot, T.; Guenther, E.; Hatzes, A.; Hébrard, G.; Kabath, P.; Jorda, L.; Lammer, H.; Léger, A.; Llebaria, A.; Magain, P.; Mazeh, T.; Moutou, C.; Ollivier, M.; Pätzold, M.; Pont, F.; Rabus, M.; Renner, S.; Rouan, D.; Shporer, A.; Samuel, B.; Schneider, J.; Triaud, A. H. M. J.; Wuchterl, G.

    2009-10-01

    Aims: The CoRoT space mission continues to photometrically monitor about 12 000 stars in its field-of-view for a series of target fields to search for transiting extrasolar planets ever since 2007. Deep transit signals can be detected quickly in the “alarm-mode” in parallel to the ongoing target field monitoring. CoRoT's first planets have been detected in this mode. Methods: The CoRoT raw lightcurves are filtered for orbital residuals, outliers, and low-frequency stellar signals. The phase folded lightcurve is used to fit the transit signal and derive the main planetary parameters. Radial velocity follow-up observations were initiated to secure the detection and to derive the planet mass. Results: We report the detection of CoRoT-5b, detected during observations of the LRa01 field, the first long-duration field in the galactic anti-center direction. CoRoT-5b is a “hot Jupiter-type” planet with a radius of 1.388+0.046-0.047 R_Jup, a mass of 0.467+0.047-0.024 M_Jup, and therefore, a mean density of 0.217+0.031-0.025 g cm-3. The planet orbits an F9V star of 14.0 mag in 4.0378962 ± 0.0000019 days at an orbital distance of 0.04947+0.00026-0.00029 AU. Observations made with SOPHIE spectrograph at the Observatoire de Haute Provence (07B.PNP.MOUT), France, and HARPS spectrograph at ESO La Silla Observatory (072.C-0488(E), 082.C-0312(A)), and partly based on observations made at the Anglo-Australian Telescope. The CoRoT space mission, launched on December 27, 2006, was developed and is operated by CNES, with the contribution of Austria, Belgium, Brasil, ESA, Germany, and Spain.

  11. Mass Determination Of Directly Imaged Planet Candidates

    NASA Astrophysics Data System (ADS)

    Schmidt, Tobias; Neuhauser, R.; Seifahrt, A.

    2011-09-01

    About 20 sub-stellar companions with large separations (> 50 AU) to their young primary stars and brown dwarfs are confirmed by both common proper motion and late-M / early-L type spectra. The origin and early evolution of these objects is still under debate. While often these sub-stellar companions are regarded as brown dwarfs, they could possibly also be massive planets, the mass estimates are very uncertain so far. They are companions to primary stars or brown dwarfs in young associations and star forming regions like Taurus, Upper Scorpius, the TW Hya association, Beta Pic moving group, TucHor association, Lupus, Ophiuchus, and Chamaeleon, hence their ages and distances are well known, in contrast to free-floating brown dwarfs. Here we present how mass estimates of such young directly imaged companions can be derived, using e.g. evolutionary models, which are however currently almost uncalibrated by direct mass measurements of young objects. An empirical classification by medium-resolution spectroscopy is currently not possible, because a spectral sequence that is taking the lower gravity into account, is not existing. This problem leads to an apparent mismatch between spectra of old field type objects and young low-mass companions at the same effective temperature, hampering a determination of temperature and surface gravity independent from models. We show that from spectra of the objects, using the advantages of light concentration by an AO-assisted integral field spectrograph, temperature, extinction, metallicity and surface gravity can be derived using non-equilibrium radiative transfer atmosphere models as comparison and that this procedure as well allows a mass determination in combination with the luminosities found by the direct observations, as has recently been done by us for several young sub-stellar companions, as e.g. GQ Lup, CT Cha or UScoCTIO 108.

  12. The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars

    NASA Astrophysics Data System (ADS)

    Zechmeister, M.; Kürster, M.; Endl, M.; Lo Curto, G.; Hartman, H.; Nilsson, H.; Henning, T.; Hatzes, A. P.; Cochran, W. D.

    2013-04-01

    . For some other stars the variations could be attributed to stellar activity, as e.g. the magnetic cycle in the case of HR 8323. Conclusions: The occurrence of two Jupiter-mass planets in our sample is in line with the estimate of 10% for the frequency of giant planets with periods smaller than 10 yr around solar-like stars. We have not detected a Jupiter analogue, while the detections limits for circular orbits indicate at 5 AU a sensitivity for minimum mass of at least 1MJup (2MJup) for 13% (61%) of the stars. Based on observations collected at the European Southern Observatory, La Silla Chile, ESO programmes 50.7-0095, 51.7-0054, 52.7-0002, 53.7-0064, 54.E-0424, 55.E-0361, 56.E-0490, 57.E-0142, 58.E-0134, 59.E-0597, 60.E-0386, 61.E-0589, 62.L-0490, 64.L-0568, 66.C-0482, 67.C-0296, 69.C-0723, 70.C-0047, 71.C-0599, 072.C-0513, 073.C-0784, 074.C-0012, 076.C-0878, 077.C-0530, 078.C-0833, 079.C-0681. Also based on data obtained from the ESO Science Archive Facility.Appendices are available in electronic form at http://www.aanda.orgTables of the radial velocities, bisector spans, and log R'_HK are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A78

  13. Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing

    SciTech Connect

    Gaudi, B; Bennett, D; Udalski, A; Gould, A; Christie, G; Maoz, D; Dong, S; McCormick, J; Szymanski, M; Tristram, P; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; DePoy, D; Han, C; Kaspi, S; Lee, C; Mallia, F; Natusch, T; Pogge, R; Park, B; Abe, F; Bond, I; Botzler, C; Fukui, A; Hearnshaw, J; Itow, Y; Kamiya, K; Korpela, A; Kilmartin, P; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N; Sako, T; Saito, T; Sato, S; Skuljan, L; Sullivan, D; Sumi, T; Sweatman, W; Yock, P; Albrow, M; Beaulieu, J; Burgdorf, M; Cook, K; Coutures, C; Dominik, M; Dieters, S; Fouque, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2007-11-08

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the first detection of a multiple-planet system with microlensing. We identify two planets with masses of {approx} 0.71 and {approx} 0.27 times the mass of Jupiter and orbital separations of {approx} 2.3 and {approx} 4.6 astronomical units orbiting a primary of mass {approx} 0.50 solar masses. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only 6 confirmed microlensing planet detections suggests that solar system analogs may be common.

  14. The occurrence and mass distribution of close-in super-Earths, Neptunes, and Jupiters.

    PubMed

    Howard, Andrew W; Marcy, Geoffrey W; Johnson, John Asher; Fischer, Debra A; Wright, Jason T; Isaacson, Howard; Valenti, Jeff A; Anderson, Jay; Lin, Doug N C; Ida, Shigeru

    2010-10-29

    The questions of how planets form and how common Earth-like planets are can be addressed by measuring the distribution of exoplanet masses and orbital periods. We report the occurrence rate of close-in planets (with orbital periods less than 50 days), based on precise Doppler measurements of 166 Sun-like stars. We measured increasing planet occurrence with decreasing planet mass (M). Extrapolation of a power-law mass distribution fitted to our measurements, df/dlogM = 0.39 M(-0.48), predicts that 23% of stars harbor a close-in Earth-mass planet (ranging from 0.5 to 2.0 Earth masses). Theoretical models of planet formation predict a deficit of planets in the domain from 5 to 30 Earth masses and with orbital periods less than 50 days. This region of parameter space is in fact well populated, implying that such models need substantial revision.

  15. How the presence of a gas giant affects the formation of mean-motion resonances between two low-mass planets in a locally isothermal gaseous disc

    NASA Astrophysics Data System (ADS)

    Podlewska-Gaca, E.; Szuszkiewicz, E.

    2014-03-01

    In this paper we investigate the possibility of a migration-induced resonance locking in systems containing three planets, namely an Earth analogue (1 M⊕), a super-Earth (4 M⊕) and a gas giant (one Jupiter mass). The planets have been listed in order of increasing orbital periods. All three bodies are embedded in a locally isothermal gaseous disc and orbit around a solar mass star. We are interested in answering the following questions: will the low-mass planets form the same resonant structures with each other in the vicinity of the gas giant as in the case when the gas giant is absent? More in general, how will the presence of the gas giant affect the evolution of the two low-mass planets? When there is no gas giant in the system, it has been already shown that if the two low-mass planets undergo a convergent differential migration, they will capture each other in a mean-motion resonance. For the choices of disc parameters and planet masses made in this paper, the formation of the 5:4 resonance in the absence of the Jupiter has been observed in a previous investigation and confirmed here. In this work we add a gas giant on the most external orbit of the system in such a way that its differential migration is convergent with the low-mass planets. We show that the result of this set-up is the speeding up of the migration of the super-Earth and, after that, all three planets become locked in a triple mean-motion resonance. However, this resonance is not maintained due to the low-mass planet eccentricity excitation, a fact that leads to close encounters between planets and eventually to the ejection from the internal orbits of one or both low-mass planets. We have observed that the ejected low-mass planets can leave the system, fall into a star or become the external planet relative to the gas giant. In our simulations the latter situation has been observed for the super-Earth. It follows from the results presented here that the presence of a Jupiter-like planet

  16. Jupiter - friend or foe?

    NASA Astrophysics Data System (ADS)

    Horner, J.; Jones, B. W.

    2007-08-01

    Throughout both popular science and academia, there is a pervasive belief that Jupiter has acted as a celestial shield, reducing the impact rate on the Earth, and making the planet a significantly more conducive site for the evolution and survival of life. This old idea has, however, undergone little detailed scrutiny. In the first of a series of studies aimed at a better understanding of this idea, we examine the variation in the impact rate on the Earth which results from bodies moving inwards from the Edgeworth- Kuiper belt as a function of the mass of a giant planet in Jupiter's orbit. The results are not entirely what would be expected under the "Jupiter Shield" paradigm.

  17. Detecting Earth-Mass Planets with Gravitational Microlensing

    NASA Astrophysics Data System (ADS)

    Bennett, David P.; Rhie, Sun Hong

    1996-11-01

    We show that Earth-mass planets orbiting stars in the Galactic disk and bulge can be detected by monitoring microlensed stars in the Galactic bulge. The star and its planet act as a binary lens which generates a light curve that can differ substantially from the light curve due only to the star itself. We show that the planetary signal remains detectable for planetary masses as small as an Earth mass when realistic source star sizes are included in the light curve calculation. These planets are detectable if they reside in the "lensing zone," which is centered between 1 and 4 AU from the lensing star and spans about a factor of 2 in distance. If we require a minimum deviation of 4% from the standard point-lens microlensing light curve, then we find that more than 2% of all M⊕ planets and 10% of all 10 M⊕ in the lensing zone can be detected. If a third of all lenses have no planets, a third have 1 M⊕ planets, and the remaining third have 10 M⊕ planets then we estimate that an aggressive ground-based microlensing planet search program could find one Earth-mass planet and half a dozen 10 M⊕ planets per year.

  18. HAT-P-34b-HAT-P-37b: Four Transiting Planets More Massive than Jupiter Orbiting Moderately Bright Stars

    NASA Astrophysics Data System (ADS)

    Bakos, G. Á.; Hartman, J. D.; Torres, G.; Béky, B.; Latham, D. W.; Buchhave, L. A.; Csubry, Z.; Kovács, G.; Bieryla, A.; Quinn, S.; Szklenár, T.; Esquerdo, G. A.; Shporer, A.; Noyes, R. W.; Fischer, D. A.; Johnson, J. A.; Howard, A. W.; Marcy, G. W.; Sato, B.; Penev, K.; Everett, M.; Sasselov, D. D.; Fűrész, G.; Stefanik, R. P.; Lázár, J.; Papp, I.; Sári, P.

    2012-07-01

    We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33 M J and periods from 1.33 to 5.45 days. These planets orbit relatively bright F and G dwarf stars (from V = 10.16 to V = 13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33 M J), has a high eccentricity of e = 0.441 ± 0.032 at a period of P = 5.452654 ± 0.000016 days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters. 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. Keck time has been granted by NOAO (A289Hr) and NASA (N167Hr and N029Hr). Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias.

  19. Formation and composition of planets around very low mass stars

    NASA Astrophysics Data System (ADS)

    Alibert, Y.; Benz, W.

    2017-01-01

    Context. The recent detection of planets around very low mass stars raises the question of the formation, composition, and potential habitability of these objects. Aims: We use planetary system formation models to infer the properties, in particular their radius distribution and water content, of planets that may form around stars ten times less massive than the Sun. Methods: Our planetary system formation and composition models take into account the structure and evolution of the protoplanetary disk, the planetary mass growth by accretion of solids and gas, as well as planet-planet, planet-star, and planet-disk interactions. Results: We show that planets can form at small orbital period in orbit about low-mass stars. We show that the radius of the planets is peaked at about 1 R⊕ and that they are, in general, volatile rich especially if proto-planetary disks orbiting this type of stars are long lived. Conclusions: Close-in planets orbiting low-mass stars similar in terms of mass and radius to those recently detected can be formed within the framework of the core-accretion paradigm as modeled here. The properties of protoplanetary disks, and their correlation with the stellar type, are key to understand their composition.

  20. Astrometric observations of the faint satellites of Jupiter and minor planets, 1974-1977

    NASA Technical Reports Server (NTRS)

    Benedict, G. R.; Shelus, P. J.; Mulholland, J. D.

    1978-01-01

    Precise positions of the faint satellites VI-XII of Jupiter during the 1974 opposition, and for Jupiter XIII during the 1976-1977 and 1977-1978 oppositions, have been obtained from plates taken with the 2.1-m Otto Struve reflector of the McDonald Observatory by the use of a new quasi-automatic plate measurement and reduction procedure on a PDS microdensitometer. Observations of selected asteroids, including two of 1977 UB (Chiron) are given also.

  1. A STELLAR-MASS-DEPENDENT DROP IN PLANET OCCURRENCE RATES

    SciTech Connect

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-10

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R {sub ⊕}) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ∼10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  2. Instability of mass transfer in a planet-star system

    NASA Astrophysics Data System (ADS)

    Jia, Shi; Spruit, H. C.

    2017-02-01

    We show that the angular momentum exchange mechanism governing the evolution of mass-transferring binary stars does not apply to Roche lobe filling planets, because most of the angular momentum of the mass-transferring stream is absorbed by the host star. Apart from a correction for the difference in specific angular momentum of the stream and the centre of mass of the planet, the orbit does not expand much on Roche lobe overflow. We explore the conditions for dynamically unstable Roche lobe overflow as a function of planetary mass and mass and radius (age) of host star and equation of state of planet. For a Sun-like host, gas giant planets in a range of mass and entropy can undergo dynamical mass transfer. Examples of the evolution of the mass transfer process are given. Dynamic mass transfer of rocky planets depends somewhat sensitively on equation of state used. Silicate planets in the range 1 < Mp < 10 M⊕ typically go through a phase of dynamical mass transfer before settling to slow overflow when their mass drops to less than 1 M⊕.

  3. On the gravitational signature of zonal flows in Jupiter-like planets: An analytical solution and its numerical validation

    NASA Astrophysics Data System (ADS)

    Kong, Dali; Zhang, Keke; Schubert, Gerald

    2017-02-01

    It is expected that the Juno spacecraft will provide an accurate spectrum of the Jovian zonal gravitational coefficients that would be affected by both the deep zonal flow, if it exists, and the basic rotational distortion. We derive the first analytical solution, under the spheroidal-shape approximation, for the density anomaly induced by an internal zonal flow in rapidly rotating Jupiter-like planets. We compare the density anomaly of the analytical solution to that obtained from a fully numerical solution based on a three-dimensional finite element method; the two show excellent agreement. We apply the analytical solution to a rapidly rotating Jupiter-like planet and show that there exists a close relationship between the spatial structure of the zonal flow and the spectrum of zonal gravitational coefficients. We check the accuracy of the spheroidal-shape approximation by computing both the spheroidal and non-spheroidal solutions with exactly the same physical parameters. We also discuss implications of the new analytical solution for interpreting the future high-precision gravitational measurements of the Juno spacecraft.

  4. Planetary populations in the mass-period diagram: A statistical treatment of exoplanet formation and the role of planet traps

    SciTech Connect

    Hasegawa, Yasuhiro; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2013-11-20

    The rapid growth of observed exoplanets has revealed the existence of several distinct planetary populations in the mass-period diagram. Two of the most surprising are (1) the concentration of gas giants around 1 AU and (2) the accumulation of a large number of low-mass planets with tight orbits, also known as super-Earths and hot Neptunes. We have recently shown that protoplanetary disks have multiple planet traps that are characterized by orbital radii in the disks and halt rapid type I planetary migration. By coupling planet traps with the standard core accretion scenario, we showed that one can account for the positions of planets in the mass-period diagram. In this paper, we demonstrate quantitatively that most gas giants formed at planet traps tend to end up around 1 AU, with most of these being contributed by dead zones and ice lines. We also show that a large fraction of super-Earths and hot Neptunes are formed as 'failed' cores of gas giants—this population being constituted by comparable contributions from dead zone and heat transition traps. Our results are based on the evolution of forming planets in an ensemble of disks where we vary only the lifetimes of disks and their mass accretion rates onto the host star. We show that a statistical treatment of the evolution of a large population of planetary cores caught in planet traps accounts for the existence of three distinct exoplanetary populations—the hot Jupiters, the more massive planets around r = 1 AU, and the short-period super-Earths and hot Neptunes. There are very few populations that feed into the large orbital radii characteristic of the imaged Jovian planet, which agrees with recent surveys. Finally, we find that low-mass planets in tight orbits become the dominant planetary population for low-mass stars (M {sub *} ≤ 0.7 M {sub ☉}).

  5. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Unruh, Y. C.; Koskinen, T. T.; Sanz-Forcada, J.

    2015-04-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - ɛ Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale the EUV regions of the solar spectrum based upon stellar X-ray emission. This new method produces an outcome in terms of the planet's neutral upper atmosphere very similar to that obtained using a detailed coronal model of the host star. Our results indicate that in planets subjected to radiation from active stars, the transition from Jeans escape to a regime of hydrodynamic escape at the top of the atmosphere occurs at larger orbital distances than for planets around low activity stars (such as the Sun).

  6. Jupiter: Cosmic Jekyll and Hyde.

    PubMed

    Grazier, Kevin R

    2016-01-01

    It has been widely reported that Jupiter has a profound role in shielding the terrestrial planets from comet impacts in the Solar System, and that a jovian planet is a requirement for the evolution of life on Earth. To evaluate whether jovians, in fact, shield habitable planets from impacts (a phenomenon often referred to as the "Jupiter as shield" concept), this study simulated the evolution of 10,000 particles in each of the jovian inter-planet gaps for the cases of full-mass and embryo planets for up to 100 My. The results of these simulations predict a number of phenomena that not only discount the "Jupiter as shield" concept, they also predict that in a Solar System like ours, large gas giants like Saturn and Jupiter had a different, and potentially even more important, role in the evolution of life on our planet by delivering the volatile-laden material required for the formation of life. The simulations illustrate that, although all particles occupied "non-life threatening" orbits at their onset of the simulations, a significant fraction of the 30,000 particles evolved into Earth-crossing orbits. A comparison of multiple runs with different planetary configurations revealed that Jupiter was responsible for the vast majority of the encounters that "kicked" outer planet material into the terrestrial planet region, and that Saturn assisted in the process far more than has previously been acknowledged. Jupiter also tends to "fix" the aphelion of planetesimals at its orbit irrespective of their initial starting zones, which has the effect of slowing their passages through the inner Solar System, and thus potentially improving the odds of accretion of cometary material by terrestrial planets. As expected, the simulations indicate that the full-mass planets perturb many objects into the deep outer Solar System, or eject them entirely; however, planetary embryos also did this with surprising efficiency. Finally, the simulations predict that Jupiter's capacity to

  7. Voyager 2 Jupiter encounter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A NASA News Release is presented which contains the following: (1) general release; (2) two views of Voyager 2 flight past Jupiter; (3) Voyager mission summary; (4) Voyager 1 science results; (5) Jupiter science objectives; (6) Jupiter the planet and its satellites; (7) Voyager experiments; (8) planet comparison; (9) a list of Voyager science investigators and (10) the Voyager team.

  8. Fu Ori outbursts and the planet-disc mass exchange

    NASA Astrophysics Data System (ADS)

    Nayakshin, Sergei; Lodato, Giuseppe

    2012-10-01

    It has been recently proposed that giant protoplanets migrating inwards through the disc more rapidly than they contract could be tidally disrupted when they fill their Roche lobes ˜0.1 au away from their parent protostars. Here we consider the process of mass and angular momentum exchange between the tidally disrupted planet and the surrounding disc in detail. We find that the planet's adiabatic mass-radius relation and its ability to open a deep gap in the disc determine whether the disruption proceeds as a sudden runaway or a balanced quasi-static process. In the latter case, the planet feeds the inner disc through its Lagrangian L1 point like a secondary star in a stellar binary system. As the planet loses mass, it gains specific angular momentum and normally migrates in the outward direction until the gap closes. Numerical experiments show that planet disruption outbursts are preceded by long 'quiescent' periods during which the disc inward of the planet is empty. The hole in the disc is created when the planet opens a deep gap, letting the inner disc to drain on to the star while keeping the outer one stalled behind the planet. We find that the mass-losing planet embedded in a realistic protoplanetary disc spawns an extremely rich set of variability patterns. In a subset of parameter space, there is a limit cycle behaviour caused by non-linear interaction between the planet mass-loss and the disc hydrogen ionization instability. We suggest that tidal disruptions of young massive planets near their stars may be responsible for the observed variability of young accreting protostars such as FU Ori, EXor and T Tauri stars in general.

  9. Jupiter - Friend or Foe?

    NASA Astrophysics Data System (ADS)

    Horner, J.; Jones, B. W.

    2008-09-01

    It has long been believed that the planet Jupiter has played a beneficial role in the development of life on the Earth, acting as a shield from objects which would otherwise go on to significantly raise the impact flux experienced by our planet. Without Jupiter, the story goes, the Earth would have experienced a far greater number of impacts, making it far less hospitable to burgeoning life. In an on-going series of separate studies[1,2], we have examined the effects of varying the mass of Jupiter on the impact flux that the Earth would experience from Near-Earth Objects sourced from the Asteroid belt, short-period comets sourced from the Edgeworth-Kuiper belt, and long-period comets sourced from the Oort cloud. The results are remarkable - it seems that, far from being a shield, Jupiter actually acts to increase the impact flux experienced by the Earth over that which would be expected without the planet. Still more surprising, in the cases of the asteroids and Edgeworth-Kuiper belt objects, it seems that a Jupiter around 0.2 times the mass of "our Jupiter" would be even more threatening, sending a still greater number of objects our way. In order to simulate such disparate populations, different approaches to population construction were needed. The asteroidal and short-period comet populations each contained 100,000 test particles, moving on orbits typical of their class. The asteroids were initially distributed between 2 and 4 AU, with orbits of varying eccentricity and inclination, with number density varying as a function of semi-major axis. The short-period cometary flux was obtained through simulation of a population based on the subset of known Centaurs and Scattered Disk Objects which are Neptune-crossing, and have perihelia beyond the orbit of Uranus. These objects are the parents of the short-period comets, and were chosen since they are a population beyond the current influence of the planet Jupiter. Since our goal was to study the effect of Jupiter

  10. Trapping planets in an evolving protoplanetary disk: preferred time, locations, and planet mass

    NASA Astrophysics Data System (ADS)

    Baillié, K.; Charnoz, S.; Pantin, E.

    2016-05-01

    Context. Planet traps are necessary to prevent forming planets from falling onto their host star by type I inward migration. Surface mass density and temperature gradient irregularities favor the apparition of traps (planet accumulation region) and deserts (planet depletion zone). These features are found at the dust sublimation lines and heat transition barriers. Aims: We study how planets may remain trapped or escape these traps as they grow and as the disk evolves viscously with time. Methods: We numerically model the temporal viscous evolution of a protoplanetary disk by coupling its dynamics, thermodynamics, geometry, and composition. The resulting midplane density and temperature profiles allow the modeling of the interactions of this type of evolving disk with potential planets, even before the steady state is reached. Results: We follow the viscous evolution of a minimum mass solar nebula and compute the Lindblad and corotation torques that this type of disk would exert on potential planets of various masses that are located within the planetary formation region. We determine the position of planet traps and deserts in relationship with the sublimation lines, shadowed regions, and heat transition barriers. We notice that the planet mass affects the trapping potential of the mentioned structures through the saturation of the corotation torque. Planets that are a few tens of Earth masses can be trapped at the sublimation lines until they reach a certain mass while planets that are more massive than 100 M⊕ can only be trapped permanently at the heat transition barriers. They may also open gaps beyond 5 au and enter type II migration. Conclusions: Coupling a bimodal planetary migration model with a self-consistent evolved disk, we were able to distinguish several potential planet populations after five million years of evolution: two populations of giant planets that could stay trapped around 5.5 and 9 au and possibly open gaps, some super-Earths trapped

  11. Small Friends of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Nunez, Luis Ernesto; Johnson, John A.

    2017-01-01

    Hot Jupiters are Jupiter-sized gas giant exoplanets that closely orbit their host star in periods of about 10 days or less. Early models hypothesized that these exoplanets formed away from the star, then over time drifted to their characteristically closer locations. However, new theories predict that Hot Jupiters form at their close proximity during the process of core accretion (Batygin et al. 2015). In fact, a super-Earth and a Neptune-sized exoplanet have already been detected in the Hot Jupiter-hosting star WASP-47 (Becker et al. 2015). We will present our analysis of radial velocity time series plots to determine whether low-mass, short-period planets have been previously overlooked in systems of stars which host Hot Jupiters.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851.

  12. Atmospheric circulations of terrestrial planets orbiting low mass stars

    NASA Astrophysics Data System (ADS)

    Edson, Adam Robert

    Atmospheres of planets orbiting low mass stars have properties unlike those typically studied by climatologists. One of the most glaring differences is that the rotation is "trapped" for planets orbiting within the habitable zone of the star. This lack of a typical "day" changes these planets' dynamics. Previous work includes that of Gareth Williams and Manoj Joshi. Joshi discussed planets with 10-day orbits only. Williams focused on planets with differing rotation rates, but still rotating relative to their star. Here, tidally locked planets with a variety of orbital periods ranging from 1 to 100 days are discussed. The GENESIS model is used to simulate these planets, and the data are analyzed for waves, energy fluxes, and habitability. The major components of the energy fluxes are the mean meridional circulation (i.e., the Hadley cell) and stationary eddies in the form of a wave number 1 stationary Rossby wave. A transition point in the atmospheric circulation is identified for orbital periods between 100 hours and 101 hours for dry planets. For the wet planets, the transition occurs near 96-hour rotation period. This transition occurs when the Rossby radius of deformation approaches the planet's radius and is associated with the increasing importance of the wave number two stationary eddy as the Rossby radius approaches the planetary radius. The most habitable dry planet is found to be the 2400-hour orbiter. For the wet planets, the 24-hour rotator is most habitable. The most habitable wet planet is the 24-hour rotator, with the least habitable wet planet being the 2400-hour rotator. The difference in the rotation period of the most habitable planets between the dry planets and the wet planets is caused by the availability of water vapor as a greenhouse gas, the added heat transport through sea ice movement, and the larger heat capacity for the wet planets. When realistic planets are modeled, the habitable surface area and average surface temperature is

  13. AN UNDERSTANDING OF THE SHOULDER OF GIANTS: JOVIAN PLANETS AROUND LATE K DWARF STARS AND THE TREND WITH STELLAR MASS

    SciTech Connect

    Gaidos, Eric; Fischer, Debra A.; Mann, Andrew W.; Howard, Andrew W.

    2013-07-01

    Analyses of exoplanet statistics suggest a trend of giant planet occurrence with host star mass, a clue to how planets like Jupiter form. One missing piece of the puzzle is the occurrence around late K dwarf stars (masses of 0.5-0.75 M{sub Sun} and effective temperatures of 3900-4800 K). We analyzed four years of Doppler radial velocity (RVs) data for 110 late K dwarfs, one of which hosts two previously reported giant planets. We estimate that 4.0% {+-} 2.3% of these stars have Saturn-mass or larger planets with orbital periods <245 days, depending on the planet mass distribution and RV variability of stars without giant planets. We also estimate that 0.7% {+-} 0.5% of similar stars observed by Kepler have giant planets. This Kepler rate is significantly (99% confidence) lower than that derived from our Doppler survey, but the difference vanishes if only the single Doppler system (HIP 57274) with completely resolved orbits is considered. The difference could also be explained by the exclusion of close binaries (without giant planets) from the Doppler but not Kepler surveys, the effect of long-period companions and stellar noise on the Doppler data, or an intrinsic difference between the two populations. Our estimates for late K dwarfs bridge those for solar-type stars and M dwarfs, and support a positive trend with stellar mass. Small sample size precludes statements about finer structure, e.g., a ''shoulder'' in the distribution of giant planets with stellar mass. Future surveys such as the Next Generation Transit Survey and the Transiting Exoplanet Satellite Survey will ameliorate this deficiency.

  14. Advanced Ion Mass Spectrometer for Giant Planet Ionosphere, Magnetospheres and Moons

    NASA Astrophysics Data System (ADS)

    Sittler, Edward; Cooper, John; Paschalidis, Nick; Jones, Sarah; Brinkerhoff, William; Paterson, William; Ali, Ashraf; Coplan, Michael; Chornay, Dennis; Sturner, Steve; Benna, Mehdi; Bateman, Fred; Fontaine, Dominique; Verdeil, Christophe; Andre, Nicolas; Blanc, Michel; Wurz, Peter

    2017-01-01

    We present our Advanced Ion Mass Spectrometer (AIMS) for outer planet missions which has been under development from various NASA sources (NASA Living with a Star Instrument Development (LWSID), NASA Astrobiology Instrument Development (ASTID), NASA Goddard Internal Research and Development (IRAD)s) to measure elemental, isotopic, and simple molecular composition abundances of 1 V to 25 kV hot ions with wide field-of-view (FOV) in the 1 - 60 amu mass range at mass resolution M/ ΔM <= 60 over a wide dynamic range of particle intensities and penetrating radiation background from the inner magnetospheres of Jupiter and Saturn to the outer magnetospheric boundary regions and the upstream solar wind. This instrument will work for both spinning spacecraft and 3-axis stabilized spacecraft. AIMS will measure the ion velocity distribution functions (VDF) for the individual ion species from which velocity moments will give their ion density, flow velocity and temperature.

  15. Exotic Earths: forming habitable worlds with giant planet migration.

    PubMed

    Raymond, Sean N; Mandell, Avi M; Sigurdsson, Steinn

    2006-09-08

    Close-in giant planets (e.g., "hot Jupiters") are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered "hot Earths." Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.

  16. Terrestrial planet formation in a protoplanetary disk with a local mass depletion: A successful scenario for the formation of Mars

    SciTech Connect

    Izidoro, A.; Winter, O. C.; Haghighipour, N.; Tsuchida, M. E-mail: nader@ifa.hawaii.edu

    2014-02-10

    Models of terrestrial planet formation for our solar system have been successful in producing planets with masses and orbits similar to those of Venus and Earth. However, these models have generally failed to produce Mars-sized objects around 1.5 AU. The body that is usually formed around Mars' semimajor axis is, in general, much more massive than Mars. Only when Jupiter and Saturn are assumed to have initially very eccentric orbits (e ∼ 0.1), which seems fairly unlikely for the solar system, or alternately, if the protoplanetary disk is truncated at 1.0 AU, simulations have been able to produce Mars-like bodies in the correct location. In this paper, we examine an alternative scenario for the formation of Mars in which a local depletion in the density of the protosolar nebula results in a non-uniform formation of planetary embryos and ultimately the formation of Mars-sized planets around 1.5 AU. We have carried out extensive numerical simulations of the formation of terrestrial planets in such a disk for different scales of the local density depletion, and for different orbital configurations of the giant planets. Our simulations point to the possibility of the formation of Mars-sized bodies around 1.5 AU, specifically when the scale of the disk local mass-depletion is moderately high (50%-75%) and Jupiter and Saturn are initially in their current orbits. In these systems, Mars-analogs are formed from the protoplanetary materials that originate in the regions of disk interior or exterior to the local mass-depletion. Results also indicate that Earth-sized planets can form around 1 AU with a substantial amount of water accreted via primitive water-rich planetesimals and planetary embryos. We present the results of our study and discuss their implications for the formation of terrestrial planets in our solar system.

  17. DETECTABILITY OF TRANSITING JUPITERS AND LOW-MASS ECLIPSING BINARIES IN SPARSELY SAMPLED PAN-STARRS-1 SURVEY DATA

    SciTech Connect

    Dupuy, Trent J.; Liu, Michael C.

    2009-10-20

    We present detailed simulations of the Pan-STARRS-1 (PS1) multi-epoch, multiband 3pi Survey in order to assess its potential yield of transiting planets and eclipsing binaries. This survey differs from dedicated transit surveys in that it will cover the entire northern sky but provide only sparsely sampled light curves. Since most eclipses would be detected at only a single epoch, the 3pi Survey will be most sensitive to deep eclipses (approx>0.10 mag) caused by Jupiters transiting M dwarfs and eclipsing stellar/substellar binaries. The survey will measure parallaxes for the approx4 x 10{sup 5} stars within 100 pc, which will enable a volume-limited eclipse search, reducing the number of astrophysical false positives compared with previous magnitude-limited searches. Using the best available empirical data, we constructed a model of the extended solar neighborhood that includes stars, brown dwarfs, and a realistic binary population. We computed the yield of deeply eclipsing systems using both a semianalytic and a full Monte Carlo approach. We examined statistical tests for detecting single-epoch eclipses in sparsely sampled data and assessed their vulnerability to false positives due to stellar variability. Assuming a short-period planet frequency of 0.5% for M dwarfs, our simulations predict that about a dozen transiting Jupiters around low-mass stars (M {sub *} < 0.3 M {sub sun}) within 100 pc are potentially detectable in the PS1 3pi Survey, along with approx300 low-mass eclipsing binaries (both component masses <0.5 M {sub sun}), including approx10 eclipsing field brown dwarfs. Extensive follow-up observations would be required to characterize these candidate eclipsing systems, thereby enabling comprehensive tests of structural models and novel insights into the planetary architecture of low-mass stars.

  18. Hot Jupiters and cool stars

    SciTech Connect

    Villaver, Eva; Mustill, Alexander J.; Livio, Mario; Siess, Lionel

    2014-10-10

    Close-in planets are in jeopardy, as their host stars evolve off the main sequence (MS) to the subgiant and red giant phases. In this paper, we explore the influences of the stellar mass (in the range 1.5-2 M {sub ☉}), mass-loss prescription, planet mass (from Neptune up to 10 Jupiter masses), and eccentricity on the orbital evolution of planets as their parent stars evolve to become subgiants and red giants. We find that planet engulfment along the red giant branch is not very sensitive to the stellar mass or mass-loss rates adopted in the calculations, but quite sensitive to the planetary mass. The range of initial separations for planet engulfment increases with decreasing mass-loss rates or stellar masses and increasing planetary masses. Regarding the planet's orbital eccentricity, we find that as the star evolves into the red giant phase, stellar tides start to dominate over planetary tides. As a consequence, a transient population of moderately eccentric close-in Jovian planets is created that otherwise would have been expected to be absent from MS stars. We find that very eccentric and distant planets do not experience much eccentricity decay, and that planet engulfment is primarily determined by the pericenter distance and the maximum stellar radius.

  19. The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Cumming, Andrew; Butler, R. Paul; Marcy, Geoffrey W.; Vogt, Steven S.; Wright, Jason T.; Fischer, Debra A.

    2008-05-01

    We analyze 8 years of precise radial velocity measurements from the Keck Planet Search, characterizing the detection threshold, selection effects, and completeness of the survey. We first carry out a systematic search for planets, by assessing the false-alarm probability associated with Keplerian orbit fits to the data. This allows us to understand the detection threshold for each star in terms of the number and time baseline of the observations, and the underlying “noise” from measurement errors, intrinsic stellar jitter, or additional low-mass planets. We show that all planets with orbital periods P < 2000 days, velocity amplitudes K > 20 m s-1, and eccentricities e ≲ 0.6 have been announced, and we summarize the candidates at lower amplitudes and longer orbital periods. For the remaining stars, we calculate upper limits on the velocity amplitude of a companion. For orbital periods less than the duration of the observations, these are typically 10 m s-1 and increase ∝ P2 for longer periods. We then use the nondetections to derive completeness corrections at low amplitudes and long orbital periods and discuss the resulting distribution of minimum mass and orbital period. We give the fraction of stars with a planet as a function of minimum mass and orbital period and extrapolate to long-period orbits and low planet masses. A power-law fit for planet masses >0.3 MJ and periods < 2000 days gives a mass-period distribution dN = CMα Pβ d ln Md ln P with α = -0.31 ± 0.2, β = 0.26 ± 0.1, and the normalization constant C such that 10.5% of solar type stars have a planet with mass in the range 0.3–10 MJ and orbital period 2–2000 days. The orbital period distribution shows an increase in the planet fraction by a factor of ≈5 for orbital periods ≳300 days. Extrapolation gives 17%–20% of stars having gas giant planets within 20 AU. Finally, we constrain the occurrence rate of planets orbiting M dwarfs compared to FGK dwarfs, taking into account

  20. EXTRACTING PLANET MASS AND ECCENTRICITY FROM TTV DATA

    SciTech Connect

    Lithwick, Yoram; Xie Jiwei; Wu Yanqin

    2012-12-20

    Most planet pairs in the Kepler data that have measured transit time variations (TTVs) are near first-order mean-motion resonances. We derive analytical formulae for their TTV signals. We separate planet eccentricity into free and forced parts, where the forced part is purely due to the planets' proximity to resonance. This separation yields simple analytical formulae. The phase of the TTV depends sensitively on the presence of free eccentricity: if the free eccentricity vanishes, the TTV will be in phase with the longitude of conjunctions. This effect is easily detectable in current TTV data. The amplitude of the TTV depends on planet mass and free eccentricity, and it determines planet mass uniquely only when the free eccentricity is sufficiently small. We analyze the TTV signals of six short-period Kepler pairs. We find that three of these pairs (Kepler 18, 24, 25) have a TTV phase consistent with zero. The other three (Kepler 23, 28, 32) have small TTV phases, but ones that are distinctly non-zero. We deduce that the free eccentricities of the planets are small, {approx}< 0.01, but not always vanishing. Furthermore, as a consequence of this, we deduce that the true masses of the planets are fairly accurately determined by the TTV amplitudes, within a factor of {approx}< 2. The smallness of the free eccentricities suggests that the planets have experienced substantial dissipation. This is consistent with the hypothesis that the observed pile-up of Kepler pairs near mean-motion resonances is caused by resonant repulsion. But the fact that some of the planets have non-vanishing free eccentricity suggests that after resonant repulsion occurred there was a subsequent phase in the planets' evolution when their eccentricities were modestly excited, perhaps by interplanetary interactions.

  1. THE PHOTOECCENTRIC EFFECT AND PROTO-HOT JUPITERS. II. KOI-1474.01, A CANDIDATE ECCENTRIC PLANET PERTURBED BY AN UNSEEN COMPANION

    SciTech Connect

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher; Morton, Timothy D.; Crepp, Justin R.; Fabrycky, Daniel C.; Howard, Andrew W.

    2012-12-20

    The exoplanets known as hot Jupiters-Jupiter-sized planets with periods of less than 10 days-likely are relics of dynamical processes that shape all planetary system architectures. Socrates et al. argued that high eccentricity migration (HEM) mechanisms proposed for situating these close-in planets should produce an observable population of highly eccentric proto-hot Jupiters that have not yet tidally circularized. HEM should also create failed-hot Jupiters, with periapses just beyond the influence of fast circularization. Using the technique we previously presented for measuring eccentricities from photometry (the ''photoeccentric effect''), we are distilling a collection of eccentric proto- and failed-hot Jupiters from the Kepler Objects of Interest (KOI). Here, we present the first, KOI-1474.01, which has a long orbital period (69.7340 days) and a large eccentricity e 0.81{sup +0.10}{sub -0.07}, skirting the proto-hot Jupiter boundary. Combining Kepler photometry, ground-based spectroscopy, and stellar evolution models, we characterize host KOI-1474 as a rapidly rotating F star. Statistical arguments reveal that the transiting candidate has a low false-positive probability of 3.1%. KOI-1474.01 also exhibits transit-timing variations of the order of an hour. We explore characteristics of the third-body perturber, which is possibly the ''smoking-gun'' cause of KOI-1474.01's large eccentricity. We use the host star's period, radius, and projected rotational velocity to measure the inclination of the stellar spin. Comparing KOI 1474.01's inclination, we find that its orbit is marginally consistent with being aligned with the stellar spin axis, although a reanalysis is warranted with future additional data. Finally, we discuss how the number and existence of proto-hot Jupiters will not only demonstrate that hot Jupiters migrate via HEM, but also shed light on the typical timescale for the mechanism.

  2. The Obliquity of a Hot Jupiter in a Multi-Planet System

    NASA Astrophysics Data System (ADS)

    Fulton, Benjamin; Howard, A.; Albrecht, S.; Johnson, J. A.; Knutson, H.; Marcy, G. W.; Winn, J. N.

    2013-01-01

    We present the measured projected obliquity of a known transiting Jovian planet from the analysis of the Rossiter-McLaughlin (RM) effect in Keck-HIRES radial velocity data. We employ the new analytical approach of Hirano et al. (2011) that includes the effects of macroturbulence and instrumental broadening to accurately model the radial velocity shadow of a transiting planet, and foregoes the need to produce synthetic spectra on a case-by-case basis. RM measurements are an important tool for testing theories of planet formation and migration. To date, the measured obliquities of ~50 Jovian planets span the full range, from prograde to retrograde, with planets orbiting cool stars preferentially showing alignment of stellar spins and planetary orbits. Albrecht et al. (2012) interpret this pattern as the signature of tidal interactions with the convective envelopes of cool stars and close-in planets. This system is of particular interest because the tidal timescale for the transiting planet is relatively long and is thus a good test of the tidal-induced spin-orbit alignment theories.

  3. High-dispersion spectroscopy of extrasolar planets: from CO in hot Jupiters to O2 in exo-Earths.

    PubMed

    Snellen, Ignas

    2014-04-28

    Ground-based high-dispersion spectroscopy could reveal molecular oxygen as a biomarker gas in the atmospheres of twin-Earths transiting red dwarf stars within the next 25 years. The required contrasts are only a factor of 3 lower than that already achieved for carbon monoxide in hot Jupiter atmospheres today but will need much larger telescopes because the target stars will be orders of magnitude fainter. If extraterrestrial life is very common and can therefore be found on planets around the most nearby red dwarf stars, it may be detectable via transmission spectroscopy with the next-generation extremely large telescopes. However, it is likely that significantly more collecting area is required for this. This can be achieved through the development of low-cost flux collector technology, which combines a large collecting area with a low but sufficient image quality for high-dispersion spectroscopy of bright stars.

  4. Lone Planet Under a Cosmic Magnifying Glass

    NASA Video Gallery

    This artist's animation illustrates the technique used for finding free-floating, Jupiter-mass planets in space. Astronomers found evidence for 10 of these worlds, thought to have been ejected earl...

  5. Dynamical corotation torques on low-mass planets

    NASA Astrophysics Data System (ADS)

    Paardekooper, S.-J.

    2014-11-01

    We study torques on migrating low-mass planets in locally isothermal discs. Previous work on low-mass planets generally kept the planet on a fixed orbit, after which the torque on the planet was measured. In addition to these static torques, when the planet is allowed to migrate it experiences dynamical torques, which are proportional to the migration rate and whose sign depends on the background vortensity gradient. We show that in discs a few times more massive than the minimum-mass solar nebula, these dynamical torques can have a profound impact on planet migration. Inward migration can be slowed down significantly, and if static torques lead to outward migration, dynamical torques can take over, taking the planet beyond zero-torque lines set by saturation of the corotation torque in a runaway fashion. This means that the region in non-isothermal discs, where outward migration is possible, can be larger than what would be concluded from static torques alone.

  6. Fomalhaut's Debris Disk and Planet: Constraining the Mass of Fomalhaut b from disk Morphology

    NASA Astrophysics Data System (ADS)

    Chiang, E.; Kite, E.; Kalas, P.; Graham, J. R.; Clampin, M.

    2009-03-01

    Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M pl < 3M J, an orbital semimajor axis a pl > 101.5 AU, and an orbital eccentricity e pl = 0.11-0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a ≈ 133 AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e ≈ 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of ~ 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to ~ 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties may be large. If the apsidal misalignment proves real, our calculated upper mass limit of 3M J still holds. If the orbits are aligned, our model predicts M pl = 0.5M J, a pl = 115 AU, and e pl = 0

  7. Fomalhaut's Debris Disk and Planet: Constraining the Mass of Formalhaut B from Disk Morphology

    NASA Technical Reports Server (NTRS)

    Chiang, E.; Kite, E.; Kalas, P.; Graham, J. R.; Clampin, M.

