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Sample records for 200-inch hale telescope

  1. George Ellery Hale, Caltech Astrophysics, and the Hale 200-inch Telescope, 1920-1948

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1998-05-01

    Caltech and the 200-inch Hale telescope on Palomar are two of George Ellery Hale's many creations in Southern California. He brought the California Institute of Technology into existence in 1920; Palomar Observatory was built for it. However, even before Hale had "secured" the funds for the 200-inch, astrophysical research had been underway on the Caltech campus in Pasadena, and it intensified after the Rockefeller grant came through. Interactions between the campus, Palomar Mountain, and Mount Wilson Obervatory (one of Hale's earlier creations) played important roles in determining the course of Caltech astrophysics. Changing funding patterns (from private philanthropy to drought, then "defense" weapons-development programs, and then governmental agencies designed to support scientific research) will be briefly described. The 18-inch Schmidt, built at the Caltech (200-inch Telescope) Shop, went into operation in 1936, the first research telescope on Palomar. The 200-inch, essentially completed, was dedicated in 1948 and went into operation for regularly scheduled research observations near the end of 1949. Its coude spectrograph was completed and put into regular use in stages from 1950 to 1952, Among the most important leaders of Caltech astrophysics up to 1948 and the years immediately after it when the 200-inch went into full operation were Robert A. Millikan, Max Mason, and Lee A. DuBridge. Some of the astrophysicists who worked at Caltech and Palomar were Albert Einstein, Richard C. Tolman, Fritz Zwicky, Ira S. Bowen, John A. Anderson, Sinclair Smith, John Strong, William A. Fowler and, just at the end of this period, Jesse L. Greenstein. Some of the key staff personnel were Russell W. Porter, Don O. Hendrix (on loan), and Byron Hill.

  2. "Where to Put it? The East-West Split over the site for the 200-inch telescope"

    NASA Astrophysics Data System (ADS)

    Devorkin, D. H.

    1998-05-01

    Hale obtained the funding for his 200-inch telescope at a time when the sciences in America were trying to develop a National Research Fund through the National Academy of Sciences. His successes, and the failure of the Fund, created tensions, especially among prominent East Coast astronomers who themselves had been courting the Rockefeller International Education Board to support the development of southern hemisphere sites. This paper will explore facets of the controversy that will illuminate how Hale's plan was regarded by other astronomers, and how the dispute was finally settled by Henry Norris Russell.

  3. CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

    NASA Astrophysics Data System (ADS)

    Harding, L. K.; Hallinan, G.; Milburn, J.; Gardner, P.; Konidaris, N.; Singh, N.; Shao, M.; Sandhu, J.; Kyne, G.; Schlichting, H. E.

    2016-04-01

    The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centred at 567 nm, with Sloan u' and g' bands available on the blue arm and Sloan r', i' and z_s bands available on the red arm. Additional narrow-band filters will also become available as required. An electron multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame rates of up to 26 fps full frame (several 1000 fps windowed), over a fully corrected 5 × 5 arcmin field of view. CHIMERA was primarily developed to enable the characterization of the size distribution of sub-km Kuiper Belt Objects via stellar occultation, a science case that motivates the frame-rate, the simultaneous multi-colour imaging and the wide field of view of the instrument. In addition, it also has unique capability in the detection of faint near-Earth asteroids and will be used for the monitoring of short-duration transient and periodic sources, particularly those discovered by the intermediate Palomar Transient Factory (iPTF), and the upcoming Zwicky Transient Facility (ZTF).

  4. Four-shooter - A large format charge-coupled device camera for the Hale telescope

    NASA Technical Reports Server (NTRS)

    Gunn, James E.; Carr, Michael; Danielson, G. Edward; Lorenz, Ernest O.; Lucinio, Richard; Nenow, Victor E.; Smith, J. Devere; Westphal, James A.; Schneider, Donald P.; Zimmerman, Barbara A.

    1987-01-01

    The Hale telescope has employed an astronomical camera using four 800x800 CCDs in an optical arrangement that allows the imaging of a contiguous 1600-pixel-square region of the sky; reimaging optics are then used to yield a scale of 0.33 arcsec/pixel. Optical coatings are incorporated to yield a throughput at peak efficiency of nearly 50 percent, including telescope losses. This camera can be used in a scanning mode, in which the telescope tracking rate is offset and the charge is clocked in the chips in such a way that the charge image remains aligned with the optical image. Attention is given to the results of a survey for high-redshift quasars using this equipment, which has produced images for the most distant galaxy clusters yet discovered.

  5. PALM-3000: EXOPLANET ADAPTIVE OPTICS FOR THE 5 m HALE TELESCOPE

    SciTech Connect

    Dekany, Richard; Bouchez, Antonin; Baranec, Christoph; Hale, David; Zolkower, Jeffry; Henning, John; Croner, Ernest; McKenna, Dan; Hildebrandt, Sergi; Milburn, Jennifer; Roberts, Jennifer; Burruss, Rick; Truong, Tuan; Guiwits, Stephen; Angione, John; Trinh, Thang; Shelton, J. Christopher; Palmer, Dean; Troy, Mitchell; Tesch, Jonathan

    2013-10-20

    We describe and report first results from PALM-3000, the second-generation astronomical adaptive optics (AO) facility for the 5.1 m Hale telescope at Palomar Observatory. PALM-3000 has been engineered for high-contrast imaging and emission spectroscopy of brown dwarfs and large planetary mass bodies at near-infrared wavelengths around bright stars, but also supports general natural guide star use to V ≈ 17. Using its unique 66 × 66 actuator deformable mirror, PALM-3000 has thus far demonstrated residual wavefront errors of 141 nm rms under ∼1'' seeing conditions. PALM-3000 can provide phase conjugation correction over a 6.''4 × 6.''4 working region at λ = 2.2 μm, or full electric field (amplitude and phase) correction over approximately one-half of this field. With optimized back-end instrumentation, PALM-3000 is designed to enable 10{sup –7} contrast at 1'' angular separation, including post-observation speckle suppression processing. While continued optimization of the AO system is ongoing, we have already successfully commissioned five back-end instruments and begun a major exoplanet characterization survey, Project 1640.

  6. High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 1, data analysis and results

    NASA Astrophysics Data System (ADS)

    Erskine, David J.; Edelstein, Jerry; Wishnow, Edward H.; Sirk, Martin; Muirhead, Philip S.; Muterspaugh, Matthew W.; Lloyd, James P.; Ishikawa, Yuzo; McDonald, Eliza A.; Shourt, William V.; Vanderburg, Andrew M.

    2016-04-01

    High-resolution broadband spectroscopy at near-infrared wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar. Observations of stars were performed with the "TEDI" interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec near-infrared echelle spectrograph. These are the first multidelay EDI demonstrations on starlight, as earlier measurements used a single delay or laboratory sources. We demonstrate very high (10×) resolution boost, from original 2700 to 27,000 with current set of delays (up to 3 cm), well beyond the classical limits enforced by the slit width and detector pixel Nyquist limit. Significantly, the EDI used with multiple delays rather than a single delay as used previously yields an order of magnitude or more improvement in the stability against native spectrograph point spread function (PSF) drifts along the dispersion direction. We observe a dramatic (20×) reduction in sensitivity to PSF shift using our standard processing. A recently realized method of further reducing the PSF shift sensitivity to zero is described theoretically and demonstrated in a simple simulation which produces a 350× times reduction. We demonstrate superb rejection of fixed pattern noise due to bad detector pixels-EDI only responds to changes in pixel intensity synchronous to applied dithering. This part 1 describes data analysis, results, and instrument noise. A section on theoretical photon limited sensitivity is in a companion paper, part 2.

  7. Hubble Space Telescope First Servicing Mission Prelaunch Mission Operation Report

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Hubble Space Telescope (HST) is a high-performance astronomical telescope system designed to operate in low-Earth orbit. It is approximately 43 feet long, with a diameter of 10 feet at the forward end and 14 feet at the aft end. Weight at launch was approximately 25,000 pounds. In principle, it is no different than the reflecting telescopes in ground-based astronomical observatories. Like ground-based telescopes, the HST was designed as a general-purpose instrument, capable of using a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic allows the HST to be used as a national facility, capable of supporting the astronomical needs of an international user community. The telescope s planned useful operational lifetime is 15 years, during which it will make observations in the ultraviolet, visible, and infrared portions of the spectrum. The extended operational life of the HST is possible by using the capabilities of the Space Transportation System to periodically visit the HST on-orbit to replace failed or degraded components, install instruments with improved capabilities, re-boost the HST to higher altitudes compensating for gravitational effects, and to bring the HST back to Earth when the mission is terminated. The largest ground-based observatories, such as the 200-inch aperture Hale telescope at Palomar Mountain, California, can recognize detail in individual galaxies several billion light years away. However, like all earthbound devices, the Hale telescope is limited because of the blurring effect of the Earth s atmosphere. Further, the wavelength region observable from the Earth s surface is limited by the atmosphere to the visible part of the spectrum. The very important ultraviolet portion of the spectrum is lost. The HST uses a 2.4-meter reflective optics system designed to capture data over a wavelength region that reaches far into the ultraviolet and infrared portions of the spectrum.

  8. The Hale Effect

    ERIC Educational Resources Information Center

    Gray, Katti

    2012-01-01

    Ohio State University's (OSU) Frank W. Hale Jr. Black Cultural Center is a rarity in academia, as was its namesake. When OSU named its standout Black cultural center after the civil rights activist, professor and vice provost who championed such a place, it was commemorating what Dr. Frank W. Hale Jr. stood for. He promoted academic rigor, those…

  9. The Hale solar sector boundary

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1976-01-01

    A Hale solar sector boundary is defined as the half (Northern Hemisphere or Southern Hemisphere) of a sector boundary in which the change of sector magnetic field polarity is the same as the change of polarity from a preceding spot to a following spot. Above a Hale sector boundary the green corona has maximum brightness, while above a non-Hale boundary the green corona has a minimum brightness. The Hale portion of a photospheric sector boundary tends to have maximum magnetic field strength, while the non-Hale portion has minimum field strength.

  10. George Ellery Hale's Early Solar Research at Chicago, Kenwood, Harvard, and Yerkes Observatories, 1882-1904

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1999-05-01

    Growing up in Chicago, George Ellery Hale, later the prime spirit in founding the AAS, was a precocious boy scientist. He was deeply interested in spectroscopy and astrophysics from an early age. His wealthy parents encouraged Hale's aspirations with magazines, books, and instruments, and he acquired his first telescope when he was 14. He knew as mentors classical astronomers S. W. Burnham and George W. Hough, but he preferred astrophysics and designed his own Kenwood Physical Obseervatory around a grating in a Rowland circle mounting, fed by a heliostat, both built for him by instrument-maker John A. Brashear. For his undergraduate thesis at MIT, Hale invented and (at Harvard College Observatory) demonstrated the spectroheliograph. With it, and a high-quality 12-in refractor at his later Kenwood Astrophysical Observatory (at the same site, the Hale family home, 4 miles from the present Hilton Hotel where the SPD, HAD and AAS are meeting) Hale did excellent solar research, especially on promineneces, flocculi, and the near-ultraviolet spectrum of the chromosphere. As a teen-ager and a young adult Hale traveled widely, and met several important piuoneer solar physicists, including Charles A. Young, Jules Janssen, Samuel P. Langley, and Henry Rowland. Hale designed Yerkes Observatory for solar and stellar research, and headed the solar work himself. One of his aims always was to compare other stars with the sun. Hale's telescopes, instruments, methods, and resulting papers will be described and illustrated by numerous slides.

  11. George Ellery Hale's Later Solar Research at Mount Wilson and Pasadena, 1905-1938

    NASA Astrophysics Data System (ADS)

    Briggs, J. W.

    1999-05-01

    This presentation will briefly review Hale's most significant discoveries starting with his arrival in Pasadena and his installation of the Snow horizontal telescope. Details of a number of his important instruments will be illustrated with recent slides. The Snow telescope began at Mount Wilson as an expedition from the Yerkes Observatory of the University of Chicago. Funded at the start with the help of the Hale family fortune, the effort evolved quickly into the Mount Wilson Solar Observatory, which was supported by the Carnegie Institution from late 1904 on. Thereafter Hale continued with the development of the 60- and 150-foot solar tower telescopes and eventually the all-reflecting instrument at his remarkable solar laboratory in Pasadena. At the 60-foot, Hale and his collaborators found that magnetic fields were associated with sunspots; this achievement is regarded as Hale's greatest discovery. In later years, he took special delight in the invention of a new form of the spectroheliograph -- the spectrohelioscope -- which allowed visual solar flare patrol. Perhaps the most beautiful of Hale's solar telescopes is, in fact, the most obscure one -- a small instrument built into the new National Academy of Sciences facility in Washington, D.C., in 1924. His personal involvement with the installation of this telescope illustrates the youthful enthusiasm characteristic of much of his approach to science.

  12. What's New With Hale Bopp?

    NASA Astrophysics Data System (ADS)

    Shylaja, B. S.

    1997-06-01

    The comet Hale-Bopp has provided a great opportunity to astrophysicists. It is bright and it has been available for observations for a long period of time. A good number of large telescopes all over the northern hemisphere have been deployed for observations of this comet. Within a month of its discovery came the first result that the comet was quite active even when it was beyond Jupiter. Jets of gas and dust continued to stream out one after the other. This created the suspicion that the magnitude estimates may turn out to be only the limits rather than the actual values. The anxiety, so created disappeared only when the comet reached the visibility limits in late 1996. By the time it reached the perihelion on April 1, it was not fooling around anymore and kept up the promise of a 'civilized comet', the one that could be located without a finding chart. As is well known, the magnitude after the perihelion passage, would be slightly higher than the estimated value. The two-tail structure was first noticed a few months prior to the perihelion. The gradation in colour from blue of the ion tail to yellow of the dust tail was quite conspicuous. A simple binocular could easily resolve the two. Interestingly, just after the perihelion, there was a flare and the associated storm on the sun due to which a temporary increase in the solar wind particle density can occur. It would be extremely interesting to find the related effects on the tail, especially on the ion component. The solar and cometary physicists are (as on April 26th) eagerly looking forward to monitoring the changes. The ion tail has grown to about 15 degrees in the sky and is expected to get disrupted after the solar storm. On the other hand, the dust tail which grew to a full length of 45 degrees offered a glorious sight in the evening sky. The new moon at the time of perihelion enhanced the spectacle. In the middle of April quite suddenly, a third tail, a sharp yellow one, showed up. This was attributed

  13. ISO's analysis of Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    1997-03-01

    The European Space Agency's Infrared Space Observatory ISO inspected Comet Hall-Bopp during the spring and autumn of 1996. The need to keep ISO's telescope extremely cold restricts the spacecraft's pointing in relation to the Sun and the Earth and it ruled out observations at other times. The analyses of the 1996 observations are not yet complete, but already they give new insight into the nature of comets. Comet Hale-Bopp is believed to be a large comet with a nucleus up to 40 kilometres wide. It was discovered in July 1995 by two American astronomers working independently, Alan Hale and Thomas Bopp. At that time, the comet was a billion kilometres away from the Sun, but 200 times brighter than Halley's Comet was, when at a comparable distance. Comet Hale-Bopp will make its closest approach to the Earth on 22 March, and its closest approach to the Sun (perihelion) on 1 April 1997. Some scientific results from ISO The discovery of Comet Hale-Bopp occurred before ISO's launch in November 1995. When first observed by ISO in March and April 1996, the comet was still 700 million kilometres from the Sun, and almost as far from the Earth and ISO. With its privileged view of infrared wavebands inaccessible from the Earth's surface, ISO's photometer ISOPHOT discovered that carbon dioxide was an important constituent of the comet's emissions of vapour.ISOPHOT measured the temperature of the dust cloud around Comet Hale-Bopp. In March 1996, when the comet was still more than 700 million kilometres from the Sun, the dust cloud was at minus 120 degrees C. When ISOPHOT made similar observations in October 1996, the comet was 420 million kilometres from the Sun, and the dust cloud had warmed to about minus 50 degrees C. Intensive observations of Comet Hale-Bopp were also made by ISO's Short-Wave Spectrometer SWS, the Long-Wave Spectrometer LWS, and the ISOPHOT spectrometer PHOT-S. Results are due for publication at the end of March. They will give details about the composition

  14. ISO's analysis of Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    1997-03-01

    The European Space Agency's Infrared Space Observatory ISO inspected Comet Hall-Bopp during the spring and autumn of 1996. The need to keep ISO's telescope extremely cold restricts the spacecraft's pointing in relation to the Sun and the Earth and it ruled out observations at other times. The analyses of the 1996 observations are not yet complete, but already they give new insight into the nature of comets. Comet Hale-Bopp is believed to be a large comet with a nucleus up to 40 kilometres wide. It was discovered in July 1995 by two American astronomers working independently, Alan Hale and Thomas Bopp. At that time, the comet was a billion kilometres away from the Sun, but 200 times brighter than Halley's Comet was, when at a comparable distance. Comet Hale-Bopp will make its closest approach to the Earth on 22 March, and its closest approach to the Sun (perihelion) on 1 April 1997. Some scientific results from ISO The discovery of Comet Hale-Bopp occurred before ISO's launch in November 1995. When first observed by ISO in March and April 1996, the comet was still 700 million kilometres from the Sun, and almost as far from the Earth and ISO. With its privileged view of infrared wavebands inaccessible from the Earth's surface, ISO's photometer ISOPHOT discovered that carbon dioxide was an important constituent of the comet's emissions of vapour.ISOPHOT measured the temperature of the dust cloud around Comet Hale-Bopp. In March 1996, when the comet was still more than 700 million kilometres from the Sun, the dust cloud was at minus 120 degrees C. When ISOPHOT made similar observations in October 1996, the comet was 420 million kilometres from the Sun, and the dust cloud had warmed to about minus 50 degrees C. Intensive observations of Comet Hale-Bopp were also made by ISO's Short-Wave Spectrometer SWS, the Long-Wave Spectrometer LWS, and the ISOPHOT spectrometer PHOT-S. Results are due for publication at the end of March. They will give details about the composition

  15. It Started with George Ellery Hale

    NASA Astrophysics Data System (ADS)

    Parker, E. N.

    1999-05-01

    With his invention of the spectroheliograph, showing the structure and activity of the surface of the Sun, and with his spectroscopic determination of the magnetic character of the sunspot, Hale initiated a line of research that has brought us deeper into the mysteries of the Sun with each passing decade. The flare is perhaps the most spectacular aspect of the activity, along with the more recently discovered coronal mass ejection. However, we must not overlook the spectacular revelation, by Grotrian, Edlen, and Lyot, that the outer atmosphere of the Sun has a temperature of a million or more degrees K, providing both radio and X-ray emission. It is all too often forgotten in these heady times that, while we have a number of plausible ideas about how things work, there is not yet a clear understanding of why a late main sequence star should exhibit such effects. Magnetic fields generated by some form of MHD dynamo appear to initiate the suprathermal activity in all its many forms. The intensely fibril form of the magnetic fields seems to be a clue to the nature of the dynamo process, and the first observational priority now is to develop a 4m telescope with an adaptive optics system that can properly resolve the individual fibrils at the visible surface (0.1" or better)to determine their behavior. Indeed the nature of the sunspot, the faculae and plages,the microflare, etc. all lie at the limits of telescopic resolution. The varying brightness of the Sun seems to be a byproduct of the magnetic activity, and besides the consequences for the climate at Earth, provides another baffling clue to the puzzle. We cannot guess what further marvels will be discovered before the puzzle is resolved in hard scientific terms, but we may be certain that Hale would have been enchanted, and probably leading the charge, were he alive today.

  16. Hubble Images of Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This is a series of Hubble Space Telescope observations of the region around the nucleus of Hale-Bopp, taken on eight different dates since September 1995. They chronicle changes in the evolution of the nucleus as it moves ever closer to, and is warmed by, the sun.

    The first picture in the sequence, seen at upper left shows a strong dust outburst on the comet that occurred when it was beyond the orbit of Jupiter. Images in the Fall of 1996 show multiple jets that are presumably connected to the activation of multiple vents on the surface of the nucleus.

    In these false color images, taken with the Wide Field and Planetary Camera 2, the faintest regions are black, the brightest regions are white, and intermediate intensities are represented by different levels of red. All images are processed at the same spatial scale of 280 miles per pixel (470 kilometers), so the solid nucleus, no larger than 25 miles across, is far below Hubble's resolution.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  17. The perfect machine. Building the Palomar telescope.

    NASA Astrophysics Data System (ADS)

    Florence, R.

    The author's chronicle of the conception of the great 200-inch Palomar telescope is an inspiring account of the birth of big science and of America at its can-do apex. Countless scientists, engineers, administrators, and workmen - from Edwin Hubble, John D. Rockefeller, Elihu Root, and Andrew Carnegie, to unemployed laborers - come alive in this story of two decades of effort to create "the perfect machine".

  18. OH Jets in Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Lederer, S. M.; Campins, H.; Osip, D. J.

    1999-09-01

    Comet Hale-Bopp provided the first opportunity to examine OH jets in the coma of a comet. We presented the observations and initial results of this study in Lederer et al., EM&P, 1999. This included the identification of jets in our OH, NH, CN, C_2, C_3, and dust narrowband filter images. Here we present an analysis of the OH jets using Monte Carlo models of the inner coma. The images were acquired in March and April, 1997 using Lowell Observatory's 1.1m Hall telescope in conjunction with the 2048(2) CCD camera. The narrowband filter employed was designed to isolate the emission from OH at 3090 Angstroms. We have developed time-dependent Monte Carlo models with jets originating from (1) a nuclear molecular water source, and (2) an extended source of sub-micron organic CHON grains. We compare our observations with these models with the goal of understanding the source of the OH. The parameters that will be discussed include a) the radial profile of surface brightness for the jets and for the regions between the jets, b) the morphology of the jets, c) the enhancement of the jets above the isotropic background, and d) the evolution of the jets with time. Preliminary results suggest that an extended source is at least partially responsible for the jets. This work was supported by NASA.

  19. Stephen Hales: neglected respiratory physiologist.

    PubMed

    West, J B

    1984-09-01

    Stephen Hales was an eminent early 18th century scientist and minister of the parish of Teddington near London. He is well known for his early work on blood pressure. However, he made many contributions to respiratory physiology. He clarified the nature of the respiratory gases, distinguishing between their free (gaseous) and fixed (chemically combined) forms, demonstrated that rebreathing from a closed circuit could be extended if suitable gas absorbers were included (to remove carbon dioxide), suggested a similar device as a respirator for noxious atmospheres, invented the pneumatic trough for collecting gases, measured the size of the alveoli, calculated the surface area of the interior of the lung, calculated the time spent by the blood in a pulmonary capillary, invented the U-tube manometer, and measured intrathoracic pressures during normal and forced breathing. Hale's work is remarkable for its emphasis on the "statical" method, i.e., meticulous attention to detail in measurement and careful calculations. In his later life he made important contributions in the area of public health. He was a trustee of the new colony of Georgia and willed his own library of books to the colony though their whereabouts is unknown. He deserves more recognition in the history of respiratory physiology. PMID:6386767

  20. Pallas From The NUV To IR: A 4-Telescope Campaign

    NASA Astrophysics Data System (ADS)

    Schmidt, Britney E.; Thomas, P. C.; Bauer, J. M.; Rivkin, A. S.; Li, J. Y.; McFadden, L. A.; Mutchler, M. J.; Parker, J. W.; Stern, S. A.; Hicks, M. D.

    2008-09-01

    In July through September of 2007, we observed the third largest asteroid 2 Pallas from NUV-IR with Hubble Space Telescope, Palomar Observatory's 200-inch Hale Telescope, IRTF and Table Mountain Observatory. Using WFPC2/PC on HST, we determined Pallas’ size, shape and rotation pole: 291 x 278 x 250 km(±9), RA= 42o, Dec=-12o, (±10o). Employing the mass estimate of 1.17x10-10 +/- 0.03 Msun [1], Pallas’ density then becomes 2747 +/- 290 kg/m3, intermediate between basaltic Vesta and icy Ceres. This size is larger than most previous measurements that range from 287 x 262 x 250.5 km, ±10; km [2] to 275±3; x 252.5±2; x 234±9; km [3], with densities from 2.95-3.44 g/cm3. We explore the implications of Pallas' size and density. Pallas’ surface from the UV to the IR was characterized using HST, TMO, IRTF and Palomar. We observed Pallas with WFPC2 in 5 filters from 336 to 814nm in September 2007, and include the 2001 WFPC2 data of Storrs from 439-1042nm. We combined these with observations from TMO and will present Pallas’ colors, reflectance and phase curve. We observe surface variation of 6% in the NUV-visible light curve amplitudes, greater than previous limits from ground based AO. We will also present photometry and a phase curve from Palomar in the near-IR. Pallas’ spectrum has long been known to contain hydrated minerals[4], and we obtained new spectra from IRTF in the 3-micron region centered at different sub-Earth latitudes and longitudes. The spectra are consistent with one another within uncertainties, suggesting similar amounts of hydrated minerals across Pallas' surface on regional and hemispheric scales. [1] Goffin, B. (2001) Astronomy & Astrophysics 365, 627-630. [2] Dunham et al. (1990) Astronomical Journal 99, 1636-1652. [3] Drummond, J. D., personal communication. [4] Larson, H.P., et al. (1979) Icarus 39, 257-271.

  1. Twisting and Writhing with George Ellery Hale

    NASA Astrophysics Data System (ADS)

    Canfield, Richard C.

    2013-07-01

    Early in his productive career in astronomy, George Ellery Hale developed innovative instrumentation that allowed him to image the magnetically-dominated solar chromosphere. Among the solar phenomena he discovered were sunspot vortices, which he attributed to storms akin to cyclones in our own atmosphere. Much more recently, physicists discovered a quantity that is very well conserved in ideal magnetohydrodynamics: magnetic helicity. Our contemporary understanding of Hale's vortices as a consequence of large-scale twist in sunspot magnetic fields hinges on this conservation. I will review the crucial role that this property plays in the hemispheric and solar cycle dependences of Hales vortices, as well as solar flares and CMEs.

  2. Sheeley Receives 2009 Hale Prize

    NASA Astrophysics Data System (ADS)

    Tretkoff, Ernie

    2009-05-01

    Neil Sheeley Jr., of the Space Science Division of the Naval Research Laboratory (NRL), has been awarded the 2009 George Ellery Hale Prize by the Solar Physics Division of the American Astronomical Society (AAS). The international award recognizes work in solar astronomy done over an extended period of time. Sheeley will receive the award in June at the AAS meeting in Pasadena, Calif. Sheeley is cited "for his continuing outstanding contributions to our understanding of the solar magnetic field, coronal holes, and coronal mass ejections. His wide-ranging observational and theoretical work has laid the foundation for much current research in solar and heliospheric physics, and continues to have important applications in space weather prediction."

  3. Hubble Sees Material Ejected From Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    1995-01-01

    These NASA Hubble Space Telescope pictures of comet Hale-Bopp show a remarkable 'pinwheel' pattern and a blob of free-flying debris near the nucleus. The bright clump of light along the spiral (above the nucleus, which is near the center of the frame) may be a piece of the comet's icy crust that was ejected into space by a combination of ice evaporation and the comet's rotation, and which then disintegrated into a bright cloud of particles.

    Although the 'blob' is about 3.5 times fainter than the brightest portion at the nucleus, the lump appears brighter because it covers a larger area. The debris follows a spiral pattern outward because the solid nucleus is rotating like a lawn sprinkler, completing a single rotation about once per week.

    Ground-based observations conducted over the past two months have documented at least two separate episodes of jet and pinwheel formation and fading. By coincidence, the first Hubble images of Hale-Bopp, taken on September 26, 1995, immediately followed one of these outbursts and allow researchers to examine it at unprecedented detail. For the first time they see a clear separation between the nucleus and some of the debris being shed. By putting together information from the Hubble images and those taken during the recent outburst using the 82 cm telescope of the Teide Observatory (Tenerife, Canary Islands, Spain), astronomers find that the debris is moving away from the nucleus at a speed (projected on the sky) of about 68 miles per hour (109 kilometers per hour).

    The Hubble observations will be used to determine if Hale-Bopp is really a giant comet or rather a more moderate-sized object whose current activity is driven by outgassing from a very volatile ice which will 'burn out' over the next year. Comet Hale-Bopp was discovered on July 23, 1995 by amateur astronomers Alan Hale and Thomas Bopp. Though this comet is still well outside the orbit of Jupiter (almost 600 million miles, or one billion kilometers from Earth

  4. New Observations of Comet Hale-Bopp from La Silla

    NASA Astrophysics Data System (ADS)

    1998-10-01

    Methanol and Hydrogen Cyanide Detected at Record Distance Observations of famous Comet Hale-Bopp continue with the 15-m Swedish-ESO Submillimetre Telescope (SEST) at the La Silla Observatory. They show amazingly strong activity of this unusual object, also at the present, very large distance from the Sun. The radio observations document in detail the release of various molecules from the comet's icy nucleus. Of particular interest is the observed emission from methanol ( CH 3 OH ) and hydrogen cyanide ( HCN ) molecules, never before detected in any comet this far away. Comet Hale-Bopp still going strong Just over 18 months after its perihelion passage on April 1, 1997, Comet Hale-Bopp (official designation C/1995 O1 ) is continuing its outward journey through the Solar System. It is now about 1,000 million kilometres (6.7 AU) from the Sun and the Earth, i.e. almost at the same distance as when it was first discovered in July 1995. After having traversed the northern sky in 1996 and 1997, the comet passed the celestial equator in late June 1997 and is now seen in the southern constellation Volans (The Flying Fish), i.e. just east of the Large Magellanic Cloud. It can only be observed from southern latitudes. The comet's brightness has decreased by a factor of more than 10,000 since it was at its brightest in March 1997, just before perihelion. However, the magnitude is still around 9 - 10, or only about 20-40 times fainter than what can be seen with the unaided eye. Hale-Bopp is therefore visible in binoculars to southern observers as a fuzzy object with a diameter of a few arcminutes. New observations from La Silla Several telescopes at La Silla are following the evolution of the activity of Comet Hale-Bopp as it recedes from the Sun. In particular, the comet is observed monthly with SEST , a 15-m diameter submillimetre telescope operated jointly by the Onsala Space Observatory (OSO, Chalmers University of Technology, Gothenburg, Sweden) and ESO; it is the only

  5. Variations of Hales Discontinuity beneath South India

    NASA Astrophysics Data System (ADS)

    Goyal, Ayush; Kosre, Goukaran Kumar; Borah, Kajaljyoti

    2016-04-01

    Thermodynamic studies show the spinel-garnet transition in fertile and hot mantle should be relatively narrow and should show up in the seismological studies as a discontinuity. The evidence for a shallow lithospheric mantle discontinuity was first proposed by Hales (1969) based on seismological travel time measurement from the Early Rise experiment in the Central United States, where a ~4% increase in the S-wave velocity at a depth of 75 km was observed. The recent studies show, in cratonic blocks with colder geotherms, that it appears at greater depths and over broader intervals, that is, from the Moho to 150 km depth. Different studies interpreted that Hales discontinuity may be due to seismic anisotropy or pervasive partial melts or cation ordering in mantle olivine. In the present study an attempt is made to model the Hales discontinuity in the South Indian shield, by jointly inverting group velocity dispersion and receiver functions, calculated from teleseismic earthquakes recorded at 20 broadband seismograph locations in the study region. South Indian shield is an amalgamation of several crustal blocks, namely, Eastern Dharwar Craton (EDC), Western Dharwar Craton (WDC), Southern Granulite Terrain (SGT) etc. Inversion modeling results show deeper Hales discontinuity (~104-110 km depth) in the south of WDC and SGT, while in the north of Western Dharwar Craton and Eastern Dharwar Craton it varies from ~70-80 km. It is also observed that the Hales Discontinuity is present at greater depth in the western part of Dharwar Craton, compared to the eastern part. Details of the depth, thickness, and the cause of the Hales discontinuity are also investigated. Keywords: Hales Discontinuity, South Indian Shield, Receiver Function, Craton, Inversion modeling.

  6. Post-Perihelion HST Observations of Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Weaver, H. A.; Feldman, P. D.; A'Hearn, M. F.; Arpigny, C.; Brandt, J. C.; Stern, S. A.

    1998-01-01

    Observations of comet Hale-Bopp with HST resumed on 27 Aug 1997 (at r=2.476 AU and Delta =2.989 AU) following a 10 month hiatus during which time the comet was in the HST solar avoidance zone. The observations executed flawlessly using the newly-installed Space Telescope Imaging Spectrograph (STIS). The STIS CCD was used to image the comet, and useful spectroscopy was performed between 2100-3190 Angstroms using the G230LB and G230MB gratings. The morphology of the images closely resembled that obtained at similar heliocentric distances pre-perihelion (i.e., ``porcupine'' appearance), but the dust production rate was slightly lower post-perihelion. From the observed emission in the OH(0,0) band, we derived a preliminary value for the water production rate of ~ 3 x 10(29) molecules s(-1) , which is comparable to the pre-perihelion value. The 2-dim nature of the STIS data allowed us to map the spatial distribution of the OH emission, and the ~ 6 Angstroms resolution of the G230MB grating permits a detailed examination of the OH excitation. Preliminary analysis indicates that a conventional vectorial model can reproduce the observed OH spatial distribution. Emissions from CS and the OH(1,0) band were observed in the G230LB data. The next HST observations of Hale-Bopp are scheduled for Nov 1997, and the final observations in our program will probably take place in mid-Feb 1998.

  7. Structurally Integrated Antenna Concepts for HALE UAVs

    NASA Technical Reports Server (NTRS)

    Cravey, Robin L.; Vedeler, Erik; Goins, Larry; Young, W. Robert; Lawrence, Roland W.

    2006-01-01

    This technical memorandum describes work done in support of the Multifunctional Structures and Materials Team under the Vehicle Systems Program's ITAS (Integrated Tailored Aero Structures) Project during FY 2005. The Electromagnetics and Sensors Branch (ESB) developed three ultra lightweight antenna concepts compatible with HALE UAVs (High Altitude Long Endurance Unmanned Aerial Vehicles). ESB also developed antenna elements that minimize the interaction between elements and the vehicle to minimize the impact of wing flexure on the EM (electromagnetic) performance of the integrated array. In addition, computer models were developed to perform phase correction for antenna arrays whose elements are moving relative to each other due to wing deformations expected in HALE vehicle concepts. Development of lightweight, conformal or structurally integrated antenna elements and compensating for the impact of a lightweight, flexible structure on a large antenna array are important steps in the realization of HALE UAVs for microwave applications such as passive remote sensing and communications.

  8. A determination of the HDO/H2O ratio in comet C/1995 O1 (Hale-Bopp).

    PubMed

    Meier, R; Owen, T C; Matthews, H E; Jewitt, D C; Bockelée-Morvan, D; Biver, N; Crovisier, J; Gautier, D

    1998-02-01

    Deuterated water (HDO) was detected in comet C/1995 O1 (Hale-Bopp) with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred D/H ratio in Hale-Bopp's water is (3.3 +/- 0.8) x 10(-4). This result is consistent with in situ measurements of comet P/Halley and the value found in C/1996 B2 (Hyakutake). This D/H ratio, higher than that in terrestrial water and more than 10 times the value for protosolar H2, implies that comets cannot be the only source for the oceans on Earth. PMID:9452379

  9. A determination of the HDO/H2O ratio in comet C/1995 O1 (Hale-Bopp)

    NASA Technical Reports Server (NTRS)

    Meier, R.; Owen, T. C.; Matthews, H. E.; Jewitt, D. C.; Bockelee-Morvan, D.; Biver, N.; Crovisier, J.; Gautier, D.

    1998-01-01

    Deuterated water (HDO) was detected in comet C/1995 O1 (Hale-Bopp) with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred D/H ratio in Hale-Bopp's water is (3.3 +/- 0.8) x 10(-4). This result is consistent with in situ measurements of comet P/Halley and the value found in C/1996 B2 (Hyakutake). This D/H ratio, higher than that in terrestrial water and more than 10 times the value for protosolar H2, implies that comets cannot be the only source for the oceans on Earth.

  10. A determination of the HDO/H2O ratio in comet C/1995 O1 (Hale-Bopp).

    PubMed

    Meier, R; Owen, T C; Matthews, H E; Jewitt, D C; Bockelée-Morvan, D; Biver, N; Crovisier, J; Gautier, D

    1998-02-01

    Deuterated water (HDO) was detected in comet C/1995 O1 (Hale-Bopp) with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred D/H ratio in Hale-Bopp's water is (3.3 +/- 0.8) x 10(-4). This result is consistent with in situ measurements of comet P/Halley and the value found in C/1996 B2 (Hyakutake). This D/H ratio, higher than that in terrestrial water and more than 10 times the value for protosolar H2, implies that comets cannot be the only source for the oceans on Earth.

  11. LOOKING ALONG HALE ALII AVENUE TOWARD SHIPYARD AREA. FACILITIES 1040 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING ALONG HALE ALII AVENUE TOWARD SHIPYARD AREA. FACILITIES 1040 AND 1041 (QUARTERS 1 AND J) AT LEFT. VIEW FACING SOUTHWEST. - U.S. Naval Base, Pearl Harbor, Naval Housing Area Hale Alii, Hale Alii Avenue, Eighth Street, & Avenue D, Pearl City, Honolulu County, HI

  12. (abstract) Spectra of Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Hanner, M. S.; Hayward, T. L.; Lynch, D. K.; Russell, R. W.

    1996-01-01

    The spectra of Hale-Bopp were acquired in mid-1996 at R > 3.5 AU. Strong silicate emission is present in all the spectra. The shape of the feature is very similar to that seen in comet P/Halley. This is the first time that a strong silicate feature has been detected in a comet beyond 2 AU.

  13. A Cold, Dusty Comet: A Study of Hale-Bopp 8 and 11 Years After Perihelion

    NASA Astrophysics Data System (ADS)

    Kramer, Emily A.; Fernandez, Y. R.; Kelley, M. S.; Woodney, L.

    2009-09-01

    Comet Hale-Bopp offered us an unprecedented opportunity to observe a large, bright comet in great detail. Since its 1997 perihelion, continued observations have let us observe how its activity has changed over time. Here we present 2005 and 2008 Spitzer Space Telescope observations of Hale-Bopp that show a coma and tail, which is uncommon given its heliocentric distance -- 21.6 AU in 2005 and 27.2 AU in 2008. It is rare to see comets with such extended emission this far from the Sun. The data for this project were obtained with the Multiband Imaging Photometer for Spitzer using the 24 micron channel. We are modeling Hale-Bopp's morphology in the Spitzer images to understand the nature of the dust coma and tail. To do this we will use a Monte Carlo dynamical model created by one of our team members[1] that will yield the dust production rate, dust emission history, dust grain sizes, and dust grain speeds. Some questions which will be answered include: How old is the dust? Is it comprised of large, old grains or small, newer grains? What is its likely composition? How does it differ from dust released near perihelion or pre-perihelion? Are the dust properties determined by the comet's activity mechanism? By answering these and other fundamental questions, we hope to gain insight into the nature of Hale-Bopp's behavior and evolution. Our overarching goal is to use Hale-Bopp and other distant, active comets to understand cometary activity and the structure of cometary nuclei, which is related to icy planetesimal formation and evolution. Support for this work was provided by NASA through an award issued by the Spitzer Science Center via JPL/Caltech. Reference: [1] Kelley, M.S., et al., Icarus 193, 572

  14. Evolution of the outgassing of comet Hale-Bopp (C/1995 O1) from radio observations.

    PubMed

    Biver, N; Bockelée-Morvan, D; Colom, P; Crovisier, J; Davies, J K; Dent, W R; Despois, D; Gérard, E; Lellouch, E; Rauer, H; Moreno, R; Paubert, G

    1997-03-28

    Spectra obtained from ground-based radio telescopes show the progressive release of CO, CH3OH, HCN, H2O (from OH), H2S, CS, H2CO, CH3CN, and HNC as comet Hale-Bopp (C/1995 01) approached the sun from 6.9 to 1.4 astronomical units (AU). The more volatile species were relatively more abundant in the coma far from the sun, but there was no direct correlation between overabundance and volatility. Evidence for H2O sublimation from icy grains was seen beyond 3.5 AU from the sun. The change from a CO-driven coma to an H2O-driven coma occurred at about 3 AU. The gas outflow velocity and temperature increased as Hale-Bopp approached the sun.

  15. Infrared Radiation from Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Chandra; Hoyle, Fred

    The infrared spectrum of Comet Hale-Bopp over the wavelength range 7.5 to 45 micrometers, obtained when it was at a heliocentric distance of 2.9 AU, is shown to be consistent with a model dominated by a mixed microbial culture including diatoms with an approximately 10% mass contribution from crystalline olivine. Crystalline olivine by itself is unable to account for the data.

  16. Measurements of [C I] 9850 A Emission from Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Oliversen, R. J.; Doane, N.; Scherb, F.; Harris, W. M.; Morgenthaler, J. P.

    2002-01-01

    We present quantitative measurements of cometary [C I] 9850 A, emission obtained during observations of comet Hale-Bopp (C/1995 O1) in 1997 March and April. The observations were carried out using a high-resolution (lambda/Delta lambda approx. 40,000) Fabry-Perot/CCD spectrometer at the McMath-Pierce solar telescope on Kitt Peak. This forbidden line, the carbon analog of [O I] 6300 A, is emitted in the radiative decay of C(1D) atoms. In the absence of other sources and sinks, [C I] 9850 A emission may be used as a direct tracer of CO photodissociation in comets. However, in Hale-Bopp's large, dense coma, other processes, such as collisional excitation of ground-state C(3P), dissociative recombination of CO+, and collisional dissociation of CO and CO2 may produce significant amounts of C(1D). The long C(1D) radiative lifetime (approx. 4000 s) makes collisional de-excitation (quenching) the primary loss mechanism in the inner coma. Thus, a detailed, self-consistent global model of collisional and photochemical interactions is necessary to fully account for [C I] 9850 A emission in comet Hale-Bopp.

  17. Deuterium in comet C/1995 O1 (Hale-Bopp): detection of DCN.

    PubMed

    Meier, R; Owen, T C; Jewitt, D C; Matthews, H E; Senay, M; Biver, N; Bockel e-Morvan, D; Crovisier, J; Gautier, D

    1998-03-13

    Deuterated hydrogen cyanide (DCN) was detected in a comet, C/1995 O1 (Hale-Bopp), with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred deuterium/hydrogen (D/H) ratio in hydrogen cyanide (HCN) is (D/H)HCN = (2.3 +/- 0.4) x 10(-3). This ratio is higher than the D/H ratio found in cometary water and supports the interstellar origin of cometary ices. The observed values of D/H in water and HCN imply a kinetic temperature >/=30 +/- 10 K in the fragment of interstellar cloud that formed the solar system. PMID:9497286

  18. Deuterium in comet C/1995 O1 (Hale-Bopp): detection of DCN

    NASA Technical Reports Server (NTRS)

    Meier, R.; Owen, T. C.; Jewitt, D. C.; Matthews, H. E.; Senay, M.; Biver, N.; Bockel e-Morvan, D.; Crovisier, J.; Gautier, D.

    1998-01-01

    Deuterated hydrogen cyanide (DCN) was detected in a comet, C/1995 O1 (Hale-Bopp), with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred deuterium/hydrogen (D/H) ratio in hydrogen cyanide (HCN) is (D/H)HCN = (2.3 +/- 0.4) x 10(-3). This ratio is higher than the D/H ratio found in cometary water and supports the interstellar origin of cometary ices. The observed values of D/H in water and HCN imply a kinetic temperature >/=30 +/- 10 K in the fragment of interstellar cloud that formed the solar system.

  19. Deuterium in comet C/1995 O1 (Hale-Bopp): detection of DCN.

    PubMed

    Meier, R; Owen, T C; Jewitt, D C; Matthews, H E; Senay, M; Biver, N; Bockel e-Morvan, D; Crovisier, J; Gautier, D

    1998-03-13

    Deuterated hydrogen cyanide (DCN) was detected in a comet, C/1995 O1 (Hale-Bopp), with the use of the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. The inferred deuterium/hydrogen (D/H) ratio in hydrogen cyanide (HCN) is (D/H)HCN = (2.3 +/- 0.4) x 10(-3). This ratio is higher than the D/H ratio found in cometary water and supports the interstellar origin of cometary ices. The observed values of D/H in water and HCN imply a kinetic temperature >/=30 +/- 10 K in the fragment of interstellar cloud that formed the solar system.

  20. A dynamical analysis of the dust tail of Comet C/1995 O1 (Hale-Bopp) at high heliocentric distances

    NASA Astrophysics Data System (ADS)

    Kramer, Emily A.; Fernandez, Yanga R.; Lisse, Carey M.; Kelley, Michael S. P.; Woodney, Laura M.

    2014-07-01

    Comet C/1995 O1 (Hale-Bopp) has provided an unprecedented opportunity to observe a bright comet over a wide range of heliocentric distances. We present here Spitzer Space Telescope observations of Hale-Bopp from 2005 to 2008 that show a distinct coma and tail, the presence of which is uncommon given its large heliocentric distance (21.6 AU and 27.2 AU, respectively). The morphology of the dust is compared to dynamical models to understand the activity of the comet. Our analysis shows that the shape of Hale-Bopp’s dust tail in these images cannot be explained using the usual Finson-Probstein (solar gravity + solar radiation pressure) dynamical model. Several alternative explanations are explored. The analysis suggests that the most likely cause of the discrepancy is that the dust is being charged by the solar wind, then being affected by the interplanetary magnetic field via the Lorentz force. Though this effect has been explored previously, if correct, this seems to be the first time that the Lorentz force has been required to model a cometary dust tail. The analysis also suggests that Hale-Bopp was actively emitting particles when these images were taken, and the tail characteristics changed between observations.

  1. On Jack Hale's problem for impulsive systems

    NASA Astrophysics Data System (ADS)

    Bonotto, E. M.; Gimenes, L. P.; Souto, G. M.

    2015-07-01

    An interesting problem of Jack Hale deals with the existence of a maximal compact invariant set in discrete dynamical systems. A solution for this problem is known for locally bounded dynamical systems. Following this line of research, we consider in this paper a class of systems whose continuous dynamics are interrupted by abrupt changes of state and we present sufficient conditions to obtain the existence of a maximal compact invariant set for a system in this class. We use the theory of asymptotic compactness to get the results.

  2. Jets in Comet Hale-Bopp (1995 O1)

    NASA Astrophysics Data System (ADS)

    Lederer, S. M.; Campins, H.; Osip, D. J.

    1999-12-01

    Comet Hale-Bopp provided the first opportunity to examine OH jets in the coma of a comet. We presented the observations and initial results of this study in Lederer et al., EM&P, 1999. This included the identification of jets in our OH, NH, CN, C2, C3, and dust narrowband filter images. Here we present an analysis of these jets with emphasis on the OH jets using Monte Carlo models of the inner coma. The images were acquired in March and April, 1997 using Lowell Observatory's 1.1m Hall telescope in conjunction with the 20482 CCD camera. The narrowband filters employed were designed to isolate the continuum in several bandpasses as well as emission from the gas species. We have developed time-dependent Monte Carlo models with OH jets originating from (1) a nuclear molecular water source, and (2) an extended source of sub-micron organic CHON grains. We compare our observations with these models with the goal of understanding the source of the OH. The parameters that will be discussed include a) the morphology of the jets, b) the enhancement of the jets above the isotropic background, c) the expansion velocity of the jets, and d) the evolution of the jets with time. Preliminary results suggest that an extended source is at least partially responsible for these jets. This work was supported by NASA.

  3. Explorer of the universe. A biography of George Ellery Hale.

    NASA Astrophysics Data System (ADS)

    Wright, H.

    When first published in 1966, Helen Wright's Explorer of the universe brought public recognition to astronomer George Ellery Hale's (1868 - 1938) pre-eminent role in 20th-century science. With this timely republication (featuring a new introduction by Alan Sandage and a complete index), Hale's accomplishments and his fascinating, mercurial personality are brought to life for a new generation. Drawing on extensive research and interviews with Hale's colleagues, associates, and friends, as well as many of the astronomers he inspired, this work is an authoriative and affectionate biography and a revealing look back at the birth and development of modern astrophysics.

  4. Stephen Hales and the measurement of blood pressure.

    PubMed

    Lewis, O

    1994-12-01

    Natural philosopher and inventor, Stephen Hales (1677-1761), undertook a lengthy series of experiments on animals described in Haemastaticks (1733) which led to the first direct measurement of blood pressure. Hales retained his interest in health and disease throughout his life, and this prompted what he regarded as his most important work: the invention of ventilation systems for use in ships or prisons. Hales was the 'perpetual curate' of Teddington, Middlesex, and he combined a mechanistic, quantitative approach to his experimental work with a need and, as he saw it, a duty to discover and wonder at the wisdom and goodness of God by studying His creation. PMID:7884783

  5. Twisting and Writhing with George Ellery Hale

    NASA Astrophysics Data System (ADS)

    Canfield, Richard C.

    2013-06-01

    Early in his productive career in astronomy, George Ellery Hale developed innovative solar instrumentation that allowed him to make narrow-band images. Among the solar phenomena he discovered were sunspot vortices, which he attributed to storms akin to cyclones in our own atmosphere. Using the concept of magnetic helicity, physicists and mathematicians describe the topology of magnetic fields, including twisting and writhing. Our contemporary understanding of Hale's vortices as a consequence of large-scale twist in sunspot magnetic fields hinges on a key property of helicity: conservation. I will describe the critical role that this property plays, when applied to twist and writhe, in a fundamental aspect of global solar magnetism: the hemispheric and solar cycle dependences of active region electric currents with respect to magnetic fields. With the advent of unbroken sequences of high-resolution magnetic images, such as those presently available from the Helioseismic and Magnetic Imager on Solar Dynamics Observatory, the flux of magnetic helicity through the photosphere can be observed quantitatively. As magnetic flux tubes buoy up through the convection zone, buffeted and shredded by turbulence, they break up into fragments by repeated random bifurcation. We track these rising flux fragments in the photosphere, and calculate the flux of energy and magnetic helicity there. Using a quantitative model of coronal currents, we also track connections between these fragments to calculate the energy and magnetic helicity stored at topological interfaces that are in some ways analogous to the storage of stress at faults in the Earth's crust. Comparison of these values to solar flares and interplanetary coronal mass ejections implies that this is the primary storage mechanism for energy and magnetic helicity released in those phenomena, and suggests a useful tool for quantitative prediction of geomagnetic storms.

  6. The infrared spectrum of comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Crovisier, J.; Leech, K.; Bockelee-Morvan, D.; Brooke, T. Y.; Hanner, M. S.; Altieri, B.; Keller, H. U.; Lellouch, E.

    1997-01-01

    The infrared spectroscopic observations of the comet C/1995 O1 (Hale-Bopp), in April and September-October 1996, are summarized. High resolution spectra were obtained with the long and short wavelength spectrometers of the Infrared Space Observatory (ISO). The results showed that the dust in this comet contains crystalline silicates. The dust of Hale-Bopp is rather similar to that observed in the circumstellar disks of Vega-type stars.

  7. Comet Hale-Bopp in the constellation Andromeda

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Comet Hale-Bopp was photographed in the constellation Andromeda by George Shelton, photographer for The Bionetics Corp., at 8:14 p.m. on March 31, 1997, from Merritt Island, Florida, close to the Kennedy Space Center. During this 24-hour period, Comet Hale- Bopp is making its closest approach to the Sun.

  8. Notes on Species of the Lichen Genus Canoparmelia Elix & Hale in South Korea

    PubMed Central

    Jayalal, Udeni; Joshi, Santosh; Oh, Soon-Ok; Park, Jung-Shin

    2012-01-01

    Detailed descriptions of five species of the lichen genus Canoparmelia Elix & Hale. are presented. Until now, three species of the genus Canoparmelia, including C. apata (Krempelh.) Elix & Hale, C. owariensis (Asah.) Elix, and C. texana (Tuck.) Elix & Hale have been reported in South Korea. Canoparmelia carneopruinata (Zahlbr.) Elix & Hale, C. crozalsiana (de Lesd.) Elix & Hale, and C. ecaperata (Müll. Arg.) Elix & Hale are new to the South Korean lichen flora. An artificial key is provided for all species of Canoparmelia, including the three new records. PMID:23115507

  9. Comets after Hyakutake and Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Mumma, Michael J.

    1999-01-01

    Being icy, cometary nuclei are the most easily modified bodies in the solar system - even modest heating is sufficient to induce significant weight loss. This sublimative loss and longterm storage far from the sun protect the nucleus against internal warming and ensure that cometary nuclei today contain the least processed material remaining from the early nebula - or perhaps from the natal cloud. The chemical compositions of ices, low temperature-refractory organics, and refractory minerals (and their physical states) provide sensitive probes of the origin and history of this material. The fortunate appearance of Hyakutake and Hale-Bopp has provided a wealth of information on these Oort cloud comets, obtained with a wide range of astronomical approaches. I will review certain key results for these comets, such as chemical abundances, isotopic abundance ratios, nuclear spin statistics, and nuclear vs extended production of "parent volatiles", and will illustrate how these test the origins of cometary material. A comparison with 1P/Halley--a third comet from the giant planet nebular region--will be discussed in the context of heterogeneity among these bodies.

  10. Image examination of comet Hale-Bopp and α Gem.

    NASA Astrophysics Data System (ADS)

    Li, Qiusha; Zhang, Bairong; Wang, Feng

    A new Astronomy Video Image Acquisition System (AVIAS) is used in the image processing of comet Hale-Bopp and α Gem which were recorded by a video camera (Panasonic-NV-S880EN) on May 1, 1997. It is shown that the details of multi-integration images for comet Hale-Bopp and α Gem are more distinct than that of single image. The faint star near α Gem cannot be found in the single frame image but can be recognized in the multi-integration image.

  11. Hale, George Ellery (1868-1938)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    American astrophysicist, born in Chicago, IL, as an undergraduate at MIT invented the spectroheliograph, which made it possible to photograph the Sun's prominences in daylight. At the University of Chicago he used a 40 in lens as the basis for the telescope of the Yerkes Observatory, completed 1897. Founded Mount Wilson Observatory, where he discovered the magnetic fields in sunspots. Planned and...

  12. Vibration and aeroelastic analysis of highly flexible HALE aircraft

    NASA Astrophysics Data System (ADS)

    Chang, Chong-Seok

    The highly flexible HALE (High Altitude Long Endurance) aircraft analysis methodology is of interest because early studies indicated that HALE aircraft might have different vibration and aeroelastic characteristics from those of conventional aircraft. Recently the computer code Nonlinear Aeroelastic Trim And Stability of HALE Aircraft (NATASHA) was developed under NASA sponsorship. NATASHA can predict the flight dynamics and aeroelastic behavior for HALE aircraft with a flying wing configuration. Further analysis improvements for NATASHA were required to extend its capability to the ground vibration test (GVT) environment and to both GVT and aeroelastic behavior of HALE aircraft with other configurations. First, the analysis methodology, based on geometrically exact fully intrinsic beam theory, was extended to treat other aircraft cofigurations. Conventional aircraft with flexible fuselage and tail can now be modeled by treating the aircraft as an assembly of beam elements. NATASHA is now applicable to any aircraft cofiguration that can be modeled this way. The intrinsic beam formulation, which is a fundamental structural modeling approach, is now capable of being applying to a structure consisting of multiple beams by relating the virtual displacements and rotations at points where two or more beam elements are connected to each other. Additional aspects are also considered in the analysis such as auxiliary elevator input in the horizontal tail and fuselage aerodynamics. Second, the modeling approach was extended to treat the GVT environment for HALE aircraft, which have highly flexible wings. GVT has its main purpose to provide modal characteristics for model validation. A bungee formulation was developed by the augmented Lagrangian method and coupled to the intrinsic beam formulation for the GVT modeling. After the coupling procedure, the whole formulation cannot be fully intrinsic because the geometric constraint by bungee cords makes the system statically

  13. Thermophysical simulations of comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    González, M.; Gutiérrez, P. J.; Lara, L. M.

    2014-03-01

    Aims: In this work, we simulate the global behavior of comet Hale-Bopp with our thermophysical model starting with simple, homogeneous conditions, so that dust mantling and the active area develop consistently depending on the properties of the simulated nucleus. We aim to obtain a range of compatibility between our model and the observations, that can be used as constraints on some of the characteristics of cometary nuclei. Methods: Our thermophysical model includes crystallization (and release of trapped CO), sublimation/recondensation, heat and gas transport through the nucleus, and dragged dust release. We run a battery of simulations with different parameter sets selected according to our current knowledge of comets and compare our results with observational data. Initial calculations are performed for a comet radius R0 = 30 km. To match the calculated integrated H2O production to the observed rate, we renormalize to a new R, which must be within 20 and 40 km, that is a range compatible with several estimates. Further selection is performed comparing the simulated water and carbon monoxide production rate profiles with the observational profiles and checking that the observational upper/lower limits of the H2O production are fulfilled. Results: We have found a reasonable agreement between our model and the data for H2O and CO production rates, without the need of distributed sources, for the following initial conditions: the nucleus is composed of water, carbon monoxide, and dust with a moderate dust proportion, tending to be icy, with a dust-to-ice ratio of between 0.5 and 1. The water ice must be initially amorphous with 15 to 20% of trapped carbon monoxide. The icy matrix has a thermal inertia between 100 and 200 J m-2 K s-1/2, considering the initial composition with crystalline ice at 140 K. The dust follows an exponential size distribution with particles from 0.1 μm to 1 mm and leaves the comet dragged by the expelled vapor with a dragging efficiency

  14. Cometary Science After Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; DeVincenzi, Donald L. (Technical Monitor)

    2002-01-01

    Comets and the chondritic porous interplanetary dust particles (CP IDPs) that they shed in their comae are reservoirs of primitive solar nebula materials. The high porosity and fragility of cometary grains and CP IDPs, and anomalously high deuterium contents of pyroxene-rich CP IDPs imply these aggregate particles contain significant interstellar grain components. Spectrophotometry of comets at thermal IR wavelengths (3-40 microns) reveal the presence of a warm (near-IR) featureless emission modeled by amorphous carbon grains, and mid-IR and far-IR broad and narrow resonances modeled by chondritic (50% Fe and 50% Mg) amorphous and Mg-rich crystalline silicate minerals, respectively. Cometary amorphous silicate resonances are well matched by IR spectra of CP IDPs dominated by 0.1 micron spherules of Glass with Embedded Metal and Sulfides (GEMS) that are thought to be the interstellar Fe-bearing amorphous silicates produced in the cooling outflows of Asymptotic Giant Branch (AGB) stars. Acid-etched microtomed CP IDP samples, however, show that both the carbon phase (aliphatic) and the amorphous silicate phase (Mg-rich) are not optically absorbing while the embedded Fe nanoparticles make the IDPs dark. The CP IDPs suggest either significant processing has occurred in the ISM or that the AGB amorphous silicates have Mg-rich stoichiometry and possibly grew on Fe particle condensates. Cometary crystalline silicate resonances are well matched by IR spectra of laboratory submicron Mg-rich olivine crystals, [Mg(sub y),Fe(sub 1-y)]2SiO4 with y/ge0.85, and in the case of Hale-Bopp at r(sub h) less than or equal to approx. 1.5 AU, by Mg-rich pyroxene crystals, [Mg(sub x),Fe(sub 1-x)]SiO3 with x/ge0.85. While a fraction of AGB stardust (less than or equal to 15%) are Mg-rich crystals, this interstellar star dust component is insufficient to account for the deduced abundance of crystalline minerals in comet dust. An insufficient source of ISM Mg-rich crystals leads to the

  15. Comet Hale-Bopp photographed from Merritt Island

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Comet Hale-Bopp is seen in the constellation Lacerta at 5:18 a.m. on March 9, 1997. North is to the left of the comet in this photograph, which was taken on Merritt Island, Florida, near Kennedy Space Center.

  16. Modeling Coma Gas Jets in Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Lederer, S. M.; Campins, H.

    2001-01-01

    We present an analysis of OH, CN, and C2 jets observed in Comet Hale-Bopp. The relative contributions from and composition of the coma gas sources, and the parameters describing the active areas responsible for the gas jets will be discussed. Additional information is contained in the original extended abstract.

  17. STS-83 Onboard Photo: Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a Microgravity Science Laboratory-1 (MLS-1) onboard STS-83 photo of the most recent comet to date, Hale-Bopp, which passed by Earth during the spring and summer of 1997. In this view, the comet is visible during sunset. The streaks and distorted lights seen in the bottom of the photo are city lights and petroleum fires.

  18. George Ellery Hale, Ernest Fox Nichols, and Radiometry at the Yerkes Observatory

    NASA Astrophysics Data System (ADS)

    Brashear, R. S.

    1993-12-01

    In the 1890s, George Ellery Hale, Director of the Yerkes Observatory, attempted to detect the solar corona when the Sun was not in eclipse. His failure to detect the corona optically led him to see if he could discover any indications of coronal heat with the use of bolometers. At first, Hale wanted to find coronal heat during a total eclipse in order to determine whether the heat was significant enough to be measurable out of eclipse. Hale would often try to enlist the aid of others traveling to distant eclipse sights by asking them to perform certain bolometric observations. Ernest Fox Nichols's work with the modified Crookes radiometer led Hale to attempt to appropriate Nichols for his coronal research. Hale's scheme back-fired when Nichols insisted on measuring stellar heat, not coronal heat. Although Hale was initially disappointed, Nichols's results at Yerkes made Hale realize the potential value of radiometric research in astrophysical problems.

  19. Explorer of the Universe

    NASA Astrophysics Data System (ADS)

    Wright, Helen

    A reprint edition of a 1966 biography of foremost astronomer George Ellery Hale, who laid much of the foundation of modern astrophysics and observational cosmology. He's best known for the planning and building of the 200-inch Hale Telescope of the Palomar Mountain Observatory. This book features a new introduction by Allan Sandage and an index not included in the original work. Since the history of astrophysics is mostly undocumented, this work provides a rare look at Hale's scientific achievements: his invention of the spectroheliograph, his discovery of the magnetic nature of sunspots, and his legendary leadership in founding the Yerkes, Mount Wilson, and Palomar Mountain Observatories.

  20. Plasma tails: Comets Hale-Bopp and Hyakutake

    SciTech Connect

    Wurden, G.A.; Wurden, A.J.; Gladstone, I.M. Jr.

    1999-02-01

    Comet Hale-Bopp was one of the largest comets ever recorded, and it exhibited both a massive dust tail and a plasma tail, which developed as it approaches the sun over the course of six months in 1996--1997. Because the dust responds to gravity and light pressure, but plasmas also respond to the local solar wind (Coulomb collisions and magnetic fields), there is typically an angular separation between the two tails, as seen in the photo above.

  1. HALE UAS Concept of Operations. Version 3.0

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This document is a system level Concept of Operations (CONOPS) from the perspective of future High Altitude Long Endurance (HALE) Unmanned Aircraft Systems (UAS) service providers and National Airspace System (NAS) users. It describes current systems (existing UAS), describes HALE UAS functions and operations to be performed (via sample missions), and offers insight into the user s environment (i.e., the UAS as a system of systems). It is intended to be a source document for NAS UAS operational requirements, and provides a construct for government agencies to use in guiding their regulatory decisions, architecture requirements, and investment strategies. Although it does not describe the technical capabilities of a specific HALE UAS system (which do, and will vary widely), it is intended to aid in requirements capture and to be used as input to the functional requirements and analysis process. The document provides a basis for development of functional requirements and operational guidelines to achieve unrestricted access into the NAS. This document is an FY06 update to the FY05 Access 5 Project-approved Concept of Operations document previously published in the Public Domain on the Access 5 open website. This version is recommended to be approved for public release also. The updates are a reorganization of materials from the previous version with the addition of an updated set of operational requirements, inclusion of sample mission scenarios, and identification of roles and responsibilities of interfaces within flight phases.

  2. Space Telescope.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  3. The Hales discontinuity and upper mantle anisotropy beneath cratons

    NASA Astrophysics Data System (ADS)

    Musacchio, G.; White, D. J.; Thomson, C. J.

    2003-04-01

    Seismic velocity discontinuities are commonly found within the upper 100 km of the mantle lithosphere, with great variability in their depth, lateral extent, and the polarity of velocity jump. Among the more commonly observed is the Hales discontinuity, identified in a variety of tectonic environments, and commonly associated with a high-velocity, highly reflective and sometimes anisotropic layer. In the Archean Western Superior Province of the Canadian Shield, long range R/WAR profiling gives a high-resolution estimate of the mantle V_P in the shallow upper mantle, providing a more certain determination of the nature of the Hales dicontinuity. Ray-based travel-time inversion of the data, have shown that Vp in the uppermost mantle is 8.0-8.3 km/s. A 15-20 km thick layer (layer-H) with >6% seismic anisotropy (N-S V_P of 8.3 km/s and E-W V_P of 8.8 km/s) dips northward at ˜10^o from a minimum depth of 48-50 km. The attitude of layer-H is consistent with the general tectonic strike; its depth range (50-75 km) falls within that of the Hales discontinuity. If a link between the Hales discontinuity and layer-H can be drawn, observations strengthen the objection that the estimated velocity contrast (0.2 to 0.4 km/s depending on the direction of wave propagation) is relatively high if layer-H represents a phase transition, and thus (re)opens the debate on the nature of shallow upper-mantle boundaries beneath continents. The high V_P and intermediate anisotropy of upper-mantle layer-H requires a harzburgite peridotitic composition with the a-axis of olivine aligned E-W. Layer-H might have emplaced during accretion (2.7 Ga Kenoran orogeny) of the North American proto-craton and be relic oceanic lithosphere. The Hales discontinuity might be an expression of continents accretion and map relic slabs in the shallow upper mantle.

  4. Measurements of 12C/13C, 14N/15N, and 32S/34S ratios in comet Hale-Bopp (C/1995 O1).

    PubMed

    Jewitt, D C; Matthews, H E; Owen, T; Meier, R

    1997-10-01

    The 12C/13C, 14N/15N, and 32S/34S isotope ratios in comet Hale-Bopp (C/1995 O1) were determined through observations taken with the James Clerk Maxwell Telescope. Measurements of rare isotopes in HCN and CS revealed isotope ratios of H12CN/H13CN = 111 +/- 12, HC14N/HC15N = 323 +/- 46, and C32S/C34S = 27 +/- 3. Within the measurement uncertainties, the isotopic ratios are consistent with solar system values. The cometary volatiles thus have an origin in the solar system and show no evidence for an interstellar component.