    2008-01-01

    Following the optical imaging of exoplanet candidate Fomalhaut b (Fom b), we present a numerical model of how Fomalhaut's debris disk is gravitationally shaped by a single interior planet. The model is simple, adaptable to other debris disks, and can be extended to accommodate multiple planets. If Fom b is the dominant perturber of the belt, then to produce the observed disk morphology it must have a mass M(sub pl) < 3M(sub J), an orbital semimajor axis a(sub pl) > 101.5AU, and an orbital eccentricity e(sub pl) = 0.11 - 0.13. These conclusions are independent of Fom b's photometry. To not disrupt the disk, a greater mass for Fom b demands a smaller orbit farther removed from the disk; thus, future astrometric measurement of Fom b's orbit, combined with our model of planet-disk interaction, can be used to determine the mass more precisely. The inner edge of the debris disk at a approximately equals 133AU lies at the periphery of Fom b's chaotic zone, and the mean disk eccentricity of e approximately equals 0.11 is secularly forced by the planet, supporting predictions made prior to the discovery of Fom b. However, previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our constraint is more reliable. It is based on a global model of the disk that is not restricted to the planet's chaotic zone boundary. Moreover, we screen disk parent bodies for dynamical stability over the system age of approximately 100 Myr, and model them separately from their dust grain progeny; the latter's orbits are strongly affected by radiation pressure and their lifetimes are limited to approximately 0.1 Myr by destructive grain-grain collisions. The single planet model predicts that planet and disk orbits be apsidally aligned. Fomalhaut b's nominal space velocity does not bear this out, but the astrometric uncertainties are difficult to quantify. Even if the apsidal misalignment proves real, our calculated upper mass limit of 3 M(sub J) still

  8. The SOPHIE search for northern extrasolar planets. V. Follow-up of ELODIE candidates: Jupiter-analogs around Sun-like stars

    NASA Astrophysics Data System (ADS)

    Boisse, I.; Pepe, F.; Perrier, C.; Queloz, D.; Bonfils, X.; Bouchy, F.; Santos, N. C.; Arnold, L.; Beuzit, J.-L.; Díaz, R. F.; Delfosse, X.; Eggenberger, A.; Ehrenreich, D.; Forveille, T.; Hébrard, G.; Lagrange, A.-M.; Lovis, C.; Mayor, M.; Moutou, C.; Naef, D.; Santerne, A.; Ségransan, D.; Sivan, J.-P.; Udry, S.

    2012-09-01

    We present radial-velocity measurements obtained in one of a number of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Haute-Provence Observatory. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years. Two new Jupiter-analog candidates are reported to orbit the bright stars HD 150706 and HD 222155 in 16.1 yr and 10.9 yr at 6.7-1.4+4.0 AU and 5.1-0.7+0.6 AU, and to have minimum masses of 2.71-0.66+1.14 MJup and 1.90-0.53+0.67 MJup, respectively. Using the measurements from ELODIE and SOPHIE, we refine the parameters of the long-period planets HD 154345b and HD 89307b, and publish the first reliable orbit for HD 24040b. This last companion has a minimum mass of 4.01 ± 0.49 MJup orbiting its star in 10.0 yr at 4.92 ± 0.38 AU. Moreover, the data provide evidence of a third bound object in the HD 24040 system. With a surrounding dust debris disk, HD 150706 is an active G0 dwarf for which we partially corrected the effect of the stellar spot on the SOPHIE radial-velocities. In contrast, HD 222155 is an inactive G2V star. In the SOPHIE measurements, an instrumental effect could be characterized and partly corrected. On the basis of the previous findings of Lovis and collaborators and since no significant correlation between the radial-velocity variations and the activity index are found in the SOPHIE data, these variations are not expected to be only due to stellar magnetic cycles. Finally, we discuss the main properties of this new population of long-period Jupiter-mass planets, which for the moment consists of fewer than 20 candidates. These stars are preferential targets either for direct-imaging or astrometry follow-up surveys to constrain the system parameters and for higher-precision radial-velocity searches for lower mass planets, aiming to find a solar system twin

  9. Interior Structure and Evolution of the Planets

    NASA Astrophysics Data System (ADS)

    Hubbard, W. B.

    Basic Concepts Presumed initial composition Comparison with stellar structure Structure of Cold Bodies T=O thermodynamics The P--> infinity limit (white dwarfs) Finite pressure theories Experimental data at high pressure The radius-mass diagram Heat Flow Review of data The Kelvin mechanism Differentiation Radioactivity Tidal Heating Other Diagnostics of Interior Structure Response to rotation Tidal response Magnetic field The Terrestrial Planets The earth and the moon Mercury Venus Mars Summary The Jovian Planets Jupiter A fundamental solar composition reference? Thermal structure and heat flow Evolution of Jupiter Saturn Differences with Jupiter Heat flow Uranus and Neptune Key differences with Jupiter and with each other Thermal structure and heat flow Jovian Planet Satellites Io's heat flow and its relation to Jupiter's structure The Galilean satellites and their relation to Jupiter's origin Conclusion References

  10. Forecaster: Mass and radii of planets predictor

    NASA Astrophysics Data System (ADS)

    Chen, Jingjing; Kipping, David

    2017-01-01

    Forecaster predicts the mass (or radius) from the radius (or mass) for objects covering nine orders-of-magnitude in mass. It is an unbiased forecasting model built upon a probabilistic mass-radius relation conditioned on a sample of 316 well-constrained objects. It accounts for observational errors, hyper-parameter uncertainties and the intrinsic dispersions observed in the calibration sample.

  11. Kepler Planet Masses and Eccentricities from Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Hadden, Sam; Lithwick, Yoram

    2017-01-01

    The Kepler mission’s census of transiting exoplanets has shown that planets between one and four times the radius of Earth with short orbital periods are extremely common. Given their small sizes, the properties of these planets can be difficult or impossible to constrain via radial velocity observations. Mutual gravitational interactions in multi-planet systems induce variations in the arrival times of planets’ transits. These variations can used to probe planets’ masses and eccentricities, which in turn constrain their compositions and formation histories. I will discuss the results of our analysis of the transit timing variations (TTVs) of 145 Kepler planets from 55 multi-planet systems. Bulk densities inferred from TTVs imply that many of these planets are covered in gaseous envelopes ranging from a few percent to ~20% of their total mass. Eccentricities in these systems are small but in a many instances definitively non-zero. These results support theoretical predictions for super-Earth/sub-Neptune planets accreting their envelopes from a depleting proto-planetary disk.

  12. An Earth-mass planet orbiting α Centauri B.

    PubMed

    Dumusque, Xavier; Pepe, Francesco; Lovis, Christophe; Ségransan, Damien; Sahlmann, Johannes; Benz, Willy; Bouchy, François; Mayor, Michel; Queloz, Didier; Santos, Nuno; Udry, Stéphane

    2012-11-08

    Exoplanets down to the size of Earth have been found, but not in the habitable zone--that is, at a distance from the parent star at which water, if present, would be liquid. There are planets in the habitable zone of stars cooler than our Sun, but for reasons such as tidal locking and strong stellar activity, they are unlikely to harbour water-carbon life as we know it. The detection of a habitable Earth-mass planet orbiting a star similar to our Sun is extremely difficult, because such a signal is overwhelmed by stellar perturbations. Here we report the detection of an Earth-mass planet orbiting our neighbour star α Centauri B, a member of the closest stellar system to the Sun. The planet has an orbital period of 3.236 days and is about 0.04 astronomical units from the star (one astronomical unit is the Earth-Sun distance).

  13. Terrestrial planets and water delivery around low-mass stars

    NASA Astrophysics Data System (ADS)

    Dugaro, A.; de Elía, G. C.; Brunini, A.; Guilera, O. M.

    2016-11-01

    Context. Theoretical and observational studies suggest that protoplanetary disks with a wide range of masses could be found around low-mass stars. Aims: We analyze planetary formation processes in systems without gas giants around M3- and M0-type stars of 0.29 M⊙ and 0.5 M⊙, respectively. In particular, we assume disks with masses of 5% and 10% of the mass of the star. Our study focuses on the formation of terrestrial-like planets and water delivery in the habitable zone (HZ). Methods: First, we use a semi-analytical model to describe the evolution of embryos and planetesimals during the gaseous phase. Then, a N-body code is used to analyze the last giant impact phase after the gas dissipation. Results: For M3-type stars, five planets with different properties are formed in the HZ. These planets have masses of 0.072 M⊕, 0.13 M⊕ (two of them), and 1.03 M⊕, and have water contents of 5.9%, 16.7%, 28.6%, and 60.6% by mass, respectively. Then, the fifth planet formed in the HZ is a dry world with 0.138 M⊕. For M0-type stars, four planets are produced in the HZ with masses of 0.28 M⊕, 0.51 M⊕, 0.72 M⊕, and 1.42 M⊕, and they have water contents of 26.7%, 45.8%, 68%, and 50.5% by mass, respectively. Conclusions: M3- and M0-type stars represent targets of interest for the search of exoplanets in the HZ. In fact, the Mars-mass planets formed around M3-type stars could maintain habitable conditions in their early histories. Thus, the search for candidates around young M3-type stars could lead to the detection of planets analogous to early Mars. Moreover, Earth-mass planets should also be discovered around M3-type stars and, sub- and super-Earths should be detected around M0-type stars. Such planets are very interesting since they could maintain habitable conditions for very long.

  14. A PRELIMINARY JUPITER MODEL

    SciTech Connect

    Hubbard, W. B.; Militzer, B.

    2016-03-20

    In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine results from ab initio computer simulations of hydrogen–helium mixtures, including immiscibility calculations, with a new nonperturbative calculation of Jupiter's zonal harmonic coefficients, to derive a self-consistent model for the planet's external gravity and moment of inertia. We assume helium rain modified the interior temperature and composition profiles. Our calculation predicts zonal harmonic values to which measurements can be compared. Although some models fit the observed (pre-Juno) second- and fourth-order zonal harmonics to within their error bars, our preferred reference model predicts a fourth-order zonal harmonic whose absolute value lies above the pre-Juno error bars. This model has a dense core of about 12 Earth masses and a hydrogen–helium-rich envelope with approximately three times solar metallicity.

  15. Exploring the Relationship Between Planet Mass and Atmospheric Metallicity for Cool Giant Planets

    NASA Astrophysics Data System (ADS)

    Thomas, Nancy H.; Wong, Ian; Knutson, Heather; Deming, Drake; Desert, Jean-Michel; Fortney, Jonathan J.; Morley, Caroline; Kammer, Joshua A.; Line, Michael R.

    2016-10-01

    Measurements of the average densities of exoplanets have begun to help constrain their bulk compositions and to provide insight into their formation locations and accretionary histories. Current mass and radius measurements suggest an inverse relationship between a planet's bulk metallicity and its mass, a relationship also seen in the gas and ice giant planets of our own solar system. We expect atmospheric metallicity to similarly increase with decreasing planet mass, but there are currently few constraints on the atmospheric metallicities of extrasolar giant planets. For hydrogen-dominated atmospheres, equilibrium chemistry models predict a transition from CO to CH4 below ~1200 K. However, with increased atmospheric metallicity the relative abundance of CH4 is depleted and CO is enhanced. In this study we present new secondary eclipse observations of a set of cool (<1200 K) giant exoplanets at 3.6 and 4.5 microns using the Spitzer Space Telescope, which allow us to constrain their relative abundances of CH4 and CO and corresponding atmospheric metallicities. We discuss the implications of our results for the proposed correlation between planet mass and atmospheric metallicity as predicted by the core accretion models and observed in our solar system.

  16. What is the Mass of a Gap-opening Planet?

    NASA Astrophysics Data System (ADS)

    Dong, Ruobing; Fung, Jeffrey

    2017-02-01

    High-contrast imaging instruments such as GPI and SPHERE are discovering gap structures in protoplanetary disks at an ever faster pace. Some of these gaps may be opened by planets forming in the disks. In order to constrain planet formation models using disk observations, it is crucial to find a robust way to quantitatively back out the properties of the gap-opening planets, in particular their masses, from the observed gap properties, such as their depths and widths. Combining 2D and 3D hydrodynamics simulations with 3D radiative transfer simulations, we investigate the morphology of planet-opened gaps in near-infrared scattered-light images. Quantitatively, we obtain correlations that directly link intrinsic gap depths and widths in the gas surface density to observed depths and widths in images of disks at modest inclinations under finite angular resolution. Subsequently, the properties of the surface density gaps enable us to derive the disk scale height at the location of the gap h, and to constrain the quantity Mp2/α, where Mp is the mass of the gap-opening planet and α characterizes the viscosity in the gap. As examples, we examine the gaps recently imaged by VLT/SPHERE, Gemini/GPI, and Subaru/HiCIAO in HD 97048, TW Hya, HD 169142, LkCa 15, and RX J1615.3-3255. Scale heights of the disks and possible masses of the gap-opening planets are derived assuming each gap is opened by a single planet. Assuming α = 10‑3, the derived planet masses in all cases are roughly between 0.1 and 1 MJ.

  17. Terrestrial Planet Formation around Low-Mass Stars: Effect of the Mass of Central Stars

    NASA Astrophysics Data System (ADS)

    Oshino, Shoichi; Matsumoto, Yuji; Kokubo, Eiichiro

    2015-12-01

    The Kepler space telescope has detected several thousand planets and candidates.Their central stars are mainly FGK-type stars.It is difficult to observe M-stars by using visible light since M-stars have their peak radiation in the infrared region.However, recently there are several survey projects for planets around M-stars such as the InfraRed Doppler (IRD) survey of the Subaru telescope.Therefore it is expected that the number of planets around M-stars will increase in the near future.The habitable zone of M-stars is closer to the stars than that of G-stars.For this reason, the possibility of finding habitable planets is expected to be higher.Here we study the formation of close-in terrestrial planets by giant impacts of protoplanets around low-mass stars by using N-body simulations.An important parameter that controls formation processes is the ratio between the physical radius of a planet and its Hill radius, which decreases with the stellar mass.We systematically change the mass of the central stars and investigate its effects on terrestrial planet formation.We find that the mass of the maximum planet decreases with the mass of central stars, while the number of planets in the system increases.We also find that the orbital separation of adjacent planets normalized by their Hill radius increases with the stellar mass.

  18. An extrasolar planetary system with three Neptune-mass planets.

    PubMed

    Lovis, Christophe; Mayor, Michel; Pepe, Francesco; Alibert, Yann; Benz, Willy; Bouchy, François; Correia, Alexandre C M; Laskar, Jacques; Mordasini, Christoph; Queloz, Didier; Santos, Nuno C; Udry, Stéphane; Bertaux, Jean-Loup; Sivan, Jean-Pierre

    2006-05-18

    Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

  19. The Photoeccentric Effect and Proto-hot Jupiters. II. KOI-1474.01, a Candidate Eccentric Planet Perturbed by an Unseen Companion

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, John Asher; Morton, Timothy D.; Crepp, Justin R.; Fabrycky, Daniel C.; Murray-Clay, Ruth A.; Howard, Andrew W.

    2012-12-01

    The exoplanets known as hot Jupiters—Jupiter-sized planets with periods of less than 10 days—likely are relics of dynamical processes that shape all planetary system architectures. Socrates et al. argued that high eccentricity migration (HEM) mechanisms proposed for situating these close-in planets should produce an observable population of highly eccentric proto-hot Jupiters that have not yet tidally circularized. HEM should also create failed-hot Jupiters, with periapses just beyond the influence of fast circularization. Using the technique we previously presented for measuring eccentricities from photometry (the "photoeccentric effect"), we are distilling a collection of eccentric proto- and failed-hot Jupiters from the Kepler Objects of Interest (KOI). Here, we present the first, KOI-1474.01, which has a long orbital period (69.7340 days) and a large eccentricity e = 0.81+0.10 -0.07, skirting the proto-hot Jupiter boundary. Combining Kepler photometry, ground-based spectroscopy, and stellar evolution models, we characterize host KOI-1474 as a rapidly rotating F star. Statistical arguments reveal that the transiting candidate has a low false-positive probability of 3.1%. KOI-1474.01 also exhibits transit-timing variations of the order of an hour. We explore characteristics of the third-body perturber, which is possibly the "smoking-gun" cause of KOI-1474.01's large eccentricity. We use the host star's period, radius, and projected rotational velocity to measure the inclination of the stellar spin. Comparing KOI 1474.01's inclination, we find that its orbit is marginally consistent with being aligned with the stellar spin axis, although a reanalysis is warranted with future additional data. Finally, we discuss how the number and existence of proto-hot Jupiters will not only demonstrate that hot Jupiters migrate via HEM, but also shed light on the typical timescale for the mechanism.

  20. INFLATING AND DEFLATING HOT JUPITERS: COUPLED TIDAL AND THERMAL EVOLUTION OF KNOWN TRANSITING PLANETS

    SciTech Connect

    Miller, N.; Fortney, J. J.; Jackson, B. E-mail: jfortney@ucolick.org

    2009-09-10

    We examine the radius evolution of close in giant planets with a planet evolution model that couples the orbital-tidal and thermal evolution. For 45 transiting systems, we compute a large grid of cooling/contraction paths forward in time, starting from a large phase space of initial semimajor axes and eccentricities. Given observational constraints at the current time for a given planet (semimajor axis, eccentricity, and system age), we find possible evolutionary paths that match these constraints, and compare the calculated radii to observations. We find that tidal evolution has two effects. First, planets start their evolution at larger semimajor axis, allowing them to contract more efficiently at earlier times. Second, tidal heating can significantly inflate the radius when the orbit is being circularized, but this effect on the radius is short-lived thereafter. Often circularization of the orbit is proceeded by a long period while the semimajor axis slowly decreases. Some systems with previously unexplained large radii that we can reproduce with our coupled model are HAT-P-7, HAT-P-9, WASP-10, and XO-4. This increases the number of planets for which we can match the radius from 24 (of 45) to as many as 35 for our standard case, but for some of these systems we are required to be viewing them at a special time around the era of current radius inflation. This is a concern for the viability of tidal inflation as a general mechanism to explain most inflated radii. Also, large initial eccentricities would have to be common. We also investigate the evolution of models that have a floor on the eccentricity, as may be due to a perturber. In this scenario, we match the extremely large radius of WASP-12b. This work may cast some doubt on our ability to accurately determine the interior heavy element enrichment of normal, noninflated close in planets, because of our dearth of knowledge about these planets' previous orbital-tidal histories. Finally, we find that the end

  1. Inflating and Deflating Hot Jupiters: Coupled Tidal and Thermal Evolution of Known Transiting Planets

    NASA Astrophysics Data System (ADS)

    Miller, N.; Fortney, J. J.; Jackson, B.

    2009-09-01

    We examine the radius evolution of close in giant planets with a planet evolution model that couples the orbital-tidal and thermal evolution. For 45 transiting systems, we compute a large grid of cooling/contraction paths forward in time, starting from a large phase space of initial semimajor axes and eccentricities. Given observational constraints at the current time for a given planet (semimajor axis, eccentricity, and system age), we find possible evolutionary paths that match these constraints, and compare the calculated radii to observations. We find that tidal evolution has two effects. First, planets start their evolution at larger semimajor axis, allowing them to contract more efficiently at earlier times. Second, tidal heating can significantly inflate the radius when the orbit is being circularized, but this effect on the radius is short-lived thereafter. Often circularization of the orbit is proceeded by a long period while the semimajor axis slowly decreases. Some systems with previously unexplained large radii that we can reproduce with our coupled model are HAT-P-7, HAT-P-9, WASP-10, and XO-4. This increases the number of planets for which we can match the radius from 24 (of 45) to as many as 35 for our standard case, but for some of these systems we are required to be viewing them at a special time around the era of current radius inflation. This is a concern for the viability of tidal inflation as a general mechanism to explain most inflated radii. Also, large initial eccentricities would have to be common. We also investigate the evolution of models that have a floor on the eccentricity, as may be due to a perturber. In this scenario, we match the extremely large radius of WASP-12b. This work may cast some doubt on our ability to accurately determine the interior heavy element enrichment of normal, noninflated close in planets, because of our dearth of knowledge about these planets' previous orbital-tidal histories. Finally, we find that the end

  2. On the Minimum Core Mass for Giant Planet Formation

    NASA Astrophysics Data System (ADS)

    Piso, Ana-Maria; Youdin, Andrew; Murray-Clay, Ruth

    2013-07-01

    The core accretion model proposes that giant planets form by the accretion of gas onto a solid protoplanetary core. Previous studies have found that there exists a "critical core mass" past which hydrostatic solutions can no longer be found and unstable atmosphere collapse occurs. This core mass is typically quoted to be around 10Me. In standard calculations of the critical core mass, planetesimal accretion deposits enough heat to alter the luminosity of the atmosphere, increasing the core mass required for the atmosphere to collapse. In this study we consider the limiting case in which planetesimal accretion is negligible and Kelvin-Helmholtz contraction dominates the luminosity evolution of the planet. We develop a two-layer atmosphere model with an inner convective region and an outer radiative zone that matches onto the protoplanetary disk, and we determine the minimum core mass for a giant planet to form within the typical disk lifetime for a variety of disk conditions. We denote this mass as critical core mass. The absolute minimum core mass required to nucleate atmosphere collapse is ˜ 8Me at 5 AU and steadily decreases to ˜ 3.5Me at 100 AU, for an ideal diatomic gas with a solar composition and a standard ISM opacity law. Lower opacity and disk temperature significantly reduce the critical core mass, while a decrease in the mean molecular weight of the nebular gas results in a larger critical core mass. Our results yield lower mass cores than corresponding studies for large planetesimal accretion rates.

  3. AB INITIO EQUATION OF STATE FOR HYDROGEN-HELIUM MIXTURES WITH RECALIBRATION OF THE GIANT-PLANET MASS-RADIUS RELATION

    SciTech Connect

    Militzer, B.; Hubbard, W. B.

    2013-09-10

    Using density functional molecular dynamics simulations, we determine the equation of state (EOS) for hydrogen-helium mixtures spanning density-temperature conditions typical of giant-planet interiors, {approx}0.2-9 g cm{sup -3} and 1000-80,000 K for a typical helium mass fraction of 0.245. In addition to computing internal energy and pressure, we determine the entropy using an ab initio thermodynamic integration technique. A comprehensive EOS table with 391 density-temperature points is constructed and the results are presented in the form of a two-dimensional free energy fit for interpolation. Deviations between our ab initio EOS and the semi-analytical EOS model by Saumon and Chabrier are analyzed in detail, and we use the results for initial revision of the inferred thermal state of giant planets with known values for mass and radius. Changes are most pronounced for planets in the Jupiter mass range and below. We present a revision to the mass-radius relationship that makes the hottest exoplanets increase in radius by {approx}0.2 Jupiter radii at fixed entropy and for masses greater than {approx}0.5 Jupiter mass. This change is large enough to have possible implications for some discrepant ''inflated giant exoplanets''.

  4. The first planet detected in the WTS: an inflated hot Jupiter in a 3.35 d orbit around a late F star

    NASA Astrophysics Data System (ADS)

    Cappetta, M.; Saglia, R. P.; Birkby, J. L.; Koppenhoefer, J.; Pinfield, D. J.; Hodgkin, S. T.; Cruz, P.; Kovács, G.; Sipőcz, B.; Barrado, D.; Nefs, B.; Pavlenko, Y. V.; Fossati, L.; del Burgo, C.; Martín, E. L.; Snellen, I.; Barnes, J.; Bayo, A.; Campbell, D. A.; Catalan, S.; Gálvez-Ortiz, M. C.; Goulding, N.; Haswell, C.; Ivanyuk, O.; Jones, H. R.; Kuznetsov, M.; Lodieu, N.; Marocco, F.; Mislis, D.; Murgas, F.; Napiwotzki, R.; Palle, E.; Pollacco, D.; Sarro Baro, L.; Solano, E.; Steele, P.; Stoev, H.; Tata, R.; Zendejas, J.

    2012-12-01

    We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope (UKIRT) in 2007 August. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J ˜ 16 were constructed for ˜60 000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main-sequence dwarf (V = 16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 d, a planetary mass of 4.01 ± 0.35 MJ and a planetary radius of 1.49-0.18+0.16 RJ. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 MJ. The high irradiation from the host star ranks the planet in the pM class. Based on observations collected at the 3.8-m United Kingdom Infrared Telescope (Hawaii, USA), the Hobby-Eberly Telescope (Texas, USA), the 2.5-m Isaac Newton Telescope (La Palma, Spain), the William Herschel Telescope (La Palma, Spain), the German-Spanish Astronomical Centre (Calar Alto, Spain), the Kitt Peak National Observatory (Arizona, USA) and the Hertfordshire's Bayfordbury Observatory.

  5. Probing Clouds in Planets with a Simple Radiative Transfer Model: The Jupiter Case

    ERIC Educational Resources Information Center

    Mendikoa, Inigo; Perez-Hoyos, Santiago; Sanchez-Lavega, Agustin

    2012-01-01

    Remote sensing of planets evokes using expensive on-orbit satellites and gathering complex data from space. However, the basic properties of clouds in planetary atmospheres can be successfully estimated with small telescopes even from an urban environment using currently available and affordable technology. This makes the process accessible for…

  6. OGLE-2016-BLG-0596Lb: A High-mass Planet from a High-magnification Pure-survey Microlensing Event

    NASA Astrophysics Data System (ADS)

    Mróz, P.; Han, C.; and; Udalski, A.; Poleski, R.; Skowron, J.; Szymański, M. K.; Soszyński, I.; Pietrukowicz, P.; Kozłowski, S.; Ulaczyk, K.; Wyrzykowski, Ł.; Pawlak, M.; OGLE group; Albrow, M. D.; Cha, S.-M.; Chung, S.-J.; Jung, Y. K.; Kim, D.-J.; Kim, S.-L.; Lee, C.-U.; Lee, Y.; Park, B.-G.; Pogge, R. W.; Ryu, Y.-H.; Shin, I.-G.; Yee, J. C.; Zhu, W.; Gould, A.; (KMTNet group

    2017-04-01

    We report the discovery of a high mass ratio planet, q = 0.012, i.e., 13 times higher than the Jupiter/Sun ratio. The host mass has not yet been measured but can be determined or strongly constrained from adaptive optics imaging. The planet was discovered in a small archival study of high-magnification events in pure-survey microlensing data, which was unbiased by the presence of anomalies. The fact that it was previously unnoticed may indicate that more such planets lie in archival data and could be discovered by a similar systematic study. In order to understand the transition from predominantly survey+followup to predominately survey-only planet detections, we conduct the first analysis of these detections in the observational (s, q) plane. Here s is the projected separation in units of the Einstein radius. We find some evidence that survey+followup is relatively more sensitive to planets near the Einstein ring, but that there is no statistical difference in sensitivity by mass ratio.

  7. Terrestrial planets in high-mass disks without gas giants

    NASA Astrophysics Data System (ADS)

    de Elía, G. C.; Guilera, O. M.; Brunini, A.

    2013-09-01

    Context. Observational and theoretical studies suggest that planetary systems consisting only of rocky planets are probably the most common in the Universe. Aims: We study the potential habitability of planets formed in high-mass disks without gas giants around solar-type stars. These systems are interesting because they are likely to harbor super-Earths or Neptune-mass planets on wide orbits, which one should be able to detect with the microlensing technique. Methods: First, a semi-analytical model was used to define the mass of the protoplanetary disks that produce Earth-like planets, super-Earths, or mini-Neptunes, but not gas giants. Using mean values for the parameters that describe a disk and its evolution, we infer that disks with masses lower than 0.15 M⊙ are unable to form gas giants. Then, that semi-analytical model was used to describe the evolution of embryos and planetesimals during the gaseous phase for a given disk. Thus, initial conditions were obtained to perform N-body simulations of planetary accretion. We studied disks of 0.1, 0.125, and 0.15 M⊙. Results: All our simulations form massive planets on wide orbits. For a 0.1 M⊙ disk, 2-3 super-Earths of 2.8 to 5.9 M⊕ are formed between 2 and 5 AU. For disks of 0.125 and 0.15 M⊙, our simulations produce a 10-17.1 M⊕ planet between 1.6 and 2.7 AU, and other super-Earths are formed in outer regions. Moreover, six planets survive in the habitable zone (HZ). These planets have masses from 1.9 to 4.7 M⊕ and significant water contents ranging from 560 to 7482 Earth oceans, where one Earth ocean represents the amount of water on Earth's surface, which equals 2.8 × 10-4M⊕. Of the six planets formed in the HZ, three are water worlds with 39%-44% water by mass. These planets start the simulations beyond the snow line, which explains their high water abundances. In general terms, the smaller the mass of the planets observed on wide orbits, the higher the possibility to find water worlds in the

  8. 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.

  9. Fast migration of low-mass planets in radiative discs

    NASA Astrophysics Data System (ADS)

    Pierens, A.

    2015-12-01

    Low-mass planets are known to undergo Type I migration and this process must have played a key role during the evolution of planetary systems. Analytical formulae for the disc torque have been derived assuming that the planet evolves on a fixed circular orbit. However, recent work has shown that in isothermal discs, a migrating protoplanet may also experience dynamical corotation torques that scale with the planet drift rate. The aim of this study is to examine whether dynamical corotation torques can also affect the migration of low-mass planets in non-isothermal discs. We performed 2D radiative hydrodynamical simulations to examine the orbital evolution outcome of migrating protoplanets as a function of disc mass. We find that a protoplanet can enter a fast migration regime when it migrates in the direction set by the entropy-related horseshoe drag and when the Toomre stability parameter is less than a threshold value below which the horseshoe region contracts into a tadpole-like region. In that case, an underdense trapped region appears near the planet, with an entropy excess compared to the ambient disc. If the viscosity and thermal diffusivity are small enough so that the entropy excess is conserved during migration, the planet then experiences strong corotation torques arising from the material flowing across the planet orbit. During fast migration, we observe that a protoplanet can pass through the zero-torque line predicted by static torques. We also find that fast migration may help in disrupting the mean-motion resonances that are formed by convergent migration of embryos.

  10. Types of Hot Jupiter Atmospheres

    NASA Astrophysics Data System (ADS)

    Bisikalo, Dmitry V.; Kaygorodov, Pavel V.; Ionov, Dmitry E.; Shematovich, Valery I.

    Hot Jupiters, i.e. exoplanet gas giants, having masses comparable to the mass of Jupiter and semimajor axes shorter than 0.1 AU, are a unique class of objects. Since they are so close to the host stars, their atmospheres form and evolve under the action of very active gas dynamical processes caused by the gravitational field and irradiation of the host star. As a matter of fact, the atmospheres of several of these planets fill their Roche lobes , which results in a powerful outflow of material from the planet towards the host star. The energy budget of this process is so important that it almost solely governs the evolution of hot Jupiters gaseous envelopes. Based on the years of experience in the simulations of gas dynamics in mass-exchanging close binary stars, we have investigated specific features of hot Jupiters atmospheres. The analytical estimates and results of 3D numerical simulations, discussed in this Chapter, show that the gaseous envelopes around hot Jupiters may be significantly non-spherical and, at the same time, stationary and long-lived. These results are of fundamental importance for the interpretation of observational data.

  11. Masses, Radii, and Cloud Properties of the HR 8799 Planets

    NASA Technical Reports Server (NTRS)

    Marley, Mark S.; Saumon, Didier; Cushing, Michael; Ackerman, Andrew S.; Fortney, Jonathan J.; Freedman, Richard

    2012-01-01

    The near-infrared colors of the planets directly imaged around the A star HR 8799 are much redder than most field brown dwarfs of the same effective temperature. Previous theoretical studies of these objects have compared the photometric and limited spectral data of the planets to the predictions of various atmosphere and evolution models and concluded that the atmospheres of planets b, c, and d are unusually cloudy or have unusual cloud properties. Most studies have also found that the inferred radii of some or all of the planets disagree with expectations of standard giant planet evolution models. Here we compare the available data to the predictions of our own set of atmospheric and evolution models that have been extensively tested against field L and T dwarfs, including the reddest L dwarfs. Unlike almost all previous studies we specify mutually self-consistent choices for effective temperature, gravity, cloud properties, and planetary radius. This procedure yields plausible and self-consistent values for the masses, effective temperatures, and cloud properties of all three planets. We find that the cloud properties of the HR 8799 planets are in fact not unusual but rather follow previously recognized trends including a gravity dependence on the temperature of the L to T spectral transition, some reasons for which we discuss. We find that the inferred mass of planet b is highly sensitive to the H and K band spectrum. Solutions for planets c and particularly d are less certain but are consistent with the generally accepted constraints on the age of the primary star and orbital dynamics. We also confirm that as for L and T dwarfs and solar system giant planets, non-equilibrium chemistry driven by atmospheric mixing is also important for these objects. Given the preponderance of data suggesting that the L to T spectral type transition is gravity dependent, we present a new evolution calculation that predicts cooling tracks on the near-infrared color

  12. THE DEUTERIUM-BURNING MASS LIMIT FOR BROWN DWARFS AND GIANT PLANETS

    SciTech Connect

    Spiegel, David S.; Burrows, Adam; Milsom, John A. E-mail: burrows@astro.princeton.edu

    2011-01-20

    There is no universally acknowledged criterion to distinguish brown dwarfs from planets. Numerous studies have used or suggested a definition based on an object's mass, taking the {approx}13 Jupiter mass (M{sub J} ) limit for the ignition of deuterium. Here, we investigate various deuterium-burning masses for a range of models. We find that, while 13 M{sub J} is generally a reasonable rule of thumb, the deuterium fusion mass depends on the helium abundance, the initial deuterium abundance, the metallicity of the model, and on what fraction of an object's initial deuterium abundance must combust in order for the object to qualify as having burned deuterium. Even though, for most proto-brown dwarf conditions, 50% of the initial deuterium will burn if the object's mass is {approx}(13.0 {+-} 0.8) M{sub J} , the full range of possibilities is significantly broader. For models ranging from zero-metallicity to more than three times solar metallicity, the deuterium-burning mass ranges from {approx}11.0 M{sub J} (for three times solar metallicity, 10% of initial deuterium burned) to {approx}16.3 M{sub J} ( for zero metallicity, 90% of initial deuterium burned).

  13. Discovery and Mass Measurements of a Cold, 10-Earth Mass Planet and Its Host Star

    NASA Technical Reports Server (NTRS)

    Barry, Richard K.; Muraki, Y.; Han, C.; Bennett, D. P.; Gaudi, B. S.

    2011-01-01

    We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method. This planet has a mass of mp = 10.4 +/- M(Earth) and orbits a star of Mstar = 0.56 +/- 0.09 M(Sun) at a semi-major axis of a = 3.2 + 1.9/-0.5 AU, and an orbital period of 7.6 +7.7/-1.5 yrs. The planet and host star mass measurements are due to the measurement of the microlensing parallax effect. This measurement was primarily due to the orbital motion of the Earth, but the analysis also demonstrates the capability measure micro lensing parallax with the Deep Impact (or EPOXI) spacecraft in a Heliocentric orbit. The planet mass and orbital distance are similar to predictions for the critical core mass needed to accrete a substantial gaseous envelope, and thus may indicate that this planet is a failed gas giant. This and future microlensing detections will test planet formation theory predictions regarding the prevalence and masses of such planets

  14. Discovery and Mass Measurements of a Cold, Sub-Neptune Mass Planet and Its Host Star

    NASA Technical Reports Server (NTRS)

    Barry, Richard K., Jr.

    2011-01-01

    The gravitational microlensing exoplanet detection method is uniquely sensitive to cold, low-mass planets which orbit beyond the snow-line, where the most massive planets are thought to form. The early statistical results from microlensing indicate that Neptune-Saturn mass planets located beyond the snow-line are substantially more common than their counterparts in closer orbits that have found by the Doppler radial velocity method. We present the discovery of the planet MOA-2009-BLG-266Lb, which demonstrates that the gravitational microlensing method also has the capability to measure the masses of cold, low-mass planets. The mass measurements of the host star and the planet are made possible by the detection of the microlensing parallax signal due to the orbital motion or the Earth as well as observations from the EPOXI spacecraft in a Heliocentric orbit. The microlensing light curve indicates a planetary host star mass of M(sun) = 0.54 + / - 0.05M(sun) located at a distance of DL= 2.94 _ 0.21 kpc, orbited by a planet of mass mp= 9.8 +/-1.1M(Earth) with a semi-major axis of a = 3.1(+1.9-0.4)MAU.

  15. OGLE-2012-BLG-0563Lb: A Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO Imaging

    NASA Astrophysics Data System (ADS)

    Fukui, A.; Gould, 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.; Bhattacharya, A.; 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.; MOA Collaboration; 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.; μFUN Collaboration; Szymański, M. K.; Pietrzyński, G.; Soszyński, I.; Poleski, R.; Kozłowski, S.; Pietrukowicz, P.; Ulaczyk, K.; Wyrzykowski, Ł.; OGLE Collaboration; Bramich, D. M.; Browne, P.; Dominik, M.; Horne, K.; Ipatov, S.; Kains, N.; Snodgrass, C.; Steele, I. A.; RoboNet Collaboration

    2015-08-01

    We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio of ˜ 1× {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 Infrared Camera and Spectrograph instruments, allowing us to constrain the absolute physical parameters of the planetary system. With the help of spectroscopic information about the source star obtained during the high-magnification state by Bensby et al., we find that the lens system is located at 1.3{}-0.8+0.6 kpc from us, and consists of an M dwarf (0.34 {}-0.20+0.12M{}⊙ ) orbited by a Saturn-mass planet (0.39 {}-0.23+0.14MJup) at the projected separation of 0.74{}-0.42+0.26 AU (close model) or 4.3{}-2.5+1.5 AU (wide model). The probability of contamination in the host star’s flux, which would reduce the masses by a factor of up to three, is estimated to be 17%. This possibility can be tested by future high-resolution imaging. We also estimate the (J-{K}{{s}}) and (H-{K}{{s}}) colors of the host star, which are marginally consistent with a low metallicity mid-to-early M dwarf, although further observations are required for the metallicity to be conclusive. This is the fifth sub-Jupiter-mass (0.2\\lt {m}{{p}}/{M}{Jup}\\lt 1) microlensing planet around an M dwarf with the mass well constrained. The relatively rich harvest of sub-Jupiters around M dwarfs is contrasted with a possible paucity of ˜1-2 Jupiter-mass planets around the same type of star, which can be explained by the planetary formation process in the core-accretion scheme.

  16. [Extrasolar terrestrial planets and possibility of extraterrestrial life].

    PubMed

    Ida, Shigeru

    2003-12-01

    Recent development of research on extrasolar planets are reviewed. About 120 extrasolar Jupiter-mass planets have been discovered through the observation of Doppler shift in the light of their host stars that is caused by acceleration due to planet orbital motions. Although the extrasolar planets so far observed may be limited to gas giant planets and their orbits differ from those of giant planets in our Solar system (Jupiter and Saturn), the theoretically predicted probability of existence of extrasolar terrestrial planets that can have liquid water ocean on their surface is comparable to that of detectable gas giant planets. Based on the number of extrasolar gas giants detected so far, about 100 life-sustainable planets may exist within a range of 200 light years. Indirect observation of extrasolar terrestrial planets would be done with space telescopes within several years and direct one may be done within 20 years. The latter can detect biomarkers on these planets as well.

  17. The Structural and Thermal Evolution of Transiting Exoplanets: From Hot Jupiters to Kepler's Super Earths

    SciTech Connect

    Fortney, Jonathan

    2011-06-11

    Large numbers of exoplanets can now be seen to transit their parent stars, which allows for measurements of their radii, masses, and densities. We can now begin to examine the Jupiter-class gas giant planets as a class of astrophysical objects. At the same time, thanks to NASA’s Kepler telescope, the number of transiting planets below 10 Earth masses is now moving beyond just a handful. For the Jupiter-like planets, we model their interior structure and find several interesting properties regarding the amount of ice and rock within these planets, which gives us clues to their formation. For the lowest-mass planets, such as the 6-planet Kepler-11 system, signs point to a large populations of mini-Neptunes---low-mass, low-density planets with hydrogen-dominated atmospheres. The Kepler-11 system may tell us much about the evaporation of the atmospheres of these kinds of planets.

  18. A rocky planet transiting a nearby low-mass star.

    PubMed

    Berta-Thompson, Zachory K; Irwin, Jonathan; Charbonneau, David; Newton, Elisabeth R; Dittmann, Jason A; Astudillo-Defru, Nicola; Bonfils, Xavier; Gillon, Michaël; Jehin, Emmanuël; Stark, Antony A; Stalder, Brian; Bouchy, Francois; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Mayor, Michel; Neves, Vasco; Pepe, Francesco; Santos, Nuno C; Udry, Stéphane; Wünsche, Anaël

    2015-11-12

    M-dwarf stars--hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun--are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the planet is too hot to be habitable but is cool enough to support a substantial atmosphere, one that has probably been considerably depleted of hydrogen. Because the host star is nearby and only 21 per cent the radius of the Sun, existing and upcoming telescopes will be able to observe the composition and dynamics of the planetary atmosphere.

  19. MEASURING THE MASS OF SOLAR SYSTEM PLANETS USING PULSAR TIMING

    SciTech Connect

    Champion, D. J.; Hobbs, G. B.; Manchester, R. N.; Edwards, R. T.; Burke-Spolaor, S.; Sarkissian, J. M.; Backer, D. C.; Bailes, M.; Bhat, N. D. R.; Van Straten, W.; Coles, W.; Demorest, P. B.; Ferdman, R. D.; Purver, M. B.; Folkner, W. M.; Hotan, A. W.; Kramer, M.; Lommen, A. N.; Nice, D. J.; Stairs, I. H.

    2010-09-10

    High-precision pulsar timing relies on a solar system ephemeris in order to convert times of arrival (TOAs) of pulses measured at an observatory to the solar system barycenter. Any error in the conversion to the barycentric TOAs leads to a systematic variation in the observed timing residuals; specifically, an incorrect planetary mass leads to a predominantly sinusoidal variation having a period and phase associated with the planet's orbital motion about the Sun. By using an array of pulsars (PSRs J0437-4715, J1744-1134, J1857+0943, J1909-3744), the masses of the planetary systems from Mercury to Saturn have been determined. These masses are consistent with the best-known masses determined by spacecraft observations, with the mass of the Jovian system, 9.547921(2) x10{sup -4} M {sub sun}, being significantly more accurate than the mass determined from the Pioneer and Voyager spacecraft, and consistent with but less accurate than the value from the Galileo spacecraft. While spacecraft are likely to produce the most accurate measurements for individual solar system bodies, the pulsar technique is sensitive to planetary system masses and has the potential to provide the most accurate values of these masses for some planets.

  20. Interiors of giant planets inside and outside the solar system.

    PubMed

    Guillot, T

    1999-10-01

    An understanding of the structure and composition of the giant planets is rapidly evolving because of (i) high-pressure experiments with the ability to study metallic hydrogen and define the properties of its equation of state and (ii) spectroscopic and in situ measurements made by telescopes and satellites that allow an accurate determination of the chemical composition of the deep atmospheres of the giant planets. However, the total amount of heavy elements that Jupiter, Saturn, Uranus, and Neptune contain remains poorly constrained. The discovery of extrasolar giant planets with masses ranging from that of Saturn to a few times the mass of Jupiter opens up new possibilities for understanding planet composition and formation. Evolutionary models predict that gaseous extrasolar giant planets should have a variety of atmospheric temperatures and chemical compositions, but the radii are estimated to be close to that of Jupiter (between 0.9 and 1.7 Jupiter radii), provided that they contain mostly hydrogen and helium.

  1. The use of transit timing to detect terrestrial-mass extrasolar planets.

    PubMed

    Holman, Matthew J; Murray, Norman W

    2005-02-25

    Future surveys for transiting extrasolar planets are expected to detect hundreds of jovian-mass planets and tens of terrestrial-mass planets. For many of these newly discovered planets, the intervals between successive transits will be measured with an accuracy of 0.1 to 100 minutes. We show that these timing measurements will allow for the detection of additional planets in the system (not necessarily transiting) by their gravitational interaction with the transiting planet. The transit-time variations depend on the mass of the additional planet, and in some cases terrestrial-mass planets will produce a measurable effect. In systems where two planets are seen to transit, the density of both planets can be determined without radial-velocity observations.

  2. ATMOSPHERIC CHEMISTRY IN GIANT PLANETS, BROWN DWARFS, AND LOW-MASS DWARF STARS. III. IRON, MAGNESIUM, AND SILICON

    SciTech Connect

    Visscher, Channon; Lodders, Katharina; Fegley, Bruce E-mail: lodders@wustl.ed

    2010-06-20

    We use thermochemical equilibrium calculations to model iron, magnesium, and silicon chemistry in the atmospheres of giant planets, brown dwarfs, extrasolar giant planets (EGPs), and low-mass stars. The behavior of individual Fe-, Mg-, and Si-bearing gases and condensates is determined as a function of temperature, pressure, and metallicity. Our equilibrium results are thus independent of any particular model atmosphere. The condensation of Fe metal strongly affects iron chemistry by efficiently removing Fe-bearing species from the gas phase. Monatomic Fe is the most abundant Fe-bearing gas throughout the atmospheres of EGPs and L dwarfs, and in the deep atmospheres of giant planets and T dwarfs. Mg- and Si-bearing gases are effectively removed from the atmosphere by forsterite (Mg{sub 2}SiO{sub 4}) and enstatite (MgSiO{sub 3}) cloud formation. Monatomic Mg is the dominant magnesium gas throughout the atmospheres of EGPs and L dwarfs and in the deep atmospheres of giant planets and T dwarfs. Silicon monoxide (SiO) is the most abundant Si-bearing gas in the deep atmospheres of brown dwarfs and EGPs, whereas SiH{sub 4} is dominant in the deep atmosphere of Jupiter and other gas giant planets. Several other Fe-, Mg-, and Si-bearing gases become increasingly important with decreasing effective temperature. In principle, a number of Fe, Mg, and Si gases are potential tracers of weather or diagnostic of temperature in substellar atmospheres.

  3. A lower radius and mass for the transiting extrasolar planet HAT-P-8 b

    NASA Astrophysics Data System (ADS)

    Mancini, L.; Southworth, J.; Ciceri, S.; Fortney, J. J.; Morley, C. V.; Dittmann, J. A.; Tregloan-Reed, J.; Bruni, I.; Barbieri, M.; Evans, D. F.; D'Ago, G.; Nikolov, N.; Henning, Th.

    2013-03-01

    Context. The extrasolar planet HAT-P-8 b was thought to be one of the more inflated transiting hot Jupiters. Aims: By using new and existing photometric data, we computed precise estimates of the physical properties of the system. Methods: We present photometric observations comprising eleven light curves covering six transit events, obtained using five medium-class telescopes and telescope-defocussing technique. One transit was simultaneously obtained through four optical filters, and two transits were followed contemporaneously from two observatories. We modelled these and seven published datasets using the jktebop code. The physical parameters of the system were obtained from these results and from published spectroscopic measurements. In addition, we investigated the theoretically-predicted variation of the apparent planetary radius as a function of wavelength, covering the range 330-960 nm. Results: We find that HAT-P-8 b has a significantly lower radius (1.321 ± 0.037 RJup) and mass (1.275 ± 0.053 MJup) compared to previous estimates (1.50-0.06+0.08 R_{Jup} and 1.52-0.16+0.18 M_{Jup} respectively). We also detect a radius variation in the optical bands that, when compared with synthetic spectra of the planet, may indicate the presence of a strong optical absorber, perhaps TiO and VO gases, near the terminator of HAT-P-8 b. Conclusions: These new results imply that HAT-P-8 b is not significantly inflated, and that its position in the planetary mass-radius diagram is congruent with those of many other transiting extrasolar planets. Full Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A11

  4. Accretion of the gaseous envelope of Jupiter around a 5 10 Earth-mass core

    NASA Astrophysics Data System (ADS)

    Hubickyj, Olenka; Bodenheimer, Peter; Lissauer, Jack J.