  5. Operation of the University of Hawaii 2.2M Telescope on Mauna Kea

    NASA Technical Reports Server (NTRS)

    McLaren, Robert A.

    1999-01-01

    This paper presents a final report from March 1, 1997-February 28, 1999 on the Operation of the University of Hawaii 2.2M Telescope on Mauna Kea. The topics include: 1) Telescope and Instrumentation (Newsletter and Documentation, Scheduling Periods); and 2) Scientific Highlights (The Outer Solar System-Trans-Neptunian Objects and the Kuiper Belt, Comet Hale-Bopp, Near-Earth Asteroids, Asteroid Families, and Galileo Mission Support).

  6. The activity and size of the nucleus of comet Hale-Bopp (C/1995 O1) [see comment].

    PubMed

    Weaver, H A; Feldman, P D; A'Hearn, M F; Arpigny, C; Brandt, J C; Festou, M C; Haken, M; McPhate, J B; Stern, S A; Tozzi, G P

    1997-03-28

    Analysis of Hubble Space Telescope (HST) images of comet Hale-Bopp (C/1995 O1) suggests that the effective diameter of the nucleus is between 27 to 42 kilometers, which is at least three times larger than that of comet P/Halley. The International Ultraviolet Explorer and HST spectra showed emissions from OH (a tracer of H2O) and CS (a tracer of CS2) starting in April 1996, and from the CO Cameron system (which primarily traces CO2) starting in June 1996. The variation of the H2O production rate with heliocentric distance was consistent with sublimation of an icy body near its subsolar point. The heliocentric variation in the production rates of CS2 and dust was different from that of H2O, which implies that H2O sublimation did not control the CS2 or dust production during these observations. PMID:9072959

  7. The activity and size of the nucleus of comet Hale-Bopp (C/1995 O1) [see comment].

    PubMed

    Weaver, H A; Feldman, P D; A'Hearn, M F; Arpigny, C; Brandt, J C; Festou, M C; Haken, M; McPhate, J B; Stern, S A; Tozzi, G P

    1997-03-28

    Analysis of Hubble Space Telescope (HST) images of comet Hale-Bopp (C/1995 O1) suggests that the effective diameter of the nucleus is between 27 to 42 kilometers, which is at least three times larger than that of comet P/Halley. The International Ultraviolet Explorer and HST spectra showed emissions from OH (a tracer of H2O) and CS (a tracer of CS2) starting in April 1996, and from the CO Cameron system (which primarily traces CO2) starting in June 1996. The variation of the H2O production rate with heliocentric distance was consistent with sublimation of an icy body near its subsolar point. The heliocentric variation in the production rates of CS2 and dust was different from that of H2O, which implies that H2O sublimation did not control the CS2 or dust production during these observations.

  8. Essayists, essays, and hosts: Daniel Hale Williams Medical Reading Club.

    PubMed Central

    Greene Reed, T.; Evans, C. C.

    1996-01-01

    The 66-year-old Daniel Hale Williams Medical Reading Club is an independent reading club comprised of 65 physicians in the metropolitan Washington, DC, area. Members representing all specialty fields meet six times a year for dinner and fellowship, to consider topics of common interest to the profession, and to hear a prepared lecture given by a featured essayist. Club members take turns as hosts for each meeting. This article gives a historical list of these meetings, naming the essayist and the topic, the hosts, and the site of the meetings. PMID:8918074

  9. Hco+ in the Coma of Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Lovell, A. J.; Schloerb, F. P.; Bergin, E. A.; Dickens, J. E.; De Vries, C. H.; Senay, M. C.; Irvine, W. M.

    1997-05-01

    Maps of comet C/1995 O1 (Hale-Bopp) in the millimeter-wave emission of the ion HCO^+ revealed a local minimum near the nucleus position, with a maximum about 100,000 km in the antisolar direction. These observed features of the HCO^+ emission require a low abundance of HCO^+ due to enhanced destruction in the inner coma of the comet, within a region of low electron temperature (T_e). To set constraints on the formation of HCO^+ in the coma, as well as the location and magnitude of the transition to higher T_e, the data are compared with the results of ion-molecule chemistry models.

  10. HCO+ in the coma of comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Lovell, A. J.; Schloerb, F. P.; Bergin, E. A.; Dickens, J. E.; Devries, C. H.; Senay, M. C.; Irvine, W. M.; Ferris, J. P. (Principal Investigator)

    1997-01-01

    Maps of comet C/1995 O1 (Hale-Bopp) in the millimeter-wave emission of the ion HCO+ revealed a local minimum near the nucleus position, with a maximum about 100,000 km in the antisolar direction. These observed features of the HCO+ emission require a low abundance of HCO+ due to enhanced destruction in the inner coma of the comet, within a region of low electron temperature (Te). To set constraints on the formation of HCO+ in the coma, as well as the location and magnitude of the transition to higher Te, the data are compared with the results of ion-molecule chemistry models.

  11. Geology and ground-water resources of Hale County, Texas

    USGS Publications Warehouse

    Cronin, J.G.; Wells, Lloyd C.

    1963-01-01

    It is estimated that in 1955 about 39 million acre-feet of water was in storage in the Ogallala formation in Hale County; however, only about 16 million is theoretically available to wells, and a somewhat smaller amount is practically available. About 3 million acre-feet was removed from storage during 1938-55. Water levels in wells have declined more or less steadily since 1938, and it is apparent that the ground-water resources of the county are insufficient to support large-scale perennial irrigation such as that of 1955.

  12. Evolution of the Activity of Comet Hale-Bopp (1995 O1) from August 1996 to April 1997

    NASA Astrophysics Data System (ADS)

    Rousselot, P.; Laffont, C.; Clairemidi, J.; Moreels, G.; Boice, D. C.

    1997-07-01

    A program for measuring the activity of comet Hale-Bopp was conducted at the Observatoire de Haute-Provence from August 1996 to April 1997. The program consisted of spectroscopic observations in the long-slit mode by the 193 cm telescope and of observations by the 120 cm f/6 Newton telescope equipped with a 1024 x 1024 thinned CCD. A set of four narrow-band filters and a BK7 glass plate were used. Two filters at 527 and 682 nm, Delta lambda = 2 nm were centered on the C_2(1,1) and (0,0) Swan bands. The other two filters at 527 and 682 nm, Delta lambda = 5 nm were employed to obtain the spatial distributions of the intensity and color of dust. Comet Hale-Bopp was active very early. In August 1996, at a heliocentric distance r ~ 3 AU, it already showed four jets. In September, the number of jets had increased to six. An important evolution of the coma processes occured in January 1997. A series of regularly spaced arcs are clearly distinguished in the sunward hemisphere of the coma. A detailed study of the shape of the arcs during the night of April 7-8 is presented. The ratio of the images in the 682 and 527 nm filters provides a measure of the color of the coma compared to the color of the Sun. The images depicting the ratio, i-e the color of dust, show that the arcs have a spiral shape. They are compared with images of the C_2 (1,1)/(0,0) band ratio which provide the spatial distribution of the excitation temperature of C_2. The new type of cometary processes revealed by the presence of spiral arcs produces C_2 with a high degree of excitation and are probably a result of the fragmentation of a fra! ction of the dust grains.

  13. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Clampin, Mark; Flanagan, Kathryn A.

    2012-01-01

    Space telescopes have been a dominant force in astrophysics and astronomy over the last two decades. As Lyman Spitzer predicted in 1946, space telescopes have opened up much of the electromagnetic spectrum to astronomers, and provided the opportunity to exploit the optical performance of telescopes uncompromised by the turbulent atmosphere. This special section of Optical Engineering is devoted to space telescopes. It focuses on the design and implementation of major space observatories from the gamma-ray to far-infrared, and highlights the scientific and technical breakthroughs enabled by these telescopes. The papers accepted for publication include reviews of major space telescopes spanning the last two decades, in-depth discussions of the design considerations for visible and x-ray telescopes, and papers discussing concepts and technical challenges for future space telescopes.

  14. Current Hale ROA Voice and Control Communication Practices and Performance: White Paper

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The objective of this white paper is to help achieve the ACCESS 5 goal by sharing the UNITE members knowledge of current HALE ROA communication systems with other ACCESS 5 participants so that all interested parties start from a common understanding as we begin the clarification of requirements for voice and C2 communication. This white paper is also intended to describe the point of departure for any future developments that need to be realized to achieve the long term ACCESS 5 goal. Although this white paper describes the current systems, the functional and performance requirements that are also being developed under ACCESS 5 may not require the same levels of functionality and performance as currently exist. The paper addresses the following: 1) A description of a typical current HALE ROA communications system, 2) HALE ROA communications systems performance metrics, 3) HALE ROA communications systems performance, and 5) A comparison of current HALE ROA communications systems with current regulations.

  15. The size of NGC 1068 at 10 microns

    NASA Technical Reports Server (NTRS)

    Becklin, E. E.; Neugebauer, G.; Matthews, K.; Wynn-Williams, C. G.

    1973-01-01

    The data presented show that a majority of the 10-micron emission from NGC 1068 comes from an area with a diameter of about 60 pc. The measurements described were made at 10 microns on two nights at the 200-inch Hale telescope. The data obtained agree with the results obtained by Stein et al. (1973). An approach to reconcile the new data with the variability observed by Rieke and Low (1972) is also discussed.

  16. Aerodynamic Analysis of a Hale Aircraft Joined-Wing Configuration

    NASA Astrophysics Data System (ADS)

    Sivaji, Rangarajan; Ghia, Urmila; Ghia, Karman; Thornburg, Hugh

    2003-11-01

    Aerodynamic analysis of a high-aspect ratio, joined wing of a High-Altitude Long Endurance (HALE) aircraft is performed. The requirement of high lift over extended flight periods for the HALE aircraft leads to high-aspect ratio wings experiencing significant deflections necessitating consideration of aeroelastic effects. The finite-volume solver COBALT, with Reynolds-averaged Navier-Stokes (RANS) and Detached Eddy Simulation (DES) capabilities, is used for the flow simulations. Calculations are performed at á = 0° and 12° for M = 0.6, at an altitude of 30,000 feet, at a Re per unit length of 5.6x106. The wing cross sections are NACA 4421 airfoils. Because of the high lift-to-drag ratio wings, an inviscid flow analysis is also performed. The inviscid surface pressure coefficient (Cp) is compared with the corresponding viscous Cp to examine the feasibility of the use of the inviscid pressure loads as an estimate of the total fluid loads on the structure. The viscous and inviscid Cp results compare reasonably only at á = 0°. The viscous flow is examined in detail via surface and field velocity vectors, vorticity, density and pressure contours. For á = 12°, the unsteady DES solutions show a weak shock at the aft-wing trailing edge. Also, the flow near the joint exhibits a region of mild separation.

  17. Spectrophotometry of Dust in Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Witteborn, Fred C. (Technical Monitor)

    1997-01-01

    Comets, such as Hale-Bopp (C/1995 O1), are frozen reservoirs of primitive solar nebula dust grains and ices. Analysis of the composition of cometary dust grains from infrared spectroscopic techniques permits an estimation of the types of organic and inorganic materials that constituted the early primitive solar nebula. In addition, the cometary bombardment of the Earth (approximately 3.5 Gy ago) supplied the water for the oceans and brought organic materials to Earth which may have been biogenic. Spectroscopic observations of comet Hale-Bopp suggest the possible presence of organic hydrocarbon species, silicate and olivine dust grains, and water ice. Spectroscopy near 3 microns obtained in Nov 1996 r=2.393 AU, delta=3.034 AU) shows a feature which we attribute to PAH emission. The spatial morphology of the 3.28 microns PAH feature is also presented. Optical and infrared spectrophotometric observations of comets convey valuable information about the spatial distribution and properties of dust and gas within the inner coma. In the optical and NIR shortward of 2 microns, the observed light is primarily scattered sunlight from the dust grains. At longer wavelengths, particularly in the 10 gm window, thermal emission from these grains dominates the radiation allowing an accurate estimate of grain sizes and chemical composition. Here we present an initial analysis of spectra taken with the NASA HIFOGS at 7-14 microns as part of a multiwavelength temporal study of the "comet of the century".

  18. History of Solar Magnetic Fields Since George Ellery Hale

    NASA Astrophysics Data System (ADS)

    Stenflo, J. O.

    2015-09-01

    As my own work on the Sun's magnetic field started exactly 50 years ago at Crimea in the USSR, I have been a participant in the field during nearly half the time span since Hale's discovery in 1908 of magnetic fields in sunspots. The present historical account is accompanied by photos from my personal slide collection, which show a number of the leading personalities who advanced the field in different areas: measurement techniques, from photographic to photoelectric and imaging methods in spectro-polarimetry; theoretical foundations of MHD and the origin of cosmic magnetic fields (birth of dynamo theory); the quest for increased angular resolution from national projects to international consortia (for instruments both on ground and in space); introduction of the Hanle effect in astrophysics and the Second Solar Spectrum as its playground; small-scale nature of the field, the fundamental resolution limit, and transcending it by resolution-independent diagnostics.

  19. The September 1996 outbursts of Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Larson, S. M.; Samarasinha, N.; Tao, J.; Hergenrother, C.

    2000-10-01

    Digitally enhanced pre-perihelion groundbased images of Comet Hale-Bopp taken in September 1996 show intersting morphology resulting from at least two outbursts. During that apparition, the coma was dominated by radial ``porcupine" morphology. However, a 2 magnitude outburst starting on 1996 September 9.5 UT (Tao et al., 2000, Plan. Sp. Sci. 48, 153-161) resulted in two expanding dust shells with apparent expansion speeds of 112 and 225 m/s and an arc in the NW quadrant. This morphology is very similar to that seen in post-perihelion NICMOS images of a similar outburst on 1997 August 27 (see Campins et al., DPS 2000 abstract). Similar, but less pronounced outburst activity can be seen later in the month and include evidence for ejection of discrete fragments. We explore the possible mechanisms for the observed morphology. This work is supported in part by the NASA Planetary Atmospheres Program.

  20. The Detection of Water Ice in Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Davies, John K.; Roush, Ted L.; Cruikshank, Dale P.; Bartholomew, Mary Jane; Geballe, Thomas R.; Owen, Tobias

    1996-01-01

    We present spectra of Comet Hale-Bopp (C/1995 01) covering the range 1.4-2.5 micron that were recorded when the comet was 7 AU from the Sun. These show I)road absorption features at 1.5 and 2.05 micron. We show that some, but not all, of this absorption could be matched by an intimate mixture of water ice and a low albedo material such as carbon on the nucleus. However, we recognize that it is more likely that the ice features are produced by scattering from icy grains in the coma. The absence of absorption at 1.65 micron suggests that this ice is probably in the amorphous state. An unidentified additional component may be required to account for the downward slope at the longwavelength end of the spectrum.

  1. A solar module fabrication process for HALE solar electric UAVs

    SciTech Connect

    Carey, P.G.; Aceves, R.C.; Colella, N.J.; Williams, K.A.; Sinton, R.A.; Glenn, G.S.

    1994-12-12

    We describe a fabrication process used to manufacture high power-to-weight-ratio flexible solar array modules for use on high-altitude-long-endurance (HALE) solar-electric unmanned air vehicles (UAVs). These modules have achieved power-to-weight ratios of 315 and 396 W/kg for 150{mu}m-thick monofacial and 110{mu}m-thick bifacial silicon solar cells, respectively. These calculations reflect average module efficiencies of 15.3% (150{mu}m) and 14.7% (110{mu}m) obtained from electrical tests performed by Spectrolab, Inc. under AMO global conditions at 25{degrees}C, and include weight contributions from all module components (solar cells, lamination material, bypass diodes, interconnect wires, and adhesive tape used to attach the modules to the wing). The fabrication, testing, and performance of 32 m{sup 2} of these modules will be described.

  2. Telescope Equipment

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Renaissance Telescope for high resolution and visual astronomy has five 82-degree Field Tele-Vue Nagler Eyepieces, some of the accessories that contribute to high image quality. Telescopes and eyepieces are representative of a family of optical equipment manufactured by Tele-Vue Optics, Inc.

  3. Photometric behavior of comet Hale-Bopp (C/1995 O1) before perihelion.

    PubMed

    Schleicher, D G; Lederer, S M; Millis, R L; Farnham, T L

    1997-03-28

    Narrowband photometric observations of comet Hale-Bopp (C/1995 O1) between 25 July 1995 and 15 February 1997 indicated gas and dust production rates of 20 and 100 times greater, respectively, than observed at the same heliocentric distances for comet P/Halley in 1985. Hale-Bopp produced dust at a rate greater than has been observed for any other comet at any distance since at least 1977. On the basis of the observed production rate of the hydroxyl molecule, the calculated minimum effective diameter of Hale-Bopp's nucleus is 17 kilometers, but the actual diameter of the nucleus is likely to be at least two to three times larger. The chemical composition of Hale-Bopp is consistent with that of other long-period comets originating from the Oort Cloud.

  4. Photometric behavior of comet Hale-Bopp (C/1995 O1) before perihelion.

    PubMed

    Schleicher, D G; Lederer, S M; Millis, R L; Farnham, T L

    1997-03-28

    Narrowband photometric observations of comet Hale-Bopp (C/1995 O1) between 25 July 1995 and 15 February 1997 indicated gas and dust production rates of 20 and 100 times greater, respectively, than observed at the same heliocentric distances for comet P/Halley in 1985. Hale-Bopp produced dust at a rate greater than has been observed for any other comet at any distance since at least 1977. On the basis of the observed production rate of the hydroxyl molecule, the calculated minimum effective diameter of Hale-Bopp's nucleus is 17 kilometers, but the actual diameter of the nucleus is likely to be at least two to three times larger. The chemical composition of Hale-Bopp is consistent with that of other long-period comets originating from the Oort Cloud. PMID:9072963

  5. Modelling two dust features in comet Hale-Bopp (1995 O1)

    NASA Technical Reports Server (NTRS)

    Sekaniana, Z.

    1997-01-01

    A Monte Carlo computer simulation code for generating synthetic images of dust features in comets is applied to comet Hale-Bopp to model the diurnal evolution of a bright jet and the appearance of nearly concentric halos.

  6. EVIDENCE FOR FRESH FROST LAYER ON THE BARE NUCLEUS OF COMET HALE-BOPP AT 32 AU DISTANCE

    SciTech Connect

    Szabo, Gyula M.; Kiss, Laszlo L.; Pal, Andras; Kiss, Csaba; Sarneczky, Krisztian; Juhasz, Attila; Hogerheijde, Michiel R.

    2012-12-10

    Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1% {+-} 0.9%), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.

  7. Evidence for Fresh Frost Layer on the Bare Nucleus of Comet Hale-Bopp at 32 AU Distance

    NASA Astrophysics Data System (ADS)

    Szabó, Gyula M.; Kiss, László L.; Pál, András; Kiss, Csaba; Sárneczky, Krisztián; Juhász, Attila; Hogerheijde, Michiel R.

    2012-12-01

    Here, we report that the activity of comet Hale-Bopp ceased between late 2007 and 2009 March, at about 28 AU distance from the Sun. At that time, the comet resided at a distance from the Sun that exceeded the freeze-out distance of regular comets by an order of magnitude. A Herschel Space Observatory PACS scan was taken in mid-2010, in the already inactive state of the nucleus. The albedo has been found to be surprisingly large (8.1% ± 0.9%), which exceeds the value known for any other comets. With re-reduction of archive Hubble Space Telescope images from 1995 and 1996, we confirm that the pre-perihelion albedo resembled that of an ordinary comet and was smaller by a factor of two than the post-activity albedo. Our further observations with the Very Large Telescope also confirmed that the albedo increased significantly by the end of the activity. We explain these observations by proposing gravitational redeposition of icy grains toward the end of the activity. This is plausible for such a massive body in a cold environment, where gas velocity is lowered to the range of the escape velocity. These observations also show that giant comets are not just the upscaled versions of the comets we know but can be affected by processes that are yet to be fully identified.

  8. Post-perihelion coma monitoring of comet Hale-Bopp at ESO

    NASA Astrophysics Data System (ADS)

    Boehnhardt, H.; Bonfils, X.; Petit, Y.; Hainaut, O.; Delahodde, C.; Jorda, L.; Rauer, H.; Colas, F.; Manfroid, J.; Marchis, F.; Schulz, R.; Tanabe, R.; Tozzi, G. P.

    2002-11-01

    The post-perihelion coma activity of Comet C/1995 O1 Hale-Bopp is monitored at ESO telescopes in La Silla and Paranal since Sept. 1997. Imaging through broadband filters in the visible and near-IR wavelength ranges allows to investigate the evolution of the dust coma, namely the appearance of jets, fans, shells and clouds. Long-term evolution: the comet had a porcupine-like embedded fan coma in autumn 1997 that evolved into a northern fan plus shell pattern in 1998 and remains like this since. Thus, the evolution of the coma structure post-perihelion was similar to that pre-perihelion at about the same heliocentric distances, but is occurred in reversed order. This long-term evolution can be characterized by quasi-continuous dust emission from a few (minimum 4) active regions (producing the fan structures) on the nucleus that is modulated by occasional, repetitive and short-term activity increases (generating shell features in the coma). Outbursts: a number of outbursts and unusual activity patterns occurred in the coma of the comet post-perihelion that are documented through the appearance of complex "palm-tree-like" structures of temporary nature in association with outbursts in the visual lightcurve of the comet and a series of 3 dust clouds resembling "mini-comets" and passing through the northern coma at projected velocities of 30-50m/s. The similarity of coma patterns and cometary viewing geometry from Earth before and after perihelion suggests that some nuclear regions had enhanced long-term activity, possibly driven by super-volatile ices at larger (>10AU) heliocentric distances and that the orientation of the rotation axis of the nucleus did not change much over the past 7 years.

  9. Influence of the Schwabe/Hale solar cycles on climate change during the Maunder Minimum

    NASA Astrophysics Data System (ADS)

    Miyahara, Hiroko; Yokoyama, Yusuke; Yamaguchi, Yasuhiko T.

    2010-02-01

    We have examined the variation of carbon-14 content in annual tree rings, and investigated the transitions of the characteristics of the Schwabe/Hale (11-year/22-year) solar and cosmic-ray cycles during the last 1200 years, focusing mainly on the Maunder and Spoerer minima and the early Medieval Maximum Period. It has been revealed that the mean length of the Schwabe/Hale cycles changes associated with the centennial-scale variation of solar activity level. The mean length of Schwabe cycle had been ~14 years during the Maunder Minimum, while it was ~9 years during the early Medieval Maximum Period. We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods.

  10. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Rigby, Jane R.

    2011-01-01

    The science of astronomy depends on modern-day temples called telescopes. Astronomers make pilgrimages to remote mountaintops where these large, intricate, precise machines gather light that rains down from the Universe. Bit, since Earth is a bright, turbulent planet, our finest telescopes are those that have been launched into the dark stillness of space. These space telescopes, named after heroes of astronomy (Hubble, Chandra, Spitzer, Herschel), are some of the best ideas our species has ever had. They show us, over 13 billion years of cosmic history, how galaxies and quasars evolve. They study planets orbiting other stars. They've helped us determine that 95% of the Universe is of unknown composition. In short, they tell us about our place in the Universe. The next step in this journey is the James Webb Space Telescope, being built by NASA, Europe, and Canada for a 2018 launch; Webb will reveal the first galaxies that ever formed.

  11. SNAP telescope

    SciTech Connect

    Lampton, Michael L.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro, R.; Ealet, A.; Ellis,R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar,A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland,S.E.; Huterer, D.; Karcher, A.; Kim, A.G.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder, E.V.; Loken,S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi,H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto,E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  12. Radio Telescopes

    NASA Astrophysics Data System (ADS)

    Ekers, Ron; Wilson, Thomas L.

    ``Radio Telescopes" starts with a brief historical introduction from Jansky's1931 discovery of radio emission from the Milky Way through the development ofradio telescope dishes and arrays to aperture synthesis imaging. It includessufficient basics of electromagnetic radiation to provide some understanding of thedesign and operation of radio telescopes. The criteria such as frequencyrange, sensitivity, survey speed, angular resolution, and field of view thatdetermine the design of radio telescopes are introduced. Because it is soeasy to manipulate the electromagnetic waves at radio frequencies, radiotelescopes have evolved into many different forms, sometimes with "wire"structures tuned to specific wavelengths, which look very different from anykind of classical telescope. To assist astronomers more familiar with otherwavelength domains, the appendix A.1. includes a comparison of radioand optical terminology. Some of the different types of radio telescopesincluding the filled aperture dishes, electronically steered phased arrays, andaperture synthesis radio telescopes are discussed, and there is a sectioncomparing the differences between dishes and arrays. Some of the morerecent developments including hierarchical beam forming, phased arrayfeeds, mosaicing, rotation measure synthesis, digital receivers, and longbaseline interferometers are included. The problem of increasing radiofrequency interference is discussed, and some possible mitigation strategies areoutlined.

  13. Infrared Observations Of Dust Emission From Comet Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Lisse, C. M.; Fernández, Y. R.; A'Hearn, M. F.; Kostiuk, T.; Livengood, T. A.; Käufl, H. U.; Hoffmann, W. F.; Dayal, A.; Ressler, M. E.; Hanner, M. S.; Fazio, G. G.; Hora, J. L.; Peschke, S. B.; Grün, E.; Deutsch, L. K.

    1997-07-01

    We present infrared imaging and photometry of the bright, giant comet C/1995 O1 (Hale-Bopp). The comet was observed in an extended infrared and optical observing campaign in 1996 1997. The infrared morphology of the comet was observed to change from the 6 to 8 jet “porcupine” structure in 1996 to the “pinwheel” structure seen in 1997; this has implications for the position of the rotational angular momentum vector. Long term light curves taken at 11.3 μm indicate a dust production rate that varies with heliocentric distance as ∶ r-1.4. Short term light curves taken at perihelion indicate a rotational periodicity of 11.3 hours and a projected dust outflow speed of ∶ 0.4 km s-1. The spectral energy distribution of the dust on October 31, 1996 is well modeled by a mixture of 70% silicaceous and 30% carbonaceous non-porous grains, with a small particle dominated size distribution like that seen for comet P/Halley (McDonnell et al., 1991), an overall dust production rate of 2 × 105 kg s-1, a dust-to-gas ratio of ∶5, and an albedo of 39%.

  14. Infrared telescope

    NASA Technical Reports Server (NTRS)

    Karr, G. R.; Hendricks, J. B.

    1985-01-01

    The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.

  15. Telescopic hindsight

    NASA Astrophysics Data System (ADS)

    Cox, Laurence

    2014-08-01

    In reply to the physicsworld.com blog post "Cosmic blunders that have held back science" (2 June, http://ow.ly/xwC7C), about an essay by the astronomer Avi Loeb in which he criticized, among others, his Harvard University predecessor Edward Pickering, who claimed in 1909 that telescopes had reached their optimal size.

  16. Selecting Your First Telescope.

    ERIC Educational Resources Information Center

    Harrington, Sherwood

    1982-01-01

    Designed for first-time telescope purchasers, provides information on how a telescope works; major telescope types (refractors, reflectors, compound telescopes); tripod, pier, altazimuth, and equatorial mounts; selecting a telescope; visiting an astronomy club; applications/limitations of telescope use; and tips on buying a telescope. Includes a…

  17. Highlights of the ATS 6th Annual Convention

    NASA Astrophysics Data System (ADS)

    Breyer, Walter

    The convention began with a keynote by Michael Tubridy, the engineer in charge of the restoration of the Birr Castle Leviathan of Parsonstown. The convention then moved up to Mount Wilson, where talks were heard by Christ Plicht, Peter Abrahams, John Briggs, Don Osterbrock, Robert Ariail, Gayle Riggsbee, and Walt Breyer. Tours were made of the 100-inch and 60-inch telescopes, and observing through the 60-inch finished the day. Sunday, talks were heard by Paul O'Leary, Kevin Johnson, Eugene Rudd, E.J. Hysom, Edward Young, and Rolf Willach. Tours were made of the Hale Solar Laboratory, George Ellery Hale's home, the Huntington Library, Pasadena City College Observatory's 20-inch reflector, and Griffith Observatory's 12-inch Zeiss. On Monday, a tour was made to Mount Palomar and the 200-inch Hale Telescope.

  18. RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS

    SciTech Connect

    McClintock, B. H.; Norton, A. A.; Li, J. E-mail: aanorton@stanford.edu

    2014-12-20

    Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.

  19. Re-examining Sunspot Tilt Angle to Include Anti-Hale Statistics

    NASA Astrophysics Data System (ADS)

    McClintock, B. H.; Norton, A. A.; Li, J.

    2014-12-01

    Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li & Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.

  20. Seismology at the Australian National University; an interview with Anton L. Hales

    USGS Publications Warehouse

    Spall, H.

    1980-01-01

    Dr. Anton L. Hales is a leading seismologist who has just retired as Director of the Research School of Earth Sciences at the Australian National University (ANU), Canberra. Prior to that, he headed the Geosciences Division at the University of Texas at Dallas, and, before that, he was Director of the Bernard Price Institute of Geophysical Research at the University of the Witwatersrand Johannesburg, South Africa. he is about to step down as President of the International Geodynamics Commission. Dr. Hales' research has involved marine geophysics, the travel times of seismic waves, and the structure of the Earth's crust and upper mantle. 

  1. Recent H-alpha Results on Pulsar B2224+65's Bow-Shock Nebula, the "Guitar"

    NASA Astrophysics Data System (ADS)

    Dolch, Timothy; Chatterjee, Shami; Clemens, Dan P.; Cordes, James M.; Cashmen, Lauren R.; Taylor, Brian W.

    2016-09-01

    We used the 4 m Discovery Channel Telescope (DCT) at Lowell observatory in 2014 to observe the Guitar Nebula, an Hα bow-shock nebula around the high-velocity radio pulsar B2224+65. Since the nebula's discovery in 1992, the structure of the bow-shock has undergone significant dynamical changes. We have observed the limb structure, targeting the “body” and “neck” of the guitar. Comparing the DCT observations to 1995 observations with the Palomar 200-inch Hale telescope, we found changes in both spatial structure and surface brightness in the tip, head, and body of the nebula.

  2. Hale Boggs on J. Edgar Hoover: Rhetorical Choice and Political Denunciation.

    ERIC Educational Resources Information Center

    Gibson, Dirk

    This paper examines United States Representative Hale Boggs's 1971 speech on the House floor, in which he denounced J. Edgar Hoover and the Federal Bureau of Investigation (FBI) for wiretapping members of Congress and infiltrating campus student groups. Following an introduction to the objectives of the paper, the first section reviews Boggs's…

  3. Eruptions of Comet Hale-Bopp at 6.5 AU

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, N. C.; Hoyle, F.; Lloyd, D.

    The prodigious output of dust and CO observed in comet Hale-Bopp at a heliocentric distance of 6.5 AU is strongly suggestive of high-pressure release of material from liquified subsurface domains rather than thermal evaporation from a sunlit patch of frozen CO.

  4. The Hale Position for a "Third Method" for Specific Learning Disabilities Identification: A Legal Analysis

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2013-01-01

    This short article provides a legal analysis of the Hale et al. white paper on specific learning disabilities identification. The white paper presents a purported consensus of experts that an approach combining response to intervention with severe discrepancy is consistent with the Individuals With Disabilities Education Act (IDEA). The analysis…

  5. Aaron Douglas and Hale Woodruff: African American Art Education, Gallery Work, and Expanded Pedagogy

    ERIC Educational Resources Information Center

    Bey, Sharif

    2011-01-01

    This analysis of archival materials discovered at Fisk and Atlanta Universities examines the teaching careers of Aaron Douglas and Hale Woodruff, two African American artists who came to prominence during the New Negro Movement in the 1920s and taught at historically Black universities in the 1930s and 1940s. These artists had a profound influence…

  6. Seismically-triggered Release of Shallow Groundwater Caused by the Hale Impact, Mars

    NASA Astrophysics Data System (ADS)

    Harrison, T. N.; Kennedy, M. R.

    2010-12-01

    Channels originating at or near the margins of the continuous ejecta blanket of the youthful (Late Hesperian/Early Amazonian) 140 km-diameter Hale Crater have previously been attributed to melting of ice in the target material by superheated impact melt or remobilization of saturated ejecta. However, the presence of channels in the vicinity of Hale that do not originate on or at the margins of the ejecta blanket but are similar in morphology to those that do may suggest that channel formation at Hale was triggered by seismic energy from the impact. A key example lies at 33.0°S, 39.7°W, ~250 km northwest of Hale, where a small scabland (e.g. morphologies similar to the Channeled Scabland of the Columbia River Plateau, Washington) is observed. The scabland is located too far from the Hale impact to be explained by thermal melting of subsurface ice during the impact event. The channels are not associated with the Hale ejecta blanket, and are therefore not related to dewatering processes. The channels appear to be geologically young, with few superposed craters. Distinct depositional facies are observed; the channels terminate in a topographic depression in which the channel deposits have ponded. These deposits also have very few superposed craters. Aeolian bedforms are observed atop the deposits, potentially a lag of coarse-grained sand from within the deposits. These bedforms are confined to the deposit surface and are not observed elsewhere in the area. We propose that this “mini-scabland” was formed by the release of shallow groundwater due to seismic energy from the Hale impact. Seismic energy from earthquakes can lead to groundwater release via ejection of confined groundwater and/or upwelling of an unconfined shallow water table. In the former case, the water is confined by an impermeable layer and is typically released by jetting or spouting, resulting in fissures and/or mounds referred to as mud volcanoes. The latter case produces widespread non

  7. Neutrino telescopes

    SciTech Connect

    Costantini, H.

    2012-09-15

    Neutrino astrophysics offers a new possibility to observe our Universe: high-energy neutrinos, produced by the most energetic phenomena in our Galaxy and in the Universe, carry complementary (if not exclusive) information about the cosmos: this young discipline extends in fact the conventional astronomy beyond the usual electromagnetic probe. The weak interaction of neutrinos with matter allows them to escape from the core of astrophysical objects and in this sense they represent a complementary messenger with respect to photons. However, their detection on Earth due to the small interaction cross section requires a large target mass. The aim of this article is to review the scientific motivations of the high-energy neutrino astrophysics, the detection principles together with the description of a running apparatus, the experiment ANTARES, the performance of this detector with some results, and the presentation of other neutrino telescope projects.

  8. JSC Particle Telescope

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.

    2003-01-01

    This paper presents a detailed description of the Johnson Space Center's Particle Telescope. Schematic diagrams of the telescope geometry and an electronic block diagram of the detector telescopes' components are also described.

  9. The William Ellery Hale Lectures at the National Academy of Sciences, 1914-1918

    NASA Astrophysics Data System (ADS)

    DeVorkin, David H.

    2015-01-01

    In 1913 George Ellery Hale, together with his brother William and sister Martha pledged 1000 per year for five years to inaugurate an annual series of lectures in memory of their father. The series would explore "the general subject of Evolution, which is designed to give a clear and comprehensive outline of the broad features of inorganic and organic evolution in the light of recent research." (NAS Annual Report 1914 p. 24). Here we look briefly at how evolution entered into astronomical thinking in the late 19th Century, and specifically into George Ellery Hale's universe as an organizing principle for research and institutional development, as illustrated by this lecture series, which brought the likes of Ernest Rutherford, W. W. Campbell and T. C. Chamberlin to speak before scientific Washington.

  10. Collisional quenching of OH radio emission from comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Schloerb, F. P.; Devries, C. H.; Lovell, A. J.; Irvine, W. M.; Senay, M.; Wootten, H. A.; Ferris, J. P. (Principal Investigator)

    1997-01-01

    Observations of comets in the 18-cm OH transitions offer a means to probe gas production, kinematics, and OH excitation in comets. We present initial results of OH observations of comet Hale-Bopp obtained with the NRAO 43 m antenna located in Greenbank, WV. Maps of the emission provide strong constraints on the amount of quenching of the inversion of the OH ground state A-doublet in the coma. Analysis of the total radio OH flux and maps of its radial brightness distribution indicate a quenched region on the order of approximately 500,000 km during March and April 1997. This large value is generally consistent with previous observations of radio OH quenching in lower production rate comets when the high production rate of comet Hale-Bopp is considered.

  11. Activity of Comet Hale-Bopp (1995 01) Beyond 6 AU From the Sun

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1996-01-01

    The physical evolution of comet Hale-Bopp is investigated along the preperihelic arc of its orbit at heliocentric distances larger than 6 AU. The comet's considerable intrinsic brightness and activity are explained by the existence of a relatively larg area on its nucleus surface that is a resevoir of both carbon monoxide and dust particulates. Three recuring dust emission events observed in August-October 1995 are studied in some detail.

  12. The 22-Year Hale Cycle in Cosmic Ray Flux - Evidence for Direct Heliospheric Modulation

    NASA Astrophysics Data System (ADS)

    Thomas, Simon; Owens, Mathew; Lockwood, Mike

    2013-04-01

    The ability to predict times of greater fluxes of galactic cosmic rays is important for reducing the hazards caused by these energetic particles on satellite communications, aviation and astronauts. During the 22-year Hale cycle, we see a difference in shape from a 'flat topped' to a 'spiked topped' peak in cosmic ray flux time series. It is thought that differing drift patterns for when the northern solar pole is predominantly positive (qA>0) to when the northern pole is negative (qA<0) cause this difference in cosmic ray modulation. Here, we demonstrate a link between cosmic ray modulation and properties of the large-scale heliospheric magnetic field during the declining phase of the solar cycle, when the difference between qA>0 and qA<0 cycles is most apparent. The results suggest that drift affects may not be the sole mechanism responsible for the Hale Cycle in cosmic ray flux at Earth. Further to this it is suggested that the Hale cycle in cosmic ray flux may be primarily limited to the grand solar maximum of the space-age.

  13. Grain Properties of Comet C/1995 O1 (Hale-Bopp) Deduced Through Computational Techniques

    NASA Technical Reports Server (NTRS)

    Harker, David E.; Wooden, Diane H.; Woodward, Charles E.; Lisse, Carey M.

    2001-01-01

    We present the computational analysis of the 7.6 - 13.2 micrometer infrared (IR) spectrophotometry (R approximately equal to 120) of comet C/1995 O1 (Hale-Bopp) in conjunction with concurrent observations which extend the spectral energy distribution from the near-infrared to far-infrared wavelengths. The observations include temporal epochs pre-perihelion, (1996 October UT and 1997 February UT), near perihelion (1997 April UT), and postperihelion (1997 June UT). Through the computational modeling of small amorphous carbon, and crystalline and amorphous silicate grains in Hale-Bopp's coma, we find that as the comet approached perihelion, the grain size distribution (the Hanner modified power law) steepened (N = 3.4 pre-perihelion, to N = 3.7 near and post-perihelion) along with an increase in the fractal porosity of larger (greater than 1 micrometer) grains. The peak of the grain size distribution remained constant (ap = 0.2 micrometer) at each epoch. We attribute the emergence of the 9.3 micrometer peak near perihelion to crystalline orthopyroxeno grains released from inside the nucleus. Crystalline silicates (olivine and orthopyroxene) make up about 30% (by mass) of the submicron sized (less than 1 micrometer) dust grains in Hale-Bopp's coma during each epoch.

  14. Substantial outgassing of CO from comet Hale-Bopp at large heliocentric distance.

    PubMed

    Biver, N; Rauer, H; Despois, D; Moreno, R; Paubert, G; Bockelée-Morvan, D; Colom, P; Crovisier, J; Gérard, E; Jorda, L

    1996-03-14

    When comet C/1995 O1 (Hale-Boop) was discovered, at a distance of seven astronomical units from the sun, it was more than one hundred times brighter than comet Halley at the same distance. A comet's brightness is derived from the reflection of sunlight from dust grains driven away from the nucleus by the sublimation of volatile ices. Near the sun, sublimation of water ice (a main constituent of comet nuclei) is the source of cometary activity; but at its current heliocentric distance, Hale-Boop is too cold for this process to operate. Other comets have shown activity at large distances, and in the case of comet Schwassmann-Wachmann 1, carbon monoxide has been detected in quantities sufficient to generate its observed coma. Here we report the detection of CO emission from Hale-Boop, at levels indicating a very large rate of outgassing. Several other volatile species were searched for, but not detected. Sublimation of CO therefore appears to be responsible for the present activity of this comet, and we anticipate that future observations will reveal the onset of sublimation of other volatile species as the comet continues its present journey towards the sun.

  15. Kepler and Hale observations of V523 Lyrae

    NASA Astrophysics Data System (ADS)

    Mason, E.; Howell, S. B.

    2016-05-01

    We present new observations of the cataclysmic variable (CV) V523 Lyr, a member of the open cluster NGC 6791. The Kepler Space telescope obtained photometric observations of this source and we examine the nearly three-year-long light curve. The observations show numerous small amplitude outbursts recurring on average every 33 d, intermittent quasi-periodic oscillations, and a significant fully coherent period of ~3.8 h, which we identify as the orbital period of the binary. Contemporaneous optical spectroscopy of V523 Lyr reveals a faint blue source with broad Balmer absorption lines containing narrow emission cores. Hα is in emission above the continuum. The low amplitude of the photometric signal and no detected velocity motion suggest a low orbital inclination. We discuss the properties of V523 Lyr and show that it is a member of the growing group of anomalous Z Cam type CVs, systems that show stunted outbursts, light curve standstills, and occasional deep drops in brightness.

  16. Large-Aperture [O I] 6300 A Photometry of Comet Hale-Bopp: Implications for the Photochemistry of OH

    NASA Technical Reports Server (NTRS)

    Morgenthaler, Jeffrey P.; Harris, Walter M.; Scherb, Frank; Anderson, Christopher M.; Oliversen, Ronald J.; Doane, Nathaniel E.; Combi, Michael R.; Marconi, Maximus L.; Smyth, William H.

    2001-01-01

    Large-aperture photometric observations of comet Hale-Bopp (C/1995 O1) in the forbidden red line of neutral oxygen ([O I] 6300 angstroms) with the 150 mm dual-etalon Fabry-Perot spectrometer that comprises the Wisconsin H-alpha Mapper and a 50 mm dual-etalon Fabry-Perot spectrometer at the McMath-Pierce main telescope from 1997 late February to mid April yield a total metastable O((sup 1)D) production rate of (2.3-5.9) x 10(exp 30)/s. Applying the standard H2O and OH photodissociation branching ratios, we derive a water production rate, Q(H2O), of (2.6-6.1) x 10(exp 31)/s, which disagrees with Q(H2O = 1x10(exp 31)/s determined by independent H2O, OH, and H measurements. Furthermore, our own [O I] 6300 observations of the inner coma (< 30,000 km) using the 3.5 m Wisconsin-Indiana-Yale-NOAO telescope Hydra and Densepak multi-object spectrographs yield Q(H2O) = 1 x 10(exp 31)/s. Using our [O I] 6300 data, which cover spatial scales ranging from 2,000 to 1x10(exp 6) km, and a complementary set of wide-field ground-based OH images, we can constrain the sources of the apparent excess O((sup 1)D) emission to the outer coma, where photodissociation of OH is assumed to be the dominant O((sup 1)D) production mechanism. From production rates of other oxygen-bearing volatiles (e.g., CO and CO2), we can account for at most 30% of the observed excess O((sup 1)D) emission. Since even less O((sup 1)D) should be coming from other sources (e.g., electron excitation of neutral O and distributed nonnuclear sources of H2O), we hypothesize that the bulk of the excess O((sup 1)D) is likely coming from photodissociating OH. Using the experimental OH photo-dissociation cross section of Nee and Lee at Ly-alpha as a guide in modifying the theoretical OH cross sections of van Dishoeck and Dalgarno, we can account for approximately 60% of the observed O((sup 1)D) excess without requiring major modifications to the other OH branching ratios or the total OH photodissociation lifetime.

  17. Abundant Cool Magnesium-Rich Pyroxene Crystals in Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Wooden, D. H.

    1999-01-01

    Modeling of the observed dust emission from Comet Hale-Bopp over a large range of heliocentric distances (2.8 AU - 0.93 AU -1.7 AU) led to the discovery of Mg-rich pyroxene crystals in the coma These pyroxene crystals are apparent in the 10 micron spectrum only when the comet is close to perihelion (r(sub h) = 1.2 AU) because they are cooler than the other silicate minerals. The pyroxene crystals are cooler than the other species because of their high Mg-content. They do not absorb as efficiently as the other silicate minerals. Given the same high Mg content of Mg/(Mg + Fe) = 0.9, radiative equilibrium computations show that pyroxene crystals are expected to be 150 K cooler than olivine crystals. The pyroxene crystals are also about 10x more abundant than the other silicate mineral species. Their high Mg content and relatively large abundance are in agreement with the preponderance of pyroxene interplanetary dust particles (IDPs) and the recent reanalysis of the PUMA-I flyby of Comet Halley. Before Hale-Bopp, only olivine crystals were detected spectroscopically in comets, probably because the pyroxene crystals are less optically active, hence significantly cooler and harder to detect in contrast to the warmer silicate species. Determining the relative abundances of silicate minerals depends on their Mg contents. If the pyroxene crystals in Comet Hale-Bopp are solar nebula condensates, then they probably had to form during the early FU Orionis epoch when the inner disk was hot enough and be transported out to the region of formation of icy planetesimals without being reheated. Reheating events appear to reincorporate Fe back into the crystals or form Fe-rich rims, which are not consistent with the high-Mg-content crystals. The condensation of Mg-rich pyroxene crystals is expected from solar nebula thermal equilibrium computations. However, their subsequent transport to the outer solar nebula unaltered has yet to be theoretically demonstrated. The discovery of Mg

  18. ``Beautiful and cantankerous instruments'': telescopes, technology, and astronomy's changing practice

    NASA Astrophysics Data System (ADS)

    McCray, W. Patrick

    2009-08-01

    Between the dedication of the 200” Hale Telescope in 1948 and the completion of today’s 8-10 m behemoths, astronomers’ most iconic symbol, the telescope itself—its design, its technology, and its use—was transformed as a research tool. The importance of this is deceptively simple: in astronomy, technological innovations have often led to new discoveries. Driven by the need to get as much observing time as possible and the desire to take advantage of the best observing conditions, modern observatories have experimented with new technologies and modes of collecting images and spectra. This entailed a re-casting of the telescope by astronomers and science managers as a factory of scientific data. At the same time, contemporary astronomers express considerable unease and apprehension about how these technological changes have altered, in ways subtle and profound, the nature of astronomical observing and what it meant to be an astronomer. This short essay addresses the issues associated with these recent changes in astronomical practice and their connections to astronomers’ desire for ever larger and more complex telescopes.

  19. Bright Gully Deposits in Hale Crater and Implications for Recent Water

    NASA Astrophysics Data System (ADS)

    Kolb, K. J.; McEwen, A. S.; Pelletier, J. D.; HiRISE Team

    2007-12-01

    Hale Crater, a late Hesperian / early Amazonian [Cabrol N.A. et al., 2001 Icarus 154] 120 km x 150 km impact crater, hosts a large number of gullies with a variety of orientations. Gully distributions and orientations have strong implications for distinguishing between gully formation theories, which frequently depend on insolation or a local aquifer. Several of the gullies exhibit bright deposits that are unmodified at the scale, 0.26 - 0.31 cm/pixel, of images acquired by the High Resolution Imaging Science Experiment (HiRISE) aboard the Mars Reconnaissance Orbiter (MRO). Two recently formed bright gully deposits (BGDs) imaged by the Mars Orbiter Camera (MOC) at other locations were initially interpreted as evidence for water on the surface in recent years [Malin M.C. et al., 2006 Science 314]. One of these BGDs was modelled by Pelletier et al. [2007 submitted] who found that, although water could not be ruled out in the formation of the studied BGD, dry flow was sufficient. HiRISE has imaged several other unmodified BGDs around Mars, most of which occur on steep slopes (26-35°) [McEwen A.S. et al., 2007 Science in press] in fresh craters. The slopes of one section of Hale Crater with BGDs are closer to 19-20°, which suggests that it would be difficult for a dry debris flow to form the BGDs. We investigate the distribution and orientations of gullies and BGDs, as well as slope profiles, in Hale Crater. We present results of modeling the BGDs using Mars Orbiter Laser Altimeter (MOLA) topography and available imagery and evaluate the likelihood that the BGDs required or included water in their formation.

  20. Optical observations of comet Hale-Bopp (C/1995 O1) at large heliocentric distances before perihelion.

    PubMed

    Rauer, H; Arpigny, C; Boehnhardt, H; Colas, F; Crovisier, J; Jorda, L; Küppers, M; Manfroid, J; Rembor, K; Thomas, N

    1997-03-28

    The activity of comet Hale-Bopp (C/1995 O1) was monitored monthly by optical imaging and long-slit spectroscopy of its dust and gas distribution over heliocentric distances of 4.6 to 2.9 astronomical units. The observed band intensities of the NH2 radical and the H2O+ ion cannot be explained by existing models of fluorescence excitation, warranting a reexamination of the corresponding production rates, at least at large heliocentric distances. Comparing the production rate of the CN radical to its proposed parent, HCN, shows no evidence for the need of a major additional source for CN in Hale-Bopp at large heliocentric distances. The dust and CN production rates are consistent with a significant amount of sublimation occurring from icy dust grains surrounding Hale-Bopp.

  1. Interstellar and cometary ices: Molecular emission from comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; DeVries, C. H.; Dickens, J. E.; Lovell, A. J.; Schloerb, F. P.; Senay, M.; Jewitt, D.; Matthews, H. E.

    1997-01-01

    Observations of rotational translations of neutral molecules, radicals and ions in the comet Hale-Bopp are reported on. Sample spectra and maps of the emission for the J = 1 to 0 transition of HCN, the J = 2 to 1 transition of CS and the J = 1 to 0 transition of HCO+ are presented. While the emission from HCN is typically centered on the position of the nucleus and is symmetric, the emission from HCO+ exhibits multiple peaks, together with evidence for acceleration away from the nucleus.

  2. Telescopes and space exploration

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Maran, S. P.

    1976-01-01

    The necessity for different types of telescopes for astronomical investigations is discussed. Major findings in modern astronomy by ground-based and spaceborne telescopes are presented. Observations of the Crab Nebula, solar flares, interstellar gas, and the Black Hole are described. The theory of the oscillating universe is explored. Operating and planned telescopes are described.

  3. The space telescope

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Papers concerning the development of the Space Telescope which were presented at the Twenty-first Annual Meeting of the American Astronautical Society in August, 1975 are included. Mission planning, telescope performance, optical detectors, mirror construction, pointing and control systems, data management, and maintenance of the telescope are discussed.

  4. The Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Prestage, R. M.; Constantikes, K. T.; Hunter, T. R.; King, L. J.; Lacasse, R. J.; Lockman, F. J.; Norrod, R. D.

    2009-08-01

    The Robert C. Byrd Green Bank Telescope of the National Radio Astronomy Observatory is the world's premiere single-dish radio telescope operating at centimeter to long millimeter wavelengths. This paper describes the history, construction, and main technical features of the telescope.

  5. ATST telescope mount: telescope of machine tool

    NASA Astrophysics Data System (ADS)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  6. Identification of two sources of carbon monoxide in comet Hale-Bopp.

    PubMed

    DiSanti, M A; Mumma, M J; Dello Russo, N; Magee-Sauer, K; Novak, R; Rettig, T W

    1999-06-17

    The composition of ices in comets may reflect that of the molecular cloud in which the Sun formed, or it may show evidence of chemical processing in the pre-planetary accretion disk around the proto-Sun. As carbon monoxide (CO) is ubiquitous in molecular clouds, its abundance with respect to water could help to determine the degree to which pre-cometary material was processed, although variations in CO abundance may also be influenced by the distance from the Sun at which comets formed. Observations have not hitherto provided an unambiguous measure of CO in the cometary ice (native CO). Evidence for an extended source of CO associated with comet Halley was provided by the Giotto spacecraft, but alternative interpretations exist. Here we report observations of comet Hale-Bopp which show that about half of the CO in the comet comes directly from ice stored in the nucleus. The abundance of this CO with respect to water (12 per cent) is smaller than in quiescent regions of molecular clouds, but is consistent with that measured in proto-stellar envelopes, suggesting that the ices underwent some processing before their inclusion into Hale-Bopp. The remaining CO arises in the coma, probably through thermal destruction of more complex molecules.

  7. A Revisit of Hale's and Joy's Laws of Active Regions Using SOHO MDI Obsevations

    NASA Astrophysics Data System (ADS)

    Chintzoglou, Georgios; Zhang, J.

    2011-05-01

    Hale's law of polarity defines the rule of opposite direction of two polarities of solar bipolar Active Regions in the two hemispheres. Another law, Joy's law, governs the tilt of ARs with respect to their heliographic latitudes. Both laws are essential for constraining solar dynamo models. In this study we attempt to examine these laws in great detail using a large sample of ARs. With the help of an automatic AR detection algorithm (based on morphological analysis, Zhang et. al, 2010), we have processed high resolution SOHO/MDI synoptic magnetograms over the entire solar cycle 23, we identified all active regions in a uniform and objective way and determined their physical properties, including locations, fluxes of positive and negative polarities ,as well as the direction angles of these regions. Among 1084 bipolar ARs detected, the majority of them (87%) follow Hale's polarity law, while the other 13% of ARs do not. We attribute this deviation to the complexity of AR emergence from the turbulent convection zone. Regarding the Joy's law, we find that there is only a weak positive trend between AR tilt angles and latitudes. On the other hand, the tilt angle has a broad Gaussian-like distribution, with the peak centered around zero degree, and a width of about 20 degree at half maximum. Implications of these results on solar dynamo theory will be discussed.

  8. New Molecular Species In Comet C/1995 (Hale-Bopp) Observed with the Caltech Submillimeter Observatory

    NASA Technical Reports Server (NTRS)

    Lis, D. C.; Mehringer, D. M.; Benford, D.; Gardner, M.; Phillips, T. G.; Bockelee-Morvan, D.; Biver, N.; Colom, P.; Crovisier, J.; Despois, D.; Rauer, H.

    1998-01-01

    We present millimeter-wave observations of HNCO, HC3N, SO, NH2CHO, H(13)CN, and H3O(+) in comet C/1995 O1 (Hale-Bopp) obtained in February-April, 1997 with the Caltech Submillimeter Observatory (CSO). HNCO, first detected at the CSO in comet C/1996 B2 (Hyakutake), is securely confirmed in comet Hale-Bopp via observations of three rotational transitions. The derived abundance with respect to H2O is (4-13) x 10(exp -4). HC3N, SO, and NH2CHO are detected for the first time in a comet. The fractional abundance of HC3N based on observations of three rotational lines is (1.9 +/- 0.2) x 10(exp -4). Four transitions of SO are detected and the derived fractional abundance, (2-8) x 10(exp -3), is higher than the upper limits derived from UV observations of previous comets. Observations of NH2CHO imply a fractional abundance of (1-8) x 10(exp -4). H3O(+) is detected for the first time from the ground. The H(13)CN (3-2) transition is also detected and the derived HCN/H(13)CN abundance ratio is 90 +/- 15, consistent with the terrestrial C-13/C-12 ratio. in addition, a number of other molecular species are detected, including HNC, OCS, HCO(+), CO(+), and CN (the last two are first detections in a comet at radio wavelengths).

  9. ATA50 telescope: hardware

    NASA Astrophysics Data System (ADS)

    Yeşilyaprak, C.; Yerli, S. K.; Aksaker, N.; Yildiran, Y.; Güney, Y.; Güçsav, B. B.; Özeren, F. F.; Kiliç, Y.; Shameoni, M. N.; Fişek, S.; Kiliçerkan, G.; Nasiroğlu, İ.; Özbaldan, E. E.; Yaşar, E.

    2014-12-01

    ATA50 Telescope is a new telescope with RC optics and 50 cm diameter. It was supported by Atatürk University Scientific Research Project (2010) and established at about 2000 meters altitude in city of Erzurum in Turkey last year. The observations were started a few months ago under the direction and control of Atatürk University Astrophysics Research and Application Center (ATASAM). The technical properties and infrastructures of ATA50 Telescope are presented and we have been working on the robotic automation of the telescope as hardware and software in order to be a ready-on-demand candidate for both national and international telescope networks.

  10. ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

    NASA Astrophysics Data System (ADS)

    1997-04-01

    The scientific payload was confirmed by ESA's Science Programme Committee in February. Now the scientists must perfect the full range of ultra-sensitive yet spaceworthy instruments in good time for Rosetta's despatch by an Ariane 5 launcher in January 2003. And even as most of the world was admiring Comet Hale-Bopp at its brightest, dedicated astronomers were examining the comet that will be Rosetta's target. Although too faint to be seen with the naked eye, Comet Wirtanen made its closest approach to the Sun on 14 March and a fairly close approach to the Earth on 24 March. This comet comes back every 5.5 years. Rosetta will dance attendance on Comet Wirtanen, not at the next return in 2002, nor even in 2008, but in 2013. The project is an ambitious and patient effort to achieve the most thorough investigation of a comet ever attempted. As the successor to ESA's highly successful Giotto mission to Halley's Comet and Comet Grigg-Skjellerup (which took seven years) Rosetta will spend eight years positioning itself. It will manoeuvre around the planets until it is shadowing Comet Wirtanen far beyond Mars, on nearly the same path around the Sun. In 2011 it will rendezvous with the comet and fly near it. In April 2012 Rosetta will go into a near orbit around Comet Wirtanen, and escort it for 17 busy months, as it flies in to make its closest approach to the Sun in September 2013, at the climax of the mission. "The Giotto mission placed us at the forefront of cometary exploration," comments Roger Bonnet, ESA's director of science. "The motivation came from European scientists with a sharp sense of the special importance of comets for understanding the Solar System. The same enthusiasm drives us onward to Rosetta, which will ensure our continued leadership in this important branch of space science." Scientific tasks During its prolonged operations in very close company with the comet's nucleus, Rosetta will map and examine its entire surface from distances of 10 to 50

  11. Space Infrared Telescope Facility (SIRTF) telescope overview

    NASA Technical Reports Server (NTRS)

    Schember, Helene; Manhart, Paul; Guiar, Cecilia; Stevens, James H.

    1991-01-01

    The Space Infrared Telescope Facility (SIRTF) will be the first true infrared observatory in space, building upon the technical and scientific experience gained through its two NASA survey-oriented predecessors: the Infrared Astronomical Satellite and the Cosmic Background Explorer. During its minimum five year lifetime, the SIRTF will perform pointed scientific observations at wavelengths from 1.8 to 1200 microns with an increase in sensitivity over previous missions of several orders of magnitude. This paper discusses a candidate design for the SIRTF telescope, encompassing optics, cryostat, and instrument accommodation, which has been undertaken to provide a fulcrum for the development of functional requirements, interface definition, risk assessment and cost. The telescope optics employ a baffled Ritchey-Chretien Cassegrain system with a 1-m class primary mirror, an active secondary mirror, and a stationary facetted tertiary mirror. The optics are embedded in a large superfluid He cryostat designed to maintain the entire telescope-instrument system at temperatures below 3 K.

  12. ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

    NASA Astrophysics Data System (ADS)

    1997-04-01

    The scientific payload was confirmed by ESA's Science Programme Committee in February. Now the scientists must perfect the full range of ultra-sensitive yet spaceworthy instruments in good time for Rosetta's despatch by an Ariane 5 launcher in January 2003. And even as most of the world was admiring Comet Hale-Bopp at its brightest, dedicated astronomers were examining the comet that will be Rosetta's target. Although too faint to be seen with the naked eye, Comet Wirtanen made its closest approach to the Sun on 14 March and a fairly close approach to the Earth on 24 March. This comet comes back every 5.5 years. Rosetta will dance attendance on Comet Wirtanen, not at the next return in 2002, nor even in 2008, but in 2013. The project is an ambitious and patient effort to achieve the most thorough investigation of a comet ever attempted. As the successor to ESA's highly successful Giotto mission to Halley's Comet and Comet Grigg-Skjellerup (which took seven years) Rosetta will spend eight years positioning itself. It will manoeuvre around the planets until it is shadowing Comet Wirtanen far beyond Mars, on nearly the same path around the Sun. In 2011 it will rendezvous with the comet and fly near it. In April 2012 Rosetta will go into a near orbit around Comet Wirtanen, and escort it for 17 busy months, as it flies in to make its closest approach to the Sun in September 2013, at the climax of the mission. "The Giotto mission placed us at the forefront of cometary exploration," comments Roger Bonnet, ESA's director of science. "The motivation came from European scientists with a sharp sense of the special importance of comets for understanding the Solar System. The same enthusiasm drives us onward to Rosetta, which will ensure our continued leadership in this important branch of space science." Scientific tasks During its prolonged operations in very close company with the comet's nucleus, Rosetta will map and examine its entire surface from distances of 10 to 50

  13. The composition and size distribution of the dust in the coma of Comet Hale Bopp

    NASA Astrophysics Data System (ADS)

    Min, M.; Hovenier, J. W.; de Koter, A.; Waters, L. B. F. M.; Dominik, C.

    2005-12-01

    We discuss the composition and size distribution of the dust in the coma of Comet Hale-Bopp. We do this using a model fit for the infrared emission measured by the Infrared Space Observatory (ISO) and the measured degree of linear polarization of scattered light at various phase angles and wavelengths. The effects of particle shape on the modeled optical properties of the dust grains are taken into account. Both the short wavelength (7-44 μm) and the long wavelength (44-120 μm) infrared spectrum are fitted using the same dust parameters, as well as the degree of linear polarization at twelve different wavelengths in the optical to near-infrared domains. We constrain our fit by forcing the abundances of the major rock forming chemical elements to be equal to those observed in meteorites. The infrared spectrum at long wavelengths reveals that large grains are needed in order to fit the spectral slope. The size and shape distribution we employ allows us to estimate the sizes of the crystalline silicates. The ratios of the strength of various forsterite features show that the crystalline silicate grains in Hale-Bopp must be submicrometer-sized. On the basis of our analysis the presence of large crystalline silicate grains in the coma can be excluded. Because of this lack of large crystalline grains combined with the fact that we do need large amorphous grains to fit the emission spectrum at long wavelengths, we need only approximately 4% of crystalline silicates by mass (forsterite and enstatite) to reproduce the observed spectral features. After correcting for possible hidden crystalline material included in large amorphous grains, our best estimate of the total mass fraction of crystalline material is ˜7.5%, which is significantly lower than deduced in previous studies in which the typical derived crystallinity is ˜20-30%. The implications of this low abundance of crystalline material on the possible origin and evolution of the comet are discussed. We conclude

  14. The Gas Production Rate and Coma Structure of Comet C/1995 01 (Hale-Bopp)

    NASA Technical Reports Server (NTRS)

    Morgenthaler, Jeffrey P.; Harris, Walter M.; Roesler, Frederick L.; Scherb, Frank; Anderson, Christopher M.; Doane, Nathaniel E.; Oliversen, Ronald J.

    2002-01-01

    The University of Wisconsin-Madison and NASA-Goddard conducted a comprehensive multi-wavelength observing campaign of coma emissions from comet Hale-Bopp, including OH 3080 A, [O I] 6300 A, H2O(+) 6158 A, H Balmer-alpha 6563 A, NH2 6330 A, [C I] 9850 A CN 3879 A, C2 5141 A, C3 4062 A, C I 1657 A, and the UV and optical continua. In this work, we concentrate on the results of the H2O daughter studies. Our wide-field OH 3080 A measured flux agrees with other, similar observations and the expected value calculated from published water production rates using standard H2O and OH photochemistry. However, the total [O I] 6300 A flux determined spectroscopically over a similar field-of-view was a factor of 3 - 4 higher than expected. Narrow-band [O I] images show this excess came from beyond the H2O scale length, suggesting either a previously unknown source of [O I] or an error in the standard OH + upsilon to O((sup I)D) + H branching ratio. The Hale-Bopp OH and [O I] distributions, both of which were imaged to cometocentric distances greater than 1 x 10(exp 6) km, were more spatially extended than those of comet Halley (after correcting for brightness differences), suggesting a higher bulk outflow velocity. Evidence of the driving mechanism for this outflow is found in the H(alpha) line profile, which was narrower than in comet Halley (though likely because of opacity effects, not as narrow as predicted by Monte-Carlo models). This is consistent with greater collisional coupling between the suprathermal H photodissociation products and Hale-Bopp's dense coma. Presumably because of mass loading of the solar wind by ions and ions by the neutrals, the measured acceleration of H2O(+) down the ion tail was much smaller than in comet Halley. Tailward extensions in the azimuthal distributions of OH 3080 A, [O I], and [C I], as well as a Doppler asymmetry in the [O I] line profile, suggest ion-neutral coupling. While the tailward extension in the OH can be explained by increased

  15. Model for atomic oxygen visible line emissions in Comet C/1995 O1 Hale-Bopp

    NASA Astrophysics Data System (ADS)

    Raghuram, Susarla; Bhardwaj, Anil

    2013-03-01

    We have recently developed a coupled chemistry-emission model for the green (5577 Å) and red-doublet (6300, 6364 Å) emissions of atomic oxygen on Comet C/1996 B2 Hyakutake. In the present work we applied our model to Comet C/1995 O1 Hale-Bopp, which had an order of magnitude higher H2O production rate than Comet Hyakutake, to evaluate the photochemistry associated with the production and loss of O(1S) and O(1D) atoms and emission processes of green and red-doublet lines. We present the wavelength-dependent photo-attenuation rates for different photodissociation processes forming O(1S) and O(1D). The calculated radiative efficiency profiles of O(1S) and O(1D) atoms show that in Comet Hale-Bopp the green and red-doublet emissions are emitted mostly above radial distances of 103 and 104 km, respectively. The model calculated [OI] 6300 Å emission surface brightness and average intensity over the Fabry-Pérot spectrometer field of view are consistent with the observation of Morgenthaler et al. (Morgenthaler, J.P. et al. [2001]. Astrophys. J. 563, 451-461), while the intensity ratio of green to red-doublet emission is in agreement with the observation of Zhang et al. (Zhang, H.W., Zhao, G., Hu, J.Y. [2001]. Astron. Astophys. 367 (3), 1049-1055). In Comet Hale-Bopp, for cometocentric distances less than 105 km, the intensity of [OI] 6300 Å line is mainly governed by photodissociation of H2O. Beyond 105 km, O(1D) production is dominated by photodissociation of the water photochemical daughter product OH. Whereas the [OI] 5577 Å emission line is controlled by photodissociation of both H2O and CO2. The calculated mean excess energy in various photodissociation processes show that the photodissociation of CO2 can produce O(1S) atoms with higher excess velocity compared to the photodissociation of H2O. Thus, our model calculations suggest that involvement of multiple sources in the formation of O(1S) could be a reason for the larger width of green line than that of red

  16. JWST pathfinder telescope integration

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-08-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI and T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  17. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  18. The Sardinia Radio Telescope

    NASA Astrophysics Data System (ADS)

    Grueff, G.; Alvito, G.; Ambrosini, R.; Bolli, P.; D'Amico, N.; Maccaferri, A.; Maccaferri, G.; Morsiani, M.; Mureddu, L.; Natale, V.; Olmi, L.; Orfei, A.; Pernechele, C.; Poma, A.; Porceddu, I.; Rossi, L.; Zacchiroli, G.