    2005-12-01

    New numerical simulations of the formation and evolution of Jupiter are presented. The formation model assumes that first a solid core of several M accretes from the planetesimals in the protoplanetary disk, and then the core captures a massive gaseous envelope from the protoplanetary disk. Earlier studies of the core accretion-gas capture model [Pollack, J.B., Hubickyj, O., Bodenheimer, P., Lissauer, J.J., Podolak, M., Greenzweig, Y., 1996. Icarus 124, 62-85] demonstrated that it was possible for Jupiter to accrete with a solid core of 10-30 M in a total formation time comparable to the observed lifetime of protoplanetary disks. Recent interior models of Jupiter and Saturn that agree with all observational constraints suggest that Jupiter's core mass is 0-11 M and Saturn's is 9-22 M [Saumon, G., Guillot, T., 2004. Astrophys. J. 609, 1170-1180]. We have computed simulations of the growth of Jupiter using various values for the opacity produced by grains in the protoplanet's atmosphere and for the initial planetesimal surface density, σ, in the protoplanetary disk. We also explore the implications of halting the solid accretion at selected core mass values during the protoplanet's growth. Halting planetesimal accretion at low core mass simulates the presence of a competing embryo, and decreasing the atmospheric opacity due to grains emulates the settling and coagulation of grains within the protoplanet's atmosphere. We examine the effects of adjusting these parameters to determine whether or not gas runaway can occur for small mass cores on a reasonable timescale. We compute four series of simulations with the latest version of our code, which contains updated equation of state and opacity tables as well as other improvements. Each series consists of a run without a cutoff in planetesimal accretion, plus up to three runs with a cutoff at a particular core mass. The first series of runs is computed with an atmospheric opacity due to grains (hereafter referred to as

  5. WTS1 b: The first planet detected in the WFCAM Transit Survey. An inflated hot-Jupiter in a 3.35 day orbit around a late F-star

    NASA Astrophysics Data System (ADS)

    Cappetta, M.; Saglia, R. P.; Birkby, J. L.; Koppenhoefer, J.; Pinfield, D. J.; Hodgkin, S. T.; Cruz, P.; Kovács, G.; Sipőcz, B.; RoPACS Collaboration

    2013-04-01

    We report the discovery of WTS1 b, the first extrasolar planet found by the WFCAM Transit Survey. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope (HET) allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V = 16.13), and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the companion of 3.35 days, a planetary mass of 4.01 ± 0.35 MJ, and a planetary radius of 1.49 +0.16-0.18 RJ. WTS1 b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 MJ. Based on Cappetta et al. (2012), [1].

  6. Periodic mass extinctions and the Planet X model reconsidered

    NASA Astrophysics Data System (ADS)

    Whitmire, Daniel P.

    2016-01-01

    The 27 Myr period in the fossil extinction record has been confirmed in modern data bases dating back 500 Myr, which is twice the time interval of the original analysis from 30 years ago. The surprising regularity of this period has been used to reject the Nemesis model. A second model based on the Sun's vertical Galactic oscillations has been challenged on the basis of an inconsistency in period and phasing. The third astronomical model originally proposed to explain the periodicity is the Planet X model in which the period is associated with the perihelion precession of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated to mass extinctions, a trans-Neptunian super-Earth planet has been proposed to explain the observation that the inner Oort cloud objects Sedna and 2012VP113 have perihelia that lie near the ecliptic plane. In this Letter, we reconsider the Planet X model in light of the confluence of the modern palaeontological and outer Solar system dynamical evidence.

  7. Molecular formation along the atmospheric mass loss of HD 209458b and similar Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Pinotti, R.; Boechat-Roberty, H. M.

    2016-02-01

    The chemistry along the mass loss of Hot Jupiters is generally considered to be simple, consisting mainly of atoms, prevented from forming more complex species by the intense radiation field from their host stars. In order to probe the region where the temperature is low (T<2000 K), we developed a 1D chemical and photochemical reaction model of the atmospheric mass loss of HD 209458b, involving 56 species, including carbon chain and oxygen-bearing ones, interacting through 566 reactions. The simulation results indicate that simple molecules like OH+, H2O+ and H3O+ are formed inside the region, considering that residual H2 survives in the exosphere, a possibility indicated by recent observational work. The molecules are formed and destroyed within a radial distance of less than 107 km, but the estimated integrated column density of OH+, a potential tracer of H2, is high enough to allow detection, which, once achieved, would indicate a revision of chemical models of the upper atmosphere of Hot Jupiters. For low density Hot Jupiters receiving less intense XUV radiation from their host stars than HD 209458b, molecular species could conceivably be formed with a higher total column density.

  8. Considerations on the Outward Migration of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    D'Angelo, G.; Marzari, F.

    2011-12-01

    It has been proposed that the outward orbital migration of Jupiter and Saturn, driven by a gas-dominated protosolar disk, may help explain why they did not move much closer to the Sun. It has also been suggested that some properties of the inner Solar System may be interpreted by invoking an inward migration of Jupiter and Saturn followed by outward migration, once they get caught in the 2:3 mean motion resonance. Hydrodynamical calculations indicate that outward migration of a compact Jupiter-Saturn system may arise from an imbalance between positive and negative Lindblad torques exerted on Jupiter by the disk. The torque density distribution acting on Jupiter extends over ~3 Hill radii on either side of the planet's orbit. The negative part of the distribution samples outer disk portions, partially depleted by the tidal perturbations of both planets. The positive part of the distribution samples inner disk portions, depleted only by the action of Jupiter. The net result may be a positive torque exerted on Jupiter. Saturn, trapped in resonance with Jupiter, migrates outward as well. This mechanism requires the exterior planet's mass not to exceed the interior planet's mass. Thus, it is assumed that neither planet accretes gas from the disk. Yet, models of giant planet formation indicate that these planets would accrete gas at whatever rate the disk provides (Lissauer et al., 2009, Icarus, 199, 338). We performed 2D and 3D hydrodynamical calculations of a Jupiter-Saturn system tidally interacting with a protoplanetary disk and investigated how gas accretion affects their migration history. We assumed initial conditions shown to result in the outward migration of non-accreting planets and recovered such scenario. We then allowed the planets to accrete gas at a disk-limited rate. In agreement with estimates derived for single planets, the assumed disk conditions lead to a mass-doubling time scale of the exterior planet that is 6-9 times as short as that of interior

  9. Rosuvastatin and the JUPITER trial: critical appraisal of a lifeless planet in the galaxy of primary prevention.

    PubMed

    López, Antonio; Wright, James M

    2012-01-01

    In November 2008, the JUPITER trial was published in the New England Journal of Medicine. JUPITER is an acronym for Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin. It was an AstraZeneca sponsored randomized double-blind trial comparing rosuvastatin 20 mg with placebo in 17,802 apparently healthy men and women with LDL cholesterol <3.4 mmol/L and elevated C-reactive protein (CRP). The results of the JUPITER trial have been widely publicized, and based on the trial, the main regulatory agencies have approved rosuvastatin for the indication of primary prevention of vascular events. However, the interpretation and clinical implications of the JUPITER trial have been questioned and remain controversial. The objective of this commentary is to evaluate the relevance, design, results, and conclusions of the JUPITER study.

  10. Occurrence rate of low-mass planets around nearby M dwarfs

    NASA Astrophysics Data System (ADS)

    Jones, Hugh

    2015-08-01

    We re-analyse archival radial velocities of nearby M dwarfs to constrain low-amplitude Keplerian signals. We apply a variety of signal detection criteria and photometric monitoring to assess the number of planet candidates in the sample. We use the estimated detection probability function to calculate the occurrence rate of low-mass planets around nearby M dwarfs. Our results indicate that M dwarfs are hosts to an abundance of low-mass planets and the occurrence rate of planets less massive than 10 Earth masses is of the order of one planet per star and that planets are common in the stellar habitable zones of M dwarfs.

  11. A CORRELATION BETWEEN HOST STAR ACTIVITY AND PLANET MASS FOR CLOSE-IN EXTRASOLAR PLANETS?

    SciTech Connect

    Poppenhaeger, K.; Schmitt, J. H. M. M.

    2011-07-01

    The activity levels of stars are influenced by several stellar properties, such as stellar rotation, spectral type, and the presence of stellar companions. Analogous to binaries, planetary companions are also thought to be able to cause higher activity levels in their host stars, although at lower levels. Especially in X-rays, such influences are hard to detect because coronae of cool stars exhibit a considerable amount of intrinsic variability. Recently, a correlation between the mass of close-in exoplanets and their host star's X-ray luminosity has been detected, based on archival X-ray data from the ROSAT All-Sky Survey. This finding has been interpreted as evidence for star-planet interactions. We show in our analysis that this correlation is caused by selection effects due to the flux limit of the X-ray data used and due to the intrinsic planet detectability of the radial velocity method, and thus does not trace possible planet-induced effects. We also show that the correlation is not present in a corresponding complete sample derived from combined XMM-Newton and ROSAT data.

  12. The SOPHIE search for northern extrasolar planets . I. A companion around HD 16760 with mass close to the planet/brown-dwarf transition

    NASA Astrophysics Data System (ADS)

    Bouchy, F.; Hébrard, G.; Udry, S.; Delfosse, X.; Boisse, I.; Desort, M.; Bonfils, X.; Eggenberger, A.; Ehrenreich, D.; Forveille, T.; Lagrange, A. M.; Le Coroller, H.; Lovis, C.; Moutou, C.; Pepe, F.; Perrier, C.; Pont, F.; Queloz, D.; Santos, N. C.; Ségransan, D.; Vidal-Madjar, A.

    2009-10-01

    We report on the discovery of a substellar companion or a massive Jupiter orbiting the G5V star HD 16760 using the spectrograph SOPHIE installed on the OHP 1.93-m telescope. Characteristics and performances of the spectrograph are presented, as well as the SOPHIE exoplanet consortium program. With a minimum mass of 14.3 {M}_Jup, an orbital period of 465 days and an eccentricity of 0.067, HD 16760b seems to be located just at the end of the mass distribution of giant planets, close to the planet/brown-dwarf transition. Its quite circular orbit supports a formation in a gaseous protoplanetary disk. Based on observations made with SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS/OAMP), France (program 07A.PNP.CONS). Table 2 is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/505/853

  13. Planet traps and first planets: The critical metallicity for gas giant formation

    SciTech Connect

    Hasegawa, Yasuhiro; Hirashita, Hiroyuki E-mail: hirashita@asiaa.sinica.edu.tw

    2014-06-10

    The ubiquity of planets poses an interesting question: when are first planets formed in galaxies? We investigate this by adopting a theoretical model where planet traps are combined with the standard core accretion scenario in which the efficiency of forming planetary cores directly relates to the metallicity ([Fe/H]) in disks. Three characteristic exoplanetary populations are examined: hot Jupiters, exo-Jupiters around 1 AU, and low-mass planets in tight orbits, such as super-Earths. We statistically compute planet formation frequencies (PFFs), as well as the orbital radius (〈R{sub rapid}〉) within which gas accretion becomes efficient enough to form Jovian planets, as a function of metallicity (–2 ≤ [Fe/H] ≤–0.6). We show that the total PFFs for these three populations increase steadily with metallicity. This is the direct outcome of the core accretion picture. For the metallicity range considered here, the population of low-mass planets dominates Jovian planets. The Jovian planets contribute to the PFFs above [Fe/H] ≅ –1. We find that the hot Jupiters form more efficiently than the exo-Jupiters at [Fe/H] ≲ –0.7. This arises from the slower growth of planetary cores and their more efficient radial inward transport by the host traps in lower metallicity disks. We show that the critical metallicity for forming Jovian planets is [Fe/H] ≅ –1.2 by comparing 〈R{sub rapid}〉 of hot Jupiters and low-mass planets. The comparison intrinsically links to the different gas accretion efficiency between these two types of planets. Therefore, this study implies that important physical processes in planet formation may be tested by exoplanet observations around metal-poor stars.

  14. Conditions for water ice lines and Mars-mass exomoons around accreting super-Jovian planets at 1-20 AU from Sun-like stars

    NASA Astrophysics Data System (ADS)

    Heller, R.; Pudritz, R.

    2015-06-01

    Context. The first detection of a moon around an extrasolar planet (an "exomoon") might be feasible with NASA's Kepler or ESA's upcoming PLATO space telescopes or with the future ground-based European Extremely Large Telescope. To guide observers and to use observational resources most efficiently, we need to know where the largest, most easily detected moons can form. Aims: We explore the possibility of large exomoons by following the movement of water (H2O) ice lines in the accretion disks around young super-Jovian planets. We want to know how the different heating sources in those disks affect the location of the H2O ice lines as a function of stellar and planetary distance. Methods: We simulate 2D rotationally symmetric accretion disks in hydrostatic equilibrium around super-Jovian exoplanets. The energy terms in our semi-analytical framework - (1) viscous heating; (2) planetary illumination; (3) accretional heating of the disk; and (4) stellar illumination - are fed by precomputed planet evolution models. We consider accreting planets with final masses between 1 and 12 Jupiter masses at distances between 1 and 20 AU to a solar type star. Results: Accretion disks around Jupiter-mass planets closer than about 4.5 AU to Sun-like stars do not feature H2O ice lines, whereas the most massive super-Jovians can form icy satellites as close as 3 AU to Sun-like stars. We derive an empirical formula for the total moon mass as a function of planetary mass and stellar distance and predict that super-Jovian planets forming beyond about 5 AU can host Mars-mass moons. Planetary illumination is the major heat source in the final stages of accretion around Jupiter-mass planets, whereas disks around the most massive super-Jovians are similarly heated by planetary illumination and viscous heating. This indicates a transition towards circumstellar accretion disks, where viscous heating dominates in the stellar vicinity. We also study a broad range of circumplanetary disk

  15. Mass-Radius Relation for Rocky Planets Based on PREM

    NASA Astrophysics Data System (ADS)

    Zeng, Li; Sasselov, Dimitar D.; Jacobsen, Stein B.

    2016-03-01

    Several small dense exoplanets are now known, inviting comparisons to Earth and Venus. Such comparisons require translating their masses and sizes to composition models of evolved multi-layer interior planets. Such theoretical models rely on our understanding of the Earth’s interior, as well as independently derived equations of state, but so far have not involved direct extrapolations from Earth’s seismic model: the Preliminary Reference Earth Model (PREM). To facilitate more detailed compositional comparisons between small exoplanets and the Earth, we derive here a semi-empirical mass-radius relation for two-layer rocky planets based on PREM, \\frac{R}{{R}\\oplus }=(1.07-0.21\\cdot {CMF})\\cdot {≤ft(\\frac{M}{{M}\\oplus }\\right)}1/3.7, where CMF stands for core mass fraction. It is applicable to 1 ˜ 8 M⊕ and a CMF of 0.0 ˜ 0.4. Applying this formula to Earth and Venus and several known small exoplanets with radii and masses measured to better than ˜30% precision gives a CMF fit of 0.26 ± 0.07.

  16. Gravitational energy sources in Jupiter

    NASA Technical Reports Server (NTRS)

    Flasar, F. M.

    1973-01-01

    Gravitational sources of the intrinsic luminosity of Jupiter are examined in the context of current hydrogen-helium models. When no gravitational separation of matter occurs, the amount of heat which can be released over the remaining lifetime of the planet is necessarily limited by the size of its existing reservoir of thermal energy. This conclusion rests only on the assumption that its interior is relatively cold and degenerate. If gravitational unmixing occurs, the size of the thermal reservoir does not necessarily limit the heat output. If core formation occurs, for example, then the size of the core formed will be a limiting factor. The energy released with the formation of a helium core is computed for Jupiter. A core growth rate, averaged over several billion years, of 20 trillionths of Jupiter's mass per year is required if gravitational separation is to play a significant role in the thermal evolution.

  17. Moons around Jupiter

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The New Horizons Long Range Reconnaissance Imager (LORRI) took this photo of Jupiter at 20:42:01 UTC on January 9, 2007, when the spacecraft was 80 million kilometers (49.6 million miles) from the giant planet. The volcanic moon Io is to the left of the planet; the shadow of the icy moon Ganymede moves across Jupiter's northern hemisphere.

    Ganymede's average orbit distance from Jupiter is about 1 million kilometers (620,000 miles); Io's is 422,000 kilometers (262,000 miles). Both Io and Ganymede are larger than Earth's moon; Ganymede is larger than the planet Mercury.

  18. Origins of Hot Jupiters, Revisited

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter; Laughlin, Greg

    2016-05-01

    Hot Jupiters, giant extrasolar planets with orbital periods less than ~10 days, have long been thought to form at large radial distances (a > 2AU) in protoplanetary disks, only to subsequently experience large-scale inward migration to the small orbital radii at which they are observed. Here, we propose that a substantial fraction of the hot Jupiter population forms in situ, with the Galactically prevalent short-period super-Earths acting as the source population. Our calculations suggest that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated for solid cores of 10-20 Earth masses, in line with the conventional picture of core-nucleated accretion. The planetary conglomeration process, coupled with subsequent gravitational contraction and spin down of the host star, drives sweeping secular resonances through the system, increasing the mutual inclinations of exterior, low-mass companions to hot Jupiters. Accordingly, this formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional non-transiting planets, reminiscent of those observed in large numbers by NASA’s Kepler Mission and Doppler velocity surveys. High-precision radial velocity monitoring provides the best prospect for their detection.

  19. Constraining the Masses of the Kepler-11 Planets through Radial Velocity Measurements

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard T.

    2015-01-01

    The six transiting planets of Kepler-11 have all been found to have ultra-low densities through N-body dynamical analysis of the transit timing variations (TTVs) of the six planets. Numerically reproducing TTVs has become a new method for solving the masses of planets, but this method is susceptible to certain dynamic degeneracies: the planet eccentricity is degenerate with the planet mass, and perturbations caused by non-transiting planets could be misattributed to the transiting planets. Furthermore, the masses of planets characterized by TTV analysis are systematically 2x lower than the masses (including non-detections) reported by radial velocity (RV) analysis for planets of the same radius. We address the discrepancy between the TTV- and RV-determined planet masses by measuring the RVs of Kepler-11 at opportunistic times, as determined by the ephemerides of the transiting planets. We place an upper limit on the masses of the Kepler-11 planets using RVs and preliminarily show that the RVs are consistent with the ultra-low mass scenario determined by the TTVs. The lack of disagreement between the TTVs and RVs in the Kepler-11 system bodes well for N-body simulations of TTVs for other Kepler systems that are too faint for RV follow-up.

  20. ADDITIONAL OBSERVATIONS OF PLANETS AND QUASI-STELLAR RADIO SOURCES AT 3 MM,

    DTIC Science & Technology

    MERCURY ( PLANET ), VENUS( PLANET ), PERIODIC VARIATIONS, RADIO ASTRONOMY, SPECTRUM SIGNATURES...EXTRATERRESTRIAL RADIO WAVES, SOURCES), GALAXIES, BLACKBODY RADIATION, BRIGHTNESS, TEMPERATURE, MARS( PLANET ), JUPITER( PLANET ), SATURN( PLANET

  1. An Overview of the Juno Mission to Jupiter

    NASA Technical Reports Server (NTRS)

    Grammier, Richard S.

    2006-01-01

    Arriving in orbit around the planet Jupiter in 2016 after a five-year journey, the Juno spacecraft will begin a one-year investigation of the gas giant in order to understand its origin and evolution by determining its water abundance and constraining its core mass. In addition, Juno will map the planet's magnetic and gravitational fields, map its atmosphere, and explore the three-dimensional structure of Jupiter's polar magnetosphere and auroras. Juno will discriminate among different models for giant planet formation. These investigations will be conducted over the course of thirty-two 11-day elliptical polar orbits of the planet. The orbits are designed to avoid Jupiter's highest radiation regions. The spacecraft is a spinning, solar-powered system carrying a complement of eight science instruments for conducting the investigations. The spacecraft systems and instruments take advantage of significant design and operational heritage from previous space missions.

  2. Aeronomical constraints to the minimum mass and maximum radius of hot low-mass planets

    NASA Astrophysics Data System (ADS)

    Fossati, L.; Erkaev, N. V.; Lammer, H.; Cubillos, P. E.; Odert, P.; Juvan, I.; Kislyakova, K. G.; Lendl, M.; Kubyshkina, D.; Bauer, S. J.

    2017-02-01

    Stimulated by the discovery of a number of close-in low-density planets, we generalise the Jeans escape parameter taking hydrodynamic and Roche lobe effects into account. We furthermore define Λ as the value of the Jeans escape parameter calculated at the observed planetary radius and mass for the planet's equilibrium temperature and considering atomic hydrogen, independently of the atmospheric temperature profile. We consider 5 and 10 M⊕ planets with an equilibrium temperature of 500 and 1000 K, orbiting early G-, K-, and M-type stars. Assuming a clear atmosphere and by comparing escape rates obtained from the energy-limited formula, which only accounts for the heating induced by the absorption of the high-energy stellar radiation, and from a hydrodynamic atmosphere code, which also accounts for the bolometric heating, we find that planets whose Λ is smaller than 15-35 lie in the "boil-off" regime, where the escape is driven by the atmospheric thermal energy and low planetary gravity. We find that the atmosphere of hot (i.e. Teq ⪆ 1000 K) low-mass (Mpl ⪅ 5 M⊕) planets with Λ< 15-35 shrinks to smaller radii so that their Λ evolves to values higher than 15-35, hence out of the boil-off regime, in less than ≈500 Myr. Because of their small Roche lobe radius, we find the same result also for hot (i.e. Teq⪆ 1000 K) higher mass (Mpl ⪅ 10 M⊕) planets with Λ< 15-35, when they orbit M-dwarfs. For old, hydrogen-dominated planets in this range of parameters, Λ should therefore be ≥15-35, which provides a strong constraint on the planetary minimum mass and maximum radius and can be used to predict the presence of aerosols and/or constrain planetary masses, for example.

  3. Mass Losses Of Co, Cs And Hcn On Jupiter/sl9

    NASA Astrophysics Data System (ADS)

    Moreno, Raphael; Marten, A.

    2006-09-01

    Since comet Shoemaker-Levy 9 (SL9) collided with Jupiter in 1994, the IRAM 30-m Telescope (Pico Veleta, Spain) and the 15-m JCMT (Mauna Kea,Hawaii) have regularly observed Jupiter at millimeter/submillimeter wavelengths. Molecular trace species such as HCN, CO, CS and their isotopomers have been detected in the upper atmosphere since the collision. Because of the high spectral resolution attained, our data allow one to infer both temperature and abundances in Jupiter's stratosphere with a maximum spatial resolution of 10 arcsec. We have used all these data to monitor the latitudinal spreading since the impacts occurred (Marten et al. 1995), to look for changes in their abundances with time (Moreno et al. 2001, 2003) and to determine several isotopic ratios (Matthews et al. 2002). Data taken in 2004 have shown that latitudinal distributions of all these species were almost homogeneous 10 years after impacts, as predicted by Moreno et al. 2003. Moreover, compared to 1998 results, respective mass loss factors as high as 2-7 have been determined for the three molecular main compounds (Moreno et al. 2005). In order to follow-up our monitoring, new disk mapping observations took place in May 2006 using the IRAM-30m Telescope. Here we report the results of the recent measurements of CO, CS and HCN, and also the search for new species: H2CO, H2CS, CH3CN, CH3OH. Such trace compounds could have explained the mass losses observed in 2004, but no clear detections have been obtained after reasonable integration times. Estimates of the new CO, CS and HCN total masses and upper limits for the trace species searched for will be presented. The loss mechanisms will be discussed. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  4. THE ANGLO-AUSTRALIAN PLANET SEARCH. XXII. TWO NEW MULTI-PLANET SYSTEMS

    SciTech Connect

    Wittenmyer, Robert A.; Horner, J.; Salter, G. S.; Tinney, C. G.; Bailey, J.; Tuomi, Mikko; Zhang, Z.; Butler, R. P.; Jones, H. R. A.; O'Toole, S. J.; Carter, B. D.; Jenkins, J. S.; Vogt, S. S.; Rivera, Eugenio J.

    2012-07-10

    We report the detection of two new planets from the Anglo-Australian Planet Search. These planets orbit two stars each previously known to host one planet. The new planet orbiting HD 142 has a period of 6005 {+-} 427 days, and a minimum mass of 5.3 M{sub Jup}. HD 142c is thus a new Jupiter analog: a gas-giant planet with a long period and low eccentricity (e = 0.21 {+-} 0.07). The second planet in the HD 159868 system has a period of 352.3 {+-} 1.3 days and m sin i = 0.73 {+-} 0.05 M{sub Jup}. In both of these systems, including the additional planets in the fitting process significantly reduced the eccentricity of the original planet. These systems are thus examples of how multiple-planet systems can masquerade as moderately eccentric single-planet systems.

  5. TERRESTRIAL PLANET FORMATION DURING THE MIGRATION AND RESONANCE CROSSINGS OF THE GIANT PLANETS

    SciTech Connect

    Lykawka, Patryk Sofia; Ito, Takashi

    2013-08-10

    The newly formed giant planets may have migrated and crossed a number of mutual mean motion resonances (MMRs) when smaller objects (embryos) were accreting to form the terrestrial planets in the planetesimal disk. We investigated the effects of the planetesimal-driven migration of Jupiter and Saturn, and the influence of their mutual 1:2 MMR crossing on terrestrial planet formation for the first time, by performing N-body simulations. These simulations considered distinct timescales of MMR crossing and planet migration. In total, 68 high-resolution simulation runs using 2000 disk planetesimals were performed, which was a significant improvement on previously published results. Even when the effects of the 1:2 MMR crossing and planet migration were included in the system, Venus and Earth analogs (considering both orbits and masses) successfully formed in several runs. In addition, we found that the orbits of planetesimals beyond a {approx} 1.5-2 AU were dynamically depleted by the strengthened sweeping secular resonances associated with Jupiter's and Saturn's more eccentric orbits (relative to the present day) during planet migration. However, this depletion did not prevent the formation of massive Mars analogs (planets with more than 1.5 times Mars's mass). Although late MMR crossings (at t > 30 Myr) could remove such planets, Mars-like small mass planets survived on overly excited orbits (high e and/or i), or were completely lost in these systems. We conclude that the orbital migration and crossing of the mutual 1:2 MMR of Jupiter and Saturn are unlikely to provide suitable orbital conditions for the formation of solar system terrestrial planets. This suggests that to explain Mars's small mass and the absence of other planets between Mars and Jupiter, the outer asteroid belt must have suffered a severe depletion due to interactions with Jupiter/Saturn, or by an alternative mechanism (e.g., rogue super-Earths)

  6. Secular Chaos and the Production of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Wu, Yanqin; Lithwick, Yoram

    2011-07-01

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term "secular migration") explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the "warm Jupiters" at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  7. SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS

    SciTech Connect

    Wu Yanqin; Lithwick, Yoram

    2011-07-10

    In a planetary system with two or more well-spaced, eccentric, inclined planets, secular interactions may lead to chaos. The innermost planet may gradually become very eccentric and/or inclined as a result of the secular degrees of freedom drifting toward equipartition of angular momentum deficit. Secular chaos is known to be responsible for the eventual destabilization of Mercury in our own solar system. Here we focus on systems with three giant planets. We characterize the secular chaos and demonstrate the criterion for it to occur, but leave a detailed understanding of secular chaos to a companion paper. After an extended period of eccentricity diffusion, the inner planet's pericenter can approach the star to within a few stellar radii. Strong tidal interactions and ensuing tidal dissipation extract orbital energy from the planet and pull it inward, creating a hot Jupiter. In contrast to other proposed channels for the production of hot Jupiters, such a scenario (which we term 'secular migration') explains a range of observations: the pile-up of hot Jupiters at 3 day orbital periods, the fact that hot Jupiters are in general less massive than other radial velocity planets, that they may have misaligned inclinations with respect to stellar spin, and that they have few easily detectable companions (but may have giant companions in distant orbits). Secular migration can also explain close-in planets as low in mass as Neptune; and an aborted secular migration can explain the 'warm Jupiters' at intermediate distances. In addition, the frequency of hot Jupiters formed via secular migration increases with stellar age. We further suggest that secular chaos may be responsible for the observed eccentricities of giant planets at larger distances and that these planets could exhibit significant spin-orbit misalignment.

  8. Juno: Launching to Jupiter

    NASA Video Gallery

    The Juno spacecraft will look deep beneath Jupiter's swirling curtains of clouds to decipher the planet's structure and history during a mission that will begin with a 5-year flight through deep sp...

  9. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter B.; Knutson, Heather A.; Batygin, Konstantin; Fulton, Benjamin J.; Fortney, Jonathan J.; Burrows, Adam; Wong, Ian

    2016-04-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit as a consequence of the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Owing to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity (eb) is in part dictated by its Love number ({k}{2b}), which is in turn a proxy for the degree of central mass concentration in its interior. Thus, the measurement of eb constrains {k}{2b} and allows us to place otherwise elusive constraints on the mass of HAT-P-13b's core (Mcore,b). In this study we derive new constraints on the value of eb by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that eb = 0.00700 ± 0.00100. We then use octupole-order secular perturbation theory to find the corresponding {k}{2b}={0.31}-0.05+0.08. Applying structural evolution models, we then find, with 68% confidence, that Mcore,b is less than 25 Earth masses (M⊕). The most likely value is Mcore,b = 11 M⊕, which is similar to the core mass theoretically required for runaway gas accretion. This is the tightest constraint to date on the core mass of a hot Jupiter. Additionally, we find that the measured secondary eclipse depths, which are in the 3.6 and 4.5 μm bands, best match atmospheric model predictions with a dayside temperature inversion and relatively efficient day-night circulation.

  10. In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

    NASA Astrophysics Data System (ADS)

    Batygin, Konstantin; Bodenheimer, Peter H.; Laughlin, Gregory P.

    2016-10-01

    Hot Jupiters, giant extrasolar planets with orbital periods shorter than ˜10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we offer the contrasting view that a substantial fraction of the hot Jupiter population formed in situ via the core-accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by super-Earth-type planets, comprising 10-20 Earth masses of refractory material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ˜100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems’ lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.

  11. Transiting exoplanets from the CoRoT space mission. XVII. The hot Jupiter CoRoT-17b: a very old planet

    NASA Astrophysics Data System (ADS)

    Csizmadia, Sz.; Moutou, C.; Deleuil, M.; Cabrera, J.; Fridlund, M.; Gandolfi, D.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Bruntt, H.; Carone, L.; Carpano, S.; Cavarroc, C.; Cochran, W.; Deeg, H. J.; Díaz, R. F.; Dvorak, R.; Endl, M.; Erikson, A.; Ferraz-Mello, S.; Fruth, Th.; Gazzano, J.-C.; Gillon, M.; Guenther, E. W.; Guillot, T.; Hatzes, A.; Havel, M.; Hébrard, G.; Jehin, E.; Jorda, L.; Léger, A.; Llebaria, A.; Lammer, H.; Lovis, C.; MacQueen, P. J.; Mazeh, T.; Ollivier, M.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Titz-Weider, R.; Wuchterl, G.

    2011-07-01

    We report on the discovery of a hot Jupiter-type exoplanet, CoRoT-17b, detected by the CoRoT satellite. It has a mass of 2.43 ± 0.30 MJup and a radius of 1.02 ± 0.07 RJup, while its mean density is 2.82 ± 0.38 g/cm3. CoRoT-17b is in a circular orbit with a period of 3.7681 ± 0.0003 days. The host star is an old (10.7 ± 1.0 Gyr) main-sequence star, which makes it an intriguing object for planetary evolution studies. The planet's internal composition is not well constrained and can range from pure H/He to one that can contain ~380 earth masses of heavier elements. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  12. Deep Atmosphere Ammonia Mixing Ratio at Jupiter from the Galileo Probe Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Mahaffy, P. R.; Niemann, H. B.; Demick, J. E.

    1999-01-01

    New laboratory studies employing the Engineering Unit (EU) of the Galileo Probe Mass Spectrometer (GPMS) have resulted in a substantial reduction in the previously reported upper limit on the ammonia mixing ratio derived from the GPMS experiment at Jupiter. This measurement is complicated by background ammonia contributions in the GPMS during direct atmospheric sampling produced from the preceding gas enrichment experiments. These backgrounds can be quantified with the data from the EU studies when they are carried out in a manner that duplicates the descent profile of pressure and enrichment cell loading. This background is due to the tendency of ammonia to interact strongly with the walls of the mass spectrometer and on release to contribute to the gas being directly directed into the ion source from the atmosphere through a capillary pressure reduction leak. It is evident from the GPMS and other observations that the mixing ratio of ammonia at Jupiter reaches the deep atmosphere value at substantially higher pressures than previously assumed. This is a likely explanation for the previously perceived discrepancy between ammonia values derived from ground based microwave observations and those obtained from attenuation of the Galileo Probe radio signal.

  13. HAT-P-55b: A Hot Jupiter Transiting a Sun-Like Star

    NASA Astrophysics Data System (ADS)

    Juncher, D.; Buchhave, L. A.; Hartman, J. D.; Bakos, G. Á.; Bieryla, A.; Kovács, T.; Boisse, I.; Latham, D. W.; Kovács, G.; Bhatti, W.; Csubry, Z.; Penev, K.; de Val-Borro, M.; Falco, E.; Torres, G.; Noyes, R. W.; Lázár, J.; Papp, I.; Sári, P.

    2015-09-01

    We report the discovery of a new transiting extrasolar planet, HAT-P-55b. The planet orbits a V = 13.207 +/- 0.039 sun-like star with a mass of 1.013 +/- 0.037 solar masses, a radius of 1.011 +/- 0.036 solar radii and a metallicity of -0.03 +/- 0.08. The planet itself is a typical hot Jupiter with a period of 3.5852467 +/- 0.0000064 days, a mass of 0.582 +/- 0.056 Jupiter masses and a radius of 1.182 +/- 0.055 Jupiter radii. This discovery adds to the increasing sample of transiting planets with measured bulk densities, which is needed to put constraints on models of planetary structure and formation theories.

  14. Future Direct Spectroscopic Detection of Hot Jupiters with IGRINS

    NASA Astrophysics Data System (ADS)

    Gullikson, Kevin; Endl, Mike

    2013-08-01

    With about 700 confirmed extrasolar planets, it is time to move beyond discovery and towards characterization. Perhaps the most basic parameter of an extrasolar planet is its mass; however, this is very difficult to determine if the planet does not transit the star. The radial velocity technique, still the most fruitful method of discovering planets in the solar neighborhood, can only determine a minimum planet mass. We investigate a method using the near-future IGRINS near infrared spectrograph to detect the orbital motion of the planet itself. We simulate several observations of a star with an orbiting planet, and search for the spectral signature of the planet by cross-correlating against planet model spectra. A detection appears as a strong peak in the cross-correlation function, and gives the radial velocity of the planet at the time of observation. This, combined with the motion of the star from traditional radial velocity planet search programs, can determine the actual planet mass. We find that the IGRINS instrument can detect the spectral signature from large planets on very close orbits (so-called Hot Jupiters), and that the detections can provide tight constraints on the true planet mass.

  15. Discovery of a Jupiter/Saturn analog with gravitational microlensing.

    PubMed

    Gaudi, B S; Bennett, D P; Udalski, A; Gould, A; Christie, G W; Maoz, D; Dong, S; McCormick, J; Szymanski, M K; Tristram, P J; Nikolaev, S; Paczynski, B; Kubiak, M; Pietrzynski, G; Soszynski, I; Szewczyk, O; Ulaczyk, K; Wyrzykowski, L; Depoy, D L; Han, C; Kaspi, S; Lee, C-U; Mallia, F; Natusch, T; Pogge, R W; Park, B-G; Abe, F; Bond, I A; Botzler, C S; Fukui, A; Hearnshaw, J B; Itow, Y; Kamiya, K; Korpela, A V; Kilmartin, P M; Lin, W; Masuda, K; Matsubara, Y; Motomura, M; Muraki, Y; Nakamura, S; Okumura, T; Ohnishi, K; Rattenbury, N J; Sako, T; Saito, To; Sato, S; Skuljan, L; Sullivan, D J; Sumi, T; Sweatman, W L; Yock, P C M; Albrow, M D; Allan, A; Beaulieu, J-P; Burgdorf, M J; Cook, K H; Coutures, C; Dominik, M; Dieters, S; Fouqué, P; Greenhill, J; Horne, K; Steele, I; Tsapras, Y; Chaboyer, B; Crocker, A; Frank, S; Macintosh, B

    2008-02-15

    Searches for extrasolar planets have uncovered an astonishing diversity of planetary systems, yet the frequency of solar system analogs remains unknown. The gravitational microlensing planet search method is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury. We report the detection of a multiple-planet system with microlensing. We identify two planets with masses of approximately 0.71 and approximately 0.27 times the mass of Jupiter and orbital separations of approximately 2.3 and approximately 4.6 astronomical units orbiting a primary star of mass approximately 0.50 solar mass at a distance of approximately 1.5 kiloparsecs. This system resembles a scaled version of our solar system in that the mass ratio, separation ratio, and equilibrium temperatures of the planets are similar to those of Jupiter and Saturn. These planets could not have been detected with other techniques; their discovery from only six confirmed microlensing planet detections suggests that solar system analogs may be common.

  16. Observed properties of extrasolar planets.

    PubMed

    Howard, Andrew W

    2013-05-03

    Observational surveys for extrasolar planets probe the diverse outcomes of planet formation and evolution. These surveys measure the frequency of planets with different masses, sizes, orbital characteristics, and host star properties. Small planets between the sizes of Earth and Neptune substantially outnumber Jupiter-sized planets. The survey measurements support the core accretion model, in which planets form by the accumulation of solids and then gas in protoplanetary disks. The diversity of exoplanetary characteristics demonstrates that most of the gross features of the solar system are one outcome in a continuum of possibilities. The most common class of planetary system detectable today consists of one or more planets approximately one to three times Earth's size orbiting within a fraction of the Earth-Sun distance.

  17. Extrasolar binary planets. I. Formation by tidal capture during planet-planet scattering

    SciTech Connect

    Ochiai, H.; Nagasawa, M.; Ida, S.

    2014-08-01

    We have investigated (1) the formation of gravitationally bounded pairs of gas-giant planets (which we call 'binary planets') from capturing each other through planet-planet dynamical tide during their close encounters and (2) the subsequent long-term orbital evolution due to planet-planet and planet-star quasi-static tides. For the initial evolution in phase 1, we carried out N-body simulations of the systems consisting of three Jupiter-mass planets taking into account the dynamical tide. The formation rate of the binary planets is as much as 10% of the systems that undergo orbital crossing, and this fraction is almost independent of the initial stellarcentric semimajor axes of the planets, while ejection and merging rates sensitively depend on the semimajor axes. As a result of circularization by the planet-planet dynamical tide, typical binary separations are a few times the sum of the physical radii of the planets. After the orbital circularization, the evolution of the binary system is governed by long-term quasi-static tide. We analytically calculated the quasi-static tidal evolution in phase 2. The binary planets first enter the spin-orbit synchronous state by the planet-planet tide. The planet-star tide removes angular momentum of the binary motion, eventually resulting in a collision between the planets. However, we found that the binary planets survive the tidal decay for the main-sequence lifetime of solar-type stars (∼10 Gyr), if the binary planets are beyond ∼0.3 AU from the central stars. These results suggest that the binary planets can be detected by transit observations at ≳ 0.3 AU.

  18. THE EFFECT OF MASS LOSS ON THE TIDAL EVOLUTION OF EXTRASOLAR PLANET

    SciTech Connect

    Guo, J. H.

    2010-04-01

    By combining mass loss and tidal evolution of close-in planets, we present a qualitative study on their tidal migrations. We incorporate mass loss in tidal evolution for planets with different masses and find that mass loss could interfere with tidal evolution. In an upper limit case (beta = 3), a significant portion of mass may be evaporated in a long evolution timescale. Evidence of greater modification of the planets with an initial separation of about 0.1 AU than those with a = 0.15 AU can be found in this model. With the assumption of a large initial eccentricity, the planets with initial mass <=1 M{sub J} and initial distance of about 0.1 AU could not survive. With the supposition of beta = 1.1, we find that the loss process has an effect on the planets with low mass at a {approx} 0.05 AU. In both cases, the effect of evaporation on massive planets can be neglected. Also, heating efficiency and initial eccentricity have significant influence on tidal evolution. We find that even low heating efficiency and initial eccentricity have a significant effect on tidal evolution. Our analysis shows that evaporation on planets with different initial masses can accelerate (decelerate) the tidal evolution due to the increase (decrease) in tide of the planet (star). Consequently, the effect of evaporation cannot be neglected in evolutionary calculations of close-in planets. The physical parameters of HD 209458b can be fitted by our model.

  19. Evolutionary Analysis of Gaseous Sub-Neptune-mass Planets with MESA

    NASA Astrophysics Data System (ADS)

    Chen, Howard; Rogers, Leslie A.

    2016-11-01

    Sub-Neptune-sized exoplanets represent the most common types of planets in the Milky Way, yet many of their properties are unknown. Here, we present a prescription to adapt the capabilities of the stellar evolution toolkit Modules for Experiments in Stellar Astrophysics to model sub-Neptune-mass planets with H/He envelopes. With the addition of routines treating the planet core luminosity, heavy-element enrichment, atmospheric boundary condition, and mass-loss due to hydrodynamic winds, the evolutionary pathways of planets with diverse starting conditions are more accurately constrained. Using these dynamical models, we construct mass-composition relationships of planets from 1-400 M ⊕ and investigate how mass-loss impacts their composition and evolution history. We demonstrate that planet radii are typically insensitive to the evolution pathway that brought the planet to its instantaneous mass, composition and age, with variations from hysteresis ≲ 2 % . We find that planet envelope mass-loss timescales, {τ }{env}, vary non-monotonically with H/He envelope mass fractions (at fixed planet mass). In our simulations of young (100 Myr) low-mass ({M}{{p}}≲ 10 {M}\\oplus ) planets with rocky cores, {τ }{env} is maximized at {M}{env}/{M}{{p}}=1 % to 3%. The resulting convergent mass-loss evolution could potentially imprint itself on the close-in planet population as a preferred H/He mass fraction of ˜ 1 % . Looking ahead, we anticipate that this numerical code will see widespread applications complementing both 3D models and observational exoplanet surveys.

  20. DEUTERIUM BURNING IN MASSIVE GIANT PLANETS AND LOW-MASS BROWN DWARFS FORMED BY CORE-NUCLEATED ACCRETION

    SciTech Connect

    Bodenheimer, Peter; Fortney, Jonathan J.; Saumon, Didier E-mail: gennaro.dangelo@nasa.gov E-mail: jfortney@ucolick.org

    2013-06-20

    Using detailed numerical simulations, we study the formation of bodies near the deuterium-burning limit according to the core-nucleated giant planet accretion scenario. The objects, with heavy-element cores in the range 5-30 M{sub Circled-Plus }, are assumed to accrete gas up to final masses of 10-15 Jupiter masses (M{sub Jup}). After the formation process, which lasts 1-5 Myr and which ends with a ''cold-start'', low-entropy configuration, the bodies evolve at constant mass up to an age of several Gyr. Deuterium burning via proton capture is included in the calculation, and we determined the mass, M{sub 50}, above which more than 50% of the initial deuterium is burned. This often-quoted borderline between giant planets and brown dwarfs is found to depend only slightly on parameters, such as core mass, stellar mass, formation location, solid surface density in the protoplanetary disk, disk viscosity, and dust opacity. The values for M{sub 50} fall in the range 11.6-13.6 M{sub Jup}, in agreement with previous determinations that do not take the formation process into account. For a given opacity law during the formation process, objects with higher core masses form more quickly. The result is higher entropy in the envelope at the completion of accretion, yielding lower values of M{sub 50}. For masses above M{sub 50}, during the deuterium-burning phase, objects expand and increase in luminosity by one to three orders of magnitude. Evolutionary tracks in the luminosity versus time diagram are compared with the observed position of the companion to Beta Pictoris.

  1. Reinflating Giant Planets

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-01-01

    Two new, large gas-giant exoplanets have been discovered orbiting close to their host stars. A recent study examining these planets and others like them may help us to better understand what happens to close-in hot Jupiters as their host stars reach the end of their main-sequence lives.OversizedGiantsUnbinned transit light curves for HAT-P-65b. [Adapted from Hartman et al. 2016]The discovery of HAT-P-65b and HAT-P-66b, two new transiting hot Jupiters, is intriguing. These planets have periods of just under 3 days and masses of roughly 0.5 and 0.8 times that of Jupiter, but their sizes are whats really interesting: they have inflated radii of 1.89 and 1.59 times that of Jupiter.These two planets, discovered using the Hungarian-made Automated Telescope Network (HATNet) in Arizona and Hawaii, mark the latest in an ever-growing sample of gas-giant exoplanets with radii larger than expected based on theoretical planetary structure models.What causes this discrepancy? Did the planets just fail to contract to the expected size when they were initially formed, or were they reinflated later in their lifetimes? If the latter, how? These are questions that scientists are only now starting to be able to address using statistics of the sample of close-in, transiting planets.Unbinned transit light curves for HAT-P-66b. [Hartman et al. 2016]Exploring Other PlanetsLed by Joel Hartman (Princeton University), the team that discovered HAT-P-65b and HAT-P-66b has examined these planets observed parameters and those of dozens of other known close-in, transiting exoplanets discovered with a variety of transiting exoplanet missions: HAT, WASP, Kepler, TrES, and KELT. Hartman and collaborators used this sample to draw conclusions about what causes some of these planets to have such large radii.The team found that there is a statistically significant correlation between the radii of close-in giant planets and the fractional ages of their host stars (i.e., the stars age divided by its full

  2. Pathways towards Neptune-mass Planets around Very Low-mass Stars

    NASA Astrophysics Data System (ADS)

    Dreizler, S.; Bean, J.; Seifahrt, A.; Hartman, H.; Nilsson, H.; Wiedemann, G.; Reiners, A.; Henry, T. J.