    We describe the Sardinia Radio Telescope (SRT), a new general purpose, fully steerable antenna of the National Institute for Astrophysics. The radio telescope is under construction near Cagliari (Sardinia). With its large aperture (64m diameter) and its active surface, SRT is capable of operations up to ˜100GHz, it will contribute significantly to VLBI networks and will represent a powerful single-dish radio telescope for many science fields. The radio telescope has a Gregorian optical configuration with a supplementary beam-waveguide (BWG), which provides additional focal points. The Gregorian surfaces are shaped to minimize the spill-over and standing wave. After the start of the contract for the radio telescope structural and mechanical fabrication in 2003, in the present year the foundation construction will be completed. The schedule foresees the radio telescope inauguration in late 2006.

  19. JWST Pathfinder Telescope Integration

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  20. South Pole Telescope optics.

    PubMed

    Padin, S; Staniszewski, Z; Keisler, R; Joy, M; Stark, A A; Ade, P A R; Aird, K A; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; Dobbs, M A; Halverson, N W; Heimsath, S; Hills, R E; Holzapfel, W L; Lawrie, C; Lee, A T; Leitch, E M; Leong, J; Lu, W; Lueker, M; McMahon, J J; Meyer, S S; Mohr, J J; Montroy, T E; Plagge, T; Pryke, C; Ruhl, J E; Schaffer, K K; Shirokoff, E; Spieler, H G; Vieira, J D

    2008-08-20

    The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber. PMID:18716649

  1. South Pole Telescope optics.

    PubMed

    Padin, S; Staniszewski, Z; Keisler, R; Joy, M; Stark, A A; Ade, P A R; Aird, K A; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Crawford, T M; Crites, A T; Dobbs, M A; Halverson, N W; Heimsath, S; Hills, R E; Holzapfel, W L; Lawrie, C; Lee, A T; Leitch, E M; Leong, J; Lu, W; Lueker, M; McMahon, J J; Meyer, S S; Mohr, J J; Montroy, T E; Plagge, T; Pryke, C; Ruhl, J E; Schaffer, K K; Shirokoff, E; Spieler, H G; Vieira, J D

    2008-08-20

    The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

  2. LISA Telescope Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    The results of a LISA telescope sensitivity analysis will be presented, The emphasis will be on the outgoing beam of the Dall-Kirkham' telescope and its far field phase patterns. The computed sensitivity analysis will include motions of the secondary with respect to the primary, changes in shape of the primary and secondary, effect of aberrations of the input laser beam and the effect the telescope thin film coatings on polarization. An end-to-end optical model will also be discussed.

  3. Telescope performance verification

    NASA Astrophysics Data System (ADS)

    Swart, Gerhard P.; Buckley, David A. H.

    2004-09-01

    While Systems Engineering appears to be widely applied on the very large telescopes, it is lacking in the development of many of the medium and small telescopes currently in progress. The latter projects rely heavily on the experience of the project team, verbal requirements and conjecture based on the successes and failures of other telescopes. Furthermore, it is considered an unaffordable luxury to "close-the-loop" by carefully analysing and documenting the requirements and then verifying the telescope's compliance with them. In this paper the authors contend that a Systems Engineering approach is a keystone in the development of any telescope and that verification of the telescope's performance is not only an important management tool but also forms the basis upon which successful telescope operation can be built. The development of the Southern African Large Telescope (SALT) has followed such an approach and is now in the verification phase of its development. Parts of the SALT verification process will be discussed in some detail to illustrate the suitability of this approach, including oversight by the telescope shareholders, recording of requirements and results, design verification and performance testing. Initial test results will be presented where appropriate.

  4. STS-83 Columbia on Pad 39-A with Comet Hale-Bopp in background

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The soon-to-be-spaceborne Space Shuttle Columbia gets a flyby visit from the Comet Hale-Bopp (shown as the streak at left center) while awaiting launch on the STS-83 mission. This photo was taken the night before the planned liftoff on April 4, 1997. The Rotating Service Structure at Launch Pad 39A has been moved back prior to the start of operations to fuel the external tank. The primary objective of the STS-83 flight is to operate the Microgravity Science Laboratory-1 (MSL-1), which will test some of the hardware, facilities and procedures that will be used on the International Space Station. Columbia will have a crew of seven.

  5. A solar array module fabrication process for HALE solar electric UAVs

    SciTech Connect

    Carey, P.G.; Aceves, R.C.; Colella, N.J.; Thompson, J.B.; Williams, K.A.

    1993-12-01

    We describe a fabrication process to manufacture high power to weight ratio flexible solar array modules for use on high altitude long endurance (HALE) solar electric unmanned air vehicles (UAVs). A span-loaded flying wing vehicle, known as the RAPTOR Pathfinder, is being employed as a flying test bed to expand the envelope of solar powered flight to high altitudes. It requires multiple light weight flexible solar array modules able to endure adverse environmental conditions. At high altitudes the solar UV flux is significantly enhanced relative to sea level, and extreme thermal variations occur. Our process involves first electrically interconnecting solar cells into an array followed by laminating them between top and bottom laminated layers into a solar array module. After careful evaluation of candidate polymers, fluoropolymer materials have been selected as the array laminate layers because of their inherent abilities to withstand the hostile conditions imposed by the environment.

  6. HALE UAS Command and Control Communications: Step 1 - Functional Requirements Document. Version 4.0

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The High Altitude Long Endurance (HALE) unmanned aircraft system (UAS) communicates with an off-board pilot-in-command in all flight phases via the C2 data link, making it a critical component for the UA to fly in the NAS safely and routinely. This is a new requirement in current FAA communications planning and monitoring processes. This document provides a set of comprehensive C2 communications functional requirements and performance guidelines to help facilitate the future FAA certification process for civil UAS to operate in the NAS. The objective of the guidelines is to provide the ability to validate the functional requirements and in future be used to develop performance-level requirements.

  7. Comet Hale-Bopp: Evolution Of Jets And Shells During March 1997

    NASA Astrophysics Data System (ADS)

    Schwarz, G.; Cosmovici, C. B.; Crippa, R.; Guaita, C.; Manzini, F.; Oldani, V.

    1997-07-01

    Hundreds of high quality CCD images obtained by the GAT group with the 33.5 cm reflector of the Sozzago Astronomical Observatory (SAS) provide a detailed insight into the temporal evolution of comet Hale-Bopp. The images cover the time period from May 1996 until May 1997 and allowed us to analyze various near nucleus phenomena. Among them are jet structures that were visible from August 1996 until May 1997 and shell structures that could be resolved from February 1997 to May 1997. We concentrate on the morphology of these phenomena during March 1997 and investigated them by radial masking techniques that reveal their precise shape and extent. In particular, polar coordinate representations could be used advantageously to derive numerical parameters of these features.

  8. VizieR Online Data Catalog: The ELM survey. VI. 11 new ELM WD binaries (Gianninas+, 2015)

    NASA Astrophysics Data System (ADS)

    Gianninas, A.; Kilic, M.; Brown, W. R.; Canton, P.; Kenyon, S. J.

    2016-02-01

    We used the 6.5m MMT telescope equipped with the Blue Channel spectrograph, the 200 inch Hale telescope equipped with the Double spectrograph, the Kitt Peak National Observatory 4m telescope equipped with the R-C spectrograph, and more recently with Kitt Peak Ohio State Multi-Object Spectrograph (KOSMOS), to obtain spectroscopy of our 11 targets in several observing runs. We have also been obtaining radial-velocity measurements for candidates from other sources including the Large Sky Area Multi-Object Spectroscopy Telescope (LAMOST). Those 11 new Extremely low-mass white dwarf (ELM WD) binaries bring the total of ELM WDs identified by the ELM Survey up to 73. (4 data files).

  9. Functional Requirements Document for HALE UAS Operations in the NAS: Step 1. Version 3

    NASA Technical Reports Server (NTRS)

    2006-01-01

    The purpose of this Functional Requirements Document (FRD) is to compile the functional requirements needed to achieve the Access 5 Vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the national airspace system (NAS)" for Step 1. These functional requirements could support the development of a minimum set of policies, procedures and standards by the Federal Aviation Administration (FAA) and various standards organizations. It is envisioned that this comprehensive body of work will enable the FAA to establish and approve regulations to govern safe operation of UAS in the NAS on a routine or daily "file and fly" basis. The approach used to derive the functional requirements found within this FRD was to decompose the operational requirements and objectives identified within the Access 5 Concept of Operations (CONOPS) into the functions needed to routinely and safely operate a HALE UAS in the NAS. As a result, four major functional areas evolved to enable routine and safe UAS operations for an on-demand basis in the NAS. These four major functions are: Aviate, Navigate, Communicate, and Avoid Hazards. All of the functional requirements within this document can be directly traceable to one of these four major functions. Some functions, however, are traceable to several, or even all, of these four major functions. These cross-cutting functional requirements support the "Command / Control: function as well as the "Manage Contingencies" function. The requirements associated to these high-level functions and all of their supporting low-level functions are addressed in subsequent sections of this document.

  10. The 22-Year Hale Cycle in Cosmic Ray Flux - Evidence for Direct Heliospheric Modulation

    NASA Astrophysics Data System (ADS)

    Thomas, S. R.; Owens, M. J.; Lockwood, M.

    2014-01-01

    The ability to predict times of greater galactic cosmic ray (GCR) fluxes is important for reducing the hazards caused by these particles to satellite communications, aviation, or astronauts. The 11-year solar-cycle variation in cosmic rays is highly correlated with the strength of the heliospheric magnetic field. Differences in GCR flux during alternate solar cycles yield a 22-year cycle, known as the Hale Cycle, which is thought to be due to different particle drift patterns when the northern solar pole has predominantly positive (denoted as qA>0 cycle) or negative ( qA<0) polarities. This results in the onset of the peak cosmic-ray flux at Earth occurring earlier during qA>0 cycles than for qA<0 cycles, which in turn causes the peak to be more dome-shaped for qA>0 and more sharply peaked for qA<0. In this study, we demonstrate that properties of the large-scale heliospheric magnetic field are different during the declining phase of the qA<0 and qA>0 solar cycles, when the difference in GCR flux is most apparent. This suggests that particle drifts may not be the sole mechanism responsible for the Hale Cycle in GCR flux at Earth. However, we also demonstrate that these polarity-dependent heliospheric differences are evident during the space-age but are much less clear in earlier data: using geomagnetic reconstructions, we show that for the period of 1905 - 1965, alternate polarities do not give as significant a difference during the declining phase of the solar cycle. Thus we suggest that the 22-year cycle in cosmic-ray flux is at least partly the result of direct modulation by the heliospheric magnetic field and that this effect may be primarily limited to the grand solar maximum of the space-age.

  11. LUTE telescope structural design

    NASA Technical Reports Server (NTRS)

    Ruthven, Gregory

    1993-01-01

    The major objective of the Lunar Ultraviolet Transit Experiment (LUTE) Telescope Structural Design Study was to investigate the feasibility of designing an ultralightweight 1-m aperture system within optical performance requirements and mass budget constraints. This study uses the results from our previous studies on LUTE as a basis for further developing the LUTE structural architecture. After summarizing our results in Section 2, Section 3 begins with the overall logic we used to determine which telescope 'structural form' should be adopted for further analysis and weight estimates. Specific telescope component analysis showing calculated fundamental frequencies and how they compare with our derived requirements are included. 'First-order' component stress analyses to ensure telescope optical and structural component (i.e. mirrors & main bulkhead) weights are realistic are presented. Layouts of both the primary and tertiary mirrors showing dimensions that are consistent with both our weight and frequency calculations also form part of Section 3. Section 4 presents our calculated values for the predicted thermally induced primary-to-secondary mirror despace motion due to the large temperature range over which LUTE must operate. Two different telescope design approaches (one which utilizes fused quartz metering rods and one which assumes the entire telescope is fabricated from beryllium) are considered in this analysis. We bound the secondary mirror focus mechanism range (in despace) based on these two telescope configurations. In Section 5 we show our overall design of the UVTA (Ultraviolet Telescope Assembly) via an 'exploded view' of the sub-system. The 'exploded view' is annotated to help aid in the understanding of each sub-assembly. We also include a two view layout of the UVTA from which telescope and telescope component dimensions can be measured. We conclude our study with a set of recommendations not only with respect to the LUTE structural architecture

  12. High resolution telescope

    DOEpatents

    Massie, Norbert A.; Oster, Yale

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  13. Goddard Robotic Telescope

    NASA Astrophysics Data System (ADS)

    Sakamoto, Takanori; Donato, Davide; Gehrels, Neil; Okajima, Takashi; Ukwatta, Tilan N.

    2009-05-01

    We are constructing the 14'' fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are 1) to follow-up the Swift/Fermi Gamma-Ray Bursts (GRBs) and 2) to perform the coordinated optical observations of the Fermi/Large Area Telescope (LAT) Active Galactic Nuclei (AGN). Our telescope system consists of the 14'' Celestron Optical Telescope Assembly (OTA), the Astro-Physics 1200GTO mount, the Apogee U47 CCD camera, the JMI's electronic focuser, and the Finger Lake Instrumentation's color filter wheel with U, B, V, R and I filters. With the focal reducer, 20'×20' field of view has been achieved. The observatory dome is the Astro Haven's 7 ft clam-shell dome. We started the scientific observations on mid-November 2008. While not observing our primary targets (GRBs and AGNs), we are planning to open our telescope time to the public for having a wider use of our telescope in both a different research field and an educational purpose.

  14. Video Telescope Operating Microscopy.

    PubMed

    Divers, Stephen J

    2015-09-01

    Exotic pet veterinarians frequently have to operate on small animals, and magnification is commonly used. Existing endoscopy equipment can be used with a mechanical arm and telescope to enable video telescope operating microscopy. The additional equipment items and their specifics are described, and several case examples are provided. PMID:26117519

  15. Goddard Robotic Telescope

    SciTech Connect

    Sakamoto, Takanori; Donato, Davide; Gehrels, Neil; Okajima, Takashi; Ukwatta, Tilan N.

    2009-05-25

    We are constructing the 14'' fully automated optical robotic telescope, Goddard Robotic Telescope (GRT), at the Goddard Geophysical and Astronomical Observatory. The aims of our robotic telescope are 1) to follow-up the Swift/Fermi Gamma-Ray Bursts (GRBs) and 2) to perform the coordinated optical observations of the Fermi/Large Area Telescope (LAT) Active Galactic Nuclei (AGN). Our telescope system consists of the 14'' Celestron Optical Telescope Assembly (OTA), the Astro-Physics 1200GTO mount, the Apogee U47 CCD camera, the JMI's electronic focuser, and the Finger Lake Instrumentation's color filter wheel with U, B, V, R and I filters. With the focal reducer, 20'x20' field of view has been achieved. The observatory dome is the Astro Haven's 7 ft clam-shell dome. We started the scientific observations on mid-November 2008. While not observing our primary targets (GRBs and AGNs), we are planning to open our telescope time to the public for having a wider use of our telescope in both a different research field and an educational purpose.

  16. Video Telescope Operating Microscopy.

    PubMed

    Divers, Stephen J

    2015-09-01

    Exotic pet veterinarians frequently have to operate on small animals, and magnification is commonly used. Existing endoscopy equipment can be used with a mechanical arm and telescope to enable video telescope operating microscopy. The additional equipment items and their specifics are described, and several case examples are provided.

  17. Hubble Space Telescope overview

    NASA Technical Reports Server (NTRS)

    Polidan, Ronald S.

    1991-01-01

    A general overview of the performance and current status of the Hubble Space Telescope is presented. Most key spacecraft subsystems are operating well, equaling or exceeding specifications. Spacecraft thermal properties, power, and communications, are superb. The only spacecraft subsystem to have failed, a gyro, is briefly discussed. All science instruments are functioning extremely well and are returning valuable scientific data. The two significant problems effecting the Hubble Space Telescope science return, the pointing jitter produced by thermally induced bending of the solar array wings and the optical telescope assembly spherical aberration, are discussed and plans to repair both problems are mentioned. The possible restoration of full optical performance of the axial scientific instruments through the use of the Corrective Optics Space Telescope Axial Replacement, currently under study for the 1993 servicing mission, is discussed. In addition, an overview of the scientific performance of the Hubble Space Telescope is presented.

  18. The European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Collados, M.; Bettonvil, F.; Cavaller, L.; Ermolli, I.; Gelly, B.; Pérez, A.; Socas-Navarro, H.; Soltau, D.; Volkmer, R.; EST Team

    The European Solar Telescope (EST) is a project to design, build and operate an European Solar 4-meter class telescope to be located in the Canary Islands, with the participation of institutions from fifteen European countries gathered around the consortium EAST (European Association for Solar Telescopes). The project main objective up to the present has been the development of the conceptual design study (DS) of a large aperture Solar Telescope. The study has demonstrated the scientific, technical and financial feasibility of EST. The DS has been possible thanks to the co-financing allocated specifically by the EU and the combined efforts of all the participant institutions. Different existing alternatives have been analysed for all telescope systems and subsystems, and decisions have been taken on the ones that are most compatible with the scientific goals and the technical strategies. The present status of some subsystems is reviewed in this paper.

  19. Two Easily Made Astronomical Telescopes.

    ERIC Educational Resources Information Center

    Hill, M.; Jacobs, D. J.

    1991-01-01

    The directions and diagrams for making a reflecting telescope and a refracting telescope are presented. These telescopes can be made by students out of plumbing parts and easily obtainable, inexpensive, optical components. (KR)

  20. The large binocular telescope.

    PubMed

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010. PMID:20517352

  1. The large binocular telescope.

    PubMed

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  2. Dust Morphology Of Comet Hale-Bopp (C/1995 O1): I. Pre-Perihelion Coma Structures In

    NASA Astrophysics Data System (ADS)

    Boehnhardt, H.; Birkle, K.; Fiedler, A.; Jorda, L.; Thomas, N.; Peschke, S.; Rauer, H.; Schulz, R.; Schwehm, G.; Tozzi, G.; West, R.

    1997-07-01

    In 1996 comet Hale-Bopp exhibited a porcupine-like coma with straight jets of dust emission from several active regions on the nucleus. The multi-jet coma geometry developed during the first half of 1996. While the jet orientation remained almost constant over months, the relative intensity of the jets changed with time. By using the embedded fan model of Sekanina and Boehnhardt (1997a) the jet pattern of comet Hale-Bopp in 1996 can be interpreted as boundaries of dust emission cones (fans) from four — possibly five — active regions on the nucleus (for a numerical modelling see part II of the paper by Sekanina and Boehnhardt, 1997b).

  3. Telescopic vision contact lens

    NASA Astrophysics Data System (ADS)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  4. Cooled infrared telescope development

    NASA Technical Reports Server (NTRS)

    Young, L. S.

    1976-01-01

    The feasibility of the design concept for a 1-m-aperture, cryogenically cooled telescope for Spacelab is assessed. The device makes use of double-folded Gregorian reflective optics. The planned cryogen is helium, and beryllium will be used for the 1.2 m primary mirror. Results of studies based on smaller instruments indicate that no new technology will be required to construct a Shuttle Infrared Telescope Facility which will offer improvement over the sensitivity of conventional telescopes by a factor of 1000 at 10 micrometers.

  5. Multi-use lunar telescopes

    NASA Technical Reports Server (NTRS)

    Drummond, Mark; Hine, Butler; Genet, Russell; Genet, David; Talent, David; Boyd, Louis; Trueblood, Mark; Filippenko, Alexei V. (Editor)

    1991-01-01

    The objective of multi-use telescopes is to reduce the initial and operational costs of space telescopes to the point where a fair number of telescopes, a dozen or so, would be affordable. The basic approach is to develop a common telescope, control system, and power and communications subsystem that can be used with a wide variety of instrument payloads, i.e., imaging CCD cameras, photometers, spectrographs, etc. By having such a multi-use and multi-user telescope, a common practice for earth-based telescopes, development cost can be shared across many telescopes, and the telescopes can be produced in economical batches.

  6. Thermal model of water and CO activity of Comet C/1995 O1 (Hale-Bopp)

    NASA Astrophysics Data System (ADS)

    Gortsas, N.; Kührt, E.; Motschmann, U.; Keller, H. U.

    2011-04-01

    An investigation of the activity of Comet C/1995 O1 (Hale-Bopp) with a thermophysical nucleus model that does not rely on the existence of amorphous ice is presented. Our approach incorporates recent observations allowing to constrain important parameters that control cometary activity. The model accounts for heat conduction, heat advection, gas diffusion, sublimation, and condensation in a porous ice-dust matrix with moving boundaries. Erosion due to surface sublimation of water ice leads to a moving boundary. The movement of the boundary is modeled by applying a temperature remapping technique which allows us to account for the loss in the internal energy of the eroded surface material. These kind of problems are commonly referred to as Stefan problems. The model takes into account the diurnal rotation of the nucleus and seasonal effects due to the strong obliquity of Hale-Bopp as reported by Jorda et al. (Jorda, L., Rembor, K., Lecacheux, J., Colom, P., Colas, F., Frappa, E., Lara, L.M. [1997]. Earth Moon Planets 77, 167-180). Only bulk sublimation of water and CO ice are considered without further assumptions such as amorphous ices with certain amount of occluded CO gas. Confined and localized activity patterns are investigated following the reports of Lederer and Campins (Lederer, S.M., Campins, H. [2002]. Earth Moon Planets 90, 381-389) about the chemical heterogeneity of Hale-Bopp and of Bockelée-Morvan et al. (Bockelée-Morvan, D., Henry, F., Biver, N., Boissier, J., Colom, P., Crovisier, J., Despois, D., Moreno, R., Wink, J. [2009]. Astron. Astrophys. 505, 825-843) about a strong CO source at a latitude of 20°. The best fit to the observations of Biver et al. (Biver, N. et al. [2002]. Earth Moon Planets 90, 5-14) is obtained with a low thermal conductivity of 0.01 W m -1 K -1. This is in agreement with recent results of the Deep Impact mission to 9P/Tempel 1 (Groussin, O., A'Hearn, M.F., Li, J.-Y., Thomas, P.C., Sunshine, J.M., Lisse, C.M., Meech, K

  7. Webb Telescope: Planetary Evolution

    NASA Video Gallery

    Stars and planets form in the dark, inside vast, cold clouds of gas and dust. The James Webb Space Telescope's large mirror and infrared sensitivity will let astronomers peer inside dusty knots whe...

  8. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Schloerb, F. Peter; Carrasco, Luis

    2004-10-01

    We present a summary of the Large Millimeter Telescope Project and its present status. The Large Millimeter Telescope (LMT) is a joint project of the University of Massachusetts (UMass) in the USA and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Mexico to build a 50m-diameter millimeter-wave telescope. The LMT is being built at an altitude of 4600 m atop Volcan Sierra Negra, an extinct volcanic peak in the state of Puebla, Mexico, approximately 100 km east of the city of Puebla. Construction of the antenna is now well underway. The basic structure with a limited number of surface panels is expected to be completed in 2005. Engineering acceptance and telescope commissioning are expected to be completed in 2007.

  9. Composite Space Telescope Truss

    NASA Video Gallery

    NASA engineers are recycling an idea for a lightweight, compact space telescope structure from the early 1990s. The 315 struts and 84 nodes were originally designed to enable spacewalking astronaut...

  10. Building a Telescope.

    ERIC Educational Resources Information Center

    Linas, Chris F.

    1988-01-01

    Provides information on the parts, materials, prices, dimensions, and tools needed for the construction of a telescope that can be used in high school science laboratories. Includes step-by-step directions and a diagram for assembly. (RT)

  11. Shuttle Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Mccarthy, S. G.

    1976-01-01

    The Shuttle Infrared Telescope Facility (SIRTF) will combine high sensitivity with the flexibility offered by the Space Transportation System. A recently completed study has generated a preliminary design which demonstrates the feasibility of SIRTF. The 1.0 to 1.5 meter aperture, f/8 Gregorian telescope will be cooled to 20 K by a stored supercritical helium system. The telescope will be pointed and stabilized at two levels: the European-developed Instrument Pointing System provides primary pointing and stabilization; and an internal star tracker senses residual errors and drives a folding mirror inside the telescope to null the errors. The folding mirror can also be driven by square or triangular waves to provide space chopping or small-area scanning.

  12. New National Capability in NIMR: Rational, Development and application of meteorological sensors for HALE UAV

    NASA Astrophysics Data System (ADS)

    Choi, Reno K. Y.; Min, Seunghyun; Klein, Marian; Ha, Jong-Chul; Cho, Young-Jun; Cho, ChunHo

    2015-04-01

    Joint Civilian-Military Committee, under Advisory Council on Science and Technology, awarded an ambitious technology demonstration project to build a HALE (High-Altitude Long Endurance) UAV (Unmanned Aerial Vehicle) till 2017. NIMR (National Institute of Meteorological Research) is responsible for developing a payload for meteorological observation, which the committee welcomed not only for technological challenges but also for scientific advances for all parties. NIMR is also responsible for providing numerical weather predictions for flight safety for overall project. HALE UAV is an aircraft that aims to operate at lower stratospheric altitudes for days and weeks. It is an altitude where air becomes thin to prevent operation of conventional jet engines and only military reconnaissance aircrafts have reached at this high or above around 18~21km Since only a couple of unmanned aircraft demonstrated its potential scientific value, atmospheric research at stratospheric altitude offers unique opportunity of monitoring complete troposphere at close range. With advantages from both satellite (consistent observation) and airborne platforms (spatial flexibility), i.e. pseudo-satellite, water content monitoring in the atmosphere enables us to improve prediction of entire life cycle of tropical storms and torrential rains and snows, in addition to better understanding of tropopause dynamics and its prediction capability. This meteorological instrument challenges very limited payload design requirements, i.e. 4kg of weight and 50W of power consumption. With such constraints, NIMR determines to develop passive microwave radiometers (15~100GHz) onboard in the interest of 3D water vapor profiles, along with optical camera for cloud observation. There are number of technical challenges to achieve the goal, such as 1) mechanical and electronic design that works in -75°C and 60hPa with weight and power constraints, and 2) miniaturisation of conventional meteorological instruments

  13. Telescopes in History

    NASA Astrophysics Data System (ADS)

    Bond, P.; Murdin, P.

    2000-11-01

    The precise origins of the optical telescope are hidden in the depths of time. In the thirteenth century Roger Bacon claimed to have devised a combination of lenses which enabled him to see distant objects as if they were near. Others who have an unsubstantiated claim to have invented the telescope in the sixteenth century include an Englishman, Leonard DIGGES, and an Italian, Giovanni Batista Po...

  14. Hubble Space Telescope Configuration

    NASA Technical Reports Server (NTRS)

    1985-01-01

    This image illustrates the overall Hubble Space Telescope (HST) configuration. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  15. LISA Telescope Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. As with any optical system, even one with such very large separations between the transmitting and receiving, telescopes, a sensitivity analysis should be performed to see how, in this case, the far field phase varies when the telescope parameters change as a result of small temperature changes.

  16. Hale cycle effects in cosmic ray east-west anisotropy and interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Ahluwalia, H. S.

    1993-01-01

    We have reanalyzed diurnal anisotropy data obtained with the shielded ion chamber (IC) at Cheltenham/Fredericksburg and the neutron monitor (NM) at Swarthmore/Newark. IC data are for the 1936-1977 period and NM data are for the 1965-1988 period. We have corrected IC data for the diurnal temperature effect. Application of this correction results in a better agreement between IC and other data sets, thereby making it possible to study the long-term changes in the diurnal anisotropy using IC data. The behavior of the annual mean east-west anisotropy is studied for 53 years of observations. The period encompasses more than two solar magnetic (Hale) cycles. Its amplitude undergoes the expected 11 and 22 year variations, with the largest changes occurring near solar activity minima. Moreover, the data indicate the presence of the subsidiary maxima for the entire 53-year period, following the solar polar field reversals, during the declining phases of activity cycles when high-speed solar wind streams are present in the heliosphere. The data suggest that the amplitude of the subsidiary maximum is large when the solar polar magnetic field points toward the sun in the Northern Hemisphere, and radial anisotropy is absent.

  17. Founded in 1895 by George E. Hale and James E. Keeler: The Astrophysical Journal Centennial

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1995-05-01

    A brief history of the Astrophysical Journal is given, concentrating on its beginnings, its predecessor and rival journals, the astrophysicists who founded it, and the growth and development of astrophysics in the century since then. Later stages in the Journal's history are related, in less detail, down to the present. Some of the first papers in new fields, such as radio astronomy, balloon astronomy, space astronomy, and X-ray astronomy are mentioned. A few of the financial crises are described, as well as one or two attempts to undercut the Journal. Slides of all the managing editors: George Ellery Hale (1895-1904), Edwin B. Frost (1905-32), Otto Struve (1932-47), William W. Morgan (1947-52), S. Chandrasekhar (1952-71), and Helmut A. Abt (1971- ) will be shown. Slides of other editors, including Benjamin A. Gould (Astronomical Journal), William W. Payne (Sidereal Messenger), Edward S. Holden (PASP), and W. W. Campbell (Lick Observatory Bulletins) will also be shown, and their publications discussed.

  18. HCO+ imaging of comet Hale-Bopp (C/1995 O1)

    NASA Technical Reports Server (NTRS)

    Lovell, A. J.; Schloerb, F. P.; Dickens, J. E.; DeVries, C. H.; Senay, M. C.; Irvine, W. M.

    1998-01-01

    The HCO+ J = 1-0 rotational transition at 89.189 GHz has been mapped in comet Hale-Bopp (C/1995 O1) over a total of 38 individual days spanning the period 1997 March 10-June 20 with the Five College Radio Astronomy Observatory 14 m antenna. HCO+ is detectable over an extended region of the comet, with the peak emission commonly located 50,000-100,000 km in the antisolar direction. Maps made throughout the apparition show significant variability in the structure of the HCO+ coma, sometimes on timescales of several hours. The HCO+ brightness is usually depressed at the nucleus position, and on some occasions, the emission is spread into a ring around the position of the nucleus. Individual spectra within the maps display broad (approximately 4 km s-1) lines redshifted by 1-2 km s-1 or more from the nominal velocity of the nucleus, with the redshift typically increasing in the antisolar direction. The spectra and maps may be generally explained by models in which the ions are accelerated tailward at a rate on the order of 10 cm s-2, provided that HCO+ is destroyed within 50,000-100,000 km of the nucleus.

  19. Morfología de la Coma del Cometa Hale - Bopp

    NASA Astrophysics Data System (ADS)

    Gil-Hutton, R.; Caballero, M.; Coldwell, G.; Cañada, M.; Godoy, G.; Trozzo, C.; Gómez, G.

    Para lograr comprender plenamente los procesos físicos que se desarrollan en los núcleos cometarios y obtener un modelo que explique, no sólo su actividad, sino también sus efectos sobre la coma, es necesario obtener información detallada para el mayor número de cometas posible, siendo las características más interesantes para estudiar la ubicación de las regiones activas, la presencia de jets, las tasas de producción de gas y polvo y la interacción de la coma con el viento solar. En la actualidad, con técnicas de procesamiento de imágenes y tecnología CCD se pueden obtener este tipo de datos para cometas que ingresan al sistema solar interior y estudiar, de esta manera, la morfología de sus comas, tratando de correlacionar la actividad detectada con algún modelo teórico. En este trabajo se presenta un estudio parcial de la actividad desarrollada por el cometa Hale-Bopp, y sus efectos sobre la morfología de su coma, desde agosto de 1995 hasta la fecha en base a imágenes adquiridas con el telescopio de 0.76 m. de la Estación Astronómica Dr. Carlos Ulrrico Cesco.

  20. The Multiple-Mirror Telescope

    ERIC Educational Resources Information Center

    Carleton, Nathaniel P.; Hoffmann, William F.

    1978-01-01

    Describes the basic design and principle of operating an optical-infrared telescope, the MMT. This third largest telescope in the world represents a new stage in telescope design; it uses a cluster of six reflecting telescopes, and relies on an automatic sensing and control system. (GA)

  1. The South Pole Telescope

    SciTech Connect

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  2. Robotic and Survey Telescopes

    NASA Astrophysics Data System (ADS)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  3. Telescope Adaptive Optics Code

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The defaultmore » parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST« less

  4. Spectroradiometry with space telescopes

    NASA Astrophysics Data System (ADS)

    Pauluhn, Anuschka; Huber, Martin C. E.; Smith, Peter L.; Colina, Luis

    2015-12-01

    Radiometry, i.e. measuring the power of electromagnetic radiation—hitherto often referred to as "photometry"—is of fundamental importance in astronomy. We provide an overview of how to achieve a valid laboratory calibration of space telescopes and discuss ways to reliably extend this calibration to the spectroscopic telescope's performance in space. A lot of effort has been, and still is going into radiometric "calibration" of telescopes once they are in space; these methods use celestial primary and transfer standards and are based in part on stellar models. The history of the calibration of the Hubble Space Telescope serves as a platform to review these methods. However, we insist that a true calibration of spectroscopic space telescopes must directly be based on and traceable to laboratory standards, and thus be independent of the observations. This has recently become a well-supported aim, following the discovery of the acceleration of the cosmic expansion by use of type-Ia supernovae, and has led to plans for launching calibration rockets for the visible and infrared spectral range. This is timely, too, because an adequate exploitation of data from present space missions, such as Gaia, and from many current astronomical projects like Euclid and WFIRST demands higher radiometric accuracy than is generally available today. A survey of the calibration of instruments observing from the X-ray to the infrared spectral domains that include instrument- or mission-specific estimates of radiometric accuracies rounds off this review.

  5. Monolithic afocal telescope

    NASA Technical Reports Server (NTRS)

    Roberts, William T. (Inventor)

    2010-01-01

    An afocal monolithic optical element formed of a shallow cylinder of optical material (glass, polymer, etc.) with fast aspheric surfaces, nominally confocal paraboloids, configured on the front and back surfaces. The front surface is substantially planar, and this lends itself to deposition of multi-layer stacks of thin dielectric and metal films to create a filter for rejecting out-of-band light. However, an aspheric section (for example, a paraboloid) can either be ground into a small area of this surface (for a Cassegrain-type telescope) or attached to the planar surface (for a Gregorian-type telescope). This aspheric section of the surface is then silvered to create the telescope's secondary mirror. The rear surface of the cylinder is figured into a steep, convex asphere (again, a paraboloid in the examples), and also made reflective to form the telescope's primary mirror. A small section of the rear surface (approximately the size of the secondary obscuration, depending on the required field of the telescope) is ground flat to provide an unpowered surface through which the collimated light beam can exit the optical element. This portion of the rear surface is made to transmit the light concentrated by the reflective surfaces, and can support the deposition of a spectral filter.

  6. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  7. Amateur Telescope Making

    NASA Astrophysics Data System (ADS)

    Tonkin, Stephen

    Many amateur astronomers make their own instruments, either because of financial considerations or because they are just interested. Amateur Telescope Making offers a variety of designs for telescopes, mounts and drives which are suitable for the home-constructor. The designs range from simple to advanced, but all are within the range of a moderately well-equipped home workshop. The book not only tells the reader what he can construct, but also what it is sensible to construct given what time is available commercially. Thus each chapter begins with reasons for undertaking the project, then looks at theoretical consideration before finishing with practical instructions and advice. An indication is given as to the skills required for the various projects. Appendices list reputable sources of (mail order) materials and components. The telescopes and mounts range from "shoestring" (very cheap) instruments to specialist devices that are unavailable commercially.

  8. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Pérez-Grovas, Alfonso Serrano; Schloerb, F. Peter; Hughes, David; Yun, Min

    2006-06-01

    We present a summary of the Large Millimeter Telescope (LMT) Project and its current status. The LMT is a joint project of the University of Massachusetts (UMass) in the USA and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Mexico to build a 50m-diameter millimeter-wave telescope. The LMT site is at an altitude of 4600 m atop Volcan Sierra Negra, an extinct volcanic peak in the state of Puebla, Mexico, approximately 100 km east of the city of Puebla. Construction of the antenna steel structure has been completed and the antenna drive system has been installed. Fabrication of the reflector surface is underway. The telescope is expected to be completed in 2008.

  9. The Sardinia Radio Telescope

    NASA Astrophysics Data System (ADS)

    D'Amico, Nichi

    2011-08-01

    We present the status of the Sardinia Radio Telescope (SRT) project, a new general purpose, fully steerable 64 m diameter parabolic radio telescope under construction in Sardinia. The instrument is funded by Italian Ministry of University and Research (MIUR), by the Sardinia Regional Government (RAS), and by the Italian Space Agency (ASI), and it is charge to three research structures of the National Institute for Astrophysics (INAF): the Institute of Radio Astronomy of Bologna, the Cagliari Astronomical Observatory (in Sardinia), and the Arcetri Astrophysical Observatory in Florence. The radio telescope has a shaped Gregorian optical configuration with a 8 m diameter secondary mirror and additional Beam-Wave Guide (BWG) mirrors. One of the most challenging feature of SRT is the active surface of the primary reflector which provides good efficiency up to about 100 GHz. This paper reports on the most recent advances of the construction.

  10. Configurable Aperture Space Telescope

    NASA Technical Reports Server (NTRS)

    Ennico, Kimberly; Bendek, Eduardo

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide straw man mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible and/or UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST

  11. An Integrated Modeling Study for Coordinated Observations of H, O, OH, and H2O(+) Emissions in the Coma and Ion Tail of the Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Smyth, William H.

    2001-01-01

    This project has two overall objectives. One objective is to advance our general understanding of both the comet neutral atmosphere and the cometary plasma in the atmosphere and ion tall. The other objective is to obtain specific key information about comet Hale-Bopp that is generally important for Hale-Bopp studies. The primary emphasis in this project is to analyze, in a self-consistent manner, excellent quality high resolution image and line profile observations obtained by the University of Wisconsin for H, O, OH, and H2O+ emissions from the inner coma, outer coma, and ion tail of Hale-Bopp. The information on the spatial and velocity distributions of H2O neutral and ionized photo-products in the inner coma, outer coma, and in the H2O+ ion tail is of substantial and direct importance in the development of an integrated understanding of the complex structure and dynamics of the neutral and plasma species in the atmosphere of Hale-Bopp in particular and comets in general. The H2O production rate of Hale-Bopp is determined and, together with the other information related to the structure and dynamics of the neutral and plasma atmospheres obtained in this study, provide critical information important for a wide variety of research conducted by other groups.

  12. The Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Millis, R. L.; Dunham, E. W.; Sebring, T. A.; Smith, B. W.; de Kock, M.; Wiecha, O.

    2004-11-01

    The Discovery Channel Telescope (DCT) is a 4.2-m telescope to be built at a new site near Happy Jack, Arizona. The DCT features a large prime focus mosaic CCD camera with a 2-degree-diameter field of view especially designed for surveys of KBOs, Centaurs, NEAs and other moving or time-variable targets. The telescope can be switched quickly to a Ritchey-Chretien configuration for optical/IR spectroscopy or near-IR imaging. This flexibility allows timely follow-up physical studies of high priority objects discovered in survey mode. The ULE (ultra-low-expansion) meniscus primary and secondary mirror blanks for the telescope are currently in fabrication by Corning Glass. Goodrich Aerospace, Vertex RSI, M3 Engineering and Technology Corp., and e2v Technologies have recently completed in-depth conceptual design studies of the optics, mount, enclosure, and mosaic focal plane, respectively. The results of these studies were subjected to a formal design review in July, 2004. Site testing at the 7760-ft altitude Happy Jack site began in 2001. Differential image motion observations from 117 nights since January 1, 2003 gave median seeing of 0.84 arcsec FWHM, and the average of the first quartile was 0.62 arcsec. The National Environmental Policy Act (NEPA) process for securing long-term access to this site on the Coconino National Forest is nearing completion and ground breaking is expected in the spring of 2005. The Discovery Channel Telescope is a project of the Lowell Observatory with major financial support from Discovery Communications, Inc. (DCI). DCI plans ongoing television programming featuring the construction of the telescope and the research ultimately undertaken with the DCT. An additional partner can be accommodated in the project. Interested parties should contact the lead author.

  13. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is a photograph of giant twisters and star wisps in the Lagoon Nebula. This superb Hubble Space Telescope (HST) image reveals a pair of one-half light-year long interstellar twisters, eerie furnels and twisted rope structures (upper left), in the heart of the Lagoon Nebula (Messier 8) that lies 5,000 light-years away in the direction of the constellation Sagittarius. This image was taken by the Hubble Space Telescope Wide Field/Planetary Camera 2 (WF/PC2).

  14. Ground based automated telescope

    SciTech Connect

    Colgate, S.A.; Thompson, W.

    1980-01-01

    Recommendation that a ground-based automated telescope of the 2-meter class be built for remote multiuser use as a natural facility. Experience dictates that a primary consideration is a time shared multitasking operating system with virtual memory overlayed with a real time priority interrupt. The primary user facility is a remote terminal networked to the single computer. Many users must have simultaneous time shared access to the computer for program development. The telescope should be rapid slewing, and hence a light weight construction. Automation allows for the closed loop pointing error correction independent of extreme accuracy of the mount.

  15. Robust telescope scheduling

    NASA Technical Reports Server (NTRS)

    Swanson, Keith; Bresina, John; Drummond, Mark

    1994-01-01

    This paper presents a technique for building robust telescope schedules that tend not to break. The technique is called Just-In-Case (JIC) scheduling and it implements the common sense idea of being prepared for likely errors, just in case they should occur. The JIC algorithm analyzes a given schedule, determines where it is likely to break, reinvokes a scheduler to generate a contingent schedule for each highly probable break case, and produces a 'multiply contingent' schedule. The technique was developed for an automatic telescope scheduling problem, and the paper presents empirical results showing that Just-In-Case scheduling performs extremely well for this problem.

  16. Pointing the SOFIA Telescope

    NASA Astrophysics Data System (ADS)

    Gross, M. A. K.; Rasmussen, J. J.; Moore, E. M.

    2010-12-01

    SOFIA is an airborne, gyroscopically stabilized 2.5m infrared telescope, mounted to a spherical bearing. Unlike its predecessors, SOFIA will work in absolute coordinates, despite its continually changing position and attitude. In order to manage this, SOFIA must relate equatorial and telescope coordinates using a combination of avionics data and star identification, manage field rotation and track sky images. We describe the algorithms and systems required to acquire and maintain the equatorial reference frame, relate it to tracking imagers and the science instrument, set up the oscillating secondary mirror, and aggregate pointings into relocatable nods and dithers.

  17. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This color image from the Hubble Space Telescope (HST) shows a region in NGC 1365, a barred spiral galaxy located in a cluster of galaxies called Fornax. A barred spiral galaxy is characterized by a bar of stars, dust, and gas across its center. The black and white photograph from a ground-based telescope shows the entire galaxy, which is visible from the Southern Hemisphere. The galaxy is estimated to be 60-million light-years from Earth. This image was taken by the HST Wide Field/Planetary Camera 2 (WF/PC-2).

  18. TELESCOPES: Astronomers Overcome 'Aperture Envy'.

    PubMed

    Irion, R

    2000-07-01

    Many users of small telescopes are disturbed by the trend of shutting down smaller instruments in order to help fund bigger and bolder ground-based telescopes. Small telescopes can thrive in the shadow of giant new observatories, they say--but only if they are adapted to specialized projects. Telescopes with apertures of 2 meters or less have unique abilities to monitor broad swaths of the sky and stare at the same objects night after night, sometimes for years; various teams are turning small telescopes into robots, creating networks that span the globe and devoting them to survey projects that big telescopes don't have a prayer of tackling. PMID:17832960

  19. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Schloerb, F. Peter

    2008-07-01

    This paper, presented on behalf of the Large Millimeter Telescope (LMT) project team, describes the status and near-term plans for the telescope and its initial instrumentation. The LMT is a bi-national collaboration between Mexico and the USA, led by the Instituto Nacional de Astrofísica, Optica y Electronica (INAOE) and the University of Massachusetts at Amherst, to construct, commission and operate a 50m-diameter millimeter-wave radio telescope. Construction activities are nearly complete at the 4600m LMT site on the summit of Sierra Negra, an extinct volcano in the Mexican state of Puebla. Full movement of the telescope, under computer control in both azimuth and elevation, has been achieved. First-light at centimeter wavelengths on astronomical sources was obtained in November 2006. Installation of precision surface segments for millimeter-wave operation is underway, with the inner 32m-diameter of the surface now complete and ready to be used to obtain first light at millimeter wavelengths in 2008. Installation of the remainder of the reflector will continue during the next year and be completed in 2009 for final commissioning of the antenna. The full LMT antenna, outfitted with its initial complement of scientific instruments, will be a world-leading scientific research facility for millimeter-wave astronomy.

  20. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Hughes, D. H.; Schloerb, F. P.; LMT Project Team

    2009-05-01

    This paper, presented on behalf of the Large Millimeter Telescope (LMT) project team, describes the status and near-term plans for the telescope and its initial instrumentation. The LMT is a bi-national collaboration between México and the USA, led by the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) and the University of Massachusetts at Amherst, to construct, commission and operate a 50 m diameter millimeter-wave radio telescope. Construction activities are nearly complete at the LMT site, at an altitude of ˜ 4600 m on the summit of Sierra Negra, an extinct volcano in the Mexican state of Puebla. Full movement of the telescope, under computer control in both azimuth and elevation, has been achieved. First-light at centimeter wavelengths on astronomical sources was obtained in November 2006. Installation of precision surface segments for millimeter-wave operation is underway, with the inner 32 m diameter of the surface now complete and ready to be used to obtain first-light at millimeter wavelengths in 2008. Installation of the remainder of the reflector will continue during the next year and be completed in 2009 for final commissioning of the antenna. The full LMT antenna, outfitted with its initial complement of scientific instruments, will be a world-leading scientific research facility for millimeter-wave astronomy.

  1. Solar Rotating Fourier Telescope

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan

    1994-01-01

    Proposed telescope based on absorbing Fourier-transform grids images full Sun at unprecedented resolution. Overcomes limitations of both conventional optical and pinhole cameras. Arrays of grids and detectors configured for sensitivity to selected fourier components of x-ray images.

  2. Exploring Galileo's Telescope

    ERIC Educational Resources Information Center

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  3. The Space Telescope Observatory

    NASA Technical Reports Server (NTRS)

    Bahcall, J. N.; Odell, C. R.

    1979-01-01

    A convenient guide to the expected characteristics of the Space Telescope Observatory for astronomers and physicists is presented. An attempt is made to provide enough detail so that a professional scientist, observer or theorist, can plan how the observatory may be used to further his observing programs or to test theoretical models.

  4. The Falcon Telescope Network

    NASA Astrophysics Data System (ADS)

    Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

    2014-09-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

  5. A Simple "Tubeless" Telescope

    ERIC Educational Resources Information Center

    Straulino, S.; Bonechi, L.

    2010-01-01

    Two lenses make it possible to create a simple telescope with quite large magnification. The set-up is very simple and can be reproduced in schools, provided the laboratory has a range of lenses with different focal lengths. In this article, the authors adopt the Keplerian configuration, which is composed of two converging lenses. This instrument,…

  6. Coherent array telescopes as a fifteen meter optical telescope equivalent

    NASA Astrophysics Data System (ADS)

    Odgers, G. J.

    1982-10-01

    The potential benefits of using a mirror array to form a large optical telescope equivalent to a 15 m monolithic mirror telescope are discussed. The concept comprises 25 three meter telescopes in a circular array or 13 double unit telescopes, also in a circular array. The double-units would have individual 4.2 m instruments. Meniscus-shaped mirrors with F/2 aperture ratios would allow lightweight construction. A smaller, four double unit telescope would be equivalent to an 8.4 m telescope, larger than any existing in the world. The viewing capabilities could also be extended to the IR. Each sector of the compound telescopes, if built with 3 m apertures, could be controlled with 1/20th arsec acccuracy. Finally, the inherent long baseline of an array telescope would permit enhanced interferometric viewing.

  7. The Large Millimeter Telescope

    NASA Astrophysics Data System (ADS)

    Hughes, David H.; Jáuregui Correa, Juan-Carlos; Schloerb, F. Peter; Erickson, Neal; Romero, Jose Guichard; Heyer, Mark; Reynoso, David Huerta; Narayanan, Gopal; Perez-Grovas, Alfonso Serrano; Souccar, Kamal; Wilson, Grant; Yun, Min

    2010-07-01

    This paper describes the current status of the Large Millimeter Telescope (LMT), the near-term plans for the telescope and the initial suite of instrumentation. The LMT is a bi-national collaboration between Mexico and the USA, led by the Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE) and the University of Massachusetts at Amherst, to construct, commission and operate a 50m-diameter millimeter-wave radio telescope. Construction activities are nearly complete at the 4600m LMT site on the summit of Volcán Sierra Negra, an extinct volcano in the Mexican state of Puebla. Full movement of the telescope, under computer control in both azimuth and elevation, has been achieved. The commissioning and scientific operation of the LMT is divided into two major phases. As part of phase 1, the installation of precision surface segments for millimeter-wave operation within the inner 32m-diameter of the LMT surface is now complete. The alignment of these surface segments is underway. The telescope (in its 32-m diameter format) will be commissioned later this year with first-light scientific observations at 1mm and 3mm expected in early 2011. In phase 2, we will continue the installation and alignment of the remainder of the reflector surface, following which the final commissioning of the full 50-m LMT will take place. The LMT antenna, outfitted with its initial complement of scientific instruments, will be a world-leading scientific research facility for millimeter-wave astronomy.

  8. Giant Magellan Telescope: overview

    NASA Astrophysics Data System (ADS)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  9. The Greenland Telescope

    NASA Astrophysics Data System (ADS)

    Grimes, Paul; Blundell, Raymond

    2012-09-01

    In the spring of 2010, the Academia Sinica Institute of Astronomy and Astrophysics, and the Smithsonian Astrophysical Observatory, acquired the ALMA North America prototype antenna - a state-of-the-art 12-m diameter dish designed for submillimeter astronomy. Together with the MIT-Haystack Observatory and the National Radio Astronomy Observatory, the plan is to retrofit this antenna for cold-weather operation and equip it with a suite of instruments designed for a variety of scientific experiments and observations. The primary scientific goal is to image the shadow of the Super-Massive Black Hole in M87 in order to test Einstein’s theory of relativity under extreme gravity. This requires the highest angular resolution, which can only be achieved by linking this antenna with others already in place to form a telescope almost the size of the Earth. We are therefore developing plans to install this antenna at the peak of the Greenland ice-sheet. This location will produce an equivalent North-South separation of almost 9,000 km when linked to the ALMA telescope in Northern Chile, and an East-West separation of about 6,000 km when linked to SAO and ASIAA’s Submillimeter Array on Mauna Kea, Hawaii, and will provide an angular resolution almost 1000 times higher than that of the most powerful optical telescopes. Given the quality of the atmosphere at the proposed telescope location, we also plan to make observations in the atmospheric windows at 1.3 and 1.5 THz. We will present plans to retrofit the telescope for cold-weather operation, and discuss potential instrumentation and projected time-line.

  10. Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey

    2007-05-01

    The Allen Telescope Array (ATA) is a pioneering centimeter-wavelength radio telescope that will produce science that cannot be done with any other instrument. The ATA is the first radio telescope designed for commensal observing; it will undertake the most comprehensive and sensitive SETI surveys ever done as well as the deepest and largest area continuum and spectroscopic surveys. Science operations will commence this year with a 42-element array. The ATA will ultimately comprise 350 6-meter dishes at Hat Creek in California, and will make possible large, deep radio surveys that were not previously feasible. The telescope incorporates many new design features including hydroformed antenna surfaces, a log-periodic feed covering the entire range of frequencies from 500 MHz to 11.2 GHz, low noise, wide-band amplifiers with a flat response over the entire band. The full array has the sensitivity of the Very Large Array but with a survey capability that is greater by an order of magnitude due to the wide field of view of the 6-meter dishes. Even with 42 elements, the ATA will be one of the most powerful radio survey telescopes. Science goals include the Five GHz sky survey (FiGSS) to match the 1.4-GHz NRAO VLA Sky Survey (NVSS) and the Sloan Digital Sky Survey within the first year of operation with the 42 element array, and a deep all-sky survey of extragalactic hydrogen to investigate galaxy evolution and intergalactic gas accretion. Transient and variable source surveys, pulsar science, spectroscopy of new molecular species in the galaxy, large-scale mapping of galactic magnetic filaments, and wide-field imaging of comets and other solar system objects are among the other key science objectives of the ATA. SETI surveys will reach sufficient sensitivity to detect an Arecibo planetary radar from 1,000,000 stars to distances of 300 pc.

  11. Wavefront Analysis of Adaptive Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Hillman, Lloyd

    1997-01-01

    The motivation for this work came from a NASA Headquarters interest in investigating design concepts for a large space telescope employing active optics technology. The development of telescope optical requirements and potential optical design configurations is reported.

  12. The New 30 THz Solar Telescope in São Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Kudaka, A. S.; Cassiano, M. M.; Marcon, R.; Cabezas, D. P.; Fernandes, L. O. T.; Hidalgo Ramirez, R. F.; Kaufmann, P.; de Souza, R. V.

    2015-08-01

    It has been found that solar bursts exhibit one unexpected spectral component with fluxes increasing with frequency in the sub-THz range, which is distinct from the well-known microwave emission that peaks at a few to some tens of GHz. This component has been found to extend into the THz range of frequencies by recent 30 THz solar flare observations of impulsive bursts with flux intensities considerably higher than fluxes at sub-THz and microwaves frequencies. High-cadence solar observations at 30 THz (continuum) are therefore an important tool for the study of active regions and flaring events. We report the recent installation of a new 30 THz solar telescope in São Paulo, located at the top of one of the University's buildings. The instrument uses a Hale-type coelostat with two 20 cm diameter flat mirrors sending light to a 15 cm mirror Newtonian telescope. Radiation is directed to a microbolometer array camera that is kept at room temperature. Observations are usually obtained with 5 frames s^{-1} cadence. One 60 mm refractor has been added to observe H\\upalpha images simultaneously. We describe our new telescopes and the new observatory examples of the first results obtained.

  13. Science operations with Space Telescope

    NASA Astrophysics Data System (ADS)

    Giacconi, R.

    1982-08-01

    The operation, instrumentation, and expected contributions of the Space Telescope are discussed. Space Telescope capabilities are described. The organization and nature of the Space Telescope Science Institute are outlined, including the allocation of observing time and the data rights and data access policies of the institute.

  14. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1992-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  15. Lunar transit telescope lander design

    NASA Technical Reports Server (NTRS)

    Omar, Husam A.

    1991-01-01

    The Program Development group at NASA's Marshall Space Flight Center has been involved in studying the feasibility of placing a 16 meter telescope on the lunar surface to scan the skies using visible/ Ultraviolet/ Infrared light frequencies. The precursor telescope is now called the TRANSIT LUNAR TELESCOPE (LTT). The Program Development Group at Marshall Space Flight Center has been given the task of developing the basic concepts and providing a feasibility study on building such a telescope. The telescope should be simple with minimum weight and volume to fit into one of the available launch vehicles. The preliminary launch date is set for 2005. A study was done to determine the launch vehicle to be used to deliver the telescope to the lunar surface. The TITAN IV/Centaur system was chosen. The engineering challenge was to design the largest possible telescope to fit into the TITAN IV/Centaur launch system. The telescope will be comprised of the primary, secondary and tertiary mirrors and their supporting system in addition to the lander that will land the telescope on the lunar surface and will also serve as the telescope's base. The lunar lander should be designed integrally with the telescope in order to minimize its weight, thus allowing more weight for the telescope and its support components. The objective of this study were to design a lander that meets all the constraints of the launching system. The basic constraints of the TITAN IV/Centaur system are given.

  16. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Deboer, David; Ackermann, Rob; Blitz, Leo; Bock, Douglas; Bower, Geoffrey; Davis, Michael; Dreher, John; Engargiola, Greg; Fleming, Matt; Keleta, Girmay; Harp, Gerry; Lugten, John; Tarter, Jill; Thornton, Doug; Wadefalk, Niklas; Weinreb, Sander; Welch, William J.

    2004-06-01

    The Allen Telescope Array, a joint project between the SETI Institute and the Radio Astronomy Laboratory at the University of California Berkeley, is currently under development and construction at the Hat Creek Radio Observatory in northern California. It will consist of 350 6.1-m offset Gregorian antennas in a fairly densely packed configuration, with minimum baselines of less than 10 m and a maximum baseline of about 900 m. The dual-polarization frequency range spans from about 500 MHz to 11 GHz, both polarizations of which are transported back from each antenna. The first generation processor will provide 32 synthesized beams of 104 MHz bandwidth, eight at each of four tunings, as well as outputs for a full-polarization correlator at two of the tunings at the same bandwidth. This paper provides a general description of the Allen Telescope Array.

  17. Telescopes of galileo.

    PubMed

    Greco, V; Molesini, G; Quercioli, F

    1993-11-01

    The Florentine Istituto e Museo di Storia delta Scienza houses two complete telescopes and a single objective lens (reconstructed from several fragments) that can be attributed to Galileo. These optics have been partially dismantled and made available for optical testing with state-of-the-art equipment. The lenses were investigated individually; the focal length and the radii of curvature were measured, and the optical layout of the instruments was worked out. The optical quality of the surfaces and the overall performance of the two complete telescopes have been evaluated interferometrically at a wavelength of 633 nm (with a He-Ne laser source). It was found in particular that the optics of Galileo came close to attaining diffraction-limited operation.

  18. The European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Socas-Navarro, H.

    2012-12-01

    In this presentation I will describe the current status of the European Solar Telescope (EST) project. The EST design has a 4-m aperture to achieve both a large photon collection and very high spatial resolution. It includes a multi-conjugate adaptive system integrated in the light path for diffraction-limited imaging. The optical train is optimized to minimize instrumental polarization and to keep it nearly constant as the telescope tracks the sky. A suite of visible and infrared instruments are planned with a light distribution system that accomodates full interoperability and simultaneous usage. The science drivers emphasize combined observations at multiple heights in the atmosphere to build a connected view of solar magnetism from the photosphere to the corona.

  19. COROT telescope development

    NASA Astrophysics Data System (ADS)

    Viard, Thierry; Bodin, Pierre; Magnan, Alain

    2004-06-01

    COROTEL is the telescope of the future COROT satellite which aims at measuring stellar flux variations very accurately. To perform this mission, COROTEL has to be very well protected against straylight (from Sun and Earth) and must be very stable with time. Thanks to its high experience in this field, Alcatel Space has proposed an original optical concept associated with a high performance baffle. From 2001, the LAM (Laboratoire d'Astrophysique de Marseille, CNRS) has placed the telescope development contract to Alcatel Space and is presently almost finished. Based on relevant material and efficient thermal control design, COROTEL should meet its ambitious performance and bring to scientific community for the first time precious data coming from stars and their possible companions.

  20. Telescopic limiting magnitudes

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.

    1990-01-01

    The prediction of the magnitude of the faintest star visible through a telescope by a visual observer is a difficult problem in physiology. Many prediction formulas have been advanced over the years, but most do not even consider the magnification used. Here, the prediction algorithm problem is attacked with two complimentary approaches: (1) First, a theoretical algorithm was developed based on physiological data for the sensitivity of the eye. This algorithm also accounts for the transmission of the atmosphere and the telescope, the brightness of the sky, the color of the star, the age of the observer, the aperture, and the magnification. (2) Second, 314 observed values for the limiting magnitude were collected as a test of the formula. It is found that the formula does accurately predict the average observed limiting magnitudes under all conditions.

  1. The Neutrino Telescope ANTARES

    NASA Astrophysics Data System (ADS)

    Hernández, Juan José

    Neutrinos can reveal a brand new Universe at high energies. The ANTARES collaboration [1] , formed in 1996, works towards the building and deployment of a neutrino telescope. This detector could observe and study high energy astrophysical sources such as X-ray binary systems, young supernova remnants or Active Galactic Nuclei and help to discover or set exclusion limits on some of the elementary particles and objects that have been put forward as candidates to fill the Universe (WIMPS, neutralinos, topological deffects, Q-balls, etc). A neutrino telescope will certainly open a new observational window and can shed light on the most energetic phenomena of the Universe. A review of the progress made by the ANTARES collaboration to achieve this goal is presented

  2. The Large Area Telescope

    SciTech Connect

    Michelson, Peter F.; /KIPAC, Menlo Park /Stanford U., HEPL

    2007-11-13

    The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large Area Space Telescope (GLAST) mission, is an imaging, wide field-of-view, high-energy pair-conversion telescope, covering the energy range from {approx}20 MeV to more than 300 GeV. The LAT is being built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. The scientific objectives the LAT will address include resolving the high-energy gamma-ray sky and determining the nature of the unidentified gamma-ray sources and the origin of the apparently isotropic diffuse emission observed by EGRET; understanding the mechanisms of particle acceleration in celestial sources, including active galactic nuclei, pulsars, and supernovae remnants; studying the high-energy behavior of gamma-ray bursts and transients; using high-energy gamma-rays to probe the early universe to z {ge} 6; and probing the nature of dark matter. The components of the LAT include a precision silicon-strip detector tracker and a CsI(Tl) calorimeter, a segmented anticoincidence shield that covers the tracker array, and a programmable trigger and data acquisition system. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large field-of-view and ensuring that nearly all pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. This paper includes a description of each of these LAT subsystems as well as a summary of the overall performance of the telescope.

  3. [Galileo and his telescope].

    PubMed

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  4. [Galileo and his telescope].

    PubMed

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book. PMID:16929794

  5. MIRI Telescope Simulator

    NASA Astrophysics Data System (ADS)

    Belenguer, T.; Alcacera, M. A.; Aricha, A.; Balado, A.; Barandiarán, J.; Bernardo, A.; Canchal, M. R.; Colombo, M.; Diaz, E.; Eiriz, V.; Figueroa, I.; García, G.; Giménez, A.; González, L.; Herrada, F.; Jiménez, A.; López, R.; Menéndez, M.; Reina, M.; Rodríguez, J. A.; Sánchez, A.

    2008-07-01

    The MTS, MIRI Telescope Simulator, is developed by INTA as the Spanish contribution of MIRI (Mid InfraRed Instrument) on board JWST (James Web Space Telescope). The MTS is considered as optical equipment which is part of Optical Ground Support Equipment for the AIV/Calibration phase of the instrument at Rutherford Appleton Laboratory, UK. It is an optical simulator of the JWST Telescope, which will provide a diffractionlimited test beam, including the obscuration and mask pattern, in all the MIRI FOV and in all defocusing range. The MTS will have to stand an environment similar to the flight conditions (35K) but using a smaller set-up, typically at lab scales. The MTS will be used to verify MIRI instrument-level tests, based on checking the implementation/realisation of the interfaces and performances, as well as the instrument properties not subject to interface control such as overall transmission of various modes of operation. This paper includes a functional description and a summary of the development status.

  6. Hubble Space Telescope satellite

    NASA Technical Reports Server (NTRS)

    Mitchell, R. E.

    1985-01-01

    The Hubble Space Telescope, named for the American astronomer Edwin Powell Hubble, will be the largest and most powerful astronomical instrument ever orbited. Placed above the obscuring effects of the earth's atmosphere in a 600-km orbit, this remotely-controlled, free-flying satellite observatory will expand the terrestrial-equivalent resolution of the universe by a factor of seven, or a volumetric factor of 350. This telescope has a 2.4-m primary mirror and can accommodate five scientific instruments (cameras, spectrographs and photometers). The optics are suitable for a spectral range from 1100 angstrom to 1 mm wavelength. With a projected service life of fifteen years, the spacecraft can be serviced on-orbit for replacement of degraded systems, to insert advanced scientific instruments, and to reboost the telescope from decayed altitudes. The anticipated image quality will be a result of extremely precise lambda/20 optics, stringent cleanliness, and very stable pointing: jitter will be held to less than 0.01 arcsecond for indefinite observation periods, consistent with instrument apertures as small as 0.1 arcsecond.

  7. Fast Fourier transform telescope

    SciTech Connect

    Tegmark, Max; Zaldarriaga, Matias

    2009-04-15

    We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore's law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog{sub 2}N rather than N{sup 2}) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

  8. Scanning holographic lidar telescope

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Wilkerson, Thomas D.

    1993-01-01

    We have developed a unique telescope for lidar using a holographic optical element (HOE) as the primary optic. The HOE diffracts 532 nm laser backscatter making a 43 deg angle with a normal to its surface to a focus located 130 cm along the normal. The field of view scans a circle as the HOE rotates about the normal. The detector assembly and baffling remain stationary, compared to conventional scanning lidars in which the entire telescope and detector assembly require steering, or which use a large flat steerable mirror in front of the telescope to do the pointing. The spectral bandpass of our HOE is 50 nm (FWHM). Light within that bandpass is spectrally dispersed at 0.6 nm/mm in the focal plane. An aperture stop reduces the bandpass of light reaching the detector from one direction to 1 nm while simultaneously reducing the field of view to 1 mrad. Wavelengths outside the 50 nm spectral bandpass pass undiffracted through HOE to be absorbed by a black backing. Thus, the HOE combines three functions into one optic: the scanning mirror, the focusing mirror, and a narrowband filter.