    2010-10-01

    Radial velocities measured from near-infrared spectra are a potentially powerful tool to search for planets around low-mass stars. The radial velocity precision routinely obtained in the visible can, however, not be achieved in the NIR with existing techniques. In this paper, we describe a method for measuring high-precision radial velocities of a sample of the lowest-mass M dwarfs using CRIRES on the VLT. Our project makes use of a gas cell filled with ammonia to calibrate the instrument response similar to the iodine cell technique that has been used so successfully in the visible. Tests of the method based on the analysis of hundreds of spectra obtained for late M dwarfs over six months demonstrate that precisions of ˜5 m s-1 are obtainable over long timescales, and precisions better than 3 m s-1 can be obtained over timescales up to a week. This allows to search for low-mass planets, i.e., Neptune-mass or even Super-Earth planets around very low-mass stars or sub-stellar objects.

  3. Migration of Gas Giant Planets in a Gravitationally Unstable Disk

    NASA Astrophysics Data System (ADS)

    Desai, Karna Mahadev; Steiman-Cameron, Thomas Y.; Michael, Scott; Durisen, Richard H.

    2017-01-01

    Understanding the migration of giant planets in gravitationally unstable protoplanetary disks is important for understanding planetary system architecture, especially the existence of planets orbiting close to and at large distances from their stars. Migration rates can determine the efficiency of planet formation and survival rates of planets. We present results from simulations of 0.3, 1, and 3 Jupiter-mass planets in a 0.14 M⊙ protoplanetary disk around a 1 M⊙ star, where the disk is marginally unstable to gravitational instabilities (GIs). Each planet is simulated separately. We use CHYMERA, a radiative 3D hydrodynamics code developed by the Indiana University Hydrodynamics Group. The simulations include radiative cooling governed by realistic dust opacities. The planets are inserted into the disk, once the disk has settled into its quasi-steady GI-active phase. We simulate each of the 0.3, 1, and 3 Jupiter-mass planets by inserting it at three different locations in the disk, at the corotation radius and at the inner and outer Lindblad resonances. No matter where placed, the 3 Jupiter-mass planets tend to drift inexorably inward but with a rate that slows after many orbital periods. The 1 Jupiter-mass planets migrate mostly inward, but their motion can be delayed or reversed near the corotation of the two-armed wave. The 0.3 Jupiter-mass planets are much less predictable and frequently migrate outward. We analyze how the density of matter and waves in the disk at different azimuthal locations affect the migration.

  4. The interplanetary and near-Jupiter meteoroid environments

    NASA Technical Reports Server (NTRS)

    Humes, D. H.; Alvarez, J. M.; Oneal, R. L.; Kinard, W. H.

    1974-01-01

    The meteoroid penetration detectors on the Pioneer 10 spacecraft recorded 67 meteoroid penetrations through the 25-micron stainless steel test material while the spacecraft was between 1.0 and 5.1 AU. Ten of these penetrations occurred during the encounter with Jupiter. The cumulative spatial density of meteoroids with masses greater than 2 nanograms has been calculated from these data for interplanetary space and for the near-Jupiter space. The spatial density is found to be essentially constant in interplanetary space between 1 and 5 AU, approximately 1 meteoroid per cubic km, and 1-2 orders of magnitude greater near Jupiter. There was no increase in the spatial density of meteoroids in the asteroid belt and hence no evidence that there is a significant asteroidal component of 2-nanogram meteoroids. It is uncertain whether the meteoroids detected near Jupiter were in orbit about Jupiter or were gravitationally focused toward the planet from solar orbits.

  5. Dynamical Constraints on the Core Mass of Hot Jupiter HAT-P-13b

    NASA Astrophysics Data System (ADS)

    Buhler, Peter Benjamin; Knutson, Heather; Batygin, Konstantin; Fulton, Benjamin James; Burrows, Adam Seth; Fortney, Jonathan J.

    2016-01-01

    HAT-P-13b is a Jupiter-mass transiting exoplanet that has settled onto a stable, short-period, and mildly eccentric orbit due to the action of tidal dissipation and perturbations from a second, highly eccentric, outer companion. Due to the special orbital configuration of the HAT-P-13 system, the magnitude of HAT-P-13b's eccentricity is in part dictated by its Love number, i.e. the degree of central mass concentration in its interior. We can therefore directly constrain the fraction of HAT-P-13b's mass contained in its core by measuring its orbital eccentricity. This method offers considerable advantages over the standard approach of inferring core size based on mass and radius measurements alone. In this study we derive new constraints on the value of HAT-P-13b's eccentricity by observing two secondary eclipses of HAT-P-13b with the Infrared Array Camera on board the Spitzer Space Telescope. We fit the measured secondary eclipse times simultaneously with radial velocity measurements and find that the eccentricity of HAT-P-13b is 0.00696 ± 0.00096. We then use octupole-order secular perturbation theory to find that the corresponding Love number is 0.31 (+0.11, -0.05). Applying structural evolution models, we then find, with 68% confidence, that the core mass lies between 0-25 Earth masses, with a most likely value of the core mass of 11 Earth masses. This is the tightest constraint, to date, on the core mass of an exoplanet. We also compare the measured secondary eclipse depths, in the 3.6 and 4.5 micron bands, to the predictions of a suite of atmosphere models and find that the depths are best matched by models with a dayside temperature inversion and relatively efficient day-night circulation.

  6. TOWARD CHEMICAL CONSTRAINTS ON HOT JUPITER MIGRATION

    SciTech Connect

    Madhusudhan, Nikku; Amin, Mustafa A.; Kennedy, Grant M.

    2014-10-10

    The origin of hot Jupiters—gas giant exoplanets orbiting very close to their host stars—is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses. In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily explained by giant planets forming at large orbital separations, either by core accretion or gravitational instability, and migrating to close-in orbits via disk-free mechanisms involving dynamical encounters. Such planets also contain solar or super-solar C/O ratios. On the contrary, hot Jupiters with super-solar O and C abundances can be explained by a variety of formation-migration pathways which, however, lead to solar or sub-solar C/O ratios. Current estimates of low oxygen abundances in hot Jupiter atmospheres may be indicative of disk-free migration mechanisms. We discuss open questions in this area which future studies will need to investigate.

  7. The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high-resolution observations.

    PubMed

    Rosotti, Giovanni P; Juhasz, Attila; Booth, Richard A; Clarke, Cathie J

    2016-07-01

    We investigate the minimum planet mass that produces observable signatures in infrared scattered light and submillimetre (submm) continuum images and demonstrate how these images can be used to measure planet masses to within a factor of about 2. To this end, we perform multi-fluid gas and dust simulations of discs containing low-mass planets, generating simulated observations at 1.65, 10 and 850 μm. We show that the minimum planet mass that produces a detectable signature is ∼15 M⊕: this value is strongly dependent on disc temperature and changes slightly with wavelength (favouring the submm). We also confirm previous results that there is a minimum planet mass of ∼20 M⊕ that produces a pressure maximum in the disc: only planets above this threshold mass generate a dust trap that can eventually create a hole in the submm dust. Below this mass, planets produce annular enhancements in dust outwards of the planet and a reduction in the vicinity of the planet. These features are in steady state and can be understood in terms of variations in the dust radial velocity, imposed by the perturbed gas pressure radial profile, analogous to a traffic jam. We also show how planet masses can be derived from structure in scattered light and submm images. We emphasize that simulations with dust need to be run over thousands of planetary orbits so as to allow the gas profile to achieve a steady state and caution against the estimation of planet masses using gas-only simulations.

  8. Models of Jupiter's Growth Incorporating Thermal and Hydrodynamics Constraints

    NASA Astrophysics Data System (ADS)

    D'Angelo, G.; Lissauer, J. J.; Hubickyj, O.; Bodenheimer, P.

    2008-12-01

    We have modeled the growth of Jupiter incorporating both thermal and hydrodynamical constraints on its accretion of gas from the circumsolar disk. We have used a planetary formation code, based on a Henyey- type stellar evolution code, to compute the planet's internal structure and a three-dimensional hydrodynamics code to calculate the planet's interactions with the protoplanetary disk. Our principal results are: (1) Three dimensional hydrodynamics calculations show that the flow of gas in the circumsolar disk limits the region occupied by the planet's tenuous gaseous envelope to within about 0.25 Rh (Hill sphere radii) of the planet's center, which is much smaller than the value of ~ 1 Rh that was assumed in previous studies. (2) This smaller size of the planet's envelope increases the planet's accretion time, but only by 5-- 10%. In general, in agreement with previous results of Hubickyj et al. [Hubickyj, O., Bodenheimer, P., Lissauer, J.J., 2005. Icarus, 179, 415-431], Jupiter formation times are in the range 2.5--3 Myr, assuming a protoplanetary disk with solid surface density of 10 g/cm2 and dust opacity in the protoplanet's envelope equal to 2% that of interstellar material. Thermal pressure limits the rate at which a planet less than a few dozen times as massive as Earth can accumulate gas from the protoplanetary disk, whereas hydrodynamics regulates the growth rate for more massive planets. (3) In a protoplanetary disk whose alpha-viscosity parameter is ~ 0.004, giant planets will grow to several times the mass of Jupiter unless the disk has a small local surface density when the planet begins to accrete gas hydrodynamically, or the disk is dispersed very soon thereafter. The large number of planets known with masses near Jupiter's compared with the smaller number of substantially more massive planets is more naturally explained by planetary growth within circumstellar disks whose alpha-viscosity parameter is ~ 0.0004. (4) Capture of Jupiter's irregular

  9. X-MIME: An Imaging X-ray Spectrometer for Detailed Study of Jupiter's Icy Moons and the Planet's X-ray Aurora

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; Ramsey, B. D.; Waite, J. H.; Rehak, P.; Johnson, R. E.; Cooper, J. F.; Swartz, D. A.

    2004-01-01

    Remote observations with the Chandra X-ray Observatory and the XMM-Newton Observatory have shown that the Jovian system is a source of x-rays with a rich and complicated structure. The planet's polar auroral zones and its disk are powerful sources of x-ray emission. Chandra observations revealed x-ray emission from the Io Plasma Torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from these moons is certainly due to bombardment of their surfaces of highly energetic protons, oxygen and sulfur ions from the region near the Torus exciting atoms in their surfaces and leading to fluorescent x-ray emission lines. Although the x-ray emission from the Galilean moons is faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around these moons, operating at 200 eV and above with 150 eV energy resolution, would provide a detailed mapping (down to 40 m spatial resolution) of the elemental composition in their surfaces. Such maps would provide important constraints on formation and evolution scenarios for the surfaces of these moons. Here we describe the characteristics of X-MIME, an imaging x-ray spectrometer under going a feasibility study for the JIMO mission, with the ultimate goal of providing unprecedented x-ray studies of the elemental composition of the surfaces of Jupiter's icy moons and Io, as well as of Jupiter's auroral x-ray emission.

  10. 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.

  11. Mass, Density, and Formation Constraints in the Compact, Sub-Earth Kepler-444 System including Two Mars-mass Planets

    NASA Astrophysics Data System (ADS)

    Mills, Sean M.; Fabrycky, Daniel C.

    2017-03-01

    Kepler-444 is a five-planet system around a host star approximately 11 billion years old. The five transiting planets all have sub-Earth radii and are in a compact configuration with orbital periods between 3 and 10 days. Here, we present a transit-timing analysis of the system using the full Kepler data set in order to determine the masses of the planets. Two planets, Kepler-444 d ({M}{{d}}={0.036}-0.020+0.065 {M}\\oplus ) and Kepler-444 e ({M}{{e}}={0.034}-0.019+0.059 {M}\\oplus ), have confidently detected masses due to their proximity to resonance that creates transit-timing variations. The mass ratio of these planets combined with the magnitude of possible star–planet tidal effects suggests that smooth disk migration over a significant distance is unlikely to have brought the system to its currently observed orbital architecture without significant post-formation perturbations.

  12. The McDonald Observatory Planet Search: New Long-period Giant Planets and Two Interacting Jupiters in the HD 155358 System

    NASA Astrophysics Data System (ADS)

    Robertson, Paul; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Wittenmyer, Robert A.; Horner, J.; Brugamyer, Erik J.; Simon, Attila E.; Barnes, Stuart I.; Caldwell, Caroline

    2012-04-01

    We present high-precision radial velocity (RV) observations of four solar-type (F7-G5) stars—HD 79498, HD 155358, HD 197037, and HD 220773—taken as part of the McDonald Observatory Planet Search Program. For each of these stars, we see evidence of Keplerian motion caused by the presence of one or more gas giant planets in long-period orbits. We derive orbital parameters for each system and note the properties (composition, activity, etc.) of the host stars. While we have previously announced the two-gas-giant HD 155358 system, we now report a shorter period for planet c. This new period is consistent with the planets being trapped in mutual 2:1 mean-motion resonance. We therefore perform an in-depth stability analysis, placing additional constraints on the orbital parameters of the planets. These results demonstrate the excellent long-term RV stability of the spectrometers on both the Harlan J. Smith 2.7 m telescope and the Hobby-Eberly telescope.

  13. THE LICK-CARNEGIE EXOPLANET SURVEY: A URANUS-MASS FOURTH PLANET FOR GJ 876 IN AN EXTRASOLAR LAPLACE CONFIGURATION

    SciTech Connect

    Rivera, Eugenio J.; Laughlin, Gregory; Vogt, Steven S.; Meschiari, Stefano; Haghighipour, Nader

    2010-08-10

    Continued radial velocity (RV) monitoring of the nearby M4V red dwarf star GJ 876 with Keck/High Resolution Echelle Spectrograph has revealed the presence of a Uranus-mass fourth planetary companion in the system. The new planet has a mean period of P{sub e} = 126.6 days (over the 12.6-year baseline of the RV observations), and a minimum mass of m{sub e} sin i{sub e} = 12.9 {+-} 1.7 M {sub +}. The detection of the new planet has been enabled by significant improvements to our RV data set for GJ 876. The data have been augmented by 36 new high-precision measurements taken over the past five years. In addition, the precision of all of the Doppler measurements have been significantly improved by the incorporation of a high signal-to-noise template spectrum for GJ 876 into the analysis pipeline. Implementation of the new template spectrum improves the internal rms errors for the velocity measurements taken during 1998-2005 from 4.1 m s{sup -1} to 2.5 m s{sup -1}. Self-consistent, N-body fits to the RV data set show that the four-planet system has an invariable plane with an inclination relative to the plane of the sky of i = 59.{sup 0}5. The fit is not significantly improved by the introduction of a mutual inclination between the planets 'b' and 'c', but the new data do confirm a non-zero eccentricity, e{sub d} = 0.207 {+-} 0.055 for the innermost planet, 'd'. In our best-fit coplanar model, the mass of the new component is m{sub e} = 14.6 {+-} 1.7 M {sub +}. Our best-fitting model places the new planet in a three-body resonance with the previously known giant planets (which have mean periods of P{sub c} = 30.4 and P{sub b} = 61.1 days). The critical argument, {psi}{sub Laplace} = {lambda} {sub c} - 3{lambda} {sub b} + 2{lambda} {sub e}, for the Laplace resonance librates with an amplitude of {Delta}{psi}{sub Laplace} = 40{sup 0} {+-} 13{sup 0} about {psi}{sub Laplace} = 0{sup 0}. Numerical integration indicates that the four-planet system is stable for at least a

  14. Capture of Trojans by Jumping Jupiter

    NASA Astrophysics Data System (ADS)

    Nesvorný, David; Vokrouhlický, David; Morbidelli, Alessandro

    2013-05-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ~5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) × 10-7 for each particle in the original transplanetary disk, implying that the disk contained (3-4) × 107 planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M disk ~ 14-28 M Earth, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  15. CAPTURE OF TROJANS BY JUMPING JUPITER

    SciTech Connect

    Nesvorny, David; Vokrouhlicky, David; Morbidelli, Alessandro

    2013-05-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here, we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to {approx}5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the observed asymmetry in the number of leading and trailing Trojans. We find that the capture probability is (6-8) Multiplication-Sign 10{sup -7} for each particle in the original transplanetary disk, implying that the disk contained (3-4) Multiplication-Sign 10{sup 7} planetesimals with absolute magnitude H < 9 (corresponding to diameter D = 80 km for a 7% albedo). The disk mass inferred from this work, M{sub disk} {approx} 14-28 M{sub Earth}, is consistent with the mass deduced from recent dynamical simulations of the planetary instability.

  16. PLANET-PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS

    SciTech Connect

    Raymond, Sean N.; Armitage, Philip J.; Gorelick, Noel

    2010-03-10

    We develop an idealized dynamical model to predict the typical properties of outer extrasolar planetary systems, at radii comparable to the Jupiter-to-Neptune region of the solar system. The model is based upon the hypothesis that dynamical evolution in outer planetary systems is controlled by a combination of planet-planet scattering and planetary interactions with an exterior disk of small bodies ('planetesimals'). Our results are based on 5000 long duration N-body simulations that follow the evolution of three planets from a few to 10 AU, together with a planetesimal disk containing 50 M{sub +} from 10 to 20 AU. For large planet masses (M {approx}> M{sub Sat}), the model recovers the observed eccentricity distribution of extrasolar planets. For lower-mass planets, the range of outcomes in models with disks is far greater than that which is seen in isolated planet-planet scattering. Common outcomes include strong scattering among massive planets, sudden jumps in eccentricity due to resonance crossings driven by divergent migration, and re-circularization of scattered low-mass planets in the outer disk. We present the distributions of the eccentricity and inclination that result, and discuss how they vary with planet mass and initial system architecture. In agreement with other studies, we find that the currently observed eccentricity distribution (derived primarily from planets at a {approx}< 3 AU) is consistent with isolated planet-planet scattering. We explain the observed mass dependence-which is in the opposite sense from that predicted by the simplest scattering models-as a consequence of strong correlations between planet masses in the same system. At somewhat larger radii, initial planetary mass correlations and disk effects can yield similar modest changes to the eccentricity distribution. Nonetheless, strong damping of eccentricity for low-mass planets at large radii appears to be a secure signature of the dynamical influence of disks. Radial velocity

  17. Effect of planetary mass on the orbit of star-planet systems

    NASA Astrophysics Data System (ADS)

    Öztürk, O.; Erdem, A.

    2017-02-01

    Two main parameters, which determine the radial velocity semi-amplitude of the host star in a star-planet system, are the planet mass and the orbital period. In order to examine the effect of planet mass on the radial velocity semi-amplitude, we firstly select sensitive data of spectroscopic orbital solutions of 737 systems, given in the database of exoplanet.org. The selected systems are then categorized into 31 groups according to their orbital periods. For each group, an empirical relation between the radial velocity semi amplitude and the planet mass is obtained. In order to check the accuracy of these empirical relations, the measured and expected values of planet masses are compared.

  18. Jupiter's decisive role in the inner Solar System's early evolution.

    PubMed

    Batygin, Konstantin; Laughlin, Greg

    2015-04-07

    The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System's terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter's inward migration entrained s ≳ 10-100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System's terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.

  19. The Solar Twin Planet Search. V. Close-in, low-mass planet candidates and evidence of planet accretion in the solar twin HIP 68468

    NASA Astrophysics Data System (ADS)

    Meléndez, Jorge; Bedell, Megan; Bean, Jacob L.; Ramírez, Iván; Asplund, Martin; Dreizler, Stefan; Yan, Hong-Liang; Shi, Jian-Rong; Lind, Karin; Ferraz-Mello, Sylvio; Galarza, Jhon Yana; dos Santos, Leonardo; Spina, Lorenzo; Maia, Marcelo Tucci; Alves-Brito, Alan; Monroe, TalaWanda; Casagrande, Luca

    2017-01-01

    Context. More than two thousand exoplanets have been discovered to date. Of these, only a small fraction have been detected around solar twins, which are key stars because we can obtain accurate elemental abundances especially for them, which is crucial for studying the planet-star chemical connection with the highest precision. Aims: We aim to use solar twins to characterise the relationship between planet architecture and stellar chemical composition. Methods: We obtained high-precision (1 m s-1) radial velocities with the HARPS spectrograph on the ESO 3.6 m telescope at La Silla Observatory and determined precise stellar elemental abundances ( 0.01 dex) using spectra obtained with the MIKE spectrograph on the Magellan 6.5 m telescope. Results: Our data indicate the presence of a planet with a minimum mass of 26 ± 4 Earth masses around the solar twin HIP 68468. The planet is more massive than Neptune (17 Earth masses), but unlike the distant Neptune in our solar system (30 AU), HIP 68468c is close-in, with a semi-major axis of 0.66 AU, similar to that of Venus. The data also suggest the presence of a super-Earth with a minimum mass of 2.9 ± 0.8 Earth masses at 0.03 AU; if the planet is confirmed, it will be the fifth least massive radial velocity planet candidate discovery to date and the first super-Earth around a solar twin. Both isochrones (5.9 ± 0.4 Gyr) and the abundance ratio [Y/Mg] (6.4 ± 0.8 Gyr) indicate an age of about 6 billion years. The star is enhanced in refractory elements when compared to the Sun, and the refractory enrichment is even stronger after corrections for Galactic chemical evolution. We determined a nonlocal thermodynamic equilibrium Li abundance of 1.52 ± 0.03 dex, which is four times higher than what would be expected for the age of HIP 68468. The older age is also supported by the low log () (-5.05) and low jitter (<1 m s-1). Engulfment of a rocky planet of 6 Earth masses can explain the enhancement in both lithium and the

  20. Kepler-15b: A Hot Jupiter Enriched in Heavy Elements and the First Kepler Mission Planet Confirmed with the Hobby-Eberly Telescope

    NASA Astrophysics Data System (ADS)

    Endl, Michael; MacQueen, Phillip J.; Cochran, William D.; Brugamyer, Erik J.; Buchhave, Lars A.; Rowe, Jason; Lucas, Phillip; Isaacson, Howard; Bryson, Steve; Howell, Steve B.; Fortney, Jonathan J.; Hansen, Terese; Borucki, William J.; Caldwell, Douglas; Christiansen, Jessie L.; Ciardi, David R.; Demory, Brice-Olivier; Everett, Mark; Ford, Eric B.; Haas, Michael R.; Holman, Matthew J.; Horch, Elliott; Jenkins, Jon M.; Koch, David J.; Lissauer, Jack J.; Machalek, Pavel; Still, Martin; Welsh, William F.; Sanderfer, Dwight T.; Seader, Shawn E.; Smith, Jeffrey C.; Thompson, Susan E.; Twicken, Joseph D.

    2011-11-01

    We report the discovery of Kepler-15b (KOI-128), a new transiting exoplanet detected by NASA's Kepler mission. The transit signal with a period of 4.94 days was detected in the quarter 1 (Q1) Kepler photometry. For the first time, we have used the High Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) to determine the mass of a Kepler planet via precise radial velocity (RV) measurements. The 24 HET/HRS RVs and 6 additional measurements from the Fibre-fed Échelle Spectrograph spectrograph at the Nordic Optical Telescope reveal a Doppler signal with the same period and phase as the transit ephemeris. We used one HET/HRS spectrum of Kepler-15 taken without the iodine cell to determine accurate stellar parameters. The host star is a metal-rich ([Fe/H] = 0.36 ± 0.07) G-type main-sequence star with T eff = 5515 ± 124 K. The semi-amplitude K of the RV orbit is 78.7+8.5 -9.5 m s-1, which yields a planet mass of 0.66 ± 0.1 M Jup. The planet has a radius of 0.96 ± 0.06 R Jup and a mean bulk density of 0.9 ± 0.2 g cm-3. The radius of Kepler-15b is smaller than the majority of transiting planets with similar mass and irradiation level. This suggests that the planet is more enriched in heavy elements than most other transiting giant planets. For Kepler-15b we estimate a heavy element mass of 30-40 M ⊕. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  1. KEPLER-15b: A HOT JUPITER ENRICHED IN HEAVY ELEMENTS AND THE FIRST KEPLER MISSION PLANET CONFIRMED WITH THE HOBBY-EBERLY TELESCOPE

    SciTech Connect

    Endl, Michael; MacQueen, Phillip J.; Cochran, William D.; Brugamyer, Erik J.; Buchhave, Lars A.; Rowe, Jason; Lucas, Phillip; Isaacson, Howard; Bryson, Steve; Howell, Steve B.; Borucki, William J.; Caldwell, Douglas; Christiansen, Jessie L.; Haas, Michael R.; Fortney, Jonathan J.; Hansen, Terese; Ciardi, David R.; Everett, Mark; Ford, Eric B.; and others

    2011-11-01

    We report the discovery of Kepler-15b (KOI-128), a new transiting exoplanet detected by NASA's Kepler mission. The transit signal with a period of 4.94 days was detected in the quarter 1 (Q1) Kepler photometry. For the first time, we have used the High Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) to determine the mass of a Kepler planet via precise radial velocity (RV) measurements. The 24 HET/HRS RVs and 6 additional measurements from the Fibre-fed Echelle Spectrograph spectrograph at the Nordic Optical Telescope reveal a Doppler signal with the same period and phase as the transit ephemeris. We used one HET/HRS spectrum of Kepler-15 taken without the iodine cell to determine accurate stellar parameters. The host star is a metal-rich ([Fe/H] = 0.36 {+-} 0.07) G-type main-sequence star with T{sub eff} = 5515 {+-} 124 K. The semi-amplitude K of the RV orbit is 78.7{sup +8.5}{sub -9.5} m s{sup -1}, which yields a planet mass of 0.66 {+-} 0.1 M{sub Jup}. The planet has a radius of 0.96 {+-} 0.06 R{sub Jup} and a mean bulk density of 0.9 {+-} 0.2 g cm{sup -3}. The radius of Kepler-15b is smaller than the majority of transiting planets with similar mass and irradiation level. This suggests that the planet is more enriched in heavy elements than most other transiting giant planets. For Kepler-15b we estimate a heavy element mass of 30-40 M{sub Circled-Plus }.

  2. A limit on the presence of Earth-mass planets around a Sun-like star

    SciTech Connect

    Agol, Eric; Steffen, Jason H.; /Fermilab

    2006-10-01

    We present a combined analysis of all publicly available, visible HST observations of transits of the planet HD 209458b. We derive the times of transit, planet radius, inclination, period, and ephemeris. The transit times are then used to constrain the existence of secondary planets in the system. We show that planets near an Earth mass can be ruled out in low-order mean-motion resonance, while planets less than an Earth mass are ruled out in interior, 2:1 resonance. We also present a combined analysis of the transit times and 68 high precision radial velocity measurements of the system. These results are compared to theoretical predictions for the constraints that can be placed on secondary planets.

  3. Securing the Extremely Low-Densities of Low-Mass Planets Characterized by Transit Timing Variations

    NASA Astrophysics Data System (ADS)

    Ford, Eric B.

    2015-12-01

    Transit timing variations (TTVs) provide an excellent tool to characterize the masses and orbits of dozens of small planets, including many at orbital periods beyond the reach of both Doppler surveys and photoevaporation-induced atmospheric loss. Dynamical modeling of these systems has identified low-mass planets with surprisingly large radii and low densities (e.g., Kepler-79d, Jontof-Hutter et al. 2014; Kepler-51, Masuda 2014; Kepler-87c, Ofir et al. 2014). Additional low-density, low-mass planets will likely become public before ESS III (Jontof-Hutter et al. in prep). Collectively, these results suggest that very low density planets with masses of 2-6 MEarth are not uncommon in compact multiple planet systems. Some astronomers have questioned whether there could be an alternative interpretation of the TTV observations. Indeed, extraordinary claims require extraordinary evidence. While the physics of TTVs is rock solid, the statistical analysis of Kepler observations can be challenging, due to the complex interactions between model parameters and high-dimensional parameter spaces that must be explored. We summarize recent advances in computational statistics that enable robust characterization of planetary systems using TTVs. We present updated analyses of a few particularly interesting systems and discuss the implications for the robustness of extremely low densities for low-mass planets. Such planets pose an interesting challenge for planet formation theory and are motivating detailed theoretical studies (e.g., Lee & Chiang 2015 and associated ESS III abstracts).

  4. Chemical composition measurements of the atmosphere of Jupiter with the Galileo Probe mass spectrometer

    NASA Technical Reports Server (NTRS)

    Niemann, H. B.; Atreya, S. K.; Carignan, G. R.; Donahue, T. M.; Haberman, J. A.; Harpold, D. N.; Hartle, R. E.; Hunten, D. M.; Kasprzak, W. T.; Mahaffy, P. R.; Owen, T. C.; Spencer, N. W.

    1998-01-01

    The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995. Measurements of the chemical and isotopic composition of the Jovian atmosphere were obtained by the mass spectrometer during the descent over the 0.5 to 21 bar pressure region over a time period of approximately 1 hour. The sampling was either of atmospheric gases directly introduced into the ion source of the mass spectrometer through capillary leaks or of gas, which had been chemically processed to enhance the sensitivity of the measurement to trace species or noble gases. The analysis of this data set continues to be refined based on supporting laboratory studies on an engineering unit. The mixing ratios of the major constituents of the atmosphere hydrogen and helium have been determined as well as mixing ratios or upper limits for several less abundant species including: methane, water, ammonia, ethane, ethylene, propane, hydrogen sulfide, neon, argon, krypton, and xenon. Analysis also suggests the presence of trace levels of other 3 and 4 carbon hydrocarbons, or carbon and nitrogen containing species, phosphine, hydrogen chloride, and of benzene. The data set also allows upper limits to be set for many species of interest which were not detected. Isotope ratios were measured for 3He/4He, D/H, 13C/12C, 20Ne/22Ne, 38Ar/36Ar and for isotopes of both Kr and Xe.

  5. Catastrophic Collisions in the Terrestrial Planet Zone and the Epoch of Terrestrial Planet Formation around Intermediate Mass Stars

    NASA Astrophysics Data System (ADS)

    Melis, Carl; Zuckerman, B.; Song, I.; Rhee, J. H.; Bessell, M. S.; Murphy, S. J.

    2010-01-01

    We have completed an extensive search for stars hosting terrestrial planet zone dust by cross-correlating the Tycho-2 and IRAS catalogs. Near-infrared to far-infrared excess emission has been discovered towards a 10-20 Myr old, A-type member of the Upper-Centaurus-Lupus association. The hot dust component ( 750 K) in combination with the high fractional infrared luminosity (0.4%) suggest a recent catastrophic collision between rocky bodies in this intermediate mass star's inner planetary system. Synthesis of all published incidences of intermediate mass stars with evidence for terrestrial planet zone dust suggests that catastrophic collisions analogous to the Moon-forming event in our Solar System occur around intermediate mass stars when the star is 10-30 Myr old. Funding for this research came from NASA grants and an LLNL-Minigrant to UCLA and from the Spitzer Visiting Graduate Student Program.

  6. HABITABILITY OF EARTH-MASS PLANETS AND MOONS IN THE KEPLER-16 SYSTEM

    SciTech Connect

    Quarles, B.; Musielak, Z. E.; Cuntz, M. E-mail: zmusielak@uta.edu

    2012-05-01

    We demonstrate that habitable Earth-mass planets and moons can exist in the Kepler-16 system, known to host a Saturn-mass planet around a stellar binary, by investigating their orbital stability in the standard and extended habitable zone (HZ). We find that Earth-mass planets in satellite-like (S-type) orbits are possible within the standard HZ in direct vicinity of Kepler-16b, thus constituting habitable exomoons. However, Earth-mass planets cannot exist in planetary-like (P-type) orbits around the two stellar components within the standard HZ. Yet, P-type Earth-mass planets can exist superior to the Saturnian planet in the extended HZ pertaining to considerably enhanced back-warming in the planetary atmosphere if facilitated. We briefly discuss the potential detectability of such habitable Earth-mass moons and planets positioned in satellite and planetary orbits, respectively. The range of inferior and superior P-type orbits in the HZ is between 0.657-0.71 AU and 0.95-1.02 AU, respectively.

  7. ORBITAL MIGRATION OF LOW-MASS PLANETS IN EVOLUTIONARY RADIATIVE MODELS: AVOIDING CATASTROPHIC INFALL

    SciTech Connect

    Lyra, Wladimir; Mac Low, Mordecai-Mark; Paardekooper, Sijme-Jan E-mail: mordecai@amnh.or

    2010-06-01

    Outward migration of low-mass planets has recently been shown to be a possibility in non-barotropic disks. We examine the consequences of this result in evolutionary models of protoplanetary disks. Planet migration occurs toward equilibrium radii with zero torque. These radii themselves migrate inwards because of viscous accretion and photoevaporation. We show that as the surface density and temperature fall the planet orbital migration and disk depletion timescales eventually become comparable, with the precise timing depending on the mass of the planet. When this occurs, the planet decouples from the equilibrium radius. At this time, however, the gas surface density is already too low to drive substantial further migration. A higher mass planet, of 10 M {sub +}, can open a gap during the late evolution of the disk, and stops migrating. Low-mass planets, with 1 or 0.1 M {sub +}, released beyond 1 AU in our models avoid migrating into the star. Our results provide support for the reduced migration rates adopted in recent planet population synthesis models.

  8. Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars

    NASA Astrophysics Data System (ADS)

    Jones, M. I.; Jenkins, J. S.; Brahm, R.; Wittenmyer, R. A.; Olivares E., F.; Melo, C. H. F.; Rojo, P.; Jordán, A.; Drass, H.; Butler, R. P.; Wang, L.

    2016-05-01

    Context. Exoplanet searches have revealed interesting correlations between the stellar properties and the occurrence rate of planets. In particular, different independent surveys have demonstrated that giant planets are preferentially found around metal-rich stars and that their fraction increases with the stellar mass. Aims: During the past six years we have conducted a radial velocity follow-up program of 166 giant stars to detect substellar companions and to characterize their orbital properties. Using this information, we aim to study the role of the stellar evolution in the orbital parameters of the companions and to unveil possible correlations between the stellar properties and the occurrence rate of giant planets. Methods: We took multi-epoch spectra using FEROS and CHIRON for all of our targets, from which we computed precision radial velocities and derived atmospheric and physical parameters. Additionally, velocities computed from UCLES spectra are presented here. By studying the periodic radial velocity signals, we detected the presence of several substellar companions. Results: We present four new planetary systems around the giant stars HIP 8541, HIP 74890, HIP 84056, and HIP 95124. Additionally, we study the correlation between the occurrence rate of giant planets with the stellar mass and metallicity of our targets. We find that giant planets are more frequent around metal-rich stars, reaching a peak in the detection of f = 16.7+15.5-5.9% around stars with [Fe/H] ~ 0.35 dex. Similarly, we observe a positive correlation of the planet occurrence rate with the stellar mass, between M⋆ ~ 1.0 and 2.1 M⊙, with a maximum of f = 13.0+10.1-4.2% at M⋆ = 2.1 M⊙. Conclusions: We conclude that giant planets are preferentially formed around metal-rich stars. In addition, we conclude that they are more efficiently formed around more massive stars, in the stellar mass range of ~1.0-2.1 M⊙. These observational results confirm previous findings for solar

  9. Trojan twin planets

    NASA Astrophysics Data System (ADS)

    Dvorak, R.; Loibnegger, B.; Schwarz, R.

    2017-03-01

    The Trojan asteroids are moving in the vicinity of the stable Lagrange points L_4 and L_5 of the gas giants Jupiter, Uranus and Neptune. Their motion can be described and understood with the aid of the restricted three-body problem. As an extension of this problem we investigate how stable motion close to the Lagrange points of two massive bodies can exist. This configuration can be described as the Trojan Twin Problem when we regard the two additional bodies as having a mass significantly smaller than the the two primary bodies: a star in the center (m_1) and an additional Jupiter-like mass (m_2). Using this 4-body problem we have undertaken numerical investigations concerning possible stable "twin orbits". However, these two bodies (m_3 and m_4) in Trojan-like orbits may have quite different masses. We decided to choose 6 different scenaria for this problem: as primary body, m2, we have taken a Jupiter-like planet, a Saturn-like one, and a super-Earth with 10 Earthmasses (m_{Earth}) respectively. As quasi twin planets, we have used different mass ratios namely objects for m3 and m4 from 10m_{Earth} to Moon like ones. We found different stable configurations depending on the involved masses and the initial distances between the twins (always close to the Lagrange point). Although the formation of such a configuration seems to be not very probable we should not exclude that it exists regarding the huge number of planets even in our own galaxy. This model is of special interest when the most massive planet (m_2) is moving on an orbit in the habitable zone around a main sequence star. One can use our results of stable orbits of Trojan Twin Planets (or asteroids) for extrasolar systems having as second primary a Jupiter-like, a Saturn-like or a super-Earth like planet around a star similar to our Sun.

  10. Planet Hunters. VII. Discovery of a New Low-mass, Low-density Planet (PH3 C) Orbiting Kepler-289 with Mass Measurements of Two Additional Planets (PH3 B and D)

    NASA Astrophysics Data System (ADS)

    Schmitt, Joseph R.; Agol, Eric; Deck, Katherine M.; Rogers, Leslie A.; Gazak, J. Zachary; Fischer, Debra A.; Wang, Ji; Holman, Matthew J.; Jek, Kian J.; Margossian, Charles; Omohundro, Mark R.; Winarski, Troy; Brewer, John M.; Giguere, Matthew J.; Lintott, Chris; Lynn, Stuart; Parrish, Michael; Schawinski, Kevin; Schwamb, Megan E.; Simpson, Robert; Smith, Arfon M.

    2014-11-01

    We report the discovery of one newly confirmed planet (P = 66.06 days, R P = 2.68 ± 0.17 R ⊕) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R P = 2.15 ± 0.10 R ⊕) and Kepler-289-c (P = 125.85 days, R P = 11.59 ± 0.10 R ⊕), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a 1:2:4 Laplace resonance. The outer planet has very deep (~1.3%), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young (~1 Gyr as determined by isochrones and gyrochronology), Sun-like star with M * = 1.08 ± 0.02 M ⊙, R * = 1.00 ± 0.02 R ⊙, and T eff = 5990 ± 38 K. The middle planet's large TTV amplitude (~5 hr) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allows us to break the mass-eccentricity degeneracy and uniquely determine the masses of the inner, middle, and outer planets to be M = 7.3 ± 6.8 M ⊕, 4.0 ± 0.9M ⊕, and M = 132 ± 17 M ⊕, which we designate PH3 b, c, and d, respectively. Furthermore, the middle planet, PH3 c, has a relatively low density, ρ = 1.2 ± 0.3 g cm-3 for a planet of its mass, requiring a substantial H/He atmosphere of 2.1+0.8-0.3% by mass, and joins a growing population of low-mass, low-density planets. .

  11. Friends of Hot Jupiters. I. A Radial Velocity Search for Massive, Long-period Companions to Close-in Gas Giant Planets

    NASA Astrophysics Data System (ADS)

    Knutson, Heather A.; Fulton, Benjamin J.; Montet, Benjamin T.; Kao, Melodie; Ngo, Henry; Howard, Andrew W.; Crepp, Justin R.; Hinkley, Sasha; Bakos, Gaspar Á.; Batygin, Konstantin; Johnson, John Asher; Morton, Timothy D.; Muirhead, Philip S.

    2014-04-01

    In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 planets obtained using the Keck HIRES instrument, and find statistically significant accelerations in fifteen systems. Six of these systems have no previously reported accelerations in the published literature: HAT-P-10, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 adaptive optics (AO) imaging data to place constraints on the allowed masses and orbital periods of the companions responsible for the detected accelerations. The estimated masses of the companions range between 1-500 M Jup, with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the transiting planets in these systems, making them candidates for influencing the orbital evolution of the inner gas giant. We estimate a total occurrence rate of 51% ± 10% for companions with masses between 1-13 M Jup and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions to transiting planets with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the planets included in our survey.

  12. Friends of hot Jupiters. I. A radial velocity search for massive, long-period companions to close-in gas giant planets

    SciTech Connect

    Knutson, Heather A.; Ngo, Henry; Johnson, John Asher; Fulton, Benjamin J.; Howard, Andrew W.; Montet, Benjamin T.; Kao, Melodie; Hinkley, Sasha; Morton, Timothy D.; Muirhead, Philip S.; Crepp, Justin R.; Bakos, Gaspar Á.; Batygin, Konstantin

    2014-04-20

    In this paper we search for distant massive companions to known transiting gas giant planets that may have influenced the dynamical evolution of these systems. We present new radial velocity observations for a sample of 51 planets obtained using the Keck HIRES instrument, and find statistically significant accelerations in fifteen systems. Six of these systems have no previously reported accelerations in the published literature: HAT-P-10, HAT-P-22, HAT-P-29, HAT-P-32, WASP-10, and XO-2. We combine our radial velocity fits with Keck NIRC2 adaptive optics (AO) imaging data to place constraints on the allowed masses and orbital periods of the companions responsible for the detected accelerations. The estimated masses of the companions range between 1-500 M {sub Jup}, with orbital semi-major axes typically between 1-75 AU. A significant majority of the companions detected by our survey are constrained to have minimum masses comparable to or larger than those of the transiting planets in these systems, making them candidates for influencing the orbital evolution of the inner gas giant. We estimate a total occurrence rate of 51% ± 10% for companions with masses between 1-13 M {sub Jup} and orbital semi-major axes between 1-20 AU in our sample. We find no statistically significant difference between the frequency of companions to transiting planets with misaligned or eccentric orbits and those with well-aligned, circular orbits. We combine our expanded sample of radial velocity measurements with constraints from transit and secondary eclipse observations to provide improved measurements of the physical and orbital characteristics of all of the planets included in our survey.

  13. Formation of the giant planets

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2006-01-01

    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, which could not have condensed into solid planetesimals within the protoplanetary disk. All three (transiting) extrasolar giant planets with well determined masses and radii also must contain substantial amounts of these light gases. 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. HD 149026 b, which is slightly more massive than is Saturn, appears to have comparable quantities of light gases and heavy elements. HD 209458 b and TrES-1 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 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 growing giant planet cores become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary questions regarding the core nucleated growth model is under what conditions

  14. A closely packed system of low-mass, low-density planets transiting Kepler-11.

    PubMed

    Lissauer, Jack J; Fabrycky, Daniel C; Ford, Eric B; Borucki, William J; Fressin, Francois; Marcy, Geoffrey W; Orosz, Jerome A; Rowe, Jason F; Torres, Guillermo; Welsh, William F; Batalha, Natalie M; Bryson, Stephen T; Buchhave, Lars A; Caldwell, Douglas A; Carter, Joshua A; Charbonneau, David; Christiansen, Jessie L; Cochran, William D; Desert, Jean-Michel; Dunham, Edward W; Fanelli, Michael N; Fortney, Jonathan J; Gautier, Thomas N; Geary, John C; Gilliland, Ronald L; Haas, Michael R; Hall, Jennifer R; Holman, Matthew J; Koch, David G; Latham, David W; Lopez, Eric; McCauliff, Sean; Miller, Neil; Morehead, Robert C; Quintana, Elisa V; Ragozzine, Darin; Sasselov, Dimitar; Short, Donald R; Steffen, Jason H

    2011-02-03

    When an extrasolar planet passes in front of (transits) its star, its radius can be measured from the decrease in starlight and its orbital period from the time between transits. Multiple planets transiting the same star reveal much more: period ratios determine stability and dynamics, mutual gravitational interactions reflect planet masses and orbital shapes, and the fraction of transiting planets observed as multiples has implications for the planarity of planetary systems. But few stars have more than one known transiting planet, and none has more than three. Here we report Kepler spacecraft observations of a single Sun-like star, which we call Kepler-11, that reveal six transiting planets, five with orbital periods between 10 and 47 days and a sixth planet with a longer period. The five inner planets are among the smallest for which mass and size have both been measured, and these measurements imply substantial envelopes of light gases. The degree of coplanarity and proximity of the planetary orbits imply energy dissipation near the end of planet formation.

  15. Influence of solar flares and CME on the gaseous envelopes of hot Jupiter exoplanets

    NASA Astrophysics Data System (ADS)

    Bisikalo, Dmitry; Cherenkov, Alexander

    2015-08-01

    Hot Jupiters, i.e. exoplanets having masses comparable to the mass of Jupiter and semimajor axes shorter than 0.1~AU, have a number of outstanding features, caused mostly by their proximity to the host star. As a matter of fact, the atmospheres of several dozens of these planets fill their Roche lobes, which results in a powerful outflow of material from the planet toward the host star. In addition, since the planet orbits at a short distance, its orbital velocity is supersonic, which causes the formation of a bow shock ahead of the planet. These effects substantially change the mechanism of interaction between the planet's gaseous envelope (atmosphere) and the stellar wind. In this paper, we investigate the flow pattern in the vicinity of a typical hot Jupiter by using 3D gas dynamic simulations. By considering the star-planet interaction we study variations in the structure of the hot Jupiter's envelope and estimate the variations of atmosphere’s mass-loss rate caused by the influence of typical solar flares and coronal mass ejections.

  16. DIRECTLY IMAGING TIDALLY POWERED MIGRATING JUPITERS

    SciTech Connect

    Dong Subo; Katz, Boaz; Socrates, Aristotle

    2013-01-10

    Upcoming direct-imaging experiments may detect a new class of long-period, highly luminous, tidally powered extrasolar gas giants. Even though they are hosted by {approx} Gyr-'old' main-sequence stars, they can be as 'hot' as young Jupiters at {approx}100 Myr, the prime targets of direct-imaging surveys. They are on years-long orbits and presently migrating to 'feed' the 'hot Jupiters'. They are expected from 'high-e' migration mechanisms, in which Jupiters are excited to highly eccentric orbits and then shrink semimajor axis by a factor of {approx}10-100 due to tidal dissipation at close periastron passages. The dissipated orbital energy is converted to heat, and if it is deposited deep enough into the atmosphere, the planet likely radiates steadily at luminosity L {approx} 100-1000 L{sub Jup}(2 Multiplication-Sign 10{sup -7}-2 Multiplication-Sign 10{sup -6} L{sub Sun }) during a typical {approx} Gyr migration timescale. Their large orbital separations and expected high planet-to-star flux ratios in IR make them potentially accessible to high-contrast imaging instruments on 10 m class telescopes. {approx}10 such planets are expected to exist around FGK dwarfs within {approx}50 pc. Long-period radial velocity planets are viable candidates, and the highly eccentric planet HD 20782b at maximum angular separation {approx}0.''08 is a promising candidate. Directly imaging these tidally powered Jupiters would enable a direct test of high-e migration mechanisms. Once detected, the luminosity would provide a direct measurement of the migration rate, and together with mass (and possibly radius) estimate, they would serve as a laboratory to study planetary spectral formation and tidal physics.