  9. Obtaining a Permit-To for a Hale-Uav in Belgium

    NASA Astrophysics Data System (ADS)

    Everaerts, J.; Lewyckyj, N.

    2011-09-01

    Ever since 2000, VITO has been working on the Pegasus project. This involves a solar High Altitude Long Endurance Unmanned Aerial Vehicle (HALE-UAV) as a stratospheric platform for Earth Observation. This aircraft, called Mercator, is designed to fly for prolonged duration at altitudes up to 20 km. The technology has been proven by the aircraft's manufacturer, QinetiQ (UK) by a series of test flights over the past years, culminating in a world record flight in duration of over 14 days duration. All test flights, however, were conducted in test ranges, where other air traffic does not pose a concern. Pegasus aims to demonstrate the viability of stratospheric Earth Observation in Belgium, as a proof of concept for other areas around the world. The Belgian air space is completely different from a test range. More than 1 million aircraft movements take place over Belgium and Luxembourg every year, with routes to Amsterdam, Paris, Frankfurt, and London. Although Pegasus will usually be flying above this dense traffic, it does interfere with it during ascent and landing, and needs to be monitored during the cruise phase for safety reasons. Air traffic management in Belgium is a shared responsibility of Air Navigation Service Providers (ANSPs) Belgocontrol (civil), ATCC (military) and Eurocontrol MUAC (high altitude). In 2010, VITO applied for a permit-to-fly for a test flight of one day duration. Although the Belgian Civil Aviation Authority (CAA) had issued a regulation on UAVs in 2007, it was the first application for a permit to fly in controlled airspace. The Belgian CAA decided to use it as a test for the procedures as well. A prerequisite for flying in controlled airspace was that the aircraft has to carry a mode-S transponder and navigation lights. During first half of 2010, the ANSPs collaborated on a Temporary Operations Instruction and studied the safety impact of this flight on their operations. As an outcome, they decided that the Pegasus aircraft would be

  10. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    DeBoer, David R.; Welch, William J.; Dreher, John; Tarter, Jill; Blitz, Leo; Davis, Michael; Fleming, Matt; Bock, Douglas; Bower, Geoffrey; Lugten, John; Girmay-Keleta, G.; D'Addario, Larry R.; Harp, Gerry R.; Ackermann, Rob; Weinreb, Sander; Engargiola, Greg; Thornton, Doug; Wadefalk, Niklas

    2004-10-01

    The Allen Telescope Array, originally called the One Hectare Telescope (1hT) [1] will be a large array radio telescope whose novel characteristics will be a wide field of view (3.5 deg-GHz HPBW), continuous frequency coverage of 0.5 - 11 GHz, four dual-linear polarization output bands of 100 MHz each, four beams in each band, two 100 MHz spectral correlators for two of the bands, and hardware for RFI mitigation built in. Its scientific motivation is for deep SETI searches and, at the same time, a variety of other radio astronomy projects, including transient (e.g. pulsar) studies, HI mapping of the Milky Way and nearby galaxies, Zeeman studies of the galactic magnetic field in a number of transitions, mapping of long chain molecules in molecular clouds, mapping of the decrement in the cosmic background radiation toward galaxy clusters, and observation of HI absorption toward quasars at redshifts up to z=2. The array is planned for 350 6.1-meter dishes giving a physical collecting area of about 10,000 square meters. The large number of components reduces the price with economies of scale. The front end receiver is a single cryogenically cooled MIMIC Low Noise Amplifier covering the whole band. The feed is a wide-band log periodic feed of novel design, and the reflector system is an offset Gregorian for minimum sidelobes and spillover. All preliminary and critical design reviews have been completed. Three complete antennas with feeds and receivers are under test, and an array of 33 antennas is under construction at the Hat Creek Radio Observatory for the end of 2004. The present plan is to have a total of about 200 antennas completed by the summer of 2006 and the balance of the array finished before the end of the decade.

  11. Comparing NEO Search Telescopes

    NASA Astrophysics Data System (ADS)

    Myhrvold, Nathan

    2016-04-01

    Multiple terrestrial and space-based telescopes have been proposed for detecting and tracking near-Earth objects (NEOs). Detailed simulations of the search performance of these systems have used complex computer codes that are not widely available, which hinders accurate cross-comparison of the proposals and obscures whether they have consistent assumptions. Moreover, some proposed instruments would survey infrared (IR) bands, whereas others would operate in the visible band, and differences among asteroid thermal and visible-light models used in the simulations further complicate like-to-like comparisons. I use simple physical principles to estimate basic performance metrics for the ground-based Large Synoptic Survey Telescope and three space-based instruments—Sentinel, NEOCam, and a Cubesat constellation. The performance is measured against two different NEO distributions, the Bottke et al. distribution of general NEOs, and the Veres et al. distribution of Earth-impacting NEO. The results of the comparison show simplified relative performance metrics, including the expected number of NEOs visible in the search volumes and the initial detection rates expected for each system. Although these simplified comparisons do not capture all of the details, they give considerable insight into the physical factors limiting performance. Multiple asteroid thermal models are considered, including FRM, NEATM, and a new generalized form of FRM. I describe issues with how IR albedo and emissivity have been estimated in previous studies, which may render them inaccurate. A thermal model for tumbling asteroids is also developed and suggests that tumbling asteroids may be surprisingly difficult for IR telescopes to observe.

  12. The Planck Telescope reflectors

    NASA Astrophysics Data System (ADS)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  13. Astronomy before the telescope.

    NASA Astrophysics Data System (ADS)

    Walker, C.

    This book is the most comprehensive and authoritative survey to date of world astronomy before the telescope in AD 1609. International experts have contributed chapters examining what observations were made, what instruments were used, the effect of developments in mathematics and measurement, and the diversity of early views of cosmology and astrology. The achievements of European astronomers from prehistoric times to the Renaissance are linked with those of ancient Egypt and Mesopotamia, India and the Islamic world. Other chapters deal with early astronomy in the Far East and in the Americas, and with traditional astronomical knowledge in Africa, Australia and the Pacific.

  14. Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Nurre, G.

    1987-01-01

    The Hubble Space Telescope will employ magnetic torque controllers, which make use of the Earth's magnetic field augmented by four reaction wheels. DC torques are easily allowed for, but variations, orbit by orbit, can result in excessive wheel speeds which can excite vibratory modes in the telescope structure. If the angular momentum from aerodynamic sources exceeds its allocation of 100 Nms, the excess has to come out of the maneuvering budget since the total capacity of the momentum storage system is fixed at 500 Nms. This would mean that maneuvers could not be made as quickly, and this would reduce the amount of science return. In summary, there is a definite need for a model that accurately portrays short term (within orbit) variations in density for use in angular momentum management analyses. It would be desirable to have a simplified model that could be used for planning purposes; perhaps applicable only over a limited altitude range (400 to 700 km) and limited latitude band.

  15. Antares Reference Telescope System

    SciTech Connect

    Viswanathan, V.K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

    1983-01-01

    Antares is a 24-beam, 40-TW carbon-dioxide laser-fusion system currently nearing completion at the Los Alamos National Laboratory. The 24 beams will be focused onto a tiny target (typically 300 to 1000 ..mu..m in diameter) located approximately at the center of a 7.3-m-diameter by 9.3-m-long vacuum (10/sup -6/ torr) chamber. The design goal is to position the targets to within 10 ..mu..m of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares Reference Telescope System is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares Reference Telescope System consists of two similar electro-optical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: (1) a fixed 9X optical imaging subsystem which produces an image of the target at the vidicon; (2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; (3) an adjustable front-lighting subsystem which illuminates the target; and (4) an adjustable back-lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and trade-offs are discussed. The final system chosen (which is being built) and its current status are described in detail.

  16. Antares reference telescope system

    NASA Astrophysics Data System (ADS)

    Viswanathan, V. K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

    Antares is a 24 beam, 40 TW carbon dioxide laser fusion system currently nearing completion. The 24 beams will be focused onto a tiny target. It is to position the targets to within 10 (SIGMA)m of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares reference telescope system is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares reference telescope system consists of two similar electrooptical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: (1) a fixed 9% optical imaging subsystem which produces an image of the target at the vidicon; (2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; (3) an adjustable front lighting subsystem which illuminates the target; and (4) an adjustable back lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and tradeoffs are discussed. The final system chosen and its current status are described.

  17. SNAP Telescope Latest Developments

    NASA Astrophysics Data System (ADS)

    Lampton, M.; SNAP Collaboration

    2004-12-01

    The coming era of precision cosmology imposes new demands on space telescopes with regard to spectrophotometric accuracy and image stability. To meet these requirements for SNAP we have developed an all reflecting two-meter-class space telescope of the three-mirror anastigmat type. Our design features a large flat annular field (1.5 degrees = 580mm diameter) and a telephoto advantage of 6, delivering a 22m focal length within an optical package length of only 3.5 meters. The use of highly stable materials (Corning ULE glass and carbon-fiber reinforced cyanate ester resin for the metering structure) combined with agressive distributed thermal control and an L2 orbit location will lead to unmatched figure stability. Owing to our choice of rigid structure with nondeployable solar panels, finite-element models show no structural resonances below 10Hz. An exhaustive stray light study has been completed. Beginning in 2005, two industry studies will develop plans for fabrication, integration and test, bringing SNAP to a highly realistic level of definition. SNAP is supported by the Office of Science, US DoE, under contract DE-AC03-76SF00098.

  18. The Parkes radio telescope - 1986

    NASA Astrophysics Data System (ADS)

    Ables, J. G.; Jacka, C. E.; McConnell, D.; Schinckel, A. E.; Hunt, A. J.

    The Parkes radio telescope has been refurbished 25 years after its commisioning in 1961, with complete replacement of its drive and control systems. The new computer system distributes computing tasks among a loosely coupled network of minicomputers which communicate via full duplex serial lines. Central to the control system is the 'CLOCK' element, which relates all positioning of the telescope to absolute time and synchronizes the logging of astronomical data. Two completely independent servo loops furnish telescope positioning functions.

  19. VizieR Online Data Catalog: ATLAS 1.4GHz Data Release 2 (Hales+, 2014)

    NASA Astrophysics Data System (ADS)

    Hales, C. A.; Norris, R. P.; Gaensler, B. M.; Middelberg, E.; Chow, K. E.; Hopkins, A. M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2015-02-01

    ATLAS observations of the CDF-S and ELAIS-S1 fields were obtained with the ATCA, a synthesis telescope consisting of six 22m alt-az antennas on an east-west baseline. Each antenna is equipped with linearly polarized feeds used to measure all four polarization products (XX, YY, XY, YX), from which all four Stokes parameters (I, Q, U, V) can be derived. Noise diodes in the feed horns of each antenna replace the need to observe a polarization position angle calibrator to derive absolute XY phase. We supplemented our 1.4GHz radio observations with data at infrared and optical wavelengths. (2 data files).

  20. Telescope structures - An evolutionary overview

    NASA Technical Reports Server (NTRS)

    Meinel, Aden B.; Meinel, Marjorie P.

    1987-01-01

    A development history is presented for telescope structural support materials, design concepts, equatorial and altazimuthal orientational preferences, and mechanical control system structural realizations. In the course of 50 years after Galileo, the basic configurations of all reflecting telescopes was set for the subsequent 300 years: these were the Cassegrain, Gregorian, and Newtonian designs. The challenge of making a lightweight ribbed pyrex glass primary mirror for the 5-m Palomar telescope was met by von Karman's use of finite element analysis. Attention is given to the prospects for a 20-m deployable space-based reflecting telescope.

  1. Why Space Telescopes Are Amazing

    NASA Technical Reports Server (NTRS)

    Rigby, Jane R.

    2012-01-01

    One of humanity's best ideas has been to put telescopes in space. The dark stillness of space allows telescopes to perform much better than they can on even the darkest and clearest of Earth's mountaintops. In addition, from space we can detect colors of light, like X-rays and gamma rays, that are blocked by the Earth's atmosphere I'll talk about NASA's team of great observatories: the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory} and how they've worked together to answer key questions: When did the stars form? Is there really dark matter? Is the universe really expanding ever faster and faster?

  2. Ground-based thermal infrared observations of comet Hale-Bopp (C/1995 O1) during 1996.

    PubMed

    Hayward, T L; Hanner, M S

    1997-03-28

    Thermal infrared (IR) imaging and spectroscopy of comet Hale-Bopp (C/1995 O1) during June, August, and September 1996 traced the development of the dust coma several months before perihelion. Images revealed nightly variations in the brightness of the inner coma from 1 to 12 June that were correlated with the appearance of a northward-pointing jet. The central IR flux increased by a factor of 8 between 1 June and 30 September, and the September data showed IR jets that corresponded to similar structures that were visible in reflected sunlight at shorter wavelengths. At all epochs, 8- to 13-micrometer spectra of the central coma revealed a strong silicate emission feature, including an 11.2-micrometer feature indicative of crystalline olivine, even when the comet was at a heliocentric distance of 4.1 astronomical units.

  3. The spectrum and spatial distribution of cyanogen in comet Hale-Bopp (C/1995 O1) at large heliocentric distance.

    PubMed

    Wagner, R M; Schleicher, D G

    1997-03-28

    Optical spectra of comet Hale-Bopp (C/1995 O1) at a heliocentric distance of 6.45 astronomical units showed emission from cyanogen gas. The spatial distribution of cyanogen was considerably more diffuse and extended compared to the spatial profile of the dust or grains which were sharply peaked near the center. This behavior is consistent with comets at smaller heliocentric distances suggesting the same or a similar formation mechanism. A cyanogen gas production rate of (1.2 +/- 0.3) x10(26) molecules per second was derived. A model band profile derived from fluorescence equilibrium calculations for the comet's heliocentric velocity and distance agrees with the observed band profile.

  4. Coma Morphology Due to an Extended Active Region and Implications for the Spin State of Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Samarasinha, Nalin H.

    2000-01-01

    We show that the circular character of continuum structures observed in the coma of comet Hale-Bopp around the perihelion passage is most likely due to a dust jet from a large extended active region on the surface. Coma morphology due to a wide jet is different from that due to a narrow jet. The latter shows foreshortening effects due to observing geometry, wider jet produces more circular features. This circularization effect provides a self-consistent explanation for the evolution of near-perihelion coma morphology. No changes in the direction of the rotational angular momentum vector are required during this period in contrast to the models of Schleicher et al. This circularization effect also enables us to produce near-circular coma features in the S-E quadrant during 1997 late February and therefore questions the basic premise on which Sekanina bases his morphological arguments for a gravitationally bound satellite nucleus.

  5. Physiological and chemical response of the lichen, Flavoparmelia caperata (L.) Hale, to the urban environment of Kolkata, India.

    PubMed

    Majumder, S; Mishra, D; Ram, S S; Jana, N K; Santra, S; Sudarshan, M; Chakraborty, A

    2013-05-01

    The present study was focused on the effect of increasing urbanization including industrial and traffic activity on the accumulation of heavy metals and possible damage of selected physiological parameters (composition of assimilation pigments, membrane lipid peroxidation, and membrane integrity) of an epiphytic foliose lichen, Flavoparmelia caperata (L.) Hale. The lichen samples were collected from three different localities in and around Kolkata, India, two sites being from the urban area and one from the relatively non-polluted sub-urban area. The results showed that thalli from the urban sites have significantly higher concentrations of Fe, Cr, Cu, Zn, and Pb compared to those collected from the sub-urban site. Physiological parameters of damage also exhibited stress symptoms in thalli from the urban sites--decreased chlorophyll a indicating less photosynthetic efficiency, and increase in lipid peroxidation and electrolyte conductivity indicating cell membrane injuries. Correlation studies among metals pinpointed vehicular traffic as the main source of pollution in this area.

  6. Stephen Hales: the contributions of an Enlightenment physiologist to the study of the kidney in health and disease.

    PubMed

    Eknoyan, Garabed

    2016-02-01

    Stephen Hales (1677-1761) was an English clergyman who made major contributions to a wide range of scientific topics such as botany, chemistry, pneumatics, and physiology. Early in his career he developed a keen interest in medicine through his association with his younger physician friend at Cambridge, William Stukeley (1687-1765), with whom he dissected animals and attended experiments in the laboratory of Isaac Newton. His fame as a scientist grew and by the end of his life he had achieved an international reputation as a major scientist of the Enlightenment. He is best known for his 1733 Statical Essays, in the second part of which he describes his studies in animal physiology. Most famous amongst those are his assessments of the force of the blood, which he measured in horses and dogs. Less well known and often unrecognized are his studies on the kidney in health and disease, which are the focus of this review. Amongst others Hales described the effects of hemorrhagic shock which he observed as he bled his animals while measuring their blood pressure; he then studied the effect of increasing saline perfusion pressures on the renal secretion of urine; and delved into biochemistry in exploring the composition of and solutions to dissolve bladder stones. His 1733 statement in the introduction to his hemodynamic studies that the healthy State of the Animal principally consists, in the maintaining of a due Equilibrium between the body solids and fluids literally predicts the milieu intrieur that would ultimately be formulated in 1854 by Claude Bernard (1813-1878).

  7. Stephen Hales: the contributions of an Enlightenment physiologist to the study of the kidney in health and disease.

    PubMed

    Eknoyan, Garabed

    2016-02-01

    Stephen Hales (1677-1761) was an English clergyman who made major contributions to a wide range of scientific topics such as botany, chemistry, pneumatics, and physiology. Early in his career he developed a keen interest in medicine through his association with his younger physician friend at Cambridge, William Stukeley (1687-1765), with whom he dissected animals and attended experiments in the laboratory of Isaac Newton. His fame as a scientist grew and by the end of his life he had achieved an international reputation as a major scientist of the Enlightenment. He is best known for his 1733 Statical Essays, in the second part of which he describes his studies in animal physiology. Most famous amongst those are his assessments of the force of the blood, which he measured in horses and dogs. Less well known and often unrecognized are his studies on the kidney in health and disease, which are the focus of this review. Amongst others Hales described the effects of hemorrhagic shock which he observed as he bled his animals while measuring their blood pressure; he then studied the effect of increasing saline perfusion pressures on the renal secretion of urine; and delved into biochemistry in exploring the composition of and solutions to dissolve bladder stones. His 1733 statement in the introduction to his hemodynamic studies that the healthy State of the Animal principally consists, in the maintaining of a due Equilibrium between the body solids and fluids literally predicts the milieu intrieur that would ultimately be formulated in 1854 by Claude Bernard (1813-1878). PMID:26913873

  8. Large space telescope, phase A. Volume 3: Optical telescope assembly

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

  9. Gamma-Ray Telescopes: 400 Years of Astronomical Telescopes

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Cannizzo, John K.

    2010-01-01

    The last half-century has seen dramatic developments in gamma-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as gamma-ray bursts, blazars, Galactic transients, and the Galactic distribution of Al-26.

  10. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Astronomers using the Hubble Space Telescope (HST) have identified what may be the most luminous star known; a celestial mammoth that releases up to 10-million times the power of the Sun and is big enough to fill the diameter of Earth's orbit. The star unleashes as much energy in six seconds as our Sun does in one year. The image, taken by a UCLA-led team with the recently installed Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) aboard the HST, also reveals a bright nebula, created by extremely massive stellar eruptions. The UCLA astronomers estimate that the star, called the Pistol Star, (for the pistol shaped nebula surrounding it), is approximately 25,000 light-years from Earth, near the center of our Milky Way galaxy. The Pistol Star is not visible to the eye, but is located in the direction of the constellation Sagittarius, hidden behind the great dust clouds along the Milky Way

  11. Composite telescope technology

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Rabin, Douglas

    2014-07-01

    We report the development of optical mirrors based on polymer matrix composite materials. Advantages of this technology are low cost and versatility. By using appropriate combinations of polymers and various metallic and nonmetallic particles and fibers, the properties of the materials can be tailored to suit a wide variety of applications. We report the fabrication and testing of flat and curved mirrors made with metal powders, multiple mirrors replicated with high degree of uniformity from the same mandrels, cryogenic testing, mirrors made of ferromagnetic materials that can be actively or adaptively controlled by non-contact actuation, optics with very smooth surfaces made by replication, and by spincasting. We discuss development of a new generation of ultra-compact, low power active optics and 3D printing of athermal telescopes.

  12. Microoptical telescope compound eye.

    PubMed

    Duparré, Jacques; Schreiber, Peter; Matthes, André; Pshenay-Severin, Ekaterina; Bräuer, Andreas; Tünnermann, Andreas; Völkel, Reinhard; Eisner, Martin; Scharf, Toralf

    2005-02-01

    A new optical concept for compact digital image acquisition devices with large field of view is developed and proofed experimentally. Archetypes for the imaging system are compound eyes of small insects and the Gabor-Superlens. A paraxial 3x3 matrix formalism is used to describe the telescope arrangement of three microlens arrays with different pitch to find first order parameters of the imaging system. A 2mm thin imaging system with 21x3 channels, 70 masculinex10 masculine field of view and 4.5mm x 0.5mm image size is optimized and analyzed using sequential and non-sequential raytracing and fabricated by microoptics technology. Anamorphic lenses, where the parameters are a function of the considered optical channel, are used to achieve a homogeneous optical performance over the whole field of view. Captured images are presented and compared to simulation results. PMID:19494951

  13. The Travelling Telescope

    NASA Astrophysics Data System (ADS)

    Owen, Daniel

    2015-08-01

    The telescope has been around for over 400 years, yet most people have never looked though one. We invite people outside under the stars to learn about those curious lights in the sky, and have a close encounter with the cosmos.Our main aim is to promote science, technology, engineering, and mathematics to the young minds by inspiring, empowering and engaging them using astronomy and astrophysics tools and concepts. We would like to see Africa compete with the rest of the world and we believe this can happen through having a scientifically literate society. We also work closely wit teachers, parents and the general public to further our objectives. We will present on our recently awarded project to work with schools in rural coastal Kenya, a very poor area of the country. We will also present on other work we continue to do with schools to make our project sustainable even after the OAD funding.

  14. Actuated Hybrid Mirror Telescope

    NASA Technical Reports Server (NTRS)

    Hickey, Gregory; Redding, David; Lowman, Andrew; Cohen, David; Ohara, Catherine

    2005-01-01

    The figure depicts the planned Actuated Hybrid Mirror Telescope (AHMT), which is intended to demonstrate a new approach to the design and construction of wide-aperture spaceborne telescopes for astronomy and Earth science. This technology is also appropriate for Earth-based telescopes. The new approach can be broadly summarized as using advanced lightweight mirrors that can be manufactured rapidly at relatively low cost. More specifically, it is planned to use precise replicated metallic nanolaminate mirrors to obtain the required high-quality optical finishes. Lightweight, dimensionally stable silicon carbide (SiC) structures will support the nanolaminate mirrors in the required surface figures. To enable diffraction- limited telescope performance, errors in surface figures will be corrected by use of mirror-shape-control actuators that will be energized, as needed, by a wave-front-sensing and control system. The concepts of nanolaminate materials and mirrors made from nanolaminate materials were discussed in several previous NASA Tech Briefs articles. Nanolaminates constitute a relatively new class of materials that can approach theoretical limits of stiffness and strength. Nanolaminate mirrors are synthesized by magnetron sputter deposition of metallic alloys and/or compounds on optically precise master surfaces to obtain optical-quality reflector surfaces backed by thin shell structures. As an integral part of the deposition process, a layer of gold that will constitute the reflective surface layer is deposited first, eliminating the need for a subsequent and separate reflective-coating process. The crystallographic textures of the nanolaminate will be controlled to optimize the performance of the mirror. The entire deposition process for making a nanolaminate mirror takes less than 100 hours, regardless of the mirror diameter. Each nanolaminate mirror will be bonded to its lightweight SiC supporting structure. The lightweight nanolaminate mirrors and Si

  15. Asteroseismology with robotic telescopes

    NASA Astrophysics Data System (ADS)

    Handler, G.

    2004-10-01

    Asteroseismology explores the interior of pulsating stars by analysing their normal mode spectrum. The detection of a sufficient number of pulsation modes for seismic modelling of main sequence variables requires large quantities of high-precision time resolved photometry. Robotic telescopes have become an asset for asteroseismology because of their stable instrumentation, cost- and time-efficient operation and the potentially large amounts of observing time available. We illustrate these points by presenting selected results on several types of pulsating variables, such as δ Scuti stars (main sequence and pre-main sequence), γ Doradus stars, rapidly oscillating Ap stars and β Cephei stars, thereby briefly reviewing recent success stories of asteroseismic studies of main sequence stars.

  16. The metagenomic telescope.

    PubMed

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well-known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well-researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms. PMID:25054802

  17. The metagenomic telescope.

    PubMed

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well-known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well-researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms.

  18. The Metagenomic Telescope

    PubMed Central

    Szalkai, Balázs; Scheer, Ildikó; Nagy, Kinga; Vértessy, Beáta G.; Grolmusz, Vince

    2014-01-01

    Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well–known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair); next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well–researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis); and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms. PMID:25054802

  19. Kashima 34-m Radio Telescope

    NASA Technical Reports Server (NTRS)

    Sekido, Mamoru; Kawai, Eiji

    2013-01-01

    The Kashima 34-m radio telescope has been continuously operated and maintained by the National Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the staff, and activities during 2012.

  20. Wind buffeting of large telescopes.

    PubMed

    MacMynowski, Douglas G; Andersen, Torben

    2010-02-01

    Unsteady wind loads due to turbulence within the telescope enclosure are one of the largest dynamic disturbances for ground-based optical telescopes. The desire to minimize the response to the wind influences the design of the telescope enclosure, structure, and control systems. There is now significant experience in detailed integrated modeling to predict image jitter due to wind. Based on this experience, a relatively simple model is proposed that is verified (from a more detailed model) to capture the relevant physics. In addition to illustrating the important elements of the telescope design that influence wind response, this model is used to understand the sensitivity of telescope image jitter to a wide range of design parameters. PMID:20119010

  1. Wind buffeting of large telescopes.

    PubMed

    MacMynowski, Douglas G; Andersen, Torben

    2010-02-01

    Unsteady wind loads due to turbulence within the telescope enclosure are one of the largest dynamic disturbances for ground-based optical telescopes. The desire to minimize the response to the wind influences the design of the telescope enclosure, structure, and control systems. There is now significant experience in detailed integrated modeling to predict image jitter due to wind. Based on this experience, a relatively simple model is proposed that is verified (from a more detailed model) to capture the relevant physics. In addition to illustrating the important elements of the telescope design that influence wind response, this model is used to understand the sensitivity of telescope image jitter to a wide range of design parameters.

  2. VizieR Online Data Catalog: Cool KOIs. VI. H- and K- band spectra (Muirhead+, 2014)

    NASA Astrophysics Data System (ADS)

    Muirhead, P. S.; Becker, J.; Feiden, G. A.; Rojas-Ayala, B.; Vanderburg, A.; Price, E. M.; Thorp, R.; Law, N. M.; Riddle, R.; Baranec, C.; Hamren, K.; Schlawin, E.; Covey, K. R.; Johnson, J. A.; Lloyd, J. P.

    2014-09-01

    We observed the Cool KOIs with the TripleSpec Spectrograph at the Palomar Observatory 200 inch Hale Telescope. TripleSpec is a near-infrared slit spectrograph covering 1.0 to 2.5um simultaneously with a resolving power (λ/Δλ) of 2700. Observations were carried out in 2011 June and August for the KOIs from Borucki et al. (2011, Cat. J/ApJ/736/19), with results published in a previous letter (Muirhead et al. 2012, Cat. J/ApJ/750/L37). In July and August of 2012, we augmented observations to include all of the Cool KOIs selected in Batalha et al. (2013, Cat. J/ApJS/204/24). In 2013 July and August, we observed the remaining Cool KOIs listed on the NASA Exoplanet Archive (NEA) as of the observations. (3 data files).

  3. Metallicity of M-dwarfs from NIR Spectra

    NASA Astrophysics Data System (ADS)

    Rojas-Ayala, B.; Lloyd, J. P.

    2010-10-01

    Above solar metallicity, the number of stars with planets and presence of multiple planets increases for solar-type stars (Santos et al. 2001; Fischer & Valenti 2005). M-dwarfs planet hosts known to date have shown abundances below solar metallicity when measured with optical spectra and photometry, suggesting that M-dwarfs have a planetary formation process that differs from F-, G- and K-dwarfs. This could also be due to statistics, with only few M-dwarfs with planetary candidates known, and/or the lack of reliable abundances estimates for this type of star. We present preliminary results from near-infrared spectra of M-dwarf secondaries (with a wide solar type star companion with known metallicity) obtained with the TripleSpec spectrograph operating on the Palomar 200-inch Hale Telescope.

  4. The Discovery of Two New Cepheid Variables in M101

    NASA Astrophysics Data System (ADS)

    Cohen, J. G.

    1993-05-01

    The Four Shooter Consortium was organized in 1985 to search for Cepheid variables in M101 using the 200-inch Hale telescope. We report the discovery of two new Cepheid variables, the first with a period of 36 days and a mean magnitude in the Thuan-Gunn g color of 24.09 mag, while the second has a period of 100 days with a mean g magnitude of 22.48. There are approximately 15 other stars that are definitely variable in this magnitude range, but periods could not be determined for them. These magnitudes are transformed in a preliminary way to V, and these data are combined with the two variables previously found by Cook, Aaronson, and Illingworth (1986, Ap.J. 301, L45). We derive an apparent distance modulus to M101 of 29.4 +/-{0.15} mag. I am grateful to all of the many Palomar observers who contributed Four Shooter frames to this project.

  5. VizieR Online Data Catalog: Probing the LHS Catalog (Gizis+ 1997)

    NASA Astrophysics Data System (ADS)

    Gizis, J. E.; Reid; I. N.

    1997-11-01

    We present moderate resolution spectroscopy of 111 cool dwarf stars to supplement the observations we have already presented in the Palomar/MSU Nearby-Star Spectroscopic Survey. The sample consists of 71 suspected nearby stars added to the Preliminary Third Catalog of Nearby Stars since 1991 as well as 40 faint red stars selected from the LHS catalog. The study was aimed at identifying interesting red dwarfs, particularly new nearby, ultracool dwarfs, and very metal-poor stars. The observations were made using the Palomar 60-inch, the Hale 200-inch and the Las Campanas 100-inch telescopes between June 1995 and January 1996. The spectral resolution is approximately 3 Angstroms per pixel with wavelength coverage from 6200 to 7500 Angstroms. Table 2 contains bandstrengths for TiO, CaH, and CaOH indices. (4 data files).

  6. Seismic Imager Space Telescope

    NASA Technical Reports Server (NTRS)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; Ampuero, Jean Paul; Leprince, Sebastien; Michel, Remi

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  7. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1995-01-01

    These eerie, dark, pillar-like structures are actually columns of cool interstellar hydrogen gas and dust that are also incubators for new stars. The pillars protrude from the interior wall of a dark molecular cloud like stalagmites from the floor of a cavern. They are part of the Eagle Nebula (also called M16), a nearby star-forming region 7,000 light-years away, in the constellation Serpens. The ultraviolet light from hot, massive, newborn stars is responsible for illuminating the convoluted surfaces of the columns and the ghostly streamers of gas boiling away from their surfaces, producing the dramatic visual effects that highlight the three-dimensional nature of the clouds. This image was taken on April 1, 1995 with the Hubble Space Telescope Wide Field Planetary Camera 2. The color image is constructed from three separate images taken in the light of emission from different types of atoms. Red shows emissions from singly-ionized sulfur atoms, green shows emissions from hydrogen, and blue shows light emitted by doubly-ionized oxygen atoms.

  8. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Dreher, J.

    2006-12-01

    The ATA will be a massively parallel array of 350 6-m antennas operating from 0.5 GHz to 11.3 GHz. It will be a superb instrument for both surveys and for imaging large, complex sources. By exploiting recent drops in the cost of electronics and by adopting the simplest possible design, the cost of the ATA will be significantly less than that of existing 100-m class telescopes. The ATA offers a very large primary field of view that may be imaged with a spectralline correlator and, at the same time, be studied with 16 dual-polarization pencil beams. The ATA also will have unique capabilities for very high fidelity imaging and for RFI excision. Central to the design is a high performance, yet cost effective, antenna with a Gregorian reflector system, connected to a novel ultrawide- band, log-periodic feed. Analog fiber is used to eliminate most of the electronics that are located at the antennas in more conventional arrays, allowing for a massively parallel signal processing design that offers enormous flexibility. A 42-element version of the ATA will begin observing in 2006.