  17. Reevaluating the feasibility of ground-based Earth-mass microlensing planet detections

    SciTech Connect

    Jung, Youn Kil; Park, Hyuk; Han, Cheongho; Hwang, Kyu-Ha; Shin, In-Gu; Choi, Joon-Young

    2014-05-10

    An important strength of the microlensing method to detect extrasolar planets is its high sensitivity to low-mass planets. However, many believe that microlensing detections of Earth-mass planets from ground-based observation would be difficult because of limits set by finite-source effects. This view comes from the previous estimation of planet detection probability based on the fractional deviation of planetary signals; however, a proper probability estimation is required when considering the source brightness, which is directly related to the photometric precision. In this paper, we reevaluate the feasibility of low-mass planet detections by considering photometric precision for different populations of source stars. From this, we find that the contribution of improved photometric precision to the planetary signal of a giant-source event is large enough to compensate for the decrease in magnification excess caused by finite-source effects. As a result, we conclude that giant-source events are suitable targets for Earth-mass planet detections with significantly higher detection probability than events involved with source stars of smaller radii, and we predict that Earth-mass planets could be detected by prospective high-cadence surveys.

  18. Constraining Planetary Migration Mechanisms in Systems of Giant Planets

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Murray-Clay, Ruth A.; Johnson, John Asher

    2014-01-01

    It was once widely believed that planets formed peacefully in situ in their proto-planetary disks and subsequently remain in place. Instead, growing evidence suggests that many giant planets undergo dynamical rearrangement that results in planets migrating inward in the disk, far from their birthplaces. However, it remains debated whether this migration is caused by smooth planet-disk interactions or violent multi-body interactions. Both classes of model can produce Jupiter-mass planets orbiting within 0.1 AU of their host stars, also known as hot Jupiters. In the latter class of model, another planet or star in the system perturbs the Jupiter onto a highly eccentric orbit, which tidal dissipation subsequently shrinks and circularizes during close passages to the star. We assess the prevalence of smooth vs. violent migration through two studies. First, motivated by the predictions of Socrates et al. (2012), we search for super-eccentric hot Jupiter progenitors by using the ``photoeccentric effect'' to measure the eccentricities of Kepler giant planet candidates from their transit light curves. We find a significant lack of super- eccentric proto-hot Jupiters compared to the number expected, allowing us to place an upper limit on the fraction of hot Jupiters created by stellar binaries. Second, if both planet-disk and multi-body interactions commonly cause giant planet migration, physical properties of the proto-planetary environment may determine which is triggered. We identify three trends in which giant planets orbiting metal rich stars show signatures of planet-planet interactions: (1) gas giants orbiting within 1 AU of metal-rich stars have a range of eccentricities, whereas those orbiting metal- poor stars are restricted to lower eccentricities; (2) metal-rich stars host most eccentric proto-hot Jupiters undergoing tidal circularization; and (3) the pile-up of short-period giant planets, missing in the Kepler sample, is a feature of metal-rich stars and is

  19. Techniques for Constraining the Population of Small Close-in Planets Around Subgiants

    NASA Astrophysics Data System (ADS)

    Medina, Amber; Johnson, John A.

    2017-01-01

    Intermediate mass stars ( > 1.3 solar masses) have high occurrence rates of Jupiter mass planets in predominately long period orbits (a ~1.0 AU). However, there is a prominent gap in the planet occurrence rate for low mass planets (i.e.; super-Earths and Neptunes) < 0.5 AU from subgiants, the evolved counterpart to intermediate mass stars, known colloquially as the "Planet Desert. Thus far, using current radial velocity methods, we have not been able to detect low-mass, short period planets around subgiants due to noise from p-mode oscillations which may mimic radial velocity signals (~5 m/s) from planets in this close-in regime. Here we present our technique and preliminary results in our work towards finding elusive low-mass, short-period planets around subgiants and its implications for the Planet Desert.

  20. The Europa Jupiter system mission

    NASA Astrophysics Data System (ADS)

    Clark, K.; Stankov, A.; Pappalardo, R. T.; Greeley, R.; Blanc, M.; Lebreton, J.-P.; van Houten, T.

    2009-04-01

    Europa Jupiter System Mission (EJSM)— would be an international mission that would achieve Decadal Survey and Cosmic Vision goals. NASA and ESA have concluded a joint study of a mission to Europa, Ganymede and the Jupiter system with orbiters developed by NASA and ESA; contributions by JAXA are also possible. The baseline EJSM architecture consists of two primary elements operating in the Jovian system: the NASA-led Jupiter Europa Orbiter (JEO), and the ESA-led Jupiter Ganymede Orbiter (JGO). JEO and JGO would execute an intricately choreographed exploration of the Jupiter System be-fore settling into orbit around Europa and Ganymede, respectively. JEO and JGO would carry eleven and ten complementary instruments, respectively, to monitor dynamic phenomena (such as Io's volcanoes and Jupi-ter's atmosphere), map the Jovian magnetosphere and its interactions with the Galilean satellites, and charac-terize water oceans beneath the ice shells of Europa and Ganymede. EJSM would fully addresses high priority science objectives identified by the National Research Coun-cil's (NRC's) Decadal Survey and ESA's Cosmic Vi-sion for exploration of the outer solar system. The De-cadal Survey recommended a Europa Orbiter as the highest priority outer planet flagship mission and also identified Ganymede as a highly desirable mission tar-get. EJSM would uniquely addresse several of the cen-tral themes of ESA's Cosmic Vision Programme, through its in-depth exploration of the Jupiter system and its evolution from origin to habitability. EJSM would investigate the potential habitability of the active ocean-bearing moons Europa and Gany-mede, detailing the geophysical, compositional, geo-logical, and external processes that affect these icy worlds. EJSM would also explore Io and Callisto, Jupi-ter's atmosphere, and the Jovian magnetosphere. By understanding the Jupiter system and unraveling its history, the formation and evolution of gas giant plan-ets and their satellites would be

  1. The Europa Jupiter System Mission

    NASA Astrophysics Data System (ADS)

    Hendrix, A. R.; Clark, K.; Erd, C.; Pappalardo, R.; Greeley, R. R.; Blanc, M.; Lebreton, J.; van Houten, T.

    2009-05-01

    formation and evolution of gas giant planets and their satellites will be better known. Most important, EJSM will shed new light on the potential for the emergence of life in the celestial neighborhood and beyond. The EJSM mission architecture provides opportunities for coordinated synergistic observations by JEO and JGO of the Jupiter and Ganymede magnetospheres, the volcanoes and torus of Io, the atmosphere of Jupiter, and comparative planetology of icy satellites. Each spacecraft could and would conduct "stand-alone" measurements, including the detailed investigation of Europa and Ganymede, providing significant programmatic flexibility. Although engineering advances are needed for JEO (radiation designs) and JGO, no new technologies will be required to execute either EJSM mission element. The development schedule for the mission is such that a technology developed by 2012 - 2013 could easily be incorporated if it enhances the mission capability. Risk mitigation activities are under way to ensure that the radiation designs are implemented in the lowest-risk approach. The baseline mission concepts include robust mass and power margins.

  2. Taxonomy of the extrasolar planet.

    PubMed

    Plávalová, Eva

    2012-04-01

    When a star is described as a spectral class G2V, we know that the star is similar to our Sun. We know its approximate mass, temperature, age, and size. When working with an extrasolar planet database, it is very useful to have a taxonomy scale (classification) such as, for example, the Harvard classification for stars. The taxonomy has to be easily interpreted and present the most relevant information about extrasolar planets. I propose an extrasolar planet taxonomy scale with four parameters. The first parameter concerns the mass of an extrasolar planet in the form of units of the mass of other known planets, where M represents the mass of Mercury, E that of Earth, N Neptune, and J Jupiter. The second parameter is the planet's distance from its parent star (semimajor axis) described in a logarithm with base 10. The third parameter is the mean Dyson temperature of the extrasolar planet, for which I established four main temperature classes: F represents the Freezing class, W the Water class, G the Gaseous class, and R the Roasters class. I devised one additional class, however: P, the Pulsar class, which concerns extrasolar planets orbiting pulsar stars. The fourth parameter is eccentricity. If the attributes of the surface of the extrasolar planet are known, we are able to establish this additional parameter where t represents a terrestrial planet, g a gaseous planet, and i an ice planet. According to this taxonomy scale, for example, Earth is 1E0W0t, Neptune is 1N1.5F0i, and extrasolar planet 55 Cnc e is 9E-1.8R1.

  3. ON THE TIDAL ORIGIN OF HOT JUPITER STELLAR OBLIQUITY TRENDS

    SciTech Connect

    Dawson, Rebekah I.

    2014-08-01

    It is debated whether the two hot Jupiter populations—those on orbits misaligned from their host star's spin axis and those well-aligned—result from two migration channels or from two tidal realignment regimes. Here I demonstrate that equilibrium tides raised by a planet on its star can account for three observed spin-orbit alignment trends: the aligned orbits of hot Jupiters orbiting cool stars, the planetary mass cut-off for retrograde planets, and the stratification by planet mass of cool host stars' rotation frequencies. The first trend can be caused by strong versus weak magnetic braking (the Kraft break), rather than realignment of the star's convective envelope versus the entire star. The second trend can result from a small effective stellar moment of inertia participating in the tidal realignment in hot stars, enabling massive retrograde planets to partially realign to become prograde. The third trend is attributable to higher-mass planets more effectively counteracting braking to spin up their stars. Both hot and cool stars require a small effective stellar moment of inertia participating in the tidal realignment, e.g., an outer layer weakly coupled to the interior. I demonstrate via Monte Carlo that this model can match the observed trends and distributions of sky-projected misalignments and stellar rotation frequencies. I discuss implications for inferring hot Jupiter migration mechanisms from obliquities, emphasizing that even hot stars do not constitute a pristine sample.

  4. Constraining Planetary Migration Mechanisms with Highly Eccentric Hot Jupiter Progenitors

    NASA Astrophysics Data System (ADS)

    Dawson, Rebekah I.; Johnson, J. A.; Murray-Clay, R.; Morton, T.; Crepp, J. R.; Fabrycky, D. C.; Howard, A.

    2013-01-01

    Abstract: Hot Jupiters --- Jupiter-mass planets orbiting within 0.1 AU of their host stars --- are unlikely to have formed in situ and thus serve as evidence for the prevalence of planetary migration. However, it is debated whether the typical hot Jupiter migrated smoothly inward through the protoplanetary disk or was perturbed onto an eccentric orbit, which tidal dissipation subsequently shrank and circularized during close passages to the star. In the latter class of model, the perturber may be a stellar or planetary companion, which causes the Jupiter to undergo a temporary epoch with high eccentricity (e> 0.9). Socrates and et al. (2012) predicted that these super-eccentric hot Jupiter progenitors should be readily discoverable through the transit method by the Kepler Mission. However, eccentricities of individual transiting planets primarily come from Doppler measurements, which are unfortunately precluded by the faintness of most Kepler targets. To solve this problem, we developed a Bayesian method (the “photoeccentric effect”) for measuring an individual planet's eccentricity solely from its Kepler light curve, allowing for a tight measurement of large eccentricities. We applied this new approach to the Kepler giant planet candidates and identified KOI-1474.01 as an eccentric planet (e = 0.81+0.10/-0.07) with an average orbital period of 69.7340 days, varying by approximately 1 hour due to perturbations by a massive outer companion, which is possibly the culprit responsible for KOI-1474.01’s highly eccentric orbit. KOI-1474.01 is likely a failed hot Jupiter, too far from its host star to be tidally transformed into a hot Jupiter. We found a significant lack of super-eccentric proto-hot Jupiters compared to the number expected, allowing us to place a strong upper limit on the fraction of hot Jupiters created by stellar binaries. Our results are consistent with disks or planetary companions being the primary channel for hot Jupiter creation. Supported by

  5. Migration of accreting giant planets

    NASA Astrophysics Data System (ADS)

    Crida, A.; Bitsch, B.; Raibaldi, A.

    2016-12-01

    We present the results of 2D hydro simulations of giant planets in proto-planetary discs, which accrete gas at a more or less high rate. First, starting from a solid core of 20 Earth masses, we show that as soon as the runaway accretion of gas turns on, the planet is saved from type I migration : the gap opening mass is reached before the planet is lost into its host star. Furthermore, gas accretion helps opening the gap in low mass discs. Consequently, if the accretion rate is limited to the disc supply, then the planet is already inside a gap and in type II migration. We further show that the type II migration of a Jupiter mass planet actually depends on its accretion rate. Only when the accretion is high do we retrieve the classical picture where no gas crosses the gap and the planet follows the disc spreading. These results impact our understanding of planet migration and planet population synthesis models. The e-poster presenting these results in French can be found here: L'e-poster présentant ces résultats en français est disponible à cette adresse: http://sf2a.eu/semaine-sf2a/2016/posterpdfs/156_179_49.pdf.

  6. SHORT-DURATION LENSING EVENTS. I. WIDE-ORBIT PLANETS? FREE-FLOATING LOW-MASS OBJECTS? OR HIGH-VELOCITY STARS?

    SciTech Connect

    Di Stefano, Rosanne

    2012-08-01

    Short-duration lensing events tend to be generated by low-mass lenses or by lenses with high transverse velocities. Furthermore, for any given lens mass and speed, events of short duration are preferentially caused by nearby lenses (mesolenses) that can be studied in detail, or else by lenses so close to the source star that finite-source-size effects may be detected, yielding information about both the Einstein ring radius and the surface of the lensed star. Planets causing short-duration events may be in orbits with any orientation, and may have semimajor axes smaller than 1 AU, or they may reach the outer limits of their planetary systems, in the region corresponding to the solar system's Oort Cloud. They can have masses larger than Jupiter's or smaller than Pluto's. Lensing therefore has a unique potential to expand our understanding of planetary systems. A particular advantage of lensing is that it can provide precision measurements of system parameters, including the masses of and projected separation between star and planet. We demonstrate how the parameters can be extracted and show that a great deal can be learned. For example, it is remarkable that the gravitational mass of nearby free-floating planet-mass lenses can be measured by complementing observations of a photometric event with deep images that detect the planet itself. A fraction of short events may be caused by high-velocity stars located within a kiloparsec. Many high-velocity lenses are likely to be neutron stars that received large natal kicks. Other high-speed stars may be members of the halo population. Still others may be hypervelocity stars that have been ejected from the Galactic center, or runaway stars escaped from close binaries, possibly including the progenitor binaries of Type Ia supernovae.

  7. Short-duration Lensing Events. I. Wide-orbit Planets? Free-floating Low-mass Objects? Or High-velocity Stars?

    NASA Astrophysics Data System (ADS)

    Di Stefano, Rosanne

    2012-08-01

    Short-duration lensing events tend to be generated by low-mass lenses or by lenses with high transverse velocities. Furthermore, for any given lens mass and speed, events of short duration are preferentially caused by nearby lenses (mesolenses) that can be studied in detail, or else by lenses so close to the source star that finite-source-size effects may be detected, yielding information about both the Einstein ring radius and the surface of the lensed star. Planets causing short-duration events may be in orbits with any orientation, and may have semimajor axes smaller than 1 AU, or they may reach the outer limits of their planetary systems, in the region corresponding to the solar system's Oort Cloud. They can have masses larger than Jupiter's or smaller than Pluto's. Lensing therefore has a unique potential to expand our understanding of planetary systems. A particular advantage of lensing is that it can provide precision measurements of system parameters, including the masses of and projected separation between star and planet. We demonstrate how the parameters can be extracted and show that a great deal can be learned. For example, it is remarkable that the gravitational mass of nearby free-floating planet-mass lenses can be measured by complementing observations of a photometric event with deep images that detect the planet itself. A fraction of short events may be caused by high-velocity stars located within a kiloparsec. Many high-velocity lenses are likely to be neutron stars that received large natal kicks. Other high-speed stars may be members of the halo population. Still others may be hypervelocity stars that have been ejected from the Galactic center, or runaway stars escaped from close binaries, possibly including the progenitor binaries of Type Ia supernovae.

  8. Kepler’s Low-Mass, Low Density Planets Characterized via Transit Timing

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Ford, Eric B.; Lissauer, Jack; Rowe, Jason; Fabrycky, Daniel

    2015-08-01

    The Kepler mission has revealed an abundance of planets in a regime of mass and size that is absent from the Solar System. This includes systems of high multiplicity within 1 AU, where low-mass volatile-rich planets have been observed in compact orbital configurations, as have smaller, rocky planets. The existing sample of characterized planets on the mass-radius diagram shows no abrupt transition from rocky planets to those that must be volatile-rich, but characteristic trends are beginning to emerge. More precise characterizations of planets by mass, radius, and incident flux are revealing fundamental properties of a common class of exoplanets.There is a small sample of low mass exoplanets with known masses and radii, whose radii are known from transit depths, and whose masses are determined from radial velocity spectroscopy (RV). In the super-Earth mass range, detectability limits this sample to planets that have short orbital periods, and high incident fluxes.In the absence of mass determinations via RV observations, transit timing variations (TTVs) offer a chance to probe perturbations between planets that pass close to one another or are near resonance, and hence dynamical fits to observed transit times can be used to measure planetary masses and orbital parameters. Such modeling with Kepler data probes planetary masses over orbital periods ranging from ~5-200 days, complementing the sample of RV detections, but also with some overlap.In addition, dynamical fits to observed TTVs can tightly constrain the orbital eccentricity vectors in select cases, which can, alongside the transit light curve, tightly constrain the density and radius of the host star, and hence reduce the uncertainty on planetary radius.TTV studies have revealed a class of low-mass, low-density objects with a substantial mass fraction in the form of a voluminous H-rich atmosphere. We will present new precise planetary mass characterizations from TTVs. We find that super-Earth mass planets

  9. A Day on Jupiter (Animation)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This 'movie' strings 11 images of Jupiter captured by the New Horizons Long Range Reconnaissance Imager (LORRI) on January 9, 2007, when the spacecraft was about 80 million kilometers (49.6 million miles) from the giant planet. The sequence covers a full 10-hour rotation of Jupiter, during which the moons Ganymede and Io -- as well as the shadows they cast on Jupiter -- move across the camera's field of view.

  10. CONSEQUENCES OF THE EJECTION AND DISRUPTION OF GIANT PLANETS

    SciTech Connect

    Guillochon, James; Ramirez-Ruiz, Enrico; Lin, Douglas

    2011-05-10

    The discovery of Jupiter-mass planets in close orbits about their parent stars has challenged models of planet formation. Recent observations have shown that a number of these planets have highly inclined, sometimes retrograde orbits about their parent stars, prompting much speculation as to their origin. It is known that migration alone cannot account for the observed population of these misaligned hot Jupiters, which suggests that dynamical processes after the gas disk dissipates play a substantial role in yielding the observed inclination and eccentricity distributions. One particularly promising candidate is planet-planet scattering, which is not very well understood in the nonlinear regime of tides. Through three-dimensional hydrodynamical simulations of multi-orbit encounters, we show that planets that are scattered into an orbit about their parent stars with closest approach distance being less than approximately three times the tidal radius are either destroyed or completely ejected from the system. We find that as few as 9 and as many as 12 of the currently known hot Jupiters have a maximum initial apastron for scattering that lies well within the ice line, implying that these planets must have migrated either before or after the scattering event that brought them to their current positions. If stellar tides are unimportant (Q{sub *} {approx}> 10{sup 7}), disk migration is required to explain the existence of the hot Jupiters present in these systems. Additionally, we find that the disruption and/or ejection of Jupiter-mass planets deposits a Sun's worth of angular momentum onto the host star. For systems in which planet-planet scattering is common, we predict that planetary hosts have up to a 35% chance of possessing an obliquity relative to the invariable plane of greater than 90{sup 0}.

  11. Atmospheric escape by magnetically driven wind from gaseous planets

    SciTech Connect

    Tanaka, Yuki A.; Suzuki, Takeru K.; Inutsuka, Shu-ichiro

    2014-09-01

    We calculate the mass loss driven by magnetohydrodynamic (MHD) waves from hot Jupiters by using MHD simulations in one-dimensional flux tubes. If a gaseous planet has a magnetic field, MHD waves are excited by turbulence at the surface, dissipate in the upper atmosphere, and drive gas outflows. Our calculation shows that mass-loss rates are comparable to the observed mass-loss rates of hot Jupiters; therefore, it is suggested that gas flow driven by MHD waves can play an important role in the mass loss from gaseous planets. The mass-loss rate varies dramatically with the radius and mass of a planet: a gaseous planet with a small mass but an inflated radius produces a very large mass-loss rate. We also derive an analytical expression for the dependence of mass-loss rate on planet radius and mass that is in good agreement with the numerical calculation. The mass-loss rate also depends on the amplitude of the velocity dispersion at the surface of a planet. Thus, we expect to infer the condition of the surface and the internal structure of a gaseous planet from future observations of mass-loss rate from various exoplanets.

  12. Stability of Earth-mass Planets in the Kepler-68 System

    NASA Astrophysics Data System (ADS)

    Kane, Stephen R.

    2015-11-01

    A key component of characterizing multi-planet exosystems is testing the orbital stability based on the observed properties. Such characterization not only tests the validity of how observations are interpreted but can also place additional constraints upon the properties of the detected planets. The Kepler mission has identified hundreds of multi-planet systems but there are a few that have additional non-transiting planets and also have well characterized host stars. Kepler-68 is one such system for which we are able to provide a detailed study of the orbital dynamics. We use the stellar parameters to calculate the extent of the habitable zone (HZ) for this system, showing that the outer planet lies within that region. We use N-body integrations to study the orbital stability of the system, in particular placing an orbital inclination constraint on the outer planet of i > 5°. Finally, we present the results of an exhaustive stability simulation that investigates possible locations of stable orbits for an Earth-mass planet. We show that there are several islands of stability within the HZ that could harbor such a planet, most particularly at the 2:3 mean motion resonance with the outer planet.

  13. A HOT GAP AROUND JUPITER'S ORBIT IN THE SOLAR NEBULA

    SciTech Connect

    Turner, N. J.; Choukroun, M.; Castillo-Rogez, J.; Bryden, G.

    2012-04-01

    The Sun was an order of magnitude more luminous during the first few hundred thousand years of its existence, due in part to the gravitational energy released by material accreting from the solar nebula. If Jupiter was already near its present mass, the planet's tides opened an optically thin gap in the nebula. Using Monte Carlo radiative transfer calculations, we show that sunlight absorbed by the nebula and re-radiated into the gap raised temperatures well above the sublimation threshold for water ice, with potentially drastic consequences for the icy bodies in Jupiter's feeding zone. Bodies up to a meter in size were vaporized within a single orbit if the planet was near its present location during this early epoch. Dust particles lost their ice mantles, and planetesimals were partially to fully devolatilized, depending on their size. Scenarios in which Jupiter formed promptly, such as those involving a gravitational instability of the massive early nebula, must cope with the high temperatures. Enriching Jupiter in the noble gases through delivery trapped in clathrate hydrates will be more difficult, but might be achieved by either forming the planet much farther from the star or capturing planetesimals at later epochs. The hot gap resulting from an early origin for Jupiter also would affect the surface compositions of any primordial Trojan asteroids.

  14. Companion-driven dynamics in hot Jupiter systems

    NASA Astrophysics Data System (ADS)

    Ngo, Henry; Batygin, Konstantin; Knutson, Heather A.; Lewis, Nikole K.; de Wit, Julien

    2015-08-01

    Hot Jupiters are giant planets found on orbits that lie in close proximity to their host stars. In this region, the process of tidal dissipation is believed to be generally efficient, and should act to circularize planetary orbits on timescales much shorter than the inferred ages of the observed stars. However, at time of writing, one in six known hot Jupiters have eccentricities inconsistent with zero at the three sigma level and about one in twelve have eccentricities greater than 0.2. This discrepancy hints at the existence of a dynamical mechanism that acts to maintain hot Jupiter eccentricities in face of tidal dissipation for extended periods of time. Our recent radial velocity (RV) and direct imaging surveys find that 70% of hot Jupiter systems are expected to host a distant planetary or stellar mass companion. In this work, we examine whether dynamical interactions with these long period companions could be responsible for the excited hot Jupiter eccentricities. Specifically, we consider the one of the most eccentric known hot Jupiter systems, HAT-P-2, as a case study. The inner planet in this system has a mass approximately ten times that of Jupiter, a semi-major axis of 0.07 AU, and an orbital eccentricity of 0.5. Long-term radial velocity monitoring has revealed the presence of an even more massive outer companion located beyond 4 AU with a partially constrained orbit. We examine different dynamical scenarios for this system in order to determine whether or not this outer companion might be responsible for the inner planet's unusually large orbital eccentricity, and make predictions for the short-term orbital evolution of the system.

  15. Ammonium Hydrosulfide and Jupiter's Great Red Spot

    NASA Astrophysics Data System (ADS)

    Loeffler, M. J.; Hudson, R.; Chanover, N.; Simon, A. A.

    2014-12-01

    The color and composition of Jupiter's Great Red Spot (GRS) has been debated for more than a century. While there are numerous hypotheses for the origin of Jupiter's GRS, recent work suggests that the GRS's color could originate from multiple components (Carlson et al., 2012; Simon et al., submitted). In light of this, we have recently begun conducting in situ laboratory experiments that test whether ammonium hydrosulfide, NH4SH, or its radiation decomposition products contribute to the GRS spectrum. In this presentation, we will discuss some of our most recent results, where we have studied the stability of NH4SH samples as a function of temperature using infrared and mass spectrometry. Funding for this work has been provided by NASA's Planetary Atmospheres and Outer Planets Research programs. ReferencesCarlson, R. W., K. H. Baines, M. S. Anderson, G. Filacchione. Chromophores from photolyzed ammonia reacting with acetylene: Application to Jupiter's Great Red Spot, DPS, 44, 2012. Simon, A. A., J. Legarreta, F. Sanz-Requena, S. Perez-Hoyos, E. Garcia-Melendo, R. W. Carlson. Spectral Comparison and Stability of Red Regions on Jupiter. J. Geophys. Res. - Planets, submitted.

  16. Jupiter: its captured satellites.

    PubMed

    Bailey, J M

    1971-08-27

    Because of the small size and irregular orbits of the seven outer satellites of Jupiter, it is often assumed that they were derived by capture. The conditions whereby Jupiter can capture satellites have therefore been examined. Relationships derived on the basis of the three-body problem for planets in elliptical orbits enable the dimensions of the capture orbits around Jupiter to be calculated. It is found that Jupiter may capture satellites through the inner Lagrangian point when at perihelion or at aphelion. Captures at perihelion should give rise to satellites in direct orbits of 11.48 x 10(6) kilometers and capture at aphelion to retrograde orbits of 21.7 x 10(6) kilometers. The correspondence with the seven outer satellites suggests that Jupiter VI, VIl, and X in direct orbits at 11.47, 11.74, and 11.85 x 10(6) kilometers were captured at Jupiter perihelion, whereas Jupiter VIII, IX, XI, and XII in retrograde orbits of 23.5, 23.7, 22.5, and 21.2 x 10(6) kilometers were captured when Jupiter was at aphelion. Examination of the precapture orbits indicates that the seven outer satellites were derived from the asteroid belt.

  17. Planet traps and planetary cores: origins of the planet-metallicity correlation

    SciTech Connect

    Hasegawa, Yasuhiro; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2014-10-10

    Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ≅ 1 AU, and the low-mass planets. We show using a statistical approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = –0.2 to –0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M {sub c,} {sub crit}) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > –0.6, our models predict that the most likely value of the 'mean' critical core mass of Jovian planets is (M {sub c,} {sub crit}) ≅ 5 M {sub ⊕} rather than 10 M {sub ⊕}. This implies that grain opacities in accreting envelopes should be reduced in order to lower M {sub c,} {sub crit}.

  18. ORBITAL MIGRATION OF INTERACTING LOW-MASS PLANETS IN EVOLUTIONARY RADIATIVE TURBULENT MODELS

    SciTech Connect

    Horn, Brandon; Mac Low, Mordecai-Mark; Lyra, Wladimir; Sandor, Zsolt E-mail: wlyra@amnh.org E-mail: zsolt.sandor@uibk.ac.at

    2012-05-01

    The torques exerted by a locally isothermal disk on an embedded planet lead to rapid inward migration. Recent work has shown that modeling the thermodynamics without the assumption of local isothermality reveals regions where the net torque on an embedded planet is positive, leading to outward migration of the planet. When a region with negative torque lies directly exterior to this, planets in the inner region migrate outward and planets in the outer region migrate inward, converging where the torque is zero. We incorporate the torques from an evolving non-isothermal disk into an N-body simulation to examine the behavior of planets or planetary embryos interacting in the convergence zone. We find that mutual interactions do not eject objects from the convergence zone. Small numbers of objects in a laminar disk settle into near resonant orbits that remain stable over the 10 Myr periods that we examine. However, either or both increasing the number of planets or including a correlated, stochastic force to represent turbulence drives orbit crossings and mergers in the convergence zone. These processes can build gas giant cores with masses of order 10 Earth masses from sub-Earth mass embryos in 2-3 Myr.

  19. THE MASS OF Kepler-93b AND THE COMPOSITION OF TERRESTRIAL PLANETS

    SciTech Connect

    Dressing, Courtney D.; Charbonneau, David; Dumusque, Xavier; Gettel, Sara; Latham, David W.; Buchhave, Lars A.; Johnson, John Asher; Lopez-Morales, Mercedes; Pepe, Francesco; Udry, Stéphane; Lovis, Christophe; Collier Cameron, Andrew; Haywood, Raphaëlle D.; Molinari, Emilio; Cosentino, Rosario; Fiorenzano, Aldo F. M.; Harutyunyan, Avet; Affer, Laura; Bonomo, Aldo S.; Figueira, Pedro; and others

    2015-02-20

    Kepler-93b is a 1.478 ± 0.019 R {sub ⊕} planet with a 4.7 day period around a bright (V = 10.2), astroseismically characterized host star with a mass of 0.911 ± 0.033 M {sub ☉} and a radius of 0.919 ± 0.011 R {sub ☉}. Based on 86 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 32 archival Keck/HIRES observations, we present a precise mass estimate of 4.02 ± 0.68 M {sub ⊕}. The corresponding high density of 6.88 ± 1.18 g cm{sup –3} is consistent with a rocky composition of primarily iron and magnesium silicate. We compare Kepler-93b to other dense planets with well-constrained parameters and find that between 1 and 6 M {sub ⊕}, all dense planets including the Earth and Venus are well-described by the same fixed ratio of iron to magnesium silicate. There are as of yet no examples of such planets with masses >6 M {sub ⊕}. All known planets in this mass regime have lower densities requiring significant fractions of volatiles or H/He gas. We also constrain the mass and period of the outer companion in the Kepler-93 system from the long-term radial velocity trend and archival adaptive optics images. As the sample of dense planets with well-constrained masses and radii continues to grow, we will be able to test whether the fixed compositional model found for the seven dense planets considered in this paper extends to the full population of 1-6 M {sub ⊕} planets.

  20. Measuring the Masses of K2 Planets with HARPS-N to Determine the Conditions Under Which Planets Retain, or Lose, their Primordial Envelopes

    NASA Astrophysics Data System (ADS)

    Lopez-Morales, Mercedes

    One of the main findings of NASA's Kepler Mission has been an abundance of planets with radii between that of Neptune and Earth around solar type stars, the so-called miniNeptunes and super-Earths. There is no equivalent of those planets in our Solar System, but about 80 percent of the candidates in the Kepler catalog are in this size range. Therefore, they appear to be the most common type of planets around solar type stars. In spite of their large numbers, we still know very little about the masses of mini-Neptunes and super-Earths, and their densities. There has been some recent progress on this topic, for e.g. as part of an ongoing XRP proposal (14-XRP14_20071; P.I. Charbonneau), our team has measured precise masses for 8 planets with radii between 1 and 2.5 Earths with HARPS-N, and found that all planets smaller than 1.6 Earth radii have core masses consistent with Earth's, while all planets larger than 1.6 Earth radii have H/He envelopes. The current hypothesis is that this is an insolation effect, since all the rocky planets with precise mass measurements are in very short orbits. However, that hypothesis has not been fully tested, and many other questions about the formation and evolution of these small planets remain unsolved, i.e. what is the rocky/non-rocky ratio of these planets? Are the observed rocky planets evaporated cores of sub-Neptunes, or did they form as bare cores? Can very short period planets retain a significant envelope? Is the currently hypothesized non-rocky/rocky transition at 1.5-1.7 Earth radii real? Precision radial velocity mass measurements so far suffer from an observational bias, in which larger radius planets with small radial velocity signals have been overlooked. These cases would form a population of very low-mass, gaseous planets, which 1) disagree with the current conclusion that all low mass planets below 6 Earth masses are rocky, 2) serve to test current formation/gas accretion and evaporation models, and 3) have large

  1. Accurate Empirical Radii and Masses of Planets and Their Host Stars with Gaia Parallaxes

    NASA Astrophysics Data System (ADS)

    Stassun, Keivan G.; Collins, Karen A.; Gaudi, B. Scott

    2017-03-01

    We present empirical measurements of the radii of 116 stars that host transiting planets. These radii are determined using only direct observables—the bolometric flux at Earth, the effective temperature, and the parallax provided by the Gaia first data release—and thus are virtually model independent, with extinction being the only free parameter. We also determine each star’s mass using our newly determined radius and the stellar density, a virtually model independent quantity itself from previously published transit analyses. These stellar radii and masses are in turn used to redetermine the transiting-planet radii and masses, again using only direct observables. The median uncertainties on the stellar radii and masses are 8% and 30%, respectively, and the resulting uncertainties on the planet radii and masses are 9% and 22%, respectively. These accuracies are generally larger than previously published model-dependent precisions of 5% and 6% on the planet radii and masses, respectively, but the newly determined values are purely empirical. We additionally report radii for 242 stars hosting radial-velocity (non-transiting) planets, with a median achieved accuracy of ≈2%. Using our empirical stellar masses we verify that the majority of putative “retired A stars” in the sample are indeed more massive than ∼1.2 {M}ȯ . Most importantly, the bolometric fluxes and angular radii reported here for a total of 498 planet host stars—with median accuracies of 1.7% and 1.8%, respectively—serve as a fundamental data set to permit the re-determination of transiting-planet radii and masses with the Gaia second data release to ≈3% and ≈5% accuracy, better than currently published precisions, and determined in an entirely empirical fashion.

  2. GAP OPENING BY EXTREMELY LOW-MASS PLANETS IN A VISCOUS DISK

    SciTech Connect

    Duffell, Paul C.; MacFadyen, Andrew I. E-mail: macfadyen@nyu.edu

    2013-05-20

    By numerically integrating the compressible Navier-Stokes equations in two dimensions, we calculate the criterion for gap formation by a very low mass (q {approx} 10{sup -4}) protoplanet on a fixed orbit in a thin viscous disk. In contrast with some previously proposed gap-opening criteria, we find that a planet can open a gap even if the Hill radius is smaller than the disk scale height. Moreover, in the low-viscosity limit, we find no minimum mass necessary to open a gap for a planet held on a fixed orbit. In particular, a Neptune-mass planet will open a gap in a minimum mass solar nebula with suitably low viscosity ({alpha} {approx}< 10{sup -4}). We find that the mass threshold scales as the square root of viscosity in the low mass regime. This is because the gap width for critical planet masses in this regime is a fixed multiple of the scale height, not of the Hill radius of the planet.

  3. Jupiter's Role in Sculpting the Early Solar System

    NASA Astrophysics Data System (ADS)

    Naoz, Smadar

    2015-03-01

    Recent observations made by the Kepler space mission, combined with statistical analysis of existing ground and space-based data, have shown that planets somewhat bigger than the Earth - but substantially smaller than Jupiter - ;are extremely common in our Galaxy (1-4). These systems are typically found to be tightly packed, nearly coplanar, and have nearly circular orbits. Furthermore, these planets tend to have very short-period orbits, ranging from days to months. In contrast, our innermost planet, Mercury, orbits the Sun once every 88 d. Thus, taken at face value, these observations imply that the architecture of our Solar System is unique compared with the galactic population. In other words, why are there no short-period planets in our Solar System? In PNAS, Batygin and Laughlin (5) demonstrate that Jupiter is to blame. In particular, Jupiter's inward-followed-by-outward migration during the Solar System's early evolution could have driven a collisional cascade that would grind planetesimals to smaller size. Gas drag, which dominates these small planetesimals, may then have driven preexisting short-period planets into the Sun. Thus, Batygin and Laughlin (5) suggest that the terrestrial planets in our Solar System are in fact "second-generation planets," which formed after the first short-period planets were destroyed, in mass-dispersed, gas-depleted conditions (see Fig. 1 for the description of the scenario). The developed model suggests that systems with short-period Earth and super-Earth planets are anticorrelated with the existence of giant planets within the same system.

  4. Jupiter Polar Winds Movie

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Bands of eastward and westward winds on Jupiter appear as concentric rotating circles in this movie composed of Cassini spacecraft images that have been re-projected as if the viewer were looking down at Jupiter's north pole and the planet were flattened.

    The sequence covers 70 days, from October 1 to December 9, 2000. Cassini's narrow-angle camera captured the images of Jupiter's atmosphere in the near-infrared region of the spectrum.

    What is surprising in this view is the coherent nature of the high-latitude flows, despite the very chaotic, mottled and non-banded appearance of the planet's polar regions. This is the first extended movie sequence to show the coherence and longevity of winds near the pole and the features blown around the planet by them.

    There are thousands of spots, each an active storm similar to the size to the largest of storms on Earth. Large terrestrial storms usually last only a week before they dissolve and are replaced by other storms. But many of the Jovian storms seen here, while occasionally changing latitude or merging with each other, persist for the entire 70 days. Until now, the lifetime of the high-latitude features was unknown. Their longevity is a mystery of Jovian weather.

    Cassini collected images of Jupiter for months before and after it passed the planet on December 30, 2000. Six or more images of the planet in each of several spectral filters were taken at evenly spaced intervals over the course of Jupiter's 10-hour rotation period. The entire sequence was repeated generally every other Jupiter rotation, yielding views of every sector of the planet at least once every 20 hours.

    The images used for the movie shown here were taken every 20 hours through a filter centered at a wavelength of 756 nanometers, where there are almost no absorptions in the planet's atmosphere. The images covering each rotation were mosaiced together to form a cylindrical map extending from 75 degrees north to 75 degrees south in

  5. EVIDENCE FROM THE ASTEROID BELT FOR A VIOLENT PAST EVOLUTION OF JUPITER'S ORBIT

    SciTech Connect

    Morbidelli, Alessandro; Brasser, Ramon; Gomes, Rodney; Levison, Harold F.; Tsiganis, Kleomenis

    2010-11-15

    We use the current orbital structure of large (>50 km) asteroids in the main asteroid belt to constrain the evolution of the giant planets when they migrated from their primordial orbits to their current ones. Minton and Malhotra showed that the orbital distribution of large asteroids in the main belt can be reproduced by an exponentially decaying migration of the giant planets on a timescale of {tau} {approx} 0.5 Myr. However, self-consistent numerical simulations show that the planetesimal-driven migration of the giant planets is inconsistent with an exponential change in their semi-major axes on such a short timescale. In fact, the typical timescale is {tau} {>=} 5 Myr. When giant planet migration on this timescale is applied to the asteroid belt, the resulting orbital distribution is incompatible with the observed one. However, the planet migration can be significantly sped up by planet-planet encounters. Consider an evolution where both Jupiter and Saturn have close encounters with a Neptune-mass planet (presumably Uranus or Neptune itself) and where this third planet, after being scattered inward by Saturn, is scattered outward by Jupiter. This scenario leads to a very rapid increase in the orbital separation between Jupiter and Saturn which we show here to have only mild effects on the structure of the asteroid belt. This type of evolution is called a 'jumping-Jupiter' case. Our results suggest that the total mass and dynamical excitation of the asteroid belt before migration were comparable to those currently observed. Moreover, they imply that, before migration, the orbits of Jupiter and Saturn were much less eccentric than their current ones.

  6. Exoplanet dynamics. Asynchronous rotation of Earth-mass planets in the habitable zone of lower-mass stars.

    PubMed

    Leconte, Jérémy; Wu, Hanbo; Menou, Kristen; Murray, Norman

    2015-02-06

    Planets in the habitable zone of lower-mass stars are often assumed to be in a state of tidally synchronized rotation, which would considerably affect their putative habitability. Although thermal tides cause Venus to rotate retrogradely, simple scaling arguments tend to attribute this peculiarity to the massive Venusian atmosphere. Using a global climate model, we show that even a relatively thin atmosphere can drive terrestrial planets' rotation away from synchronicity. We derive a more realistic atmospheric tide model that predicts four asynchronous equilibrium spin states, two being stable, when the amplitude of the thermal tide exceeds a threshold that is met for habitable Earth-like planets with a 1-bar atmosphere around stars more massive than ~0.5 to 0.7 solar mass. Thus, many recently discovered terrestrial planets could exhibit asynchronous spin-orbit rotation, even with a thin atmosphere.

  7. ELODIE metallicity-biased search for transiting Hot Jupiters. IV. Intermediate period planets orbiting the stars HD 43691 and HD 132406

    NASA Astrophysics Data System (ADS)

    da Silva, R.; Udry, S.; Bouchy, F.; Moutou, C.; Mayor, M.; Beuzit, J.-L.; Bonfils, X.; Delfosse, X.; Desort, M.; Forveille, T.; Galland, F.; Hébrard, G.; Lagrange, A.-M.; Loeillet, B.; Lovis, C.; Pepe, F.; Perrier, C.; Pont, F.; Queloz, D.; Santos, N. C.; Ségransan, D.; Sivan, J.-P.; Vidal-Madjar, A.; Zucker, S.

    2007-10-01

    We report here the discovery of two planet candidates as a result of our planet-search programme biased in favour of high-metallicity stars, using the ELODIE spectrograph at the Observatoire de Haute Provence. One candidate has a minimum mass m_2 sin i = 2.5 M_Jup and is orbiting the metal-rich star HD 43691 with period P = 40 days and eccentricity e=0.14. The other planet has a minimum mass m_2 sin{i} = 5.6 M_Jup and orbits the slightly metal-rich star HD 132406 with period P=974 days and eccentricity e = 0.34. Additional observations for both stars were performed using the new SOPHIE spectrograph that replaces the ELODIE instrument, allowing an improved orbital solution for the systems. Based on radial velocities collected with the ELODIE spectrograph mounted on the 193-cm telescope at the Observatoire de Haute Provence, France. Additional observations were made using the new SOPHIE spectrograph (run 06B.PNP.CONS) that replaces ELODIE.

  8. A Super-Jupiter Microlens Planet Characterized by High-Cadence KMTNeT Micorlensing Survey Observations of OGLE-2015-BLG-0954

    NASA Astrophysics Data System (ADS)

    Shin, I.-G.; Ryu, Y.-H.; Udalski, A.; Albrow, M.; Cha, S.-M.; Choi, J.-Y.; Chung, S.-J.; Han, C.; Hwang, K.-H.; Jung, Y. K.; Kim, D.-J.; Kim, S.-L.; Lee, C.-U.; Lee, Y.; Park, B.-G.; Park, H.; Pogge, R. W.; Yee, J. C.; Pietrukowicz, P.; Mroz, P.; Kozlowski, S.; Poleski, R.; Skowron, J.; Soszynski, I.; Szymanski, M. K.; Ulaczyk, K.; Wyrzykowski, L.; Pawlak, M.; Gould, A.

    2016-06-01

    We report the characterization of a massive (m_p=3.9± 1.4 M_{jup}) microlensing planet (OGLE-2015-BLG-0954Lb) orbiting an M dwarf host (M=0.33 ± 0.12 M_⊙) at a distance toward the Galactic bulge of 0.6^{+0.4}_{-0.2} kpc, which is extremely nearby by microlensing standards. The planet-host projected separation is a_perp ˜ 1.2 au. The characterization was made possible by the wide-field (4 deg^2) high cadence (Γ = 6 hr^{-1}) monitoring of the Korea Microlensing Telescope Network (KMTNet), which had two of its three telescopes in commissioning operations at the time of the planetary anomaly. The source crossing time t_*=16 min is among the shortest ever published. The high-cadence, wide-field observations that are the hallmark of KMTNet are the only way to routinely capture such short crossings. High-cadence resolution of short caustic crossings will preferentially lead to mass and distance measurements for the lens. This is because the short crossing time typically implies a nearby lens, which enables the measurement of additional effects (bright lens and/or microlens parallax). When combined with the measured crossing time, these effects can yield planet/host masses and distance.}

  9. Star Masses and Star-Planet Distances for Earth-like Habitability.

    PubMed

    Waltham, David

    2017-01-01

    This paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.64 AU. The statistical approach also demonstrates that there is a habitability issue for stars smaller than 0.65 solar masses since, otherwise, Earth would be an extremely atypical inhabited world. It is difficult to remove this anomaly using the assumption that poor habitability of planets orbiting low-mass stars results from unfavorable radiation regimes either before, or after, their stars enter the main sequence. However, the anomaly is well explained if poor habitability results from tidal locking of planets in the HZs of small stars. The expected host-star mass for planets with intelligent life then has a 95% confidence range of 0.78 M⊙ < M < 1.04 M⊙, and the range for planets with at least simple life is 0.57 M⊙ < M < 1.64 M⊙. Key Words: Habitability-Habitable zone-Anthropic-Red dwarfs-Initial mass function. Astrobiology 17, 61-77.

  10. Star Masses and Star-Planet Distances for Earth-like Habitability

    PubMed Central

    2017-01-01

    Abstract This paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.64 AU. The statistical approach also demonstrates that there is a habitability issue for stars smaller than 0.65 solar masses since, otherwise, Earth would be an extremely atypical inhabited world. It is difficult to remove this anomaly using the assumption that poor habitability of planets orbiting low-mass stars results from unfavorable radiation regimes either before, or after, their stars enter the main sequence. However, the anomaly is well explained if poor habitability results from tidal locking of planets in the HZs of small stars. The expected host-star mass for planets with intelligent life then has a 95% confidence range of 0.78 M⊙ < M < 1.04 M⊙, and the range for planets with at least simple life is 0.57 M⊙ < M < 1.64 M⊙. Key Words: Habitability—Habitable zone—Anthropic—Red dwarfs—Initial mass function. Astrobiology 17, 61–77. PMID:28103107

  11. The mass of planet GJ 676A b from ground-based astrometry. A planetary system with two mature gas giants suitable for direct imaging

    NASA Astrophysics Data System (ADS)

    Sahlmann, J.; Lazorenko, P. F.; Ségransan, D.; Astudillo-Defru, N.; Bonfils, X.; Delfosse, X.; Forveille, T.; Hagelberg, J.; Lo Curto, G.; Pepe, F.; Queloz, D.; Udry, S.; Zimmerman, N. T.

    2016-11-01

    The star GJ 676A is an M0 dwarf hosting both gas-giant and super-Earth-type planets that were discovered with radial-velocity measurements. Using FORS2/VLT, we obtained position measurements of the star in the plane of the sky that tightly constrain its astrometric reflex motion caused by the super-Jupiter planet "b" in a 1052-day orbit. This allows us to determine the mass of this planet to be , which is 40% higher than the minimum mass inferred from the radial-velocity orbit. Using new HARPS radial-velocity measurements, we improve upon the orbital parameters of the inner low-mass planets "d" and "e" and we determine the orbital period of the outer giant planet "c" to be Pc = 7340 days under the assumption of a circular orbit. The preliminary minimum mass of planet "c" is Mcsini = 6.8 MJ with an upper limit of 39 MJ that we set using NACO/VLT high-contrast imaging. We also determine precise parallaxes and relative proper motions for both GJ 676A and its wide M3 companion GJ 676B. Although the system is probably quite mature, the masses and projected separations ( 0.̋1-0.̋4) of planets "b" and "c" make them promising targets for direct imaging with future instruments in space and on extremely large telescopes. In particular, we estimate that GJ 676A b and GJ 676A c are promising targets for directly detecting their reflected light with the WFIRST space mission. Our study demonstrates the synergy of radial-velocity and astrometric surveys that is necessary to identify the best targets for such a mission. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 385.C-0416 (A,B), 086.C-0515(A), 089.C-0115(D,E), 072.C-0488(E), 180.C-0886(A), 183.C-0437(A), 085.C-0019(A), 091.C-0034(A), 095.C-0551(A), 096.C-0460(A).Full Table A.2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A77

  12. Formation and structure of the three Neptune-mass planets system around HD 69830

    NASA Astrophysics Data System (ADS)

    Alibert, Y.; Baraffe, I.; Benz, W.; Chabrier, G.; Mordasini, C.; Lovis, C.; Mayor, M.; Pepe, F.; Bouchy, F.; Queloz, D.; Udry, S.

    2006-08-01

    Since the discovery of the first giant planet outside the solar system in 1995 (Mayor & Queloz 1995, Nature, 378, 355), more than 180 extrasolar planets have been discovered. With improving detection capabilities, a new class of planets with masses 5-20 times larger than the Earth, at close distance from their parent star is rapidly emerging. Recently, the first system of three Neptune-mass planets has been discovered around the solar type star HD 69830 (Lovis et al. 2006, Nature, 441, 305). Here, we present and discuss a possible formation scenario for this planetary system based on a consistent coupling between the extended core accretion model and evolutionary models (Alibert et al. 2005a, A&A, 434, 343; Baraffe et al. 2004, A&A, 419, L13; Baraffe et al. 2006, A&A, 450, 1221). We show that the innermost planet formed from an embryo having started inside the iceline is composed essentially of a rocky core surrounded by a tiny gaseous envelope. The two outermost planets started their formation beyond the iceline and, as a consequence, accrete a substantial amount of water ice during their formation. We calculate the present day thermodynamical conditions inside these two latter planets and show that they are made of a rocky core surrounded by a shell of fluid water and a gaseous envelope.

  13. The CRIRES Search for Planets Around the Lowest-Mass Stars: Introduction and First Results

    NASA Astrophysics Data System (ADS)

    Bean, Jacob; Seifahrt, A.; Reiners, A.; Dreizler, S.; Hartman, H.; Nilsson, H.; Wiedemann, G.; Henry, T.

    2010-01-01

    We are currently carrying out a search for planets around the lowest-mass stars using the CRIRES instrument at the VLT under the auspices of an ESO Large Programme. The main purposes of this work are to illuminate the correlation between stellar mass and planet formation, improve the census of planets, and identify new planets that can be followed-up for detailed study. We have developed, and are utilizing a new type of gas cell for obtaining high-precision radial velocities of late-type stars in the nIR spectral region. Observations in the nIR offer the advantages in that the targetted stars are bright enough for high-precision spectroscopy, and that the noise contribution from stellar activity is significantly reduced. We will give an introduction to the survey and present some preliminary results.

  14. THE EFFECT OF PLANET-PLANET SCATTERING ON THE SURVIVAL OF EXOMOONS

    SciTech Connect

    Gong Yanxiang; Zhou Jilin; Xie Jiwei; Wu Xiaomei E-mail: yxgong@nju.edu.cn

    2013-05-20

    Compared to the giant planets in the solar system, exoplanets have many remarkable properties, such as the prevalence of giant planets on eccentric orbits and the presence of hot Jupiters. Planet-planet scattering (PPS) between giant planets is a possible mechanism to interpret the above and other observed properties. If the observed giant planet architectures are indeed outcomes of PPS, such a drastic dynamical process must affect their primordial moon systems. In this Letter, we discuss the effect of PPS on the survival of exoplanets' regular moons. From an observational viewpoint, some preliminary conclusions are drawn from the simulations. (1) PPS is a destructive process to the moon systems; single planets on eccentric orbits are not ideal moon-search targets. (2) If hot Jupiters formed through PPS, their original moons have little chance of survival. (3) Planets in multiple systems with small eccentricities are more likely to hold their primordial moons. (4) Compared with lower-mass planets, massive planets in multiple systems may not be the preferred moon-search targets if the system underwent a PPS history.

  15. The Dharma Planet Survey of Low-mass and Habitable Rocky Planets around Nearby Solar-type Stars

    NASA Astrophysics Data System (ADS)

    Ge, Jian; Ma, Bo; Jeram, Sarik; Sithajan, Sirinrat; Singer, Michael; Muterspaugh, Matthew W.; Varosi, Frank; Schofield, Sidney; Liu, Jian; Kimock, Benjamin; Powell, Scott; Williamson, Michael W.; Herczeg, Aleczander; Grantham, Jim; Stafford, Greg; Hille, Bruce; Rosenbaum, Gary; Savage, David; Bland, Steve; Hoscheidt, Joseph; Swindle, Scott; Waidanz, Melanie; Petersen, Robert; Grieves, Nolan; Zhao, Bo; Cassette, Anthony; Chun, Andrew; Avner, Louis; Barnes, Rory; Tan, Jonathan C.; Lopez, Eric; Dai, Ruijia

    2017-01-01

    The Dharma Planet Survey (DPS) aims to monitor ~150 nearby very bright FGK dwarfs (most of them brighter than V=7) during 2016-2019 using the TOU optical very high resolution spectrograph (R~100,000, 380-900nm) at the dedicated 50-inch Robotic Telescope on Mt. Lemmon. Operated in high vacuum (<0.01mTorr) with precisely controlled temperature (~1 mK), TOU has delivered ~ 0.5 m/s (RMS) long-term instrument stability, which is a factor of two times more stable than any of existing Doppler instruments to our best knowledge. DPS aims at reaching better than 0.5 m/s (a goal of 0.2 m/s) Doppler measurement precision for bright survey targets. With very high RV precision and high cadence (~100 observations per target randomly spread over 450 days), a large number of rocky planets, including possible habitable ones, are expected to be detected. The discovery of a Neptune mass planet and early survey results will be announced.

  16. Direct imaging search for planets around low-mass stars and spectroscopic characterization of young exoplanets

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan Peter

    Low--mass stars between 0.1--0.6 M⊙ are the most abundant members our galaxy and may be the most common sites of planet formation, but little is known about the outer architecture of their planetary systems. We have carried out a high-contrast adaptive imaging search for gas giant planets between 1--13 MJup around 122 newly identified young M dwarfs in the solar neighborhood ( ≲ 35 pc). Half of our targets are younger than 145 Myr, and 90% are younger than 580 Myr. After removing 39 resolved stellar binaries, our homogeneous sample of 83 single young M dwarfs makes it the largest imaging search for planets around low--mass stars to date. Our H- and K- band coronagraphic observations with Subaru/HiCIAO and Keck/NIRC2 achieve typical contrasts of 9--13 mag and 12--14 mag at 100, respectively, which corresponds to limiting masses of ˜1--10 M Jup at 10--30 AU for most of our sample. We discovered four brown dwarfs with masses between 25--60 MJup at projected separations of 4--190 AU. Over 100 candidate planets were discovered, nearly all of which were found to be background stars from follow-up second epoch imaging. Our null detection of planets nevertheless provides strong statistical constraints on the occurrence rate of giant planets around M dwarfs. Assuming circular orbits and a logarithmically-flat power law distribution in planet mass and semi--major axis of the form d 2N=(dloga dlogm) infinity m0 a0, we measure an upper limit (at the 95% confidence level) of 8.8% and 12.6% for 1--13 MJup companions between 10--100 AU for hot start and cold start evolutionary models, respectively. For massive gas giant planets in the 5--13 M Jup range like those orbiting HR 8799, GJ 504, and beta Pictoris, we find that fewer than 5.3% (7.8%) of M dwarfs harbor these planets between 10--100 AU for a hot start (cold start) formation scenario. Our best constraints are for brown dwarf companions; the frequency of 13--75 MJup companions between (de--projected) physical

  17. Star Masses and Star-Planet Distances for Earth-like Habitability

    NASA Astrophysics Data System (ADS)

    Waltham, David

    2017-01-01

    This paper presents statistical estimates for the location and duration of habitable zones (HZs) around stars of different mass. The approach is based upon the assumption that Earth's location, and the Sun's mass, should not be highly atypical of inhabited planets. The results support climate-model-based estimates for the location of the Sun's HZ except models giving a present-day outer-edge beyond 1.64 AU. The statistical approach also demonstrates that there is a habitability issue for stars smaller than 0.65 solar masses since, otherwise, Earth would be an extremely atypical inhabited world. It is difficult to remove this anomaly using the assumption that poor habitability of planets orbiting low-mass stars results from unfavorable radiation regimes either before, or after, their stars enter the main sequence. However, the anomaly is well explained if poor habitability results from tidal locking of planets in the HZs of small stars. The expected host-star mass for planets with intelligent life then has a 95% confidence range of 0.78 M⊙ < M < 1.04 M⊙, and the range for planets with at least simple life is 0.57 M⊙ < M < 1.64 M⊙.

  18. Galilean Moons, Kepler's Third Law, and the Mass of Jupiter

    ERIC Educational Resources Information Center

    Bates, Alan

    2013-01-01

    Simulations of physical systems are widely available online, with no cost, and are ready to be used in our classrooms. Such simulations offer an accessible tool that can be used for a range of interactive learning activities. The Jovian Moons Apple allows the user to track the position of Jupiter's four Galilean moons with a variety of…

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

    SciTech Connect

    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.; Duchene, 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.; Rantakyro, 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.

    2015-10-02

    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. As a result, 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

    DOE PAGES

    Macintosh, B.; Graham, J. R.; Barman, T.; ...

    2015-10-02

    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 twicemore » that of Jupiter. As a result, this planet also has a sufficiently low luminosity to be consistent with the “cold-start” core-accretion process that may have formed Jupiter.« less

  1. 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

    2015-10-02

    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.

  2. 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.

  3. Cold Hole Over Jupiter's Pole

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Observations with two NASA telescopes show that Jupiter has an arctic polar vortex similar to a vortex over Earth's Antarctica that enables depletion of Earth's stratospheric ozone.

    These composite images of Jupiter's north polar region from the Hubble Space Telescope (right) and the Infrared Telescope Facility (left) show a quasi-hexagonal shape that extends vertically from the stratosphere down into the top of the troposphere. A sharp temperature drop, compared to surrounding air masses, creates an eastward wind that tends to keep the polar atmosphere, including the stratospheric haze, isolated from the rest of the atmosphere.

    The linear striations in the composite projections are artifacts of the image processing. The area closest to the pole has been omitted because it was too close to the edge of the planet in the original images to represent the planet reliably.

    The composite on the right combines images from the Wide Field and Planetary Camera 2 of the Hubble Space Telescope taken at a wavelength of 890 nanometers, which shows stratospheric haze particles.

    The sharp boundary and wave-like structure of the haze layer suggest a polar vortex and a similarity to Earth's stratospheric polar clouds. Images of Jupiter's thermal radiation clinch that identification. The composite on the left, for example, is made from images taken with Jet Propulsion Laboratory's Mid-Infrared Large-Well Imager at NASA's Infrared Telescope Facility at a wavelength of 17 microns. It shows polar air mass that is 5 to 6 degrees Celsius (9 to 10 degrees Fahrenheit) colder than its surroundings, with the same border as the stratospheric haze. Similar observations at other infrared wavelengths show the cold air mass extends at least as high as the middle stratosphere down to the top of the troposphere.

    These images were taken Aug. 11 through Aug. 13, 1999, near a time when Jupiter's north pole was most visible from Earth. Other Infrared Telescope Facility images at

  4. Planet hunters. VII. Discovery of a new low-mass, low-density planet (PH3 C) orbiting Kepler-289 with mass measurements of two additional planets (PH3 B and D)

    SciTech Connect

    Schmitt, Joseph R.; Fischer, Debra A.; Wang, Ji; Margossian, Charles; Brewer, John M.; Giguere, Matthew J.; Agol, Eric; Deck, Katherine M.; Rogers, Leslie A.; Gazak, J. Zachary; Holman, Matthew J.; Jek, Kian J.; Omohundro, Mark R.; Winarski, Troy; Lintott, Chris; Simpson, Robert; Lynn, Stuart; Parrish, Michael; Schawinski, Kevin; Schwamb, Megan E.; and others

    2014-11-10

    We report the discovery of one newly confirmed planet (P = 66.06 days, R {sub P} = 2.68 ± 0.17 R {sub ⊕}) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R {sub P} = 2.15 ± 0.10 R {sub ⊕}) and Kepler-289-c (P = 125.85 days, R {sub P} = 11.59 ± 0.10 R {sub ⊕}), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a 1:2:4 Laplace resonance. The outer planet has very deep (∼1.3%), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young (∼1 Gyr as determined by isochrones and gyrochronology), Sun-like star with M {sub *} = 1.08 ± 0.02 M {sub ☉}, R {sub *} = 1.00 ± 0.02 R {sub ☉}, and T {sub eff} = 5990 ± 38 K. The middle planet's large TTV amplitude (∼5 hr) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allows us to break the mass-eccentricity degeneracy and uniquely determine the masses of the inner, middle, and outer planets to be M = 7.3 ± 6.8 M {sub ⊕}, 4.0 ± 0.9M {sub ⊕}, and M = 132 ± 17 M {sub ⊕}, which we designate PH3 b, c, and d, respectively. Furthermore, the middle planet, PH3 c, has a relatively low density, ρ = 1.2 ± 0.3 g cm{sup –3} for a planet of its mass, requiring a substantial H/He atmosphere of 2.1{sub −0.3}{sup +0.8}% by mass, and joins a growing population of low-mass, low-density planets.

  5. Chandra Probes High-Voltage Auroras on Jupiter

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Scientists have obtained new insight into the unique power source for many of Jupiter's auroras, the most spectacular and active auroras in the Solar System. Extended monitoring of the giant planet with NASA's Chandra X-ray Observatory detected the presence of highly charged particles crashing into the atmosphere above its poles. X-ray spectra measured by Chandra showed that the auroral activity was produced by ions of oxygen and other elements that were stripped of most of their electrons. This implies that these particles were accelerated to high energies in a multimillion-volt environment above the planet's poles. The presence of these energetic ions indicates that the cause of many of Jupiter's auroras is different from auroras produced on Earth or Saturn. Chandra X-ray Image of Jupiter Chandra X-ray Image of Jupiter "Spacecraft have not explored the region above the poles of Jupiter, so X-ray observations provide one of the few ways to probe that environment," said Ron Elsner of the NASA Marshall Space Flight Center in Huntsville, Alabama, and lead author on a recently published paper describing these results in the Journal for Geophysical Research. "These results will help scientists to understand the mechanism for the power output from Jupiter's auroras, which are a thousand times more powerful than those on Earth." Electric voltages of about 10 million volts, and currents of 10 million amps - a hundred times greater than the most powerful lightning bolts - are required to explain the X-ray observations. These voltages would also explain the radio emission from energetic electrons observed near Jupiter by the Ulysses spacecraft. Schematic of Jupiter's Auroral Activity Production Schematic of Jupiter's Auroral Activity Production On Earth, auroras are triggered by solar storms of energetic particles, which disturb Earth's magnetic field. Gusts of particles from the Sun can also produce auroras on Jupiter, but unlike Earth, Jupiter has another way of producing

  6. Measurement of Planet Masses with Transit Timing Variations Due to Synodic “Chopping” Effects

    NASA Astrophysics Data System (ADS)

    Deck, Katherine M.; Agol, Eric

    2015-04-01

    Gravitational interactions between planets in transiting exoplanetary systems lead to variations in the times of transit that are diagnostic of the planetary masses and the dynamical state of the system. Here we show that synodic “chopping” contributions to these transit timing variations (TTVs) can be used to uniquely measure the masses of planets without full dynamical analyses involving direct integration of the equations of motion. We present simple analytic formulae for the chopping signal, which are valid (generally \\lt 10% error) for modest eccentricities e≲ 0.1. Importantly, these formulae primarily depend on the mass of the perturbing planet, and therefore the chopping signal can be used to break the mass/free-eccentricity degeneracy, which can appear for systems near first-order mean motion resonances. Using a harmonic analysis, we apply these TTV formulae to a number of Kepler systems, which had been previously modeled with full dynamical analyses. We show that when chopping is measured, the masses of both planets can be determined uniquely, in agreement with previous results, but without the need for numerical orbit integrations. This demonstrates how mass measurements from TTVs may primarily arise from an observable chopping signal. The formula for chopping can also be used to predict the number of transits and timing precision required for future observations, such as those made by TESS or PLATO, in order to infer planetary masses through analysis of TTVs.

  7. MOA-2011-BLG-028Lb: A Neptune-mass Microlensing Planet in the Galactic Bulge

    NASA Astrophysics Data System (ADS)

    Skowron, J.; Udalski, A.; Poleski, R.; Kozłowski, S.; Szymański, M. K.; Wyrzykowski, Ł.; Ulaczyk, K.; Pietrukowicz, P.; Pietrzyński, G.; Soszyński, I.; OGLE Collaboration; Abe, F.; Bennett, D. P.; Bhattacharya, A.; Bond, I. A.; Freeman, M.; Fukui, A.; Hirao, Y.; Itow, Y.; Koshimoto, N.; Ling, C. H.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Nagakane, M.; Ohnishi, K.; Rattenbury, N.; Saito, To.; Sullivan, D. J.; Sumi, T.; Suzuki, D.; Tristram, P. J.; Yonehara, A.; MOA Collaboration; Dominik, M.; Jørgensen, U. G.; Bozza, V.; Harpsøe, K.; Hundertmark, M.; Skottfelt, J.; MiNDSTEp Collaboration

    2016-03-01

    We present the discovery of a Neptune-mass planet orbiting a 0.8+/- 0.3{M}⊙ star in the Galactic bulge. The planet manifested itself during the microlensing event MOA-2011-BLG-028/OGLE-2011-BLG-0203 as a low-mass companion to the lens star. The analysis of the light curve provides the measurement of the mass ratio (1.2+/- 0.2)× {10}-4, which indicates that the mass of the planet is 12-60 Earth masses. The lensing system is located at 7.3 ± 0.7 kpc away from the Earth near the direction of Baade’s Window. The projected separation of the planet at the time of the microlensing event was 3.1-5.2 au. Although the microlens parallax effect is not detected in the light curve of this event, preventing the actual mass measurement, the uncertainties of mass and distance estimation are narrowed by the measurement of the source star proper motion on the OGLE-III images spanning eight years, and by the low amount of blended light seen, proving that the host star cannot be too bright and massive. We also discuss the inclusion of undetected parallax and orbital motion effects into the models and their influence onto the final physical parameters estimates. Based on observations obtained with the 1.3 m Warsaw telescope at the Las Campanas Observatory operated by the Carnegie Institution of Washington.

  8. Measuring Masses and Densities of Small Planets found by NASA's Kepler Spacecraft with Radial Velocity Measurements from Keck/HIRES

    NASA Astrophysics Data System (ADS)

    Isaacson, Howard T.; Marcy, G.; Rowe, J.; Kepler Team

    2013-06-01

    We use the Keck telescope and HIRES spectrometer to measure the masses of Kepler planet candidates. Analysis of 22 Kepler-identified planetary systems, holding 42 transiting planets (candidates) and 8 newly discovered non-transiting planets are presented herein. Combining the planet radius measurements from Kepler with mass measurements from Keck, we constrain the bulk density of short period planets that range in size from 1.0 to 3.0 Earth radii. Extensive ground based observations made by the Kepler Follow-up Program (KFOP) have provided extensive details about each KOI. Reconnaissance spectroscopy was used to refine the stellar and planet properties of each KOI at an early stage. SME spectral analysis and asteroseismology, when available, are used to obtain the final stellar properties. Adaptive Optics and speckle imaging constrain the presence of background eclipsing binaries that could masquerade as transiting planets. By combining ground based follow-up observations with Kepler photometry, a false positive probability is calculated for each KOI. An MCMC analysis that combines both Kepler photometry and Keck radial velocity measurements determines the final orbital parameters and planet properties for each system. The resulting mass vs. radius diagram for the planets reveals that radii increase with mass monotonically, well represented by a power law for the smallest planets. This M-R relationship offers key insights about the internal composition of the planets and the division between rocky and gaseous planets.

  9. New strategy for planets serach in debris disks

    NASA Astrophysics Data System (ADS)

    Zakhozhay, O.

    2014-09-01

    Based on the modern theory of planet formation, planetary systems are formed in protoplanetary disks that could surround young stellar and substellar objects. Giant planets formation process starts at first 100 thousand years as a consequence of disk gravitational instability. Rocky planets form later, through the coagulation of planetesimals. Common feature in both types planets formation scenarios is that once planet reaches stable orbit (especially if orbit is circular), planet clears a gap in the disk along the planet's orbit. By the debris disk stage the gap opened by planet becomes optically thin. There are two observational methods to study the structure of debris disks: with an image and via an excess in stellar spectral energy distribution (SED) at the infrared. The image of such disk is the best way to detect the gap opened by planet and even the planet itself. It is almost impossible to detect the planet around the star by studying SED, due to the big difference of their luminosities. But it is possible to suspect planet based on the param- eters of the gap cleaned by planet, that could be derived based on the analysis of SED profile. The aim of present work is to investigate a possibility to detect planet in debris disk via SED profile analyze and to determine planets physical parameters that can be derived with this method. I will present the results of numerical calculations for systems with low-mass stellar and substellar objects at 1 Gyr. Debris disk particles radii vary from 0.1 microns to 1 meter; disk masses vary from 10**-16 to 0.05 masses of the star (that initially doesn't account extinction due to the gap opened by the planet). Width of the gap opened by the planet is determined as a diameter of Hill sphere. Planet masses are varied from 10 Earth to 10 Jupiter masses. Distance from the planet to the central star is within all possible positions along the disk radius.

  10. 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.

  11. Astronomical Papers Prepared for the Use of the American Ephemeris and Nautical Almanac. Volume 12. Coordinates of the Five Outer Planets,

    DTIC Science & Technology

    ACCURACY, ALMANACS, ARTIFICIAL SATELLITES, COMETS, CORRECTIONS, EPHEMERIDES, INTEGRATION, JUPITER( PLANET ), MOTION, NAUTICAL, NONLINEAR DIFFERENTIAL...EQUATIONS, NUMERICAL INTEGRATION, OUTER PLANETS , PLANETS , SATURN( PLANET ), SIMULTANEOUS EQUATIONS, SUN, VALUE

  12. FURTHER OBSERVATIONS OF PLANETS AND QUASI-STELLAR RADIO SOURCES AT 3 MM.

    DTIC Science & Technology

    EXTRATERRESTRIAL RADIO WAVES), (* MERCURY ( PLANET ), (*RADIO ASTRONOMY, EXTRATERRESTRIAL RADIO WAVES), PLANETARY ATMOSPHERES, SKY BRIGHTNESS, ANTENNAS...EPHEMERIDES, ASTROPHYSICS, JUPITER( PLANET ), VENUS( PLANET ), BRIGHTNESS, ATMOSPHERIC TEMPERATURE, INTENSITY, MEASUREMENT.

  13. The Orbit and Mass of the Third Planet in the Kepler-56 System

    NASA Astrophysics Data System (ADS)

    Otor, Oderah Justin; Montet, Benjamin T.; Johnson, John Asher; Charbonneau, David; Collier-Cameron, Andrew; Howard, Andrew W.; Isaacson, Howard; Latham, David W.; Lopez-Morales, Mercedes; Lovis, Christophe; Mayor, Michel; Micela, Giusi; Molinari, Emilio; Pepe, Francesco; Piotto, Giampaolo; Phillips, David F.; Queloz, Didier; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Sozzetti, Alessandro; Udry, Stéphane; Watson, Chris

    2016-12-01

    While the vast majority of multiple-planet systems have orbital angular momentum axes that align with the spin axis of their host star, Kepler-56 is an exception: its two transiting planets are coplanar yet misaligned by at least 40° with respect to the rotation axis of their host star. Additional follow-up observations of Kepler-56 suggest the presence of a massive, non-transiting companion that may help explain this misalignment. We model the transit data along with Keck/HIRES and HARPS-N radial velocity data to update the masses of the two transiting planets and infer the physical properties of the third, non-transiting planet. We employ a Markov Chain Monte Carlo sampler to calculate the best-fitting orbital parameters and their uncertainties for each planet. We find the outer planet has a period of 1002 ± 5 days and minimum mass of 5.61 ± 0.38 {M}{Jup}. We also place a 95% upper limit of 0.80 m s-1 yr-1 on long-term trends caused by additional, more distant companions.

  14. Detection of Extrasolar Planets by Transit Photometry

    NASA Technical Reports Server (NTRS)

    Borucki, William; Koch, David; Webster, Larry; Dunham, Edward; Witteborn, Fred; Jenkins, Jon; Caldwell, Douglas; Showen, Robert; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    A knowledge of other planetary systems that includes information on the number, size, mass, and spacing of the planets around a variety of star types is needed to deepen our understanding of planetary system formation and processes that give rise to their final configurations. Recent discoveries show that many planetary systems are quite different from the solar system in that they often possess giant planets in short period orbits. The inferred evolution of these planets and their orbital characteristics imply the absence of Earth-like planets near the habitable zone. Information on the properties of the giant-inner planets is now being obtained by both the Doppler velocity and the transit photometry techniques. The combination of the two techniques provides the mass, size, and density of the planets. For the planet orbiting star HD209458, transit photometry provided the first independent confirmation and measurement of the diameter of an extrasolar planet. The observations indicate a planet 1.27 the diameter of Jupiter with 0.63 of its mass (Charbonneau et al. 1999). The results are in excellent agreement with the theory of planetary atmospheres for a planet of the indicated mass and distance from a solar-like star. The observation of the November 23, 1999 transit of that planet made by the Ames Vulcan photometer at Lick Observatory is presented. In the future, the combination of the two techniques will greatly increase the number of discoveries and the richness of the science yield. Small rocky planets at orbital distances from 0.9 to 1.2 AU are more likely to harbor life than the gas giant planets that are now being discovered. However, new technology is needed to find smaller, Earth-like planets, which are about three hundred times less massive than Jupiter-like planets. The Kepler project is a space craft mission designed to discover hundreds of Earth-size planets in and near the habitable zone around a wide variety of stars. To demonstrate that the

  15. 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

  16. Extrasolar planets.

    PubMed

    Lissauer, J J; Marcy, G W; Ida, S

    2000-11-07

    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.

  17. Characterising the atmosphere of a uniquely low-density, sub-Saturn mass planet

    NASA Astrophysics Data System (ADS)

    Spake, Jessica; Anderson, D.; Barstow, J.; Evans, T.; Gillon, M.; Hebrardr, G.; Hellier, C.; Kataria, T.; Lam, K.; Nikolov, N.; Sing, D.; Triaud, A.; Wakeford, H.

    2016-08-01

    We propose to use HST and Spitzer to measure the transmission spectrum of the recently discovered, hot sub-Saturn mass exoplanet WASP-127b. Its low mass (0.19 Mj) and large radius (1.39 Rj) give it the lowest density of any exoplanet with a radial velocity measured mass. It has the largest predicted atmospheric scale height of any planet, and orbits a bright (V~10.2) star, making it an exceptional target for atmospheric characterisation via transmission spectroscopy. With HST and Spitzer, we will measure the full transmission spectrum from 0.3 to 5 microns, covering water, sodium, and potassium absorption features, and scattering by molecular hydrogen or haze. The Spitzer transit photometry at 3.6 and 4.5 microns will be used alongside the HST spectrum to break the low abundance/cloud degeneracy which prevents constraints being made on atmospheric metallicity. With a low mass of 0.19 Mj, this planet sits in an unexplored mass range at the very low-end of gas giant planets, making WASP-127b strategecally important for constraining the planetary mass-metallicity relationship, which is important for understanding planet formation mechanisms.

  18. Fomalhaut's Disk And Planet: Constraining The Mass And Orbit Of Fomalhaut-b Using Disk Morphology"

    NASA Astrophysics Data System (ADS)

    Chiang, Eugene; Kite, E.; Kalas, P.; Graham, J. R.; Clampin, M.

    2009-01-01

    We present a numerical model of how Fomalhaut b, the recently imaged exoplanet candidate, shapes Fomalhaut's debris disk. Our model indicates that Fomalhaut b must have a mass less than 3 Jupiter masses. Previous mass constraints based on disk morphology rely on several oversimplifications. We explain why our new constraints on the mass and the orbit of Fomalhaut b are more reliable. They are based on a global model of the disk that is not restricted to the chaotic zone boundary. We screen disk parent bodies, which define Fomalhaut's birth ring, for dynamical stability over the system age. Parent bodies are modelled separately from their dust grain progeny, whose orbits are strongly affected by radiation pressure and whose lifetimes are limited to about 0.1 Myr by destructive grain-grain collisions. Parent bodies are evacuated from mean-motion resonances with Fomalhaut b; these empty resonances are akin to the Kirkwood gaps opened by Jupiter. The belt contains at least 3 Earth masses of solids that are grinding down to dust, their velocity dispersions stirred so strongly by Fomalhaut b that collisions are destructive.

  19. Search for the transit of a nearby 2 Earth-mass planet

    NASA Astrophysics Data System (ADS)

    Gillon, Michael; Affer, Laura; Bonomo, Aldo; Damasso, Mario; Desidera, Silvano; Micela, Giuseppina; Rebolo, Rafael; Ribas, Ignasi; Sozzetti, Alessandro

    2016-08-01

    The frontier of exoplanetology is being pushed to the identification of Earth-sized exoplanets well-suited for detailed characterization with future observatories, notably with JWST. Transit searches targeting nearby M-dwarfs are at the forefront of this effort. Indeed, the favorable planet-star contrast ratios of M-dwarfs enable the best opportunities in the near-future for detailed characterization studies of transiting terrestrial planets and their atmospheres. In this context, we propose here to use the exquisite photometric precision of Spitzer to search for the transit of a new short-period (2.6d) very-low-mass (2 Earth-mass) super-Earth that we have just detected with the HARPS-N spectrograph. This planet orbits at <0.03 au of a nearby (18pc) M1-type dwarf, resulting in a transit probability of 8%. A transit detection would make possible to discriminate metal-rich, silicate rich, and ice-rich planetary compositions, and to test further the hypothesis that the population of dense, close-in planets of 1-6 Earth-mass can be described by a fixed Earth-like compositional model. Furthermore, it would make the planet join the handful of super-Earths well-suited for detailed atmospheric characterization with JWST, thanks to the infrared brightness (K=6.8) and the small size (0.5 solar radius) of its M-dwarf host star.

  20. A Neptune-Mass Planet Orbiting the Nearby M Dwarf GJ 436

    NASA Astrophysics Data System (ADS)

    Butler, R. Paul; Vogt, Steven S.; Marcy, Geoffrey W.; Fischer, Debra A.; Wright, Jason T.; Henry, Gregory W.; Laughlin, Greg; Lissauer, Jack J.

    2004-12-01

    We report precise Doppler measurements of GJ 436 (M2.5 V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 days, eccentricity of 0.12 (consistent with zero), and velocity semiamplitude of K=18.1 m s-1. The minimum mass (Msini) for the planet is 0.067MJup=1.2MNep=21MEarth, making it the lowest mass exoplanet yet found around a main-sequence star and the first candidate in the Neptune-mass domain. GJ 436 (mass = 0.41 Msolar) is only the second M dwarf found to harbor a planet, joining the two-planet system around GJ 876. The low mass of the planet raises questions about its constitution, with possible compositions of primarily H and He gas, ice/rock, or rock-dominated. The implied semimajor axis is a=0.028AU=14 stellar radii, raising issues of planet formation, migration, and tidal coupling with the star. GJ 436 is more than 3 Gyr old, based on both kinematic and chromospheric diagnostics. The star exhibits no photometric variability on the 2.644 day Doppler period to a limiting amplitude of 0.0004 mag, supporting the planetary interpretation of the Doppler periodicity. Photometric transits of the planet across the star are ruled out for gas giant compositions and are also unlikely for solid compositions. As the third closest known planetary system, GJ 436 warrants follow-up observations by high-resolution optical and infrared imaging and by the Space Interferometry Mission. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time has been granted by both NASA and the University of California.

  1. Full Jupiter Mosaic

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This image of Jupiter is produced from a 2x2 mosaic of photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI), and assembled by the LORRI team at the Johns Hopkins University Applied Physics Laboratory. The telescopic camera snapped the images during a 3-minute, 35-second span on February 10, when the spacecraft was 29 million kilometers (18 million miles) from Jupiter. At this distance, Jupiter's diameter was 1,015 LORRI pixels -- nearly filling the imager's entire (1,024-by-1,024 pixel) field of view. Features as small as 290 kilometers (180 miles) are visible.

    Both the Great Red Spot and Little Red Spot are visible in the image, on the left and lower right, respectively. The apparent 'storm' on the planet's right limb is a section of the south tropical zone that has been detached from the region to its west (or left) by a 'disturbance' that scientists and amateur astronomers are watching closely.

    At the time LORRI took these images, New Horizons was 820 million kilometers (510 million miles) from home -- nearly 51/2 times the distance between the Sun and Earth. This is the last full-disk image of Jupiter LORRI will produce, since Jupiter is appearing larger as New Horizons draws closer, and the imager will start to focus on specific areas of the planet for higher-resolution studies.

  2. 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.

  3. The effect of planets beyond the ice line on the accretion of volatiles by habitable-zone rocky planets

    SciTech Connect

    Quintana, Elisa V.; Lissauer, Jack J.

    2014-05-01

    Models of planet formation have shown that giant planets have a large impact on the number, masses, and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed exterior to the snow line (the region in the disk beyond which water ice can condense) to the inner region of the disk where terrestrial planets can maintain liquid water on their surfaces. We present simulations of the late stages of terrestrial planet formation from a disk of protoplanets around a solar-type star and we include a massive planet (from 1 M {sub ⊕} to 1 M {sub J}) in Jupiter's orbit at ∼5.2 AU in all but one set of simulations. Two initial disk models are examined with the same mass distribution and total initial water content, but with different distributions of water content. We compare the accretion rates and final water mass fraction of the planets that form. Remarkably, all of the planets that formed in our simulations without giant planets were water-rich, showing that giant planet companions are not required to deliver volatiles to terrestrial planets in the habitable zone. In contrast, an outer planet at least several times the mass of Earth may be needed to clear distant regions of debris truncating the epoch of frequent large impacts. Observations of exoplanets from radial velocity surveys suggest that outer Jupiter-like planets may be scarce, therefore, the results presented here suggest that there may be more habitable planets residing in our galaxy than previously thought.

  4. Characterizing the Atmosphere of a Young Planet

    NASA Technical Reports Server (NTRS)

    Marley, Mark

    2016-01-01

    Since the discovery of the young, directly imaged planet 51 Eri b, its emergent spectrum has proved challenging to interpret. The initial discovery paper (Macintosh et al. 2015) interpreted the spectrum as indicative of a low mass (few Jupiter masses), effective temperature near 700 degrees Kelvin, and partial cloudiness. Subsequent observations in the K band, however, seem to invalidate the early models. In addition, newly improved photochemical data point to the likely presence of exotic haze species in the atmosphere. In my presentation I will explore the photochemistry of the atmosphere and discuss whether disequilibrium chemistry, hazes, clouds, or non-solar abundances of heavy elements may be responsible for the unusual spectrum of this planet. The implications for the interpretation of other young Jupiters in this mass and effective temperature range will also be considered.

  5. Evolutionary Tracks of the Climate of Earth-like Planets around Different Mass Stars

    NASA Astrophysics Data System (ADS)

    Kadoya, S.; Tajika, E.

    2016-07-01

    The climatic evolution of the Earth depends strongly on the evolution of the insolation from the Sun and the amount of the greenhouse gasses, especially CO2 in the atmosphere. Here, we investigate the evolution of the climate of hypothetical Earths around stars whose masses are different from the solar mass with a luminosity evolution model of the stars, a mantle degassing model coupled with a parameterized convection model of the planetary interiors, and an energy balance climate model of the planetary surface. In the habitable zone (HZ), the climate of the planets is initially warm or hot, depending on the orbital semimajor axes. We found that, in the inner HZ, the climate of the planets becomes hotter with time owing to the increase in the luminosity of the central stars, while, in the outer HZ, it becomes colder and eventually globally ice-covered owing to the decrease in the CO2 degassing rate of the planets. The orbital condition for maintaining the warm climate similar to the present Earth becomes very limited, and more interestingly, the planet orbiting in the outer HZ becomes globally ice-covered after a certain critical age (˜3 Gyr for the hypothetical Earth with standard parameters), irrespective of the mass of the central star. This is because the critical age depends on the evolution of the planets and planetary factors, rather than on the stellar mass. The habitability of the Earth-like planet is shown to be limited with age even though it is orbiting within the HZ.

  6. Characterization of Low-mass K2 planet hosts using Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rodríguez-Martínez, Romy; Ballard, Sarah

    2017-01-01

    The raw number of discovered exoplanets now exceeds several thousand, but we must understand the stars if we aim to understand their planets in detail. Of particular interest are M dwarf stars, which are often favored for exoplanet study because (1) they host small planets in greatest abundance, (2) they make up about 70% of stars in our galaxy, and (3) the planets that orbit them that are comparatively easier to find and study than planets around larger stars. Our work aims to characterize the infrared spectra of 50 M dwarfs with new and unstudied transiting planets discovered by NASA’s K2 Mission. We employ empirical relations from the literature with magnesium, aluminum and sodium absorption lines in H and K band to determine the temperatures, radii and luminosities. In addition, we measure the deformation of the spectra in K band by water (another empirical metric for M dwarfs) which, in tandem with absorption features, is linked to [Fe/H] metallicity. We have found from a preliminary sample of 36 stars, that the temperatures range from 2,900 to 4,100 K, with radii between 0.2 R⊙ to 0.6R⊙ and log(L/L⊙) values from -3.4 to -0.5. The determination of all these properties improves our understanding of the planet’s properties, such as its size, mass, and surface temperature, and provides clues about the formation of the star and its planets.

  7. MASSIVE: A Bayesian analysis of giant planet populations around low-mass stars

    NASA Astrophysics Data System (ADS)

    Lannier, J.; Delorme, P.; Lagrange, A. M.; Borgniet, S.; Rameau, J.; Schlieder, J. E.; Gagné, J.; Bonavita, M. A.; Malo, L.; Chauvin, G.; Bonnefoy, M.; Girard, J. H.

    2016-12-01

    Context. Direct imaging has led to the discovery of several giant planet and brown dwarf companions. These imaged companions populate a mass, separation and age domain (mass >1 MJup, orbits > 5 AU, age < 1 Gyr) quite distinct from the one occupied by exoplanets discovered by the radial velocity or transit methods. This distinction could indicate that different formation mechanisms are at play. Aims: We aim at investigating correlations between the host star's mass and the presence of wide-orbit giant planets, and at providing new observational constraints on planetary formation models. Methods: We observed 58 young and nearby M-type dwarfs in L'-band with the VLT/NaCo instrument and used angular differential imaging algorithms to optimize the sensitivity to planetary-mass companions and to derive the best detection limits. We estimate the probability of detecting a planet as a function of its mass and physical separation around each target. We conduct a Bayesian analysis to determine the frequency of substellar companions orbiting low-mass stars, using a homogenous sub-sample of 54 stars. Results: We derive a frequency of for companions with masses in the range of 2-80 MJup, and % for planetary mass companions (2-14 MJup), at physical separations of 8 to 400 AU for both cases. Comparing our results with a previous survey targeting more massive stars, we find evidence that substellar companions more massive than 1 MJup with a low mass ratio Q with respect to their host star (Q < 1%), are less frequent around low-mass stars. This may represent observational evidence that the frequency of imaged wide-orbit substellar companions is correlated with stellar mass, corroborating theoretical expectations. Contrarily, we show statistical evidence that intermediate-mass ratio (1% < Q < 5%) companion with masses >2 MJup might be independent from the mass of the host star.

  8. Jupiter's outer atmosphere.

    NASA Technical Reports Server (NTRS)

    Brice, N. M.

    1973-01-01

    The current state of the theory of Jupiter's outer atmosphere is briefly reviewed. The similarities and dissimilarities between the terrestrial and Jovian upper atmospheres are discussed, including the interaction of the solar wind with the planetary magnetic fields. Estimates of Jovian parameters are given, including magnetosphere and auroral zone sizes, ionospheric conductivity, energy inputs, and solar wind parameters at Jupiter. The influence of the large centrifugal force on the cold plasma distribution is considered. The Jovian Van Allen belt is attributed to solar wind particles diffused in toward the planet by dynamo electric fields from ionospheric neutral winds, and the consequences of this theory are indicated.

  9. In search of planets and life around other stars.

    PubMed

    Lunine, J I

    1999-05-11

    The discovery of over a dozen low-mass companions to nearby stars has intensified scientific and public interest in a longer term search for habitable planets like our own. However, the nature of the detected companions, and in particular whether they resemble Jupiter in properties and origin, remains undetermined.

  10. In search of planets and life around other stars

    PubMed Central

    Lunine, Jonathan I.

    1999-01-01

    The discovery of over a dozen low-mass companions to nearby stars has intensified scientific and public interest in a longer term search for habitable planets like our own. However, the nature of the detected companions, and in particular whether they resemble Jupiter in properties and origin, remains undetermined. PMID:10318886

  11. The fate of scattered planets

    SciTech Connect

    Bromley, Benjamin C.; Kenyon, Scott J. E-mail: skenyon@cfa.harvard.edu

    2014-12-01

    As gas giant planets evolve, they may scatter other planets far from their original orbits to produce hot Jupiters or rogue planets that are not gravitationally bound to any star. Here, we consider planets cast out to large orbital distances on eccentric, bound orbits through a gaseous disk. With simple numerical models, we show that super-Earths can interact with the gas through dynamical friction to settle in the remote outer regions of a planetary system. Outcomes depend on planet mass, the initial scattered orbit, and the evolution of the time-dependent disk. Efficient orbital damping by dynamical friction requires planets at least as massive as the Earth. More massive, longer-lived disks damp eccentricities more efficiently than less massive, short-lived ones. Transition disks with an expanding inner cavity can circularize orbits at larger distances than disks that experience a global (homologous) decay in surface density. Thus, orbits of remote planets may reveal the evolutionary history of their primordial gas disks. A remote planet with an orbital distance ∼100 AU from the Sun is plausible and might explain correlations in the orbital parameters of several distant trans-Neptunian objects.

  12. ARTIST'S CONCEPT -- 'HOT JUPITER' AROUND THE STAR HD 209458

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is an artist's impression of the gas-giant planet orbiting the yellow, Sun-like star HD 209458, 150 light-years from Earth. Astronomers used NASA's Hubble Space Telescope to look at this world and make the first direct detection of an atmosphere around an extrasolar planet. The planet was not directly seen by Hubble. Instead, the presence of sodium was detected in light filtered through the planet's atmosphere when it passed in front of its star as seen from Earth (an event called a transit). The planet was discovered in 1999 by its subtle gravitational pull on the star. The planet is 70 percent the mass of Jupiter, the largest planet in our solar system. Its orbit is tilted nearly edge-on to Earth, which allows repeated transit observations. The planet is merely 4 million miles from the star. The distance between the pair is so close that the yellow star looms in the sky, with an angular diameter 23 times larger than the full Moon's diameter as seen from Earth, and glows 500 times brighter than our Sun. At this precarious distance the planet's atmosphere is heated to 2000 degrees Fahrenheit (1100 degrees Celsius). But the planet is big enough to hold onto its seething atmosphere. Illustration Credit: NASA and Greg Bacon (STScI/AVL)

  13. Interior phase transformations and mass-radius relationships of silicon-carbon planets

    SciTech Connect

    Wilson, Hugh F.; Militzer, Burkhard

    2014-09-20

    Planets such as 55 Cancri e orbiting stars with a high carbon-to-oxygen ratio may consist primarily of silicon and carbon, with successive layers of carbon, silicon carbide, and iron. The behavior of silicon-carbon materials at the extreme pressures prevalent in planetary interiors, however, has not yet been sufficiently understood. In this work, we use simulations based on density functional theory to determine high-pressure phase transitions in the silicon-carbon system, including the prediction of new stable compounds with Si{sub 2}C and SiC{sub 2} stoichiometry at high pressures. We compute equations of state for these silicon-carbon compounds as a function of pressure, and hence derive interior structural models and mass-radius relationships for planets composed of silicon and carbon. Notably, we predict a substantially smaller radius for SiC planets than in previous models, and find that mass radius relationships for SiC planets are indistinguishable from those of silicate planets. We also compute a new equation of state for iron. We rederive interior models for 55 Cancri e and are able to place more stringent restrictions on its composition.