  9. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy; Cumming, Steve

    2012-01-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is an international cooperative development and operations program between the United States National Aeronautics and Space Administration (NASA) and the German Space Agency, DLR (Deutsches Zentrum fuer Luft-und Raumfahrt). SOFIA is a 2.5 meter, optical/infrared/sub-millimeter telescope mounted in a Boeing model 747SP-21 aircraft and will be used for many basic astronomical observations performed at stratospheric altitudes. It will accommodate installation of different focal plane instruments with in-flight accessibility provided by investigators selected from the international science community. The Facility operational lifetime is planned to be greater than 20 years. This presentation will present the results of developmental testing of SOFIA, including analysis, envelope expansion and the first operational mission. It will describe a brief history of open cavities in flight, how NASA designed and tested SOFIAs cavity, as well as flight test results. It will focus on how the test team achieved key milestones by systematically and efficiently reducing the number of test points to only those absolutely necessary to achieve mission requirements, thereby meeting all requirements and saving the potential loss of program funding. Finally, it will showcase examples of the observatory in action and the first operational mission of the observatory, illustrating the usefulness of the system to the international scientific community. Lessons learned on how to whittle a mountain of test points into a manageable sum will be presented at the conclusion.

  10. IMAGING FAINT BROWN DWARF COMPANIONS CLOSE TO BRIGHT STARS WITH A SMALL, WELL-CORRECTED TELESCOPE APERTURE

    SciTech Connect

    Serabyn, E.; Mawet, D.; Bloemhof, E.; Haguenauer, P.; Mennesson, B.; Wallace, K.; Hickey, J.

    2009-05-01

    We have used our 1.6 m diameter off-axis well-corrected subaperture (WCS) on the Palomar Hale telescope in concert with a small inner-working-angle phase-mask coronagraph to image the immediate environs of a small number of nearby stars. Test cases included three stars (HD 130948, HD 49197, and HR7672) with known brown dwarf companions at small separations, all of which were detected. We also present the initial detection of a new object close to the nearby young G0V star HD171488. Follow-up observations are needed to determine if this object is a bona fide companion, but its flux is consistent with the flux of a young brown dwarf or low-mass M star at the same distance as the primary. Interestingly, at small angles our WCS coronagraph demonstrates a limiting detectable contrast comparable to that of extant Lyot coronagraphs on much larger telescopes corrected with current-generation adaptive optics (AO) systems. This suggests that small apertures corrected to extreme AO (ExAO) levels can be used to carry out initial surveys for close brown dwarf and stellar companions, leaving follow-up observations for larger telescopes.

  11. Why systems engineering on telescopes?

    NASA Astrophysics Data System (ADS)

    Swart, Gerhard P.; Meiring, Jacobus G.

    2003-02-01

    Although Systems Engineering has been widely applied to the defence industry, many other projects are unaware of its potential benefits when correctly applied, assuming that it is an expensive luxury. It seems that except in a few instances, telescope projects are no exception, prompting the writing of this paper. The authors postulate that classical Systems Engineering can and should be tailored, and then applied to telescope projects, leading to cost, schedule and technical benefits. This paper explores the essence of Systems Engineering and how it can be applied to any complex development project. The authors cite real-world Systems Engineering examples from the Southern African Large Telescope (SALT). The SALT project is the development and construction of a 10m-class telescope at the price of a 4m telescope. Although SALT resembles the groundbreaking Hobby-Eberly Telescope (HET) in Texas, the project team are attempting several challenging changes to the original design, requiring a focussed engineering approach and discernment in the definition of the telescope requirements. Following a tailored Systems Engineering approach on this project has already enhanced the quality of decisions made, improved the fidelity of contractual specifications for subsystems, and established criteria testing their performance. Systems Engineering, as applied on SALT, is a structured development process, where requirements are formally defined before the award of subsystem developmental contracts. During this process conceptual design, modeling and prototyping are performed to ensure that the requirements were realistic and accurate. Design reviews are held where the designs are checked for compliance with the requirements. Supplier factory and on-site testing are followed by integrated telescope testing, to verify system performance against the specifications. Although the SALT project is still far from completion, the authors are confident that the present benefits from

  12. Large Millimeter Telescope (LMT) status

    NASA Astrophysics Data System (ADS)

    Schloerb, F. Peter; Carrasco, Luis; Wilson, Grant W.

    2003-02-01

    We present a summary of the Large Millimeter Telescope Project and its present status. The Large Millimeter Telescope (LMT) is a joint project of the University of Massachusetts (UMass) in the USA and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Mexico to build a 50m-diameter millimeter-wave telescope. The LMT is being built at an altitude of 4600 m atop Volcan Sierra Negra, an extinct volcanic peak in the state of Puebla, Mexico, approximately 100 km east of the city of Puebla. Construction of the antenna is now well underway, and it is expected to be completed in 2004.

  13. Formation flight astronomical survey telescope

    NASA Astrophysics Data System (ADS)

    Tsunemi, Hiroshi

    2012-03-01

    Formation Flight Astronomical Survey Telescope (FFAST) is a project for hard X-ray observation. It consists of two small satellites; one (telescope satellite) has a super mirror covering the energy range up to 80 keV while the other (detector satellite) has an scintillator deposited CCD (SDCCD) having good spatial resolution and high efficiency up to 100 keV. Two satellites will be put into individual Kepler orbits forming an X-ray telescope with a focal length of 20 m. They will be not in pointing mode but in survey mode to cover a large sky region.

  14. Geodetic Observatory Wettzell - 20-m Radio Telescope and Twin Telescope

    NASA Technical Reports Server (NTRS)

    Neidhardt, Alexander; Kronschnabl, Gerhard; Schatz, Raimund

    2013-01-01

    In the year 2012, the 20-m radio telescope at the Geodetic Observatory Wettzell, Germany again contributed very successfully to the International VLBI Service for Geodesy and Astrometry observing program. Technical changes, developments, improvements, and upgrades were made to increase the reliability of the entire VLBI observing system. In parallel, the new Twin radio telescope Wettzell (TTW) got the first feedhorn, while the construction of the HF-receiving and the controlling system was continued.

  15. Ice Middleware in the New Solar Telescope's Telescope Control System

    NASA Astrophysics Data System (ADS)

    Shumko, S.

    2009-09-01

    The Big Bear Solar Observatory (BBSO) is now in the process of assembling and aligning its 1.6 m New Solar Telescope (NST). There are many challenges controlling NST and one of them is establishing reliable and robust communications between different parts of the Telescope Control System (TCS). For our TCS we selected Ice (Internet communication engine) from ZeroC, Inc. In this paper we discuss advantages of the Ice middleware, details of implementation and problems we face implementing it.

  16. The Allen Telescope Array

    NASA Astrophysics Data System (ADS)

    Bower, Geoffrey C.; Allen Telescope Array Team

    2010-01-01

    The ATA is a 42-element centimeter wavelength array located in Hat Creek, California and jointly operated by UC Berkeley Radio Astronomy Laboratory and the SETI Institute. Since the ATA dedication in Fall 2007, activities have been focused on commissioning the array, retrofitting a handful of components including the feed, developing an operations model, creation of pipeline processing for correlator imaging data, early science observations, and launching of the major surveys for which the telescope was built. The retrofit of the feed improves feed mechanical robustness as well as high frequency performance. Science programs launched include imaging radio transient and static sky surveys (ATATS and PiGSS), commensal SETI and transient surveys of the Galactic Center, targeted SETI observations of nearby stars, the Fly's Eye transient survey, broadband spectra of nearby star-forming galaxies, polarimetric observations of bright radio sources, observations of hydrogen in nearby galaxies and galaxy groups, molecular line observations in the Galaxy, and observations of Jupiter and the Moon. The baseline Square Kilometer Array (SKA) design, a large-N-small-diameter (LNSD) array with wide-band single-pixel feeds and an offset Gregorian antenna, bears a strong resemblance to the ATA. Additional ATA contributions to the SKA include configuration studies for LNSD arrays, the use of fiber optics for broadband data transmission, the use of flexible FPGA-based digital electronics, passive cooling of antennas, and implementation of commensal observing modes. The ATA is currently used for exploration of calibration and imaging algorithms necessary for the SKA. I will summarize current technical status and performance, the results from early science and surveys, and ATA contributions to SKA development.

  17. Lightweighted ZERODUR for telescopes

    NASA Astrophysics Data System (ADS)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  18. The chemical and physical properties of the hydroxide, cyanide and carbon jets in comet Hale-Bopp (1995 O1)

    NASA Astrophysics Data System (ADS)

    Lederer, Susan Maria

    Comet Hale-Bopp is the brightest comet observed in the last 25 years, and has afforded us an opportunity to gain new insights into the physical and chemical properties of comets. Coma jets are evident in continuum (dust), CN, C2 images, and for the first time in any comet, in OH narrowband images. In this study, the source of the coma jets is investigated through Monte Carlo modeling. An extended source that does not peak in productivity at the nucleus, combined with a nuclear gas source, is required to reproduce the data for all three gas species. Sub-micron organic CHON grains are the favored candidate for the extended source. Results from Monte Carlo modeling indicate that approximately 40% of the OH, 50% of the C2, and 75% of the CN is produced by the extended source. The balance for each is created by a nuclear gas source. Compared with the nuclear gas source, the composition of the extended source is depleted in OH by a factor of ˜4 to 7, and depleted in C2 by a factor of ˜2. Jet width and projected expansion velocities are estimated. The latter indicates that the gases in the coma accelerate to distances of at least 100,000 km from the nucleus. Comet Hale-Bopp's high production rates and large collisional zone explain the acceleration in the coma. The number (5) and the locations of the gas jets necessary to reproduce the observed coma morphology for all three species are constrained for images taken during April, 1997. Four of the five active areas on the comet's surface appeared to be emitting the same relative mixture of OH, CN, and C2. The fifth area (located at ˜12°S latitude) is richer in OH than the other active areas. This suggests that the composition of the nucleus is not entirely homogeneous. A high thermal inertia, which would allow production of the radicals throughout the cometary night, is not necessary to explain the existence of the anti-sunward gas jets. Instead, active areas that exist in near-twilight conditions throughout the comet

  19. Urania in the Marketplace: The Selling of Mt. Palomar

    NASA Astrophysics Data System (ADS)

    Rumstay, Kenneth S.

    2016-01-01

    The 200-inch Hale telescope atop Mt. Palomar is one of the most iconic scientific facilities ever constructed. The world's largest optical telescope for over a quarter-century, it served as a symbol of hope for America during the Great Depression and in the post-war years. In 2016 we celebrate the eightieth anniversaries of the completion of the mirror blank, the start of construction of the dome and mounting, and the beginning of astronomical research at Palomar Observatory by Fritz Zwicky (with the 18-inch Schmidt camera).During its construction, and for many years after "first light" in 1949, the Hale telescope was prominently featured in numerous magazine advertisements. Most of these represented companies directly involved in its construction, notably Corning Glass Works, which was justly proud of its magnificent accomplishment. But companies only vaguely linked to the project, or not at all, also co-opted the mystique of "the World's Largest Eye" to promote their goods or services. Surprisingly, in light of the fact that it bore responsibility for fabricating the complex and innovative mounting, the Westinghouse Electric & Manufacturing Company appears to have run only a single advertisement (in The National Geographic Magazine) touting its contribution to the project.Examples of magazine advertisements spanning the period 1936 to 1959 are presented.This work was supported by a faculty scholarship grant from Valdosta State University.

  20. Prism beamswitch for radio telescopes.

    PubMed

    Payne, J M; Ulich, B L

    1978-12-01

    A dielectric prism and switching mechanism have been constructed for beamswitching a Cassegrain radio telescope. Spatially extended radio sources may be mapped without significant confusion utilizing the sensitivity and stability inherent in the conventional Dicke radiometer.

  1. The CMS pixel luminosity telescope

    NASA Astrophysics Data System (ADS)

    Kornmayer, A.

    2016-07-01

    The Pixel Luminosity Telescope (PLT) is a new complement to the CMS detector for the LHC Run II data taking period. It consists of eight 3-layer telescopes based on silicon pixel detectors that are placed around the beam pipe on each end of CMS viewing the interaction point at small angle. A fast 3-fold coincidence of the pixel planes in each telescope will provide a bunch-by-bunch measurement of the luminosity. Particle tracking allows collision products to be distinguished from beam background, provides a self-alignment of the detectors, and a continuous in-time monitoring of the efficiency of each telescope plane. The PLT is an independent luminometer, essential to enhance the robustness on the measurement of the delivered luminosity and to reduce its systematic uncertainties. This will allow to determine production cross-sections, and hence couplings, with high precision and to set more stringent limits on new particle production.

  2. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is a cutaway illustration of the Hubble Space Telescope (HST) with callouts. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  3. Hubble Space Telescope-Concept

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is an artist's concept of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  4. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  5. Imaging phased telescope array study

    NASA Technical Reports Server (NTRS)

    Harvey, James E.

    1989-01-01

    The problems encountered in obtaining a wide field-of-view with large, space-based direct imaging phased telescope arrays were considered. After defining some of the critical systems issues, previous relevant work in the literature was reviewed and summarized. An extensive list was made of potential error sources and the error sources were categorized in the form of an error budget tree including optical design errors, optical fabrication errors, assembly and alignment errors, and environmental errors. After choosing a top level image quality requirment as a goal, a preliminary tops-down error budget allocation was performed; then, based upon engineering experience, detailed analysis, or data from the literature, a bottoms-up error budget reallocation was performed in an attempt to achieve an equitable distribution of difficulty in satisfying the various allocations. This exercise provided a realistic allocation for residual off-axis optical design errors in the presence of state-of-the-art optical fabrication and alignment errors. Three different computational techniques were developed for computing the image degradation of phased telescope arrays due to aberrations of the individual telescopes. Parametric studies and sensitivity analyses were then performed for a variety of subaperture configurations and telescope design parameters in an attempt to determine how the off-axis performance of a phased telescope array varies as the telescopes are scaled up in size. The Air Force Weapons Laboratory (AFWL) multipurpose telescope testbed (MMTT) configuration was analyzed in detail with regard to image degradation due to field curvature and distortion of the individual telescopes as they are scaled up in size.

  6. Telescope optical systems program overview

    NASA Technical Reports Server (NTRS)

    Hirschbein, Murray S.; Key, Richard W.

    1991-01-01

    Telescope Optical Systems is a new focused program of technology development that will shape and enable the new 'telescope' missions being studied and planned by NASA. The program structure contains six major elements: systems, optics, materials, structures, controls, and integration and test. Activities in each element will address key technology issues that support a wide range of user needs. Program goals, technology needs, and technology performance objectives are summarized in outline form.

  7. Global TIE (Telescopes in Education)

    NASA Astrophysics Data System (ADS)

    Mayo, L.; Schweitzer, A. E.; Clark, G.; Hoban, S.; Melsheimer, T. T.

    2001-12-01

    The NASA-sponsored Telescopes In Education (TIE) project (http://tie.jpl.nasa.gov) has been wildly successful in engaging the K-12 education community in real-time, hands-on, interactive astronomy activities. Hundreds of schools in the US, Australia, Canada, England, and Japan have participated in the TIE program, remotely controlling the 24-inch telescope at the Mount Wilson Observatory from their classrooms. In recent years, several (approximately 20 to date) other telescopes have been, or are in the process of being, outfitted for remote use as TIE affiliates. Global TIE integrates these telescopes seamlessly into one virtual observatory and provides the services required to operate this facility, including a scheduling service, tools for data manipulation, an online proposal review environment, an online "Virtual TIE Student Ap J" for publication of results, and access to related educational materials provided by the TIE community. Global TIE seeks to establish a network of research grade telescopes, no longer useful to the professional astronomical community, that can be made accessible to schools all across the country through existing IT technologies and applications. These telescopes could provide unparalleled research and educational opportunities for a broad spectrum of K-12 and college students and turns underutilized observatory facilities into valuable, state-of-the-art teaching centers.

  8. Alt-Az Spacewatch Telescope

    NASA Technical Reports Server (NTRS)

    Gehrels, Tom

    1997-01-01

    This grant funded about one third of the cost of the construction of a telescope with an aperture 1.8 meters in diameter to discover asteroids and comets and investigate the statistics of their populations and orbital distributions. This telescope has been built to the PI's specifications and installed in a dome on Kitt Peak mountain in Arizona. Funds for the dome and building were provided entirely by private sources. The dome building and telescope were dedicated in a ceremony at the site on June 7, 1997. The attached abstract describes the parameters of the telescope. The telescope is a new item of capital property. It is permanently located in University of Arizona building number 910 in the Steward Observatory compound on Kitt Peak mountain in the Tohono O'odham Nation, Arizona. fts property tag number is A252107. This grant did not include funds for the coma corrector lens, instrument derotator, CCD detector, detector electronics, or computers to acquire or process the data. It also did not include funds to operate the telescope or conduct research with it. Funds for these items and efforts are pending from NASA and other sources.

  9. Concept Design for SOAR Telescope

    NASA Astrophysics Data System (ADS)

    Sebring, T.; Cecil, G.; Krabbendam, V.; Moretto, G.

    1998-12-01

    The Southern Astrophysical Research (SOAR) telescope is a \\$28M collaboration between Brazil, NOAO, Michigan State University, and the University of North Carolina at Chapel Hill. NOAO will operate the telescope for 20 years in exchange for 30 astronomers.) The project is now fully funded. This f/16 telescope is optimized for high-quality images across the isokinetic field (0."17 FWHM degradation from the telescope+facility over a field of 7.5' diameter.) It is being designed to take up to 2 Gemini-class (2100 kg) instruments, or a combination of lighter instruments at 7 Nasmyth and bent Cassegrain foci. The facility is now under construction atop Cerro Pachon, 400m from Gemini-S. First light is currently scheduled for early 2002. Corning Inc. is preparing to fabricate the 4.2m-diameter, 7.5-10 cm thick primary mirror from ULE glass. In early 1999 contacts will be awarded for 2 major subsystems: active optics (which includes optics polishing), and the alt.-az. telescope mount. We will outline the novel strategies that are being used to control project costs while optimizing telescope performance. Instrumentation plans will also be summarized.

  10. SOFIA: Flying the Telescope

    NASA Technical Reports Server (NTRS)

    Asher, Troy A.; Cumming, Stephen B.

    2012-01-01

    and a proof of concept mission for which SOFIA was opportunely positioned is showcased. Success on this time-critical mission to observe a rare astronomical event proved the usefulness of an airborne observatory and the value in waiting for the capability provided by SOFIA. Finally, lessons learned in the test program are presented with emphasis on how lessons from previous aircraft and successful test programs were applied to SOFIA. Effective application of these lessons was crucial to the success of the SOFIA flight test program. SOFIA is an international cooperative program between NASA and the German Space Agency, DLR. It is a 2.5 meter (100-inch) telescope mounted in a Boeing 747SP aircraft used for astronomical observations at altitudes above 35,000 feet. SOFIA will accommodate a host of scientific instruments from the international science community and has a planned operational lifespan of more than 20 years.

  11. High Silicate Crystalline-to-Amorphous Ratios in Comets C/2001 Q4 (NEAT) and Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Wooden, D. H.; Harker, D. E.; Wodward, C. E.

    2004-01-01

    Crystalline silicates, by their apparent absence in the ISM, are dust grains that experienced high temperatures in the solar nebula. Mg-rich crystalline silicates formed either by condensation from hot nebular gases (1450 K) or by the annealing of Mg-rich amorphous silicates (approximately 1000 K) in shocks in the 5-10AU region or by radial transport into and out of the hot inner zones, e.g., T(sub d) greater than 1000K at r(sub h) less than 5AU, 10(exp -6) -10(exp -5) solar mass per year, alpha = 10(exp -4) of the early solar nebula. Mg-rich crystalline silicates are found in interplanetary dust particles (IDPs) and produce IR spectral features in many Oort cloud comets. In May 2004, we discovered strong crystalline silicate features in the dynamically new Oort cloud comet C/2001 Q4 (NEAT). Thermal emission modeling of comets Q4 and C/1995 O1 (Hale-Bopp) demonstrate that both these comets have similar, high silicate crystalline-toamorphous ratios of 2.4 and 2.1, respectively, indicating that these icy planetesimals aggregated from similar reservoirs of material or that crystalline silicates were widely distributed within the comet-forming zone. This argues for efficient annealing mechanisms and radial mixing.

  12. Dust Morphology Of Comet Hale-Bopp (C/1995 O1). II. Introduction Of A Working Model

    NASA Astrophysics Data System (ADS)

    Sekanina, Z.; Boehnhardt, H.

    1997-07-01

    A Monte Carlo image simulation code for dust features in comets is applied to comet Hale-Bopp in order to model the object's persistent porcupine-like appearance on high-resolution images taken between May 11 and Nov. 2, 1996. A self-consistent fan model is proposed, with six isolated sources of dust emission assumed at various locations on the surface of the rotating nucleus and with the spin axis undergoing a complex motion in an inertial coordinate system. In the framework of this model, jet pairs represent boundaries of fan-shaped formations described by dust ejected from isolated sources during periods of time when the Sun is above the local horizon. The spin axis is found to have traveled through a field of 10° by 20° during the examined period of nearly six months. Still more successful is a fan model with large diurnal dust-emission fluctuations, which is consistent with an inertially fixed position of the spin axis and requires only three discrete sources. In this scenario, the dust-emission profile is dominated by several brief flare-ups, or “puffs”, in the production of dust from one of the sources. The results are insensitive to the spin rate, but the observed dust coma appearance is more typical of a rapidly rotating comet.

  13. High Silicate Crystalline-to-Amorphous Ratios in Comets C/2001 Q4 (NEAT) and Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Wooden, D. H.; Harker, D. E.; Woodward, C. E.

    2004-01-01

    Crystalline silicates, by their apparent absence in the ISM, are dust grains that experienced high temperatures in the solar nebula. Mg-rich crystalline silicates formed either by condensation from hot nebular gases (1450 K) or by the annealing of Mg-rich amorphous silicates (approx. 1000 K) in shocks in the 5-10 AU region or by radial transport into and out of the hot inner zones, e.g., T(sub d) > 1000 K at r(sub h) < 5 AU, 10(exp -6) - 10(exp -5) M(sub O)/yr, alpha = 10(exp -4) of the early solar nebula. Mg-rich crystalline silicates are found in interplanetary dust particles (IDPs) and produce IR spectral features in many Oort cloud comets. In May 2004, we discovered strong crystalline silicate features in the dynamically new Oort cloud comet C/2001 Q4 (NEAT). Thermal emission modeling of comets Q4 and C/1995 O1 (Hale-Bopp) demonstrate that both these comets have similar, high silicate crystalline-to-amorphous ratios of 2.4 and 2.1, respectively, indicating that these icy planetesimals aggregated from similar reservoirs of material or that crystalline silicates were widely distributed within the comet-forming zone. This argues for efficient annealing mechanisms and radial mixing.

  14. Progress in a Study of Striations in the Dust Tail of Comet Hale-Bopp (C/1995 O1)

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.; Ryan, O.; Boehnhardt, H.; Birkle, K.; Engels, D.; Jaeger, M.; Keller, P.; Raab, H.

    1999-01-01

    We report preliminary results of a massive investigation of the striation patterns observed in the dust tail of comet Hale-Bopp in March and April 1997. Our findings are based on 16 wide-field photographs taken with Schmidt cameras on March 2-20, with six more, from March 31-April 8, still waiting for analysis. Altogether approximately 700 individual striae were examined on the 16 images, which were scanned and computer processed to enhance the morphology. About 5300 stria points, or some 7-8 points per stria per image on the average, were measured and their astrometric positions determined and subsequently converted to a Cartesian coordinate system, aligned with the comet's projected radius vector and centered on the nucleus. The evolution of the striated tail has been studied using the Sekanina-Farrell fragmentation hypothesis (AJ 85, 1538, 1980), previously applied to other comets. This two-step model is characterized by the time of release from the nucleus of a parent object (or objects) whose motion is assumed to have been subjected to a constant repulsive acceleration beta(sub p) (presumably due to solar radiation pressure) until the time of fragmentation.

  15. Hubble Space Telescope Scale Model

    NASA Technical Reports Server (NTRS)

    1983-01-01

    This is a photograph of a 1/15 scale model of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13- meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  16. LISA Telescope Spacer Design Issues

    NASA Technical Reports Server (NTRS)

    Livas, Jeff; Arsenovic, P.; Catelluci, K.; Generie, J.; Howard, J.; Stebbins, Howard R.; Preston, A.; Sanjuan, J.; Williams, L.; Mueller, G.

    2010-01-01

    The LISA mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of - 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. We describe the mechanical requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution, layout options for the telescope including an on- and off-axis design. Plans for fabrication and testing will be outlined.

  17. Preliminary LISA Telescope Spacer Design

    NASA Technical Reports Server (NTRS)

    Livas, J.; Arsenovic, P.; Catellucci, K.; Generie, J.; Howard, J.; Stebbins, R. T.

    2010-01-01

    The Laser Interferometric Space Antenna (LISA) mission observes gravitational waves by measuring the separations between freely floating proof masses located 5 million kilometers apart with an accuracy of approximately 10 picometers. The separations are measured interferometrically. The telescope is an afocal Cassegrain style design with a magnification of 80x. The entrance pupil has a 40 cm diameter and will either be centered on-axis or de-centered off-axis to avoid obscurations. Its two main purposes are to transform the small diameter beam used on the optical bench to a diffraction limited collimated beam to efficiently transfer the metrology laser between spacecraft, and to receive the incoming light from the far spacecraft. It transmits and receives simultaneously. The basic optical design and requirements are well understood for a conventional telescope design for imaging applications, but the LISA design is complicated by the additional requirement that the total optical path through the telescope must remain stable at the picometer level over the measurement band during the mission to meet the measurement accuracy. This poster describes the requirements for the telescope and the preliminary work that has been done to understand the materials and mechanical issues associated with the design of a passive metering structure to support the telescope and to maintain the spacing between the primary and secondary mirrors in the LISA on-orbit environment. This includes the requirements flowdown from the science goals, thermal modeling of the spacecraft and telescope to determine the expected temperature distribution,layout options for the telescope including an on- and off-axis design, and plans for fabrication and testing.

  18. Alignment and phasing of deployable telescopes

    NASA Technical Reports Server (NTRS)

    Woolf, N. J.; Ulich, B. L.

    1983-01-01

    The experiences in coaligning and phasing the Multi-Mirror Telescope (MMT), together with studies in setting up radio telescopes, are presented. These experiences are discussed, and on the basis they furnish, schemes are suggested for coaligning and phasing four large future telescopes with complex primary mirror systems. These telescopes are MT2, a 15-m-equivalent MMT, the University of California Ten Meter Telescope, the 10 m sub-mm wave telescope of the University of Arizona and the Max Planck Institute for Radioastronomy, and the Large Deployable Reflector, a future space telescope for far-IR and sub-mm waves.

  19. Uranian Equinoctial Observations

    NASA Astrophysics Data System (ADS)

    Bauer, J. M.; Hammel, H. B.; Young, L. A.; Olkin, C. B.; Goguen, J. D.; Hicks, M.; Schmidt, B.; Lainey, V.; Chanover, N. J.; Miller, C.; Hibbitts, C. A.; Baines, K. H.; Arlot, J.; Fitzsimmons, A.; Buratti, B. J.

    2008-12-01

    In December of 2007, the planet Uranus passed through its northern hemisphere spring equinox. The northernmost latitudes of the planet and regular satellites were exposed to sunlight for the first time in 42 years. Unique circumstances during the equinoctial event also concerning the viewing geometries of the rings and satellites provided rare opportunities to determine the physical nature of these elements of the Uranian system and to study the short-term and evolutionary effects of seasonal insolation in the outer solar system. Furthermore, the approaching perspective afforded opportunities to characterize details of surfaces that had not been viewable, even by Voyager 2, since the advent of modern instrumentation. We present preliminary results from these observations made over several nights during the 2006, 2007, and 2008 observing semesters. Our imaging using the Palomar adaptive optics system on the observatory's 200- inch telescope has been used to obtain high-resolution images. These observations have provided constraints on the planet's atmospheric dynamics and structure by monitoring the increasing storm activity and changing large-scale features in the atmosphere, such as the shifting polar collar, and sampling the vertical structure from multiple planetary occultations. These same images also provide unique photometric information regarding the ring-system particles by viewing the system from its dark side, accessible only during the 2007 season. Spectral and spectro-photometric observations of the newly exposed surfaces of the major satellites have also been obtained from the IRTF, the SOAR telescope, and Palomar 200-inch, including observations of some mutual event phenomena. Acknowledgements: These results are based in part on observations obtained at the Hale Telescope, Palomar Observatory, as part of a collaborative agreement between Caltech, JPL and Cornell University. Some observations were also obtained at the Infrared Telescope Facility, which

  20. James Webb Space Telescope Optical Telescope Element Mirror Coatings

    NASA Technical Reports Server (NTRS)

    Keski-Kuha, Ritva A.; Bowers, Charles W.; Quijada, Manuel A.; Heaney, James B.; Gallagher, Benjamin; McKay, Andrew; Stevenson, Ian

    2012-01-01

    James Webb Space Telescope (JWST) Optical Telescope Element (OTE) mirror coating program has been completed. The science goals of the JWST mission require a uniform, low stress, durable optical coating with high reflectivity over the JWST spectral region. The coating has to be environmentally stable, radiation resistant and compatible with the cryogenic operating environment. The large size, 1.52 m point to point, light weight, beryllium primary mirror (PM) segments and flawless coating process during the flight mirror coating program that consisted coating of 21 flight mirrors were among many technical challenges. This paper provides an overview of the JWST telescope mirror coating program. The paper summarizes the coating development program and performance of the flight mirrors.

  1. Optical Telescope Design Study Results

    NASA Astrophysics Data System (ADS)

    Livas, J.; Sankar, S.

    2015-05-01

    We report on the results of a study conducted from Nov 2012-Apr 2013 to develop a telescope design for a space-based gravitational wave detector. The telescope is needed for efficient power delivery but since it is directly in the beam path, the design is driven by the requirements for the overall displacement sensitivity of the gravitational wave observatory. Two requirements in particular, optical pathlength stability and scattered light performance, are beyond the usual specifications for good image quality encountered in traditional telescopic systems. An important element of the study was to tap industrial expertise to develop an optimized design that can be reliably manufactured. Key engineering and design trade-offs and the sometimes surprising results will be presented.

  2. ORFEUS-SPAS MAIN TELESCOPE

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the Multi-Payload Processing Facility (MPPF) at KSC, technicians hoist the orbiting and Retrievable Far and Extreme Ultraviolet Spectrograph-Shuttle Pallet Satellite (ORFEUS-SPAS) II main telescope to a vertical position prior to installing it atop the Astronomy Shuttle Pallet Satellite (ASTRO-SPAS) platform. Two spectrographs share the main telescope: the Extreme Ultraviolet Spectrograph (EUV) provided by the University of California at Berkeley, and the Far Ultraviolet Spectrograph (FUV) designed by German institutions the University of Tubingen and Landessternwarte Heidelberg and built by German company Kayser-Threde. The main telescope has a primary mirror approximately one yard (one meter) in diameter, coated with iridium to improve its light-gathering power in the ultraviolet. During the flight of ORFEUS-SPAS II on Space Shuttle Mission STS- 80, these two spectrographs -- along with a third installed separately on the ASTRO-SPAS -- will gather data about the life cycle of stars.

  3. Hubble Space Telescope Primary Mirror

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This photograph shows the Hubble Space Telescope's (HST's) Primary Mirror being polished at the the Perkin-Elmer Corporation's large optics fabrication facility. After the 8-foot diameter mirror was ground to shape and polished, the glass surface was coated with a reflective layer of aluminum and a protective layer of magnesium fluoride, 0.1- and 0.025-micrometers thick, respectively. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST and the Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  4. Hubble Space Telescope Primary Mirror

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This photograph shows engineers inspecting the Hubble Space Telescope's (HST's) Primary Mirror at the Perkin-Elmer Corporation's large optics fabrication facility. After the 8-foot diameter mirror was ground to shape and polished, the glass surface was coated with a reflective layer of aluminum and a protective layer of magnesium fluoride, 0.1- and 0.025- micrometers thick, respectively. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST and the Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  5. Hubble Space Telescope Primary Mirror

    NASA Technical Reports Server (NTRS)

    1979-01-01

    This photograph shows the Hubble Space Telescope's (HST's) Primary Mirror being ground at the Perkin-Elmer Corporation's large optics fabrication facility. After the 8-foot diameter mirror was ground to shape and polished, the glass surface was coated with a reflective layer of aluminum and a protective layer of magnesium fluoride, 0.1- and 0.025-micrometers thick, respectively. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST and the Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  6. Quantum telescope: feasibility and constraints.

    PubMed

    Kurek, A R; Pięta, T; Stebel, T; Pollo, A; Popowicz, A

    2016-03-15

    The quantum telescope is a recent idea aimed at beating the diffraction limit of spaceborne telescopes and possibly other distant target imaging systems. There is no agreement yet on the best setup of such devices, but some configurations have already been proposed. In this Letter we characterize the predicted performance of quantum telescopes and their possible limitations. Our extensive simulations confirm that the presented model of such instruments is feasible and the device can provide considerable gains in the angular resolution of imaging in the UV, optical, and infrared bands. We argue that it is generally possible to construct and manufacture such instruments using the latest or soon to be available technology. We refer to the latest literature to discuss the feasibility of the proposed QT system design. PMID:26977642

  7. The Spitzer Space Telescope Mission

    NASA Technical Reports Server (NTRS)

    Werner, M. W.

    2005-01-01

    The Spitzer Space Telescope, NASA's Great Observatory for infrared astronomy, was launched 2003 August 25 and is returning excellent scientific data from its Earth-trailing solar orbit