  14. Topics in Extrasolar Planet Characterization

    NASA Astrophysics Data System (ADS)

    Howe, Alex Ryan

    I present four papers exploring different topics in the area of characterizing the atmospheric and bulk properties of extrasolar planets. In these papers, I present two new codes, in various forms, for modeling these objects. A code to generate theoretical models of transit spectra of exoplanets is featured in the first paper and is refined and expanded into the APOLLO code for spectral modeling and parameter retrieval in the fourth paper. Another code to model the internal structure and evolution of planets is featured in the second and third papers. The first paper presents transit spectra models of GJ 1214b and other super-Earth and mini-Neptune type planets--planets with a "solid", terrestrial composition and relatively small planets with a thick hydrogen-helium atmosphere, respectively--and fit them to observational data to estimate the atmospheric compositions and cloud properties of these planets. The second paper presents structural models of super-Earth and mini-Neptune type planets and estimates their bulk compositions from mass and radius estimates. The third paper refines these models with evolutionary calculations of thermal contraction and ultraviolet-driven mass loss. Here, we estimate the boundaries of the parameter space in which planets lose their initial hydrogen-helium atmospheres completely, and we also present formation and evolution scenarios for the planets in the Kepler-11 system. The fourth paper uses more refined transit spectra models, this time for hot jupiter type planets, to explore the methods to design optimal observing programs for the James Webb Space Telescope to quantitatively measure the atmospheric compositions and other properties of these planets.

  15. Constraining the mass of the planet(s) sculpting a disk cavity. The intriguing case of 2MASS J16042165-2130284

    NASA Astrophysics Data System (ADS)

    Canovas, H.; Hardy, A.; Zurlo, A.; Wahhaj, Z.; Schreiber, M. R.; Vigan, A.; Villaver, E.; Olofsson, J.; Meeus, G.; Ménard, F.; Caceres, C.; Cieza, L. A.; Garufi, A.

    2017-01-01

    Context. The large cavities observed in the dust and gas distributions of transition disks may be explained by planet-disk interactions. At 145 pc, 2MASS J16042165-2130284 (J1604) is a 5-12 Myr old transitional disk with different gap sizes in the mm- and μm-sized dust distributions (outer edges at 79 and at 63 au, respectively). Its 12CO emission shows a 30 au cavity. This radial structure suggests that giant planets are sculpting this disk. Aims: We aim to constrain the masses and locations of plausible giant planets around J1604. Methods: We observed J1604 with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) at the Very Large Telescope (VLT), in IRDIFS_EXT, pupil-stabilized mode, obtaining YJH-band images with the integral field spectrograph (IFS) and K1K2-band images with the Infra-Red Dual-beam Imager and Spectrograph (IRDIS). The dataset was processed exploiting the angular differential imaging (ADI) technique with high-contrast algorithms. Results: Our observations reach a contrast of ΔK,ΔYH 12 mag from 0".15 to 0".80 ( 22 to 115 au), but no planet candidate is detected. The disk is directly imaged in scattered light at all bands from Y to K, and it shows a red color. This indicates that the dust particles in the disk surface are mainly ≳0.3 μm-sized grains. We confirm the sharp dip/decrement in scattered light in agreement with polarized light observations. Comparing our images with a radiative transfer model we argue that the southern side of the disk is most likely the nearest. Conclusions: This work represents the deepest search yet for companions around J1604. We reach a mass sensitivity of ≳2-3 MJup from 22 to 115 au according to a hot start scenario. We propose that a brown dwarf orbiting inside of 15 au and additional Jovian planets at larger radii could account for the observed properties of J1604 while explaining our lack of detection. Based on observations made with the VLT, program 095.C-0673(A).The reduced images (FITS

  16. WARM JUPITERS NEED CLOSE ''FRIENDS'' FOR HIGH-ECCENTRICITY MIGRATION—A STRINGENT UPPER LIMIT ON THE PERTURBER'S SEPARATION

    SciTech Connect

    Dong, Subo; Katz, Boaz; Socrates, Aristotle

    2014-01-20

    We propose a stringent observational test on the formation of warm Jupiters (gas-giant planets with 10 days ≲ P ≲ 100 days) by high-eccentricity (high-e) migration mechanisms. Unlike hot Jupiters, the majority of observed warm Jupiters have pericenter distances too large to allow efficient tidal dissipation to induce migration. To access the close pericenter required for migration during a Kozai-Lidov cycle, they must be accompanied by a strong enough perturber to overcome the precession caused by general relativity, placing a strong upper limit on the perturber's separation. For a warm Jupiter at a ∼ 0.2 AU, a Jupiter-mass (solar-mass) perturber is required to be ≲ 3 AU (≲ 30 AU) and can be identified observationally. Among warm Jupiters detected by radial velocities (RVs), ≳ 50% (5 out of 9) with large eccentricities (e ≳ 0.4) have known Jovian companions satisfying this necessary condition for high-e migration. In contrast, ≲ 20% (3 out of 17) of the low-e (e ≲ 0.2) warm Jupiters have detected additional Jovian companions, suggesting that high-e migration with planetary perturbers may not be the dominant formation channel. Complete, long-term RV follow-ups of the warm-Jupiter population will allow a firm upper limit to be put on the fraction of these planets formed by high-e migration. Transiting warm Jupiters showing spin-orbit misalignments will be interesting to apply our test. If the misalignments are solely due to high-e migration as commonly suggested, we expect that the majority of warm Jupiters with low-e (e ≲ 0.2) are not misaligned, in contrast with low-e hot Jupiters.

  17. Imaging Extrasolar Giant Planets

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.

    2016-10-01

    High-contrast adaptive optics (AO) imaging is a powerful technique to probe the architectures of planetary systems from the outside-in and survey the atmospheres of self-luminous giant planets. Direct imaging has rapidly matured over the past decade and especially the last few years with the advent of high-order AO systems, dedicated planet-finding instruments with specialized coronagraphs, and innovative observing and post-processing strategies to suppress speckle noise. This review summarizes recent progress in high-contrast imaging with particular emphasis on observational results, discoveries near and below the deuterium-burning limit, and a practical overview of large-scale surveys and dedicated instruments. I conclude with a statistical meta-analysis of deep imaging surveys in the literature. Based on observations of 384 unique and single young (≈5-300 Myr) stars spanning stellar masses between 0.1 and 3.0 M ⊙, the overall occurrence rate of 5-13 M Jup companions at orbital distances of 30-300 au is {0.6}-0.5+0.7 % assuming hot-start evolutionary models. The most massive giant planets regularly accessible to direct imaging are about as rare as hot Jupiters are around Sun-like stars. Dividing this sample into individual stellar mass bins does not reveal any statistically significant trend in planet frequency with host mass: giant planets are found around {2.8}-2.3+3.7 % of BA stars, <4.1% of FGK stars, and <3.9% of M dwarfs. Looking forward, extreme AO systems and the next generation of ground- and space-based telescopes with smaller inner working angles and deeper detection limits will increase the pace of discovery to ultimately map the demographics, composition, evolution, and origin of planets spanning a broad range of masses and ages.

  18. MIGRATION THEN ASSEMBLY: FORMATION OF NEPTUNE-MASS PLANETS INSIDE 1 AU

    SciTech Connect

    Hansen, Brad M. S.; Murray, Norm

    2012-06-01

    We demonstrate that the observed distribution of 'hot Neptune'/'super-Earth' systems is well reproduced by a model in which planet assembly occurs in situ, with no significant migration post-assembly. This is achieved only if the amount of mass in rocky material is {approx}50-100 M{sub Circled-Plus} interior to 1 AU. Such a reservoir of material implies that significant radial migration of solid material takes place, and that it occurs before the stage of final planet assembly. The model not only reproduces the general distribution of mass versus period but also the detailed statistics of multiple planet systems in the sample. We furthermore demonstrate that cores of this size are also likely to meet the criterion to gravitationally capture gas from the nebula, although accretion is rapidly limited by the opening of gaps in the gas disk. If the mass growth is limited by this tidal truncation, then the scenario sketched here naturally produces Neptune-mass objects with substantial components of both rock and gas, as is observed. The quantitative expectations of this scenario are that most planets in the 'hot Neptune/super-Earth' class inhabit multiple-planet systems, with characteristic orbital spacings. The model also provides a natural division into gas-rich (hot Neptune) and gas-poor (super-Earth) classes at fixed period. The dividing mass ranges from {approx}3 M{sub Circled-Plus} at 10 day orbital periods to {approx}10 M{sub Circled-Plus} at 100 day orbital periods. For orbital periods <10 days, the division is less clear because a gas atmosphere may be significantly eroded by stellar radiation.

  19. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie Anne; Ford, Eric B.

    2015-08-01

    The Kepler Mission has discovered thousands of super-Earths, paving the way for the first statistical studies of the dynamics, formation, and evolution of these planets. Planetary masses are an important physical property that these studies consider, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern for these studies is therefore how to map the measured radii to mass estimates, in this regime of planetary sizes where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters given the data. We analyze how the details depend on the radius range of the sample, and on the method used to provide the mass measurements. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/M_Earth = 2.7 (R/R_Earth)^1.2 and a scatter in mass of 1.7 M_Earth is the "best-fit" probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes.

  20. Migration of icy planetesimals to forming terrestrial planets

    NASA Astrophysics Data System (ADS)

    Ipatov, Sergei I.; Marov, Mikhail

    2016-07-01

    Our studies of migration of planetesimals from the feeding zone of Jupiter and Saturn to forming terrestrial planets were based on computer simulations of the orbital evolution of 10^4 planetesimals under the gravitational influence of planets. In series JN, all planets were considered in present orbits with present masses, and in series JS, Uranus and Neptune were excluded. Initial eccentricities and inclinations of planetesimals were 0.3 and 0.15 rad, respectively. Their initial semi-major axes were between 4.5 and 12 AU. Masses of planets moving in the orbits of the terrestrial planets were equal to present masses of the planets in series JS and JN, and were smaller by a factor of 10 in series JS_{01} and JN_{01}. The obtained results show that the ratio of the fraction of the planetesimals collided with an embryo of the Earth's embryo was about 2\\cdot10^{-6} and 4\\cdot10^{-7} for the mass of the embryo equal to the Earth mass and to 10% of the Earth mass, respectively. We concluded that during the growth of the mass of the Earth's embryo up to a half of the present mass of the Earth, the amount of water delivered to the embryo could be about 30% of all water delivered to the Earth from the feeding zone of Jupiter and Saturn. The total mass of water delivered to the Earth from the feeding zones of the giant planets and beyond these zones could be comparable with the mass of the Earth's oceans. A half of this water could come from the feeding zone of Jupiter and Saturn, and another half from more distant regions. Most of the water that was delivered from the distant regions to the Earth's embryo came when its mass was not small (e.g., was mainly greater than a half of the Earth mass). In series JS, the ratio of the mass of water delivered to a planet to the mass of the planet for the Earth was smaller by a factor of 2, 1.25, and 1.3 than for Mars, Venus and Mercury, respectively. For series JN, the above values of the factor were equal to 3.4, 0.7 i 0.8. For

  1. HAT-P-65b and HAT-P-66b: Two Transiting Inflated Hot Jupiters and Observational Evidence for the Reinflation of Close-in Giant Planets

    NASA Astrophysics Data System (ADS)

    Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Penev, K.; Bieryla, A.; Latham, D. W.; Kovács, G.; Torres, G.; Csubry, Z.; de Val-Borro, M.; Buchhave, L.; Kovács, T.; Quinn, S.; Howard, A. W.; Isaacson, H.; Fulton, B. J.; Everett, M. E.; Esquerdo, G.; Béky, B.; Szklenar, T.; Falco, E.; Santerne, A.; Boisse, I.; Hébrard, G.; Burrows, A.; Lázár, J.; Papp, I.; Sári, P.

    2016-12-01

    We present the discovery of the transiting exoplanets HAT-P-65b and HAT-P-66b, with orbital periods of 2.6055 and 2.9721 days, masses of 0.527+/- 0.083 {M}{{J}} and 0.783+/- 0.057 {M}{{J}}, and inflated radii of 1.89+/- 0.13 {R}{{J}} and {1.59}-0.10+0.16 {R}{{J}}, respectively. They orbit moderately bright (V=13.145+/- 0.029 and V=12.993+/- 0.052) stars of mass 1.212+/- 0.050 {M}⊙ and {1.255}-0.054+0.107 {M}⊙ . The stars are at the main-sequence turnoff. While it is well known that the radii of close-in giant planets are correlated with their equilibrium temperatures, whether or not the radii of planets increase in time as their hosts evolve and become more luminous is an open question. Looking at the broader sample of well-characterized close-in transiting giant planets, we find that there is a statistically significant correlation between planetary radii and the fractional ages of their host stars, with a false-alarm probability of only 0.0041%. We find that the correlation between the radii of planets and the fractional ages of their hosts is fully explained by the known correlation between planetary radii and their present-day equilibrium temperatures; however, if the zero-age main-sequence equilibrium temperature is used in place of the present-day equilibrium temperature, then a correlation with age must also be included to explain the planetary radii. This suggests that, after contracting during the pre-main-sequence, close-in giant planets are reinflated over time due to the increasing level of irradiation received from their host stars. Prior theoretical work indicates that such a dynamic response to irradiation requires a significant fraction of the incident energy to be deposited deep within the planetary interiors. Based on observations obtained with the Hungarian-made Automated Telescope Network. Based on observations obtained at the W. M. Keck Observatory, which is operated by the University of California and the California Institute of Technology

  2. Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets

    NASA Astrophysics Data System (ADS)

    Heller, R.; Barnes, R.

    2015-04-01

    The Kepler space telescope has proven capable of detecting transits of objects almost as small as the Earth's Moon. Some studies suggest that moons as small as 0.2 Earth masses can be detected in the Kepler data by transit timing variations and transit duration variations of their host planets. If such massive moons exist around giant planets in the stellar habitable zone (HZ), then they could serve as habitats for extraterrestrial life. While earlier studies on exomoon habitability assumed the host planet to be in thermal equilibrium with the absorbed stellar flux, we here extend this concept by including the planetary luminosity from evolutionary shrinking. Our aim is to assess the danger of exomoons to be in a runaway greenhouse state due to extensive heating from the planet. We apply pre-computed evolution tracks for giant planets to calculate the incident planetary radiation on the moon as a function of time. Added to the stellar flux, the total illumination yields constraints on a moon's habitability. Ultimately, we include tidal heating to evaluate a moon's energy budget. We use a semi-analytical formula to parameterize the critical flux for the moon to experience a runaway greenhouse effect. Planetary illumination from a 13-Jupiter-mass planet onto an Earth-sized moon at a distance of ten Jupiter radii can drive a runaway greenhouse state on the moon for about 200 million years (Myr). When stellar illumination equivalent to that received by Earth from the Sun is added, then the runaway greenhouse holds for about 500 Myr. After 1000 Myr, the planet's habitable edge has moved inward to about six Jupiter radii. Exomoons in orbits with eccentricities of 0.1 experience strong tidal heating; they must orbit a 13-Jupiter-mass host beyond 29 or 18 Jupiter radii after 100 Myr (at the inner and outer boundaries of the stellar HZ, respectively), and beyond 13 Jupiter radii (in both cases) after 1000 Myr to be habitable. If a roughly Earth-sized, Earth-mass moon would

  3. Numerical Simulations of Disk-Planet Interactions

    NASA Astrophysics Data System (ADS)

    D'Angelo, Gennaro

    2003-06-01

    The aim of this thesis is the study the dynamical interactions occurring between a forming planet and its surrounding protostellar environment. This task is accomplished by means of both 2D and 3D numerical simulations. The first part of this work concerned global simulations in 3D. These were intended to investigate large-scale effects caused by a Jupiter-size body still in the process of accreting matter from its surroundings. Simulations show that, despite a density gap forms along the orbital path, Jupiter-mass protoplanets still accrete at a rate on the order of 0.01 Earth's masses per year when they are embedded in a minimum-mass Solar nebula. In the same conditions, the migration time scale due to gravitational torques by the disk is around 100000 years. The second part of the work was dedicated to perform 2D calculations, by employing a nested-grid technique. This method allows to carry out global simulations of planets orbiting in disks and, at the same time, to resolve in great detail the dynamics of the flow inside the Roche lobe of both massive and low-mass planets. Regardless of the planet mass, the high resolution supplied by the nested-grid technique permits an evaluation of the torques, resulting from short and very short range gravitational interactions, more reliable than the one previously estimated with the aid of numerical methods. Likewise, the mass flow onto the planet is computed in a more accurate fashion. Resulting migration time scales are in the range from 20000 years, for intermediate-mass planets, to 1000000 years, for very low-mass as well as high-mass planets. Circumplanetary disks form inside of the Roche lobe of Jupiter-size secondaries. In order to evaluate the consequences of the flat geometry on the local flow structure around planets, 3D nested-grid simulations were carried out to investigate a range of planetary masses spanning from 1.5 Earth's masses to one Jupiter's mass. Outcomes show that migration rates are relatively

  4. Structure and Evolution of Internally Heated Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Youdin, Andrew N.

    2015-11-01

    The transit radii of many close-in extrasolar giant planets, or "hot Jupiters," are systematically larger than those expected from models considering only cooling from an initial high-entropy state. Though these planets receive strong irradiation, with equilibrium temperatures of 1000-2500 Kelvin, the absorption of stellar incident flux in the upper atmosphere alone cannot explain these anomalous radii. More promising mechanisms involve irradiation-driven meteorological activity, which penetrates much deeper into the planet than direct stellar heating. This circulation can lead to large-scale mixing and downward transport of kinetic energy, both processes whereby a fraction of the stellar incident power is transported downwards to the interior of the planet. Here we consider how deposition of heat at different pressure levels or structural locations within a planet affects the resulting evolution. To do so, we run global gas giant evolutionary models with with the stellar structure code MESA including additional energy dissipation. We find that relatively shallow atmospheric heating alone can explain the transit radii of the hot Jupiter sample, but heating in the convective zone is an order of magnitude more efficient regardless of exact location. Additionally, a small difference in atmospheric heating location can have a significant effect on radius evolution, especially near the radiative-convective boundary. The most efficient location to heat the planet is at the radiative-convective boundary or deeper. We expect that shear instabilities at this interface may naturally explain energy dissipation at the radiative-convective boundary, which typically lies at a pressure of ~1 kilobar after 5 Gyr for a planet with the mass and incident stellar flux of HD 209458b. Hence, atmospheric processes are most efficient at explaining the bloated radii of hot Jupiters if they can transport incident stellar power downwards to the top of the inner convective zone.

  5. TOO LITTLE, TOO LATE: HOW THE TIDAL EVOLUTION OF HOT JUPITERS AFFECTS TRANSIT SURVEYS OF CLUSTERS

    SciTech Connect

    Debes, John H.; Jackson, Brian

    2010-11-10

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense Hubble Space Telescope search for transits. We find that in older clusters, one expects to detect fewer transiting planets by a factor of 2 for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of the semimajor axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  6. Too Little, Too Late: How the Tidal Evolution of Hot Jupiters Affects Transit Surveys of Clusters

    NASA Technical Reports Server (NTRS)

    Debes, John H.; Jackson, Brian

    2010-01-01

    The tidal evolution of hot Jupiters may change the efficiency of transit surveys of stellar clusters. The orbital decay that hot Jupiters suffer may result in their destruction, leaving fewer transiting planets in older clusters. We calculate the impact tidal evolution has for different assumed stellar populations, including that of 47 Tuc, a globular cluster that was the focus of an intense HST search for transits. We find that in older clusters one expects to detect fewer transiting planets by a factor of two for surveys sensitive to Jupiter-like planets in orbits out to 0.5 AU, and up to a factor of 25 for surveys sensitive to Jupiter-like planets in orbits out to 0.08 AU. Additionally, tidal evolution affects the distribution of transiting planets as a function of semi-major axis, producing larger orbital period gaps for transiting planets as the age of the cluster increases. Tidal evolution can explain the lack of detected exoplanets in 47 Tuc without invoking other mechanisms. Four open clusters residing within the Kepler fields of view have ages that span 0.4-8 Gyr-if Kepler can observe a significant number of planets in these clusters, it will provide key tests for our tidal evolution hypothesis. Finally, our results suggest that observers wishing to discover transiting planets in clusters must have sufficient accuracy to detect lower mass planets, search larger numbers of cluster members, or have longer observation windows to be confident that a significant number of transits will occur for a population of stars.

  7. Jupiter's Water Worlds

    NASA Technical Reports Server (NTRS)

    Pappalardo, R. T.

    2004-01-01

    When the twin Voyager spacecraft cruised past Jupiter in 1979, they did more than rewrite the textbooks on the giant planet. Their cameras also unveiled the astounding diversity of the four planet-size moons of ice and stone known as the Galilean satellites. The Voyagers revealed the cratered countenance of Callisto, the valleys and ridges of Ganymede, the cracked face of Europa, and the spewing volcanoes of Io. But it would take a spacecraft named for Italian scientist Galileo, who discovered the moons in 1610, to reveal the true complexity of these worlds and to begin to divulge their interior secrets. Incredibly, the Galileo data strongly suggest that Jupiter's three large icy moons (all but rocky Io) hide interior oceans.

  8. Planets around Low-mass Stars (PALMS). IV. The Outer Architecture of M Dwarf Planetary Systems

    NASA Astrophysics Data System (ADS)

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Tamura, Motohide

    2015-01-01

    We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (gsim1 M Jup) around 122 newly identified nearby (lsim40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M ⊙) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M Jup at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M Jup; L0+2-1; 120 ± 20 AU), GJ 3629 B (64+30-23 M Jup; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M Jup; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M Jup; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M Jup planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M Jup range like those orbiting HR 8799 and β Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M Jup) companions to single M dwarfs between 10-100 AU is 2.8+2.4-1.5%. Altogether we find that giant planets, especially massive ones, are rare

  9. PLANETS AROUND LOW-MASS STARS (PALMS). IV. THE OUTER ARCHITECTURE OF M DWARF PLANETARY SYSTEMS

    SciTech Connect

    Bowler, Brendan P.; Liu, Michael C.; Shkolnik, Evgenya L.; Tamura, Motohide

    2015-01-01

    We present results from a high-contrast adaptive optics imaging search for giant planets and brown dwarfs (≳1 M {sub Jup}) around 122 newly identified nearby (≲40 pc) young M dwarfs. Half of our targets are younger than 135 Myr and 90% are younger than the Hyades (620 Myr). After removing 44 close stellar binaries (implying a stellar companion fraction of >35.4% ± 4.3% within 100 AU), 27 of which are new or spatially resolved for the first time, our remaining sample of 78 single M dwarfs makes this the largest imaging search for planets around young low-mass stars (0.1-0.6 M {sub ☉}) to date. Our H- and K-band coronagraphic observations with Keck/NIRC2 and Subaru/HiCIAO achieve typical contrasts of 12-14 mag and 9-13 mag at 1'', respectively, which correspond to limiting planet masses of 0.5-10 M {sub Jup} at 5-33 AU for 85% of our sample. We discovered four young brown dwarf companions: 1RXS J235133.3+312720 B (32 ± 6 M {sub Jup}; L0{sub −1}{sup +2}; 120 ± 20 AU), GJ 3629 B (64{sub −23}{sup +30} M {sub Jup}; M7.5 ± 0.5; 6.5 ± 0.5 AU), 1RXS J034231.8+121622 B (35 ± 8 M {sub Jup}; L0 ± 1; 19.8 ± 0.9 AU), and 2MASS J15594729+4403595 B (43 ± 9 M {sub Jup}; M8.0 ± 0.5; 190 ± 20 AU). Over 150 candidate planets were identified; we obtained follow-up imaging for 56% of these but all are consistent with background stars. Our null detection of planets enables strong statistical constraints on the occurrence rate of long-period giant planets around single M dwarfs. We infer an upper limit (at the 95% confidence level) of 10.3% and 16.0% for 1-13 M {sub Jup} planets between 10-100 AU for hot-start and cold-start (Fortney) evolutionary models, respectively. Fewer than 6.0% (9.9%) of M dwarfs harbor massive gas giants in the 5-13 M {sub Jup} range like those orbiting HR 8799 and β Pictoris between 10-100 AU for a hot-start (cold-start) formation scenario. The frequency of brown dwarf (13-75 M {sub Jup}) companions to single

  10. A Transiting Jupiter Analog

    NASA Astrophysics Data System (ADS)

    Kipping, D. M.; Torres, G.; Henze, C.; Teachey, A.; Isaacson, H.; Petigura, E.; Marcy, G. W.; Buchhave, L. A.; Chen, J.; Bryson, S. T.; Sandford, E.

    2016-04-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of (0.91+/- 0.02) {R}{{J}}, a low orbital eccentricity ({0.06}-0.04+0.10), and an equilibrium temperature of (131+/- 3) K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric coverage, we are able to uniquely and precisely measure the orbital period of this post snow-line planet (1071.2323 ± 0.0006d), paving the way for follow-up of this K = 11.8 mag target.

  11. Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass Stars

    NASA Astrophysics Data System (ADS)

    Ciesla, Fred J.; Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-05-01

    Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our solar system. Here we consider how the water content of planetesimals may be higher in many planetary systems, as they could lack the short-lived radionuclides that drove water loss in carbonaceous chondrites in our solar system. Using N-body simulations, we explore how planetary accretion would be different if bodies beyond the water line contained a water-mass fraction consistent with chemical equilibrium calculations, and more similar to comets, as opposed to the more traditional water-depleted values. We apply this model to consider planet formation around stars of different masses and identify trends in the properties of habitable zone planets and planetary system architecture that could be tested by ongoing exoplanet census data collection. Comparison of such data with the model-predicted trends will serve to evaluate how well the N-body simulations and the initial conditions used in studies of planetary accretion can be used to understand this stage of planet formation.

  12. VOLATILE DELIVERY TO PLANETS FROM WATER-RICH PLANETESIMALS AROUND LOW-MASS STARS

    SciTech Connect

    Ciesla, Fred J.; Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-05-01

    Most models of volatile delivery to accreting terrestrial planets assume that the carriers for water are similar in water content to the carbonaceous chondrites in our solar system. Here we consider how the water content of planetesimals may be higher in many planetary systems, as they could lack the short-lived radionuclides that drove water loss in carbonaceous chondrites in our solar system. Using N-body simulations, we explore how planetary accretion would be different if bodies beyond the water line contained a water-mass fraction consistent with chemical equilibrium calculations, and more similar to comets, as opposed to the more traditional water-depleted values. We apply this model to consider planet formation around stars of different masses and identify trends in the properties of habitable zone planets and planetary system architecture that could be tested by ongoing exoplanet census data collection. Comparison of such data with the model-predicted trends will serve to evaluate how well the N-body simulations and the initial conditions used in studies of planetary accretion can be used to understand this stage of planet formation.

  13. A FRAMEWORK FOR CHARACTERIZING THE ATMOSPHERES OF LOW-MASS LOW-DENSITY TRANSITING PLANETS

    SciTech Connect

    Fortney, Jonathan J.; Nettelmann, Nadine; Mordasini, Christoph; Kempton, Eliza M.-R.; Greene, Thomas P.; Zahnle, Kevin

    2013-09-20

    We perform modeling investigations to aid in understanding the atmospheres and composition of small planets of ∼2-4 Earth radii, which are now known to be common in our Galaxy. GJ 1214b is a well-studied example whose atmospheric transmission spectrum has been observed by many investigators. Here we take a step back from GJ 1214b to investigate the role that planetary mass, composition, and temperature play in impacting the transmission spectra of these low-mass low-density (LMLD) planets. Under the assumption that these planets accrete modest hydrogen-dominated atmospheres and planetesimals, we use population synthesis models to show that predicted metal enrichments of the H/He envelope are high, with metal mass fraction Z{sub env} values commonly 0.6-0.9, or ∼100-400+ times solar. The high mean molecular weight of such atmospheres (μ ≈ 5-12) would naturally help to flatten the transmission spectrum of most LMLD planets. The high metal abundance would also provide significant condensible material for cloud formation. It is known that the H/He abundance in Uranus and Neptune decreases with depth, and we show that atmospheric evaporation of LMLD planets could expose atmospheric layers with gradually higher Z{sub env}. However, values of Z{sub env} close to solar composition can also arise, so diversity should be expected. Photochemically produced hazes, potentially due to methane photolysis, are another possibility for obscuring transmission spectra. Such hazes may not form above T{sub eq} of ∼800-1100 K, which is testable if such warm, otherwise low mean molecular weight atmospheres are stable against atmospheric evaporation. We find that available transmission data are consistent with relatively high mean molecular weight atmospheres for GJ 1214b and 'warm Neptune' GJ 436b. We examine future prospects for characterizing GJ 1214b with Hubble and the James Webb Space Telescope.

  14. Jupiter before Juno: State of the atmosphere at cloud level in 2016 from PlanetCam observations in the 0.4-1.7 microns wavelength range and amateur observations in the visible

    NASA Astrophysics Data System (ADS)

    Hueso, Ricardo; Sanchez-Lavega, Agustin; Perez-Hoyos, Santiago; Rojas, Jose Felix; Iñurrigarro, Peio; Mendikoa, Iñigo; Go, Christopher; PVOL-IOPW Team

    2016-10-01

    The arrival of Juno to Jupiter provides a unique opportunity to link findings of the inner structure of the planet with astronomical observations of its meteorology at cloud level. Long time base observations of Jupiter's atmosphere before and during the Juno mission are critical in providing context to Junocam observations and may benefit the interpretation of the MWR data on the lower atmosphere structure as well as Juno data on the depth of the zonal winds. We have performed a long campaign of observations in the visible with the PlanetCam lucky imaging instrument in the 2.2m telescope at Calar Alto Observatory in Spain with observations obtained in December 2015 and in March, May, June and July 2016. In observations under good atmospheric seeing, the instrument allows to obtain images with a spatial resolution of 0.05'' in the visible and 0.1'' from 1.0 to 1.7 microns. The later is an interesting range of wavelengths for observing Jupiter because of the existence of several strong and weak methane absorption bands not generally used in high-resolution ground-based observations of the planet. A combination of images using narrow filters centered in methane absorption bands and their adjacent continuum allows studying the vertical structure of the clouds at horizontal spatial scales of 350-1000 km over the planet depending on the atmospheric seeing and filter used. The best images can be further processed showing features at spatial resolutions of about 150 km. We have also monitored the state of the atmosphere with images obtained by amateur astronomers contributing to the Planetary Virtual Observatory Laboratory database (http://pvol.ehu.eus). Based on both datasets we present zonal winds from -70 to +75 deg with an accuracy of 10 m/s in the low latitudes and 25 m/s in subpolar latitudes. Relative altitude maps of features observed in bands J, H and others with different methane absorption will be presented.

  15. The International Deep Planet Survey. II. The frequency of directly imaged giant exoplanets with stellar mass

    NASA Astrophysics Data System (ADS)

    Galicher, R.; Marois, C.; Macintosh, B.; Zuckerman, B.; Barman, T.; Konopacky, Q.; Song, I.; Patience, J.; Lafrenière, D.; Doyon, R.; Nielsen, E. L.

    2016-10-01

    Context. Radial velocity and transit methods are effective for the study of short orbital period exoplanets but they hardly probe objects at large separations for which direct imaging can be used. Aims: We carried out the international deep planet survey of 292 young nearby stars to search for giant exoplanets and determine their frequency. Methods: We developed a pipeline for a uniform processing of all the data that we have recorded with NIRC2/Keck II, NIRI/Gemini North, NICI/Gemini South, and NACO/VLT for 14 yr. The pipeline first applies cosmetic corrections and then reduces the speckle intensity to enhance the contrast in the images. Results: The main result of the international deep planet survey is the discovery of the HR 8799 exoplanets. We also detected 59 visual multiple systems including 16 new binary stars and 2 new triple stellar systems, as well as 2279 point-like sources. We used Monte Carlo simulations and the Bayesian theorem to determine that 1.05+2.80-0.70% of stars harbor at least one giant planet between 0.5 and 14 MJ and between 20 and 300 AU. This result is obtained assuming uniform distributions of planet masses and semi-major axes. If we consider power law distributions as measured for close-in planets instead, the derived frequency is 2.30+5.95-1.55%, recalling the strong impact of assumptions on Monte Carlo output distributions. We also find no evidence that the derived frequency depends on the mass of the hosting star, whereas it does for close-in planets. Conclusions: The international deep planet survey provides a database of confirmed background sources that may be useful for other exoplanet direct imaging surveys. It also puts new constraints on the number of stars with at least one giant planet reducing by a factor of two the frequencies derived by almost all previous works. Tables 11-15 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  16. Jupiter and the Voyager mission

    USGS Publications Warehouse

    Soderblom, L.; Spall, Henry

    1980-01-01

    In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year. 

  17. Jupiter - Solid or Gaseous? Ask Juno

    NASA Astrophysics Data System (ADS)

    Ackerman, J. A., Jr.

    2015-12-01

    Data from Cassini, Galileo, S-L 9 and Ulysses suggest Jupiter and Saturn are solid, frozen, Methane Gas Hydrate (MGH) planets. The bulk of these giants formed slow and cold by the natural accretion of snowflakes at their current orbital radii in the presence of methane, forming rigid incompressible bodies. MGH, (CH4)8(H2O)46 (d=0.9), is consistent with the abundances of the elements comprising the Earth (H>O>C). Their combined MGH comprises >250 earth-masses of H2O. Jupiter (d=1.33) incorporated most of the heavy elements in the nascent solar system, exemplified by an enormously enhanced D/H. The temperature excess of Jupiter's atmosphere is the result of an impact ~6,000 years BP, triggering an incredibly energetic fusion explosion which ejected the masses of the proto-Galilean moons. It also initiated a continuing fusion furnace in the crater producing a jet of hot gases extending >2x106 km, beyond Callisto. The jet has slowly diminished over 6,000 years, resulting in the differences in the four Galilean Moons. The mass ejection (ang. mom.) slowed Jupiter's rotation until ~1930, currently interpreted as a drift of the Great Red Spot. A diminishing fusion reaction (D + p → 3He + γ) continues to this day, producing Jupiter's atmospheric 'temperature excess'. Jupiter's rapid rotation deflects the rising vortex of hot gases from the fusion reaction horizontally, driving multiple zonal vortices, constrained by the frozen MGH surface <1000 km below the cloud tops. It appears as the tilted Great Red Spot (GRS), ~30,000 km to the west of the crater at 22 o S Lat., which has remained unchanged in the last 350 years - impossible due to the enormous Coliolis effect. Streams of 3He produced in the fusion reaction exiting Jupiter through the center of the GRS have been detected by the Galileo probe and orbiter, Ulysses, and Cassini. The fusion releases methane, also heavy elements which oxidize as they rise, producing the cloud-top colors. The MGH hypothesis explains the

  18. The depths of clouds on Jupiter: Observational constraints on the O/H ratio

    NASA Astrophysics Data System (ADS)

    Wong, M. H.; Bjoraker, G. L.; De Pater, I.; Adamkovics, M.

    2015-12-01

    The oxygen abundance in Jupiter is an important constraint on planet formation and conditions in protoplanetary disks. Oxygen, in the form of water, is also dynamically significant in Jupiter's atmosphere: as a tracer of circulation and as a carrier of latent heat. We have developed a technique to measure the depth of opaque cloud tops in Jupiter's atmosphere (Bjoraker et al. 2015; this meeting; also Astrophysical Journal in press). We measure resolved CH3D line shapes in the 5-μm window of Jupiter's spectrum to distinguish between cloud-top pressure levels of about 3 to 10 bars. We will use the retrieved cloud top pressure levels to place lower limits on the O/H ratio in Jupiter, based on Keck/NIRSPEC spectra acquired in January 2013. Since our spectra do not directly give the temperature/pressure profile in the cloud layer, constraining the O/H ratio requires independent atmospheric structure data. We will review observational and theoretical constraints on Jupiter's thermal structure, which lead to uncertainty bounds on the O/H ratio we derive. Preliminary work to date suggests that our technique may be able to determine whether or not the Galileo Probe Mass Spectrometer O/H measurement can be representative of the planet's bulk abundance, and whether O is supersolar in Jupiter like the other volatile elements C, N, and S. If we can distinguish between O/H lower limits of 10x and 3x solar, we will be able to test the hypothesis that Jupiter's volatiles must have been delivered via water ice clathrates. [This conference abstract is supported by NASA grant NNX11AM55G issued through the Outer Planets Research Program, and by grants NNX11AJ47G, NNX14AJ43G, and NNX1AJ41G through the Planetary Astronomy and Solar System Observations Programs.

  19. Microlens Masses from Astrometry and Parallax in Space-based Surveys: From Planets to Black Holes

    NASA Astrophysics Data System (ADS)

    Gould, Andrew; Yee, Jennifer C.

    2014-03-01

    We show that space-based microlensing experiments can recover lens masses and distances for a large fraction of all events (those with individual photometric errors <~ 0.01 mag) using a combination of one-dimensional microlens parallaxes and astrometric microlensing. This will provide a powerful probe of the mass distributions of planets, black holes, and neutron stars, the distribution of planets as a function of Galactic environment, and the velocity distributions of black holes and neutron stars. While systematics are in principle a significant concern, we show that it is possible to vet against all systematics (known and unknown) using single-epoch precursor observations with the Hubble Space Telescope roughly 10 years before the space mission.

  20. Microlens masses from astrometry and parallax in space-based surveys: From planets to black holes

    SciTech Connect

    Gould, Andrew; Yee, Jennifer C.

    2014-03-20

    We show that space-based microlensing experiments can recover lens masses and distances for a large fraction of all events (those with individual photometric errors ≲ 0.01 mag) using a combination of one-dimensional microlens parallaxes and astrometric microlensing. This will provide a powerful probe of the mass distributions of planets, black holes, and neutron stars, the distribution of planets as a function of Galactic environment, and the velocity distributions of black holes and neutron stars. While systematics are in principle a significant concern, we show that it is possible to vet against all systematics (known and unknown) using single-epoch precursor observations with the Hubble Space Telescope roughly 10 years before the space mission.

  1. Barnard’s Star: Planets or Pretense

    NASA Astrophysics Data System (ADS)

    Bartlett, Jennifer L.; Ianna, P. A.

    2014-01-01

    Barnard’s Star remains popular with planet hunters because it is not only an extremely near, high proper motion star, but also the object of early planet-detection claims. In 1963, van de Kamp explained perturbations in its proper motion by the presence of a planet. In 1969, he produced another single-planet solution and a two-planet solution to the astrometric wobbles detected. At least 19 studies have failed to confirm his results using a range of techniques, including radial velocity, direct imaging, and speckle interferometry. However, most of them lacked the sensitivity to detect the planets he described, including astrometric studies at the McCormick and Naval Observatories. However, radial-velocity monitoring of Barnard’s Star at Lick and Keck Observatories from 1987 through 2012 appears to have ruled out such planets. Based upon observations made at the Sproul Observatory between 1916 and 1962, van de Kamp claimed that Barnard’s Star had a planet with about 1.6 times the mass of Jupiter and an orbital period of 24 years. After accounting for instrumentation effects that might have been partially responsible for his initial results, he continued to assert that this red dwarf had two planets. In his 1982 analysis of ~20,000 exposures collected between 1938 and 1981, he calculated that two planets with 0.7- and 0.5-Jupiter masses in 12- and 20-year orbits, respectively, orbited the second-closest stellar system to our own. Starting in 1995, the dramatic successes of radial velocity searches for extrasolar planets drove van de Kamp’s unsubstantiated claims from popular consciousness. Although many low-mass stellar companions were discovered through astrometry, the technique has been less successful for planets: “The Extrasolar Planets Encyclopaedia” identifies one such discovery out of the 997 planets listed on 2013 September 23. Although Barnard’s Star has lost its pretensions to hosting the first extrasolar planets known, its intrinsic

  2. The High-Energy Radiation Environment of Planets around Low-Mass Stars

    NASA Astrophysics Data System (ADS)

    Shkolnik, Evgenya; Miles, Brittany; Barman, Travis; Peacock, Sarah

    2015-12-01

    Low-mass stars are the dominant planet hosts averaging about one planet per star. Many of these planets orbit in the canonical habitable zone (HZ) of the star where, if other conditions allowed, liquid water may exist on the surface.A planet’s habitability, including atmospheric retention, is strongly dependent on the star’s ultraviolet (UV) emission, which chemically modifies, ionizes, and even erodes the atmosphere over time including the photodissociation of important diagnostic molecules, e.g. H2O, CH4, and CO2. The UV spectral slope of a low-mass star can enhance atmospheric lifetimes, and increase the detectability of biologically generated gases. But, a different slope may lead to the formation of abiotic oxygen and ozone producing a false-positive biosignature for oxygenic photosynthesis. Realistic constraints on the incident UV flux over a planet’s lifetime are necessary to explore the cumulative effects on the evolution, composition, and fate of a HZ planetary atmosphere.NASA’s Galaxy Evolution Explorer (GALEX) provides a unique data set with which to study the broadband UV emission from many hundreds of M dwarfs. The GALEX satellite has imaged nearly 3/4 of the sky simultaneously in two UV bands: near-UV (NUV; 175-275 nm) and far-UV (FUV; 135-175 nm). With these data these, we are able to calculate the mean UV emission and its level of variability at these wavelengths over critical planet formation and evolution time scales to better understand the probable conditions in HZ planetary atmospheres.In the near future, dedicated CubeSats (miniaturized satellites for space research) to monitor M dwarf hosts of transiting exoplanets will provide the best opportunity to measure their UV variability, constrain the probabilities of detecting habitable (and inhabited) planets, and provide the correct context within which to interpret IR transmission and emission spectroscopy of transiting exoplanets.

  3. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie A.; Ford, Eric B.

    2016-07-01

    The Kepler Mission has discovered thousands of planets with radii <4 {R}\\oplus , paving the way for the first statistical studies of the dynamics, formation, and evolution of these sub-Neptunes and super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern is therefore how to map the measured radii to mass estimates in this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters. We analyze how the results depend on the radius range of the sample, and on how the masses were measured. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/{M}\\oplus =2.7{(R/{R}\\oplus )}1.3, a scatter in mass of 1.9{M}\\oplus , and a mass constraint to physically plausible densities, is the “best-fit” probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes (R pl < 4 {R}\\oplus ). More broadly, this work provides a framework for further analyses of the M-R relation and its probable dependencies on period and stellar properties.

  4. Super-massive planets around late-type stars—the case of OGLE-2012-BLG-0406Lb

    SciTech Connect

    Poleski, Radosław; Gould, Andrew; Udalski, Andrzej; Szymański, Michał K.; Soszyński, Igor; Kubiak, Marcin; Pietrzyński, Grzegorz; Kozłowski, Szymon; Pietrukowicz, Paweł; Ulaczyk, Krzysztof; Skowron, Jan; Wyrzykowski, Łukasz; Dong, Subo

    2014-02-10

    Super-Jupiter-mass planets should form only beyond the snow line of host stars. However, the core accretion theory of planetary formation does not predict super-Jupiters forming around low-mass hosts. We present a discovery of a 3.9 ± 1.2 M {sub Jup} mass planet orbiting the 0.59 ± 0.17 M {sub ☉} star using the gravitational microlensing method. During the event, the projected separation of the planet and the star is 3.9 ± 1.0 AU, i.e., the planet is significantly further from the host star than the snow line. This is the fourth such planet discovered using the microlensing technique and challenges the core accretion theory.

  5. KEPLER-6b: A TRANSITING HOT JUPITER ORBITING A METAL-RICH STAR

    SciTech Connect

    Dunham, Edward W.; Borucki, William J.; Koch, David G.; Lissauer, Jack J.; Batalha, Natalie M.; Buchhave, Lars A.; Furesz, Gabor; Geary, John C.; Latham, David W.; Brown, Timothy M.; Caldwell, Douglas A.; Jenkins, Jon M.; Cochran, William D.; Endl, Michael; Fischer, Debra; Gautier, Thomas N.; Gould, Alan; Howell, Steve B.; Kjeldsen, Hans

    2010-04-20

    We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H]= +0.34{+-}0.04. The planet's mass is about 2/3 that of Jupiter, M {sub P} = 0.67 M {sub J}, and the radius is 30% larger than that of Jupiter, R {sub P} = 1.32 R {sub J}, resulting in a density of {rho}{sub P} = 0.35 g cm{sup -3}, a fairly typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, M {sub *} = 1.21 M {sub sun}, and larger than the Sun, R {sub *} = 1.39 R {sub sun}.

  6. KEPLER PLANETS: A TALE OF EVAPORATION

    SciTech Connect

    Owen, James E.; Wu, Yanqin E-mail: wu@astro.utoronto.ca

    2013-10-01

    Inspired by the Kepler mission's planet discoveries, we consider the thermal contraction of planets close to their parent star, under the influence of evaporation. The mass-loss rates are based on hydrodynamic models of evaporation that include both X-ray and EUV irradiation. We find that only low mass planets with hydrogen envelopes are significantly affected by evaporation, with evaporation being able to remove massive hydrogen envelopes inward of ∼0.1 AU for Neptune-mass objects, while evaporation is negligible for Jupiter-mass objects. Moreover, most of the evaporation occurs in the first 100 Myr of stars' lives when they are more chromospherically active. We construct a theoretical population of planets with varying core masses, envelope masses, orbital separations, and stellar spectral types, and compare this population with the sizes and densities measured for low-mass planets, both in the Kepler mission and from radial velocity surveys. This exercise leads us to conclude that evaporation is the driving force of evolution for close-in Kepler planets. In fact, some 50% of the Kepler planet candidates may have been significantly eroded. Evaporation explains two striking correlations observed in these objects: a lack of large radius/low density planets close to the stars and a possible bimodal distribution in planet sizes with a deficit of planets around 2 R{sub ⊕}. Planets that have experienced high X-ray exposures are generally smaller than this size, and those with lower X-ray exposures are typically larger. A bimodal planet size distribution is naturally predicted by the evaporation model, where, depending on their X-ray exposure, close-in planets can either hold on to hydrogen envelopes ∼0.5%-1% in mass or be stripped entirely. To quantitatively reproduce the observed features, we argue that not only do low-mass Kepler planets need to be made of rocky cores surrounded with hydrogen envelopes, but few of them should have initial masses above 20 M

  7. The fates of Solar system analogues with one additional distant planet

    NASA Astrophysics Data System (ADS)

    Veras, Dimitri

    2016-12-01

    The potential existence of a distant planet (`Planet Nine') in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main-sequence star into a white dwarf, Jupiter, Saturn, Uranus and Neptune are currently assumed to survive in expanded but otherwise unchanged orbits. However, a sufficiently distant and sufficiently massive extra planet would alter this quiescent end scenario through the combined effects of Solar giant branch mass-loss and Galactic tides. Here, I estimate bounds for the mass and orbit of a distant extra planet that would incite future instability in systems with a Sun-like star and giant planets with masses and orbits equivalent to those of Jupiter, Saturn, Uranus and Neptune. I find that this boundary is diffuse and strongly dependent on each of the distant planet's orbital parameters. Nevertheless, I claim that instability occurs more often than not when the planet is as massive as Jupiter and harbours a semimajor axis exceeding about 300 au, or has a mass of a super-Earth and a semimajor axis exceeding about 3000 au. These results hold for orbital pericentres ranging from 100 to at least 400 au. This instability scenario might represent a common occurrence, as potentially evidenced by the ubiquity of metal pollution in white dwarf atmospheres throughout the Galaxy.

  8. Terrestrial planet formation from a truncated disk -- The 'Grand Tack'

    NASA Astrophysics Data System (ADS)

    Walsh, K. J.; Morbidelli, A.; Raymond, S.; O'Brien, D. P.; Mandell, A. M.

    2012-12-01

    A new terrestrial planet formation model (Walsh et al., 2011) explores the effects of a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation (Masset & Snellgrove 2001, Morbidelli & Crida 2007, Pierens & Nelson 2008, Pierens & Raymond 2011). The inward migration of Jupiter truncates the disk of planetesimals and embryos in the terrestrial planet region. Subsequent accretion in that region then forms the terrestrial planets, in particular it produces the correct Earth/Mars mass ratio, which has been difficult to reproduce in simulations with a self-consistent set of initial conditions (see, eg. Raymond et al. 2009, Hansen 2009). Additionally, the outward migration of the giant planets populates the asteroid belt with distinct populations of bodies, with the inner belt filled by bodies originating inside of 3 AU, and the outer belt filled with bodies originating from beyond the giant planets. This differs from previous models of terrestrial planet formation due to the early radial mixing of material due to the giant planet's substantial migration. Specifically, the assumption that the current radial distribution of material in the inner Solar System is reflective of the primordial distribution of material in that region is no longer necessary. We will discuss the implications of this model in relation to previous models of terrestrial planet formation as well as available chemical and isotopic constraints.

  9. Rapid heating of the atmosphere of an extrasolar planet.

    PubMed

    Laughlin, Gregory; Deming, Drake; Langton, Jonathan; Kasen, Daniel; Vogt, Steve; Butler, Paul; Rivera, Eugenio; Meschiari, Stefano

    2009-01-29

    Near-infrared observations of more than a dozen 'hot-Jupiter' extrasolar planets have now been reported. These planets display a wide diversity of properties, yet all are believed to have had their spin periods tidally spin-synchronized with their orbital periods, resulting in permanent star-facing hemispheres and surface flow patterns that are most likely in equilibrium. Planets in significantly eccentric orbits can enable direct measurements of global heating that are largely independent of the details of the hydrodynamic flow. Here we report 8-microm photometric observations of the planet HD 80606b during a 30-hour interval bracketing the periastron passage of its extremely eccentric 111.4-day orbit. As the planet received its strongest irradiation (828 times larger than the flux received at apastron) its maximum 8-microm brightness temperature increased from approximately 800 K to approximately 1,500 K over a six-hour period. We also detected a secondary eclipse for the planet, which implies an orbital inclination of i approximately 90 degrees , fixes the planetary mass at four times the mass of Jupiter, and constrains the planet's tidal luminosity. Our measurement of the global heating rate indicates that the radiative time constant at the planet's 8-microm photosphere is approximately 4.5 h, in comparison with 3-5 days in Earth's stratosphere.

  10. YOUNG SOLAR SYSTEM's FIFTH GIANT PLANET?

    SciTech Connect

    Nesvorny, David

    2011-12-15

    Studies of solar system formation suggest that the solar system's giant planets formed and migrated in the protoplanetary disk to reach the resonant orbits with all planets inside {approx}15 AU from the Sun. After the gas disk's dispersal, Uranus and Neptune were likely scattered by the gas giants, and approached their current orbits while dispersing the transplanetary disk of planetesimals, whose remains survived to this time in the region known as the Kuiper Belt. Here we performed N-body integrations of the scattering phase between giant planets in an attempt to determine which initial states are plausible. We found that the dynamical simulations starting with a resonant system of four giant planets have a low success rate in matching the present orbits of giant planets and various other constraints (e.g., survival of the terrestrial planets). The dynamical evolution is typically too violent, if Jupiter and Saturn start in the 3:2 resonance, and leads to final systems with fewer than four planets. Several initial states stand out in that they show a relatively large likelihood of success in matching the constraints. Some of the statistically best results were obtained when assuming that the solar system initially had five giant planets and one ice giant, with the mass comparable to that of Uranus and Neptune, and which was ejected to interstellar space by Jupiter. This possibility appears to be conceivable in view of the recent discovery of a large number of free-floating planets in interstellar space, which indicates that planet ejection should be common.

  11. On the Eccentricities of Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Marzari, F.; Weidenschilling, S. J.

    1999-09-01

    Extrasolar planets (ESPs) seem to be divided into two groups: circular orbits very close to their stars, or eccentric orbits at larger distances. The latter may be the result of gravitational scattering of planets that formed in unstable orbits (Weidenschilling and Marzari 1996, Nature 384, 619). For systems of three Jupiter-mass planets, the most common outcome is ejection of one planet, leaving the others in stable orbits with significant eccentricities and mutual inclinations. We have compiled statistics for orbital elements of the survivors. At the time of ejection, the eccentricity of the inner one has a broad distribution with modal value 0.5, ranging from about 0.1 to 0.9; smaller and larger values are rare. In contrast, among observed eccentric ESPs only 2 of 11 have e > 0.5, and none have e > 0.7, although there is no observational bias against detection of planets on eccentric orbits. One possible explanation is a large cross-section for young gas giant planets still in their contraction phase, so that non-collisional encounters yield smaller velocity changes. However, even if the effective radius is twice Jupiter's present value, the eccentricity distribution does not change significantly. The "snapshot" distribution at the time one planet is ejected may be misleading. The orbits of the remaining planets are subject to mutual perturbations. The inner planet's eccentricity may oscillate with large amplitude on timescales of 10(7) - 10(8) y. Peak values bring some periastrons low enough for tides to circularize orbits. For planets with large initial eccentricities, the time-averaged e is lower, yielding better agreement with the observed distribution. Still, some orbits with eccentricities up to 0.9, should be detected in a large enough sample of ESPs. If none are found, their absence would argue against gravitational scattering as a general phenomenon in planetary systems.

  12. A nebula of gases from Io surrounding Jupiter.

    PubMed

    Krimigis, Stamatios M; Mitchell, Donald G; Hamilton, Douglas C; Dandouras, Jannis; Armstrong, Thomas P; Bolton, Scott J; Cheng, Andrew F; Gloeckler, George; Hsieh, K C; Keath, Edwin P; Krupp, Norbert; Lagg, Andreas; Lanzerotti, Louis J; Livi, Stefano; Mauk, Barry H; McEntire, Richard W; Roelof, Edmond C; Wilken, Berend; Williams, Donald J

    2002-02-28

    Several planetary missions have reported the presence of substantial numbers of energetic ions and electrons surrounding Jupiter; relativistic electrons are observable up to several astronomical units (au) from the planet. A population of energetic (>30[?]keV) neutral particles also has been reported, but the instrumentation was not able to determine the mass or charge state of the particles, which were subsequently labelled energetic neutral atoms. Although images showing the presence of the trace element sodium were obtained, the source and identity of the neutral atoms---and their overall significance relative to the loss of charged particles from Jupiter's magnetosphere---were unknown. Here we report the discovery by the Cassini spacecraft of a fast (>103[?]km[?]s-1) and hot magnetospheric neutral wind extending more than 0.5[?]au from Jupiter, and the presence of energetic neutral atoms (both hot and cold) that have been accelerated by the electric field in the solar wind. We suggest that these atoms originate in volcanic gases from Io, undergo significant evolution through various electromagnetic interactions, escape Jupiter's magnetosphere and then populate the environment around the planet. Thus a 'nebula' is created that extends outwards over hundreds of jovian radii.

  13. Jupiter: Giant of the solar system. [its solar orbits

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Jupiter, its relationship to the other planets in the solar system, its twelve natural satellites, solar orbit and the appearance of Jupiter in the sky, and the sightings and motions of Jupiter in 1973 are discussed. Educational study projects for students are also included.

  14. 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

  15. Effects of Magnetism on the Atmospheres and Evolution of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Komacek, Thaddeus D.; Rogers, Tamara M.; Barman, Travis S.; Showman, Adam P.; Youdin, Andrew N.

    2014-11-01

    Magnetic effects imprint potentially observable features of close-in extrasolar giant planets, or "hot Jupiters," through two mechanisms: the Lorentz force, which modifies atmospheric dynamics, and Ohmic dissipation, which may have a large impact on the structure and evolution of a planet. We present results from a 3D anelastic magnetohydrodynamic (MHD) model, taking into account purely resistive MHD. We demonstrate that magnetic effects may cause a transition from the expected superrotation in purely hydrodynamic models to subrotation (i.e. wind reversal) at high equilibrium temperatures and magnetic field strengths. This reduction of wind speeds correspondingly reduces hot spot displacement, forcing MHD atmospheric hot spots to be found westward of their hydrodynamic counterparts. For the case of HD 209458b, we do not expect that atmospheric Ohmic dissipation has a large enough magnitude to explain its observed radius, even when scaling the dissipated power into the planetary convective zone. However, the efficacy of Ohmic dissipation is expected to be greater for hot Jupiters with a lower mass than HD 209458b, as these planets have less partial degeneracy and larger pressure scale heights. Hence, Ohmic dissipation can likely explain why a subset of transiting hot Jupiters appear inflated, but other mechanisms may be required to explain those with a mass comparable to or greater than 0.7 Jupiter masses.

  16. Kepler-424 b: A "Lonely" Hot Jupiter that Found a Companion

    NASA Astrophysics Data System (ADS)

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Havel, Mathieu; Lucas, Phillip; Howell, Steve B.; Fischer, Debra; Quintana, Elisa; Ciardi, David R.

    2014-11-01

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be "lonely". This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to \\upsilon Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M ⊕. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

  17. Kepler-424 b: A 'lonely' hot Jupiter that found A companion

    SciTech Connect

    Endl, Michael; Caldwell, Douglas A.; Barclay, Thomas; Huber, Daniel; Havel, Mathieu; Howell, Steve B.; Quintana, Elisa; Isaacson, Howard; Buchhave, Lars A.; Brugamyer, Erik; Robertson, Paul; Cochran, William D.; MacQueen, Phillip J.; Lucas, Phillip; Fischer, Debra; Ciardi, David R.

    2014-11-10

    Hot Jupiter systems provide unique observational constraints for migration models in multiple systems and binaries. We report on the discovery of the Kepler-424 (KOI-214) two-planet system, which consists of a transiting hot Jupiter (Kepler-424b) in a 3.31 day orbit accompanied by a more massive outer companion in an eccentric (e = 0.3) 223 day orbit. The outer giant planet, Kepler-424c, is not detected transiting the host star. The masses of both planets and the orbital parameters for the second planet were determined using precise radial velocity (RV) measurements from the Hobby-Eberly Telescope (HET) and its High Resolution Spectrograph (HRS). In stark contrast to smaller planets, hot Jupiters are predominantly found to be lacking any nearby additional planets; they appear to be {sup l}onely{sup .} This might be a consequence of these systems having a highly dynamical past. The Kepler-424 planetary system has a hot Jupiter in a multiple system, similar to υ Andromedae. We also present our results for Kepler-422 (KOI-22), Kepler-77 (KOI-127), Kepler-43 (KOI-135), and Kepler-423 (KOI-183). These results are based on spectroscopic data collected with the Nordic Optical Telescope (NOT), the Keck 1 telescope, and HET. For all systems, we rule out false positives based on various follow-up observations, confirming the planetary nature of these companions. We performed a comparison with planetary evolutionary models which indicate that these five hot Jupiters have heavy element contents between 20 and 120 M {sub ⊕}.

  18. A young massive planet in a star-disk system.

    PubMed

    Setiawan, J; Henning, Th; Launhardt, R; Müller, A; Weise, P; Kürster, M

    2008-01-03

    There is a general consensus that planets form within disks of dust and gas around newly born stars. Details of their formation process, however, are still a matter of ongoing debate. The timescale of planet formation remains unclear, so the detection of planets around young stars with protoplanetary disks is potentially of great interest. Hitherto, no such planet has been found. Here we report the detection of a planet of mass (9.8+/-3.3)M(Jupiter) around TW Hydrae (TW Hya), a nearby young star with an age of only 8-10 Myr that is surrounded by a well-studied circumstellar disk. It orbits the star with a period of 3.56 days at 0.04 au, inside the inner rim of the disk. This demonstrates that planets can form within 10 Myr, before the disk has been dissipated by stellar winds and radiation.

  19. Close approach maneuvers around an oblate planet

    NASA Astrophysics Data System (ADS)

    Oliveira, G. M. C.; Prado, A. F. B. A.; Sanchez, D. M.

    2015-10-01

    There are many applications of the close approach maneuvers in astronautics, and several missions used this technique in the last decades. In the present work, those close approach maneuvers are revisited, but now considering that the spacecraft passes around an oblate planet. This fact changes the distribution of mass of the planet, increasing the mass in the region of the equator, so increasing the gravitational forces in the equatorial plane. Since the present study is limited to planar trajectories, there is an increase in the variation of energy given by the maneuver. The planet Jupiter is used as the body for the close approach, but the value of J2 is varied in a large range to simulate situations of other celestial bodies that have larger oblateness, but the same mass ratio. This is particularly true in recent discovered exoplanets, and this first study can help the study of the dynamics around those bodies.

  20. PLANET HUNTERS: A TRANSITING CIRCUMBINARY PLANET IN A QUADRUPLE STAR SYSTEM

    SciTech Connect

    Schwamb, Megan E.; Schawinski, Kevin; Orosz, Jerome A.; Welsh, William F.; and others

    2013-05-10

    We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every {approx}137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625. The 6.18 {+-} 0.17 R{sub Circled-Plus} planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 {+-} 0.044 R{sub Sun }, 1.528 {+-} 0.087 M{sub Sun }) and M dwarf (0.378 {+-} 0.023 R{sub Sun }, 0.408 {+-} 0.024 M{sub Sun }). For the planet, we find an upper mass limit of 169 M{sub Circled-Plus} (0.531 Jupiter masses) at the 99.7% confidence level. With a radius and mass less than that of Jupiter, PH1b is well within the planetary regime. Outside the planet's orbit, at {approx}1000 AU, a previously unknown visual binary has been identified that is likely bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

  1. Planet Hunters: A Transiting Circumbinary Planet in a Quadruple Star System

    NASA Astrophysics Data System (ADS)

    Schwamb, Megan E.; Orosz, Jerome A.; Carter, Joshua A.; Welsh, William F.; Fischer, Debra A.; Torres, Guillermo; Howard, Andrew W.; Crepp, Justin R.; Keel, William C.; Lintott, Chris J.; Kaib, Nathan A.; Terrell, Dirk; Gagliano, Robert; Jek, Kian J.; Parrish, Michael; Smith, Arfon M.; Lynn, Stuart; Simpson, Robert J.; Giguere, Matthew J.; Schawinski, Kevin

    2013-05-01

    We report the discovery and confirmation of a transiting circumbinary planet (PH1b) around KIC 4862625, an eclipsing binary in the Kepler field. The planet was discovered by volunteers searching the first six Quarters of publicly available Kepler data as part of the Planet Hunters citizen science project. Transits of the planet across the larger and brighter of the eclipsing stars are detectable by visual inspection every ~137 days, with seven transits identified in Quarters 1-11. The physical and orbital parameters of both the host stars and planet were obtained via a photometric-dynamical model, simultaneously fitting both the measured radial velocities and the Kepler light curve of KIC 4862625. The 6.18 ± 0.17 R ⊕ planet orbits outside the 20 day orbit of an eclipsing binary consisting of an F dwarf (1.734 ± 0.044 R ⊙, 1.528 ± 0.087 M ⊙) and M dwarf (0.378 ± 0.023 R ⊙, 0.408 ± 0.024 M ⊙). For the planet, we find an upper mass limit of 169 M ⊕ (0.531 Jupiter masses) at the 99.7% confidence level. With a radius and mass less than that of Jupiter, PH1b is well within the planetary regime. Outside the planet's orbit, at ~1000 AU, a previously unknown visual binary has been identified that is likely bound to the planetary system, making this the first known case of a quadruple star system with a transiting planet.

  2. PLANETS AROUND THE K-GIANTS BD+20 274 AND HD 219415

    SciTech Connect

    Gettel, S.; Wolszczan, A.; Niedzielski, A.; Nowak, G.; Adamow, M.; Zielinski, P.; Maciejewski, G. E-mail: alex@astro.psu.edu

    2012-09-01

    We present the discovery of planet-mass companions to two giant stars by the ongoing Penn State-Torun Planet Search conducted with the 9.2 m Hobby-Eberly Telescope. The less massive of these stars, K5-giant BD+20 274, has a 4.2 M{sub J} minimum mass planet orbiting the star at a 578 day period and a more distant, likely stellar-mass companion. The best currently available model of the planet orbiting the K0-giant HD 219415 points to a {approx}> Jupiter-mass companion in a 5.7 year, eccentric orbit around the star, making it the longest period planet yet detected by our survey. This planet has an amplitude of {approx}18 m s{sup -1}, comparable to the median radial velocity 'jitter', typical of giant stars.

  3. Planets in Transit V Passages of Discovery

    NASA Astrophysics Data System (ADS)

    Castellano, T. P.

    2003-05-01

    Eclipses of the Sun have long influenced culture, history, and science. The analogous but much more subtle phenomena of a transit of the Sun by Mercury was first predicted by Johannes Kepler. Soon, predictions of transits of Venus inspired bold expeditions to better understand the scale of our solar system. These passages of discovery sometimes succeeded scientifically but always captured the public imagination and played an unexpected role in history. The possibility of detecting planets outside the solar system by the transit method was first outlined by Otto Struve in 1952. Early inquiries usually assumed that extrasolar planetary systems would have a distribution of planetary radii and orbital sizes like the solar system. The detection of transits from the ground in such systems would be daunting. The recent, unexpected discovery of a class of extrasolar planets (by the radial velocity technique) with orbital periods less than a week and masses near to the planet Jupiter has resulted in a resurgence of interest in the transit method. These so called "hot Jupiters", can produce transits that are likely enough, frequent enough, the transit method. These so called "hot Jupiters", can produce transits that are likely enough, frequent enough, and deep enough that ground-based transit searches can be successful. In November 1999, a planet orbiting the star HD 209458 was found to transit, and many measurements of the transit have since been made that challenge formation and evolution theories. Numerous ground based searches for transits are now underway. Several planned high precision space-based missions designed to detect transits of earth-sized planets, also have the potential to detect transits of hundreds of "hot Jupiters". These efforts and the upcoming transit of the Sun by Venus on June 8, 2004 present an opportunity for transits to once again capture the public imagination and perhaps play a role in history.

  4. Searching for Planets Around other Stars

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In this colloquim presentation, Professor of Astronomy, Geoffrey Marcy discusses the discovery of planets orbiting other stars. Using the Doppler shift caused by stellar wobble that is caused by nearby planetary mass, astronomers have been able to infer the existence of Jupiter-sized planets around other stars. Using a special spectrometer at Lick Observatory, the wobble of several stars have been traced over the years required to generate an accurate pattern required to infer the stellar wobble. Professor Marcy, discusses the findings of planets around 47 Ursae Majoris, 16 Cygni B, 51 Pegasus, and 56 Rho 1 Cne. In the case of 56 Rho 1 Cne the planet appears to be close to the star, within 1.5 astronomical units. The observations from the smaller Lick Observatory will be augmented by new observations from the larger telescope at the Kek observatory. This move will allow observations of smaller planets, as opposed to the massive planets thus far discovered. The astronomers also hope to observe smaller stars with the Kek data. Future spaceborne observations will allow the discovery of even smaller planets. A spaceborne interferometer is in the planning stages, and an even larger observatory, called the Terrestrial Planet Finder, is hoped for. Professor Marcy shows artists' renderings of two of the planets thus far discovered. He also briefly discusses planetary formation and shows slides of both observations from the Orion Nebula and models of stellar system formation.

  5. EVIDENCE FOR THE TIDAL DESTRUCTION OF HOT JUPITERS BY SUBGIANT STARS

    SciTech Connect

    Schlaufman, Kevin C.; Winn, Joshua N. E-mail: jwinn@mit.edu

    2013-08-01

    Tidal transfer of angular momentum is expected to cause hot Jupiters to spiral into their host stars. Although the timescale for orbital decay is very uncertain, it should be faster for systems with larger and more evolved stars. Indeed, it is well established that hot Jupiters are found less frequently around subgiant stars than around main-sequence stars. However, the interpretation of this finding has been ambiguous, because the subgiants are also thought to be more massive than the F- and G-type stars that dominate the main-sequence sample. Consequently, it has been unclear whether the absence of hot Jupiters is due to tidal destruction or inhibited formation of those planets around massive stars. Here we show that the Galactic space motions of the planet-hosting subgiant stars demand that on average they be similar in mass to the planet-hosting main-sequence F- and G-type stars. Therefore the two samples are likely to differ only in age, and provide a glimpse of the same exoplanet population both before and after tidal evolution. As a result, the lack of hot Jupiters orbiting subgiants is clear evidence for their tidal destruction. Questions remain, though, about the interpretation of other reported differences between the planet populations around subgiants and main-sequence stars, such as their period and eccentricity distributions and overall occurrence rates.

  6. H-alpha as a Probe of Very Low-mass Planets: The GAPplanetS Survey With the MagAO System

    NASA Astrophysics Data System (ADS)

    Close, L.; MagAO Team

    2014-03-01

    We utilized the new high-order 585 actuator Magellan Adaptive Optics system (MagAO) to obtain very high-resolution visible light images of young Transitional Disk with MagAO's VisAO science camera. In the median seeing conditions of the 6.5m Magellan telescope (0.5 - 0.7''), we find MagAO delivers 24-19% Strehl at Ha (0.656 mm). We detect a faint companion embedded in this young transitional disk system at just 86.3±1.9 mas (~12 AU) from the star. The companion is detected in both Ha and a continuum filter (Dmag=6.33±0.20 mag at Ha and 7.50±0.25 mag in the continuum filter). The Ha emission from the ~0.25 solar mass companion (EW=180 Angstroms) implies a mass accretion rate of ~5.9x10-10 Msun/yr, and a total accretion luminosity of 1.2% Lsun. Assuming a similar accretion rate, we estimate that a 1 Jupiter mass gas giant could have considerably better (50-1,000x) planet/star contrasts at Ha than at H band (COND models) for a range of optical extinctions (3.4-0 mag). We suggest that ~0.5-5 Mjup extrasolar planets in their gas accretion phase could be much more luminous at Ha than in the NIR. This is the motivation for our new MagAO GAPplanetS survey for directly imaging lowmass exoplanets in the gaps of transitional disks in the light of H-alpha with MagAO's unique SDI AO camera.

  7. The occurrence of Jovian planets and the habitability of planetary systems

    PubMed Central

    Lunine, Jonathan I.

    2001-01-01

    Planets of mass comparable to or larger than Jupiter's have been detected around over 50 stars, and for one such object a definitive test of its nature as a gas giant has been accomplished with data from an observed planetary transit. By virtue of their strong gravitational pull, giant planets define the dynamical and collisional environment within which terrestrial planets form. In our solar system, the position and timing of the formation of Jupiter determined the amount and source of the volatiles from which Earth's oceans and the source elements for life were derived. This paper reviews and brings together diverse observational and modeling results to infer the frequency and distribution of giant planets around solar-type stars and to assess implications for the habitability of terrestrial planets. PMID:11158551

  8. The occurrence of Jovian planets and the habitability of planetary systems.

    PubMed

    Lunine, J

    2001-01-30

    Planets of mass comparable to or larger than Jupiter's have been detected around over 50 stars, and for one such object a definitive test of its nature as a gas giant has been accomplished with data from an observed planetary transit. By virtue of their strong gravitational pull, giant planets define the dynamical and collisional environment within which terrestrial planets form. In our solar system, the position and timing of the formation of Jupiter determined the amount and source of the volatiles from which Earth's oceans and the source elements for life were derived. This paper reviews and brings together diverse observational and modeling results to infer the frequency and distribution of giant planets around solar-type stars and to assess implications for the habitability of terrestrial planets.

  9. Polarisation of Planets and Exoplanets

    NASA Astrophysics Data System (ADS)

    Bailey, Jeremy; Kedziora-Chudczer, Lucyna; Bott, Kimberly; Cotton, Daniel V.

    2015-11-01

    We present observations of the linear polarisation of several hot Jupiter systems with our new high-precision polarimeter HIPPI (HIgh Precision Polarimetric Instrument). By looking at the combined light of the star and planet we aim to detect the polarised light reflected from the planet's atmosphere. This can provide information on the presence of, and nature of clouds in the atmosphere, and constrain the geometric albedo of the planet. The method is applicable to both transitting and non-transitting planets, and can also be used to determine the inclination of the system, and thus the true mass for radial velocity detected planets.To predict and interpret the polarisation from such observations, we have also developed an advanced polarimetric modelling capability, by incoroporating full polarised radiative transfer into our atmospheric modelling code VSTAR. This is done using the VLIDORT vector radiative transfer solver (Spurr, 2006). The resulting code allows us to predict disc-resolved, phase-resolved, and spectrally-resolved intensity and linear polarisation for any planet, exoplanet, brown dwarf or cool star atmosphere that can be modelled with VSTAR. We have tested the code by reproducing benchmark calculations in polarised radiative transfer, and by Solar System test cases, including reproducing the classic Hansen and Hovenier (1974) calculation of the polarisation phase curves of Venus.Hansen, J.E., & Hovenier, J.W., 1974, J. Atmos. Sci., 31, 1137Spurr, R., 2006, JQSRT, 102, 316.

  10. The Anglo-Australian Planet Search Legacy

    NASA Astrophysics Data System (ADS)

    Wittenmyer, Robert A.; Tinney, Christopher G.; Butler, Paul; Horner, Jonathan; Carter, Brad; Wright, Duncan; Jones, H. R. A.

    2017-01-01

    Radial velocity searches for exoplanets have undergone a revolution in recent years: now precisions of 1 m/s or better are being demonstrated by many instruments, and new purpose-built spectrographs hold the promise of bringing Earth-mass planets into the realm of secure detectability. In the "race to the bottom," it is critical not to overlook the impact of long-running planet search programs that continue to hold the advantage of time. We highlight the continuing impact of the 18-year Anglo-Australian Planet Search: the characterisation of long-period giant planets, and the insights into the occurrence rate of Jupiter and Saturn analogs. To fully understand the origins of planetary systems and the fundamental question of how common (or rare) the architecture of the Solar system is in the Galaxy, we must continue these "legacy" surveys to probe ever-larger orbital separations.

  11. Optical Spectra of Extrasolar Giant Planets

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Hubeny, Ivan; Sudarsky, David; Burrows, Adam

    2004-01-01

    The flux distribution of a planet relative to its host star is a critical quantity for planning space observatories to detect and characterize extrasolar giant planets (EGP's). In this paper, we present optical planet-star contrasts of Jupiter-mass planets as a function of stellar type, orbital distance, and planetary cloud characteristics. As originally shown by Sudarsky et al. (2000, 2003), the phaseaveraged brightness of an EGP does not necessarily decrease monotonically with greater orbital distance because of changes in its albedo and absorption spectrum at lower temperatures. We apply our results to Eclipse, a 1.8-m optical telescope + coronograph to be proposed as a NASA Discovery mission later this year.

  12. 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.

  13. Planets under pressure

    NASA Astrophysics Data System (ADS)

    Jeanloz, Raymond

    2009-04-01

    Deep inside the planet Jupiter, diamonds hail down from hydrocarbon clouds as intense atmospheric pressures break methane into its atomic components. Further in - but still only 15% of the way to the planet's centre - the pressure reaches a million times that of the Earth's atmosphere. This is enough to transform hydrogen from the transparent, insulating gas we know at our planet's surface into a metallic fluid that sustains Jupiter's huge magnetic field. Even diamond is not forever: at pressures of 8-10 million atmospheres it is transformed into an opaque, metallic form of carbon, rather than the familiar transparent crystal.

  14. AN ULTRACOOL STAR'S CANDIDATE PLANET

    SciTech Connect

    Pravdo, Steven H.; Shaklan, Stuart B. E-mail: stuart.shaklan@jpl.nasa.gov

    2009-07-20

    We report here the discovery of the first planet around an ultracool dwarf star. It is also the first extrasolar giant planet astrometrically discovered around a main-sequence star. The statistical significance of the detection is shown in two ways. First, there is a 2 x 10{sup -8} probability that the astrometric motion fits a parallax-and-proper-motion-only model. Second, periodogram analysis shows a false alarm probability of 3 x 10{sup -5} that the discovered period is randomly generated. The planetary mass is M {sub 2} = 6.4 (+2.6,-3.1) Jupiter-masses (M {sub J}), and the orbital period is P = 0.744 (+0.013,-0.008) yr in the most likely model. In less likely models, companion masses that are higher than the 13 M {sub J} planetary mass limit are ruled out by past radial velocity (RV) measurements unless the system RV is more than twice the current upper limits and the near-periastron orbital phase was never observed. This new planetary system is remarkable, in part, because its star, VB 10, is near the lower mass limit for a star. Our astrometric observations provide a dynamical mass measurement and will in time allow us to confront the theoretical models of formation and evolution of such systems and their members. We thus add to the diversity of planetary systems and to the small number of known M-dwarf planets. Planets such as VB 10b could be the most numerous type of planets because M stars comprise >70% of all stars. To date they have remained hidden since the dominant RV planet-discovery technique is relatively insensitive to these dim, red systems.

  15. Dawes Review 7: The Tidal Downsizing Hypothesis of Planet Formation

    NASA Astrophysics Data System (ADS)

    Nayakshin, Sergei

    2017-01-01

    Tidal Downsizing scenario of planet formation builds on ideas proposed by Gerard Kuiper in 1951. Detailed simulations of self-gravitating discs, gas fragments, dust grain dynamics, and planet evolutionary calculations are summarised here and used to build a predictive population synthesis. A new interpretation of exoplanetary and debris disc data, the Solar System's origins, and the links between planets and brown dwarfs is offered. Tidal Downsizing predicts that presence of debris discs, sub-Neptune mass planets, planets more massive than 5 Jupiter masses and brown dwarfs should not correlate strongly with the metallicity of the host. For gas giants of Saturn to a few Jupiter mass, a strong host star metallicity correlation is predicted only inwards of a few AU from the host. Composition of massive cores is predicted to be dominated by rock rather than ices. Debris discs made by Tidal Downsizing have an innermost edge larger than about 1 au, have smaller total masses and are usually in a dynamically excited state. Planet formation in surprisingly young or very dynamic systems such as HL Tau and Kepler-444 may be a signature of Tidal Downsizing. Open questions and potential weaknesses of the hypothesis are pointed out.

  16. Extrasolar planets detections and statistics through gravitational microlensing

    NASA Astrophysics Data System (ADS)

    Cassan, A.

    2014-10-01

    Gravitational microlensing was proposed thirty years ago as a promising method to probe the existence and properties of compact objects in the Galaxy and its surroundings. The particularity and strength of the technique is based on the fact that the detection does not rely on the detection of the photon emission of the object itself, but on the way its mass affects the path of light of a background, almost aligned source. Detections thus include not only bright, but also dark objects. Today, the many successes of gravitational microlensing have largely exceeded the original promises. Microlensing contributed important results and breakthroughs in several astrophysical fields as it was used as a powerful tool to probe the Galactic structure (proper motions, extinction maps), to search for dark and compact massive objects in the halo and disk of the Milky Way, to probe the atmospheres of bulge red giant stars, to search for low-mass stars and brown dwarfs and to hunt for extrasolar planets. As an extrasolar planet detection method, microlensing nowadays stands in the top five of the successful observational techniques. Compared to other (complementary) detection methods, microlensing provides unique information on the population of exoplanets, because it allows the detection of very low-mass planets (down to the mass of the Earth) at large orbital distances from their star (0.5 to 10 AU). It is also the only technique that allows the discovery of planets at distances from Earth greater than a few kiloparsecs, up to the bulge of the Galaxy. Microlensing discoveries include the first ever detection of a cool super-Earth around an M-dwarf star, the detection of several cool Neptunes, Jupiters and super-Jupiters, as well as multi-planetary systems and brown dwarfs. So far, the least massive planet detected by microlensing has only three times the mass of the Earth and orbits a very low mass star at the edge of the brown dwarf regime. Several free-floating planetary-mass

  17. 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

  18. The accretion of migrating giant planets

    NASA Astrophysics Data System (ADS)

    Dürmann, Christoph; Kley, Wilhelm

    2017-02-01

    Aims: Most studies concerning the growth and evolution of massive planets focus either on their accretion or their migration only. In this work we study both processes concurrently to investigate how they might mutually affect one another. Methods: We modeled a two-dimensional disk with a steady accretion flow onto the central star and embedded a Jupiter mass planet at 5.2 au. The disk is locally isothermal and viscosity is modeled using a constant α. The planet is held on a fixed orbit for a few hundred orbits to allow the disk to adapt and carve a gap. After this period, the planet is released and free to move according to the gravitational interaction with the gas disk. The mass accretion onto the planet is modeled by removing a fraction of gas from the inner Hill sphere, and the removed mass and momentum can be added to the planet. Results: Our results show that a fast migrating planet is able to accrete more gas than a slower migrating planet. Utilizing a tracer fluid we analyzed the origin of the accreted gas originating predominantly from the inner disk for a fast migrating planet. In the case of slower migration, the fraction of gas from the outer disk increases. We also found that even for very high accretion rates, in some cases gas crosses the planetary gap from the inner to the outer disk. Our simulations show that the crossing of gas changes during the migration process as the migration rate slows down. Therefore, classical type II migration where the planet migrates with the viscous drift rate and no gas crosses the gap is no general process but may only occur for special parameters and at a certain time during the orbital evolution of the planet.

  19. Measurements of Kepler Planet Masses and Eccentricities from Transit Timing Variations: Analytic and N-body Results

    NASA Astrophysics Data System (ADS)

    Hadden, Sam; Lithwick, Yoram

    2015-12-01

    Several Kepler planets reside in multi-planet systems where gravitational interactions result in transit timing variations (TTVs) that provide exquisitely sensitive probes of their masses of and orbits. Measuring these planets' masses and orbits constrains their bulk compositions and can provide clues about their formation. However, inverting TTV measurements in order to infer planet properties can be challenging: it involves fitting a nonlinear model with a large number of parameters to noisy data, often with significant degeneracies between parameters. I present results from two complementary approaches to TTV inversion: Markov chain Monte Carlo simulations that use N-body integrations to compute transit times and a simplified analytic model for computing the TTVs of planets near mean motion resonances. The analytic model allows for straightforward interpretations of N-body results and provides an independent estimate of parameter uncertainties that can be compared to MCMC results which may be sensitive to factors such as priors. We have conducted extensive MCMC simulations along with analytic fits to model the TTVs of dozens of Kepler multi-planet systems. We find that the bulk of these sub-Jovian planets have low densities that necessitate significant gaseous envelopes. We also find that the planets' eccentricities are generally small but often definitively non-zero.

  20. Did Jupiter's core form in the innermost parts of the Sun's protoplanetary disc?

    NASA Astrophysics Data System (ADS)

    Raymond, Sean N.; Izidoro, Andre; Bitsch, Bertram; Jacobson, Seth A.

    2016-05-01

    Jupiter's core is generally assumed to have formed beyond the snow line. Here we consider an alternative scenario that Jupiter's core may have accumulated in the innermost part of the protoplanetary disc. A growing body of research suggests that small particles (`pebbles') continually drift inward through the disc. If a fraction of drifting pebbles is trapped at the inner edge of the disc, several Earth-mass cores can quickly grow. Subsequently, the core may migrate outward beyond the snow line via planet-disc interactions. Of course, to reach the outer Solar system Jupiter's core must traverse the terrestrial planet-forming region. We use N-body simulations including synthetic forces from an underlying gaseous disc to study how the outward migration of Jupiter's core sculpts the terrestrial zone. If the outward migration is fast (τmig ˜ 104 yr), the core simply migrates past resident planetesimals and planetary embryos. However, if its migration is slower (τmig ˜ 105 yr) the core clears out solids in the inner disc by shepherding objects in mean motion resonances. In many cases, the disc interior to 0.5-1 AU is cleared of embryos and most planetesimals. By generating a mass deficit close to the Sun, the outward migration of Jupiter's core may thus explain the absence of terrestrial planets closer than Mercury. Jupiter's migrating core often stimulates the growth of another large (˜Earth-mass) core - that may provide a seed for Saturn's core - trapped in an exterior resonance. The migrating core also may transport a fraction of terrestrial planetesimals, such as the putative parent bodies of iron meteorites, to the asteroid belt.

  1. Understanding Jupiter's interior

    NASA Astrophysics Data System (ADS)

    Militzer, Burkhard; Soubiran, François; Wahl, Sean M.; Hubbard, William

    2016-09-01

    This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provided constraints for the interior structure of Jupiter. We discuss typical three-layer interior models that consist of a dense central core and an inner metallic and an outer molecular hydrogen-helium layer. These models rely heavily on experiments, analytical theory, and first-principles computer simulations of hydrogen and helium to understand their behavior up to the extreme pressures ˜10 Mbar and temperatures ˜10,000 K. We review the various equations of state used in Jupiter models and compare them with shock wave experiments. We discuss the possibility that helium rain, core erosion, and double diffusive convection have affected the structure and evolution of giant planets. In July 2016 the Juno spacecraft entered orbit around Jupiter, promising high-precision measurements of the gravitational field that will allow us to test our understanding of gas giant interiors better than ever before.

  2. High Resolution Globe of Jupiter

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This true-color simulated view of Jupiter is composed of 4 images taken by NASA's Cassini spacecraft on December 7, 2000. To illustrate what Jupiter would have looked like if the cameras had a field-of-view large enough to capture the entire planet, the cylindrical map was projected onto a globe. The resolution is about 144 kilometers (89 miles) per pixel. Jupiter's moon Europa is casting the shadow on the planet.

    Cassini is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages Cassini for NASA's Office of Space Science, Washington, D.C.

  3. A 5 Micron of beta Pictoris B at a Sub-Jupiter Projected Separation: Evidence for a Misalignment Between the Planet and the Inner, Warped Disk

    NASA Technical Reports Server (NTRS)

    Currie, Thayne; Thalmann, Christian; Matsumura, Soko; Madhusudhan, Nikku; Burrows, Adam; Kuchner, Marc

    2011-01-01

    We present and analyze a new M' detection of the young exoplanet Beta Pictoris b from 2008 VLT/NaCo data at a separation of approx. = 4 AU and a high signal-to-noise rereduction of L' data taken in December 2Q09. Based on our orbital analysis, the planet's orbit is viewed almost perfectly edge-on (i approx. 89 degrees) and has a Saturn-like semimajor axis of 9.50AU(+3.93 AU)/-(1.7AU) . Intriguingly, the planet's orbit is aligned with the major axis of the outer disk (Omega approx.31 degrees) but probably misaligned with the warp/inclined disk at 80 AU often cited as a signpost for the planet's existence. Our results motivate new studies to clarify how Beta Pic b sculpts debris disk structures and whether a second planet is required to explain the warp/inclined disk

  4. Voyager to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Voyager mission to explore planets of the outer solar system is summarized. The mission schedule and profiles for encounters with Jupiter and Saturn, and possibly with Uranus and Pluto are included along with a description of the spacecraft and its trajectories. Scientific investigations to be made and the instruments carried are also discussed.

  5. ON THE SURVIVABILITY AND METAMORPHISM OF TIDALLY DISRUPTED GIANT PLANETS: THE ROLE OF DENSE CORES

    SciTech Connect

    Liu, Shang-Fei; Lin, Douglas N. C.; Guillochon, James; Ramirez-Ruiz, Enrico

    2013-01-01

    A large population of planetary candidates in short-period orbits have been found recently through transit searches, mostly with the Kepler mission. Radial velocity surveys have also revealed several Jupiter-mass planets with highly eccentric orbits. Measurements of the Rossiter-McLaughlin effect indicate that the orbital angular momentum vector of some planets is inclined relative to the spin axis of their host stars. This diversity could be induced by post-formation dynamical processes such as planet-planet scattering, the Kozai effect, or secular chaos which brings planets to the vicinity of their host stars. In this work, we propose a novel mechanism to form close-in super-Earths and Neptune-like planets through the tidal disruption of gas giant planets as a consequence of these dynamical processes. We model the core-envelope structure of gas giant planets with composite polytropes which characterize the distinct chemical composition of the core and envelope. Using three-dimensional hydrodynamical simulations of close encounters between Jupiter-like planets and their host stars, we find that the presence of a core with a mass more than 10 times that of the Earth can significantly increase the fraction of envelope which remains bound to it. After the encounter, planets with cores are more likely to be retained by their host stars in contrast with previous studies which suggested that coreless planets are often ejected. As a substantial fraction of their gaseous envelopes is preferentially lost while the dense incompressible cores retain most of their original mass, the resulting metallicity of the surviving planets is increased. Our results suggest that some gas giant planets can be effectively transformed into either super-Earths or Neptune-like planets after multiple close stellar passages. Finally, we analyze the orbits and structure of known planets and Kepler candidates and find that our model is capable of producing some of the shortest-period objects.

  6. The phase-dependent infrared brightness of the extrasolar planet upsilon Andromedae b.

    PubMed

    Harrington, Joseph; Hansen, Brad M; Luszcz, Statia H; Seager, Sara; Deming, Drake; Menou, Kristen; Cho, James Y-K; Richardson, L Jeremy

    2006-10-27

    The star upsilon Andromedae is orbited by three known planets, the innermost of which has an orbital period of 4.617 days and a mass at least 0.69 that of Jupiter. This planet is close enough to its host star that the radiation it absorbs overwhelms its internal heat losses. Here, we present the 24-micrometer light curve of this system, obtained with the Spitzer Space Telescope. It shows a variation in phase with the orbital motion of the innermost planet, demonstrating that such planets possess distinct hot substellar (day) and cold antistellar (night) faces.

  7. Jupiter Eruptions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on the image for high resolution image of Nature Cover

    Detailed analysis of two continent-sized storms that erupted in Jupiter's atmosphere in March 2007 shows that Jupiter's internal heat plays a significant role in generating atmospheric disturbances. Understanding these outbreaks could be the key to unlock the mysteries buried in the deep Jovian atmosphere, say astronomers.

    This visible-light image is from NASA's Hubble Space Telescope taken on May 11, 2007. It shows the turbulent pattern generated by the two plumes on the upper left part of Jupiter.

    Understanding these phenomena is important for Earth's meteorology where storms are present everywhere and jet streams dominate the atmospheric circulation. Jupiter is a natural laboratory where atmospheric scientists study the nature and interplay of the intense jets and severe atmospheric phenomena.

    According to the analysis, the bright plumes were storm systems triggered in Jupiter's deep water clouds that moved upward in the atmosphere vi gorously and injected a fresh mixture of ammonia ice and water about 20 miles (30 kilometers) above the visible clouds. The storms moved in the peak of a jet stream in Jupiter's atmosphere at 375 miles per hour (600 kilometers per hour). Models of the disturbance indicate that the jet stream extends deep in the buried atmosphere of Jupiter, more than 60 miles (approximately100 kilometers) below the cloud tops where most sunlight is absorbed.

  8. Atmospheric mass loss during planet formation: The importance of planetesimal impacts

    NASA Astrophysics Data System (ADS)

    Schlichting, Hilke E.; Sari, Re'em; Yalinewich, Almog

    2015-02-01

    Quantifying the atmospheric mass loss during planet formation is crucial for understanding the origin and evolution of planetary atmospheres. We examine the contributions to atmospheric loss from both giant impacts and planetesimal accretion. Giant impacts cause global motion of the ground. Using analytic self-similar solutions and full numerical integrations we find (for isothermal atmospheres with adiabatic index γ=5/3) that the local atmospheric mass loss fraction for ground velocities vg≲0.25vesc is given by χloss=(1.71, where vesc is the escape velocity from the target. Yet, the global atmospheric mass loss is a weaker function of the impactor velocity vImp and mass mImp and given by Xloss≃0.4x+1.4x2-0.8x3 (isothermal atmosphere) and Xloss≃0.4x+1.8x2-1.2x3 (adiabatic atmosphere), where x=(vImpm/vescM). Atmospheric mass loss due to planetesimal impacts proceeds in two different regimes: (1) large enough impactors m≳√{2}ρ0( (25 km for the current Earth), are able to eject all the atmosphere above the tangent plane of the impact site, which is h/2R of the whole atmosphere, where h, R and ρ0 are the atmospheric scale height, radius of the target, and its atmospheric density at the ground. (2) Smaller impactors, but above m>4πρ0h3 (1 km for the current Earth) are only able to eject a fraction of the atmospheric mass above the tangent plane. We find that the most efficient impactors (per unit impactor mass) for atmospheric loss are planetesimals just above that lower limit (2 km for the current Earth). For impactor flux size distributions parametrized by a single power law, N(>r)∝r, with differential power law index q, we find that for 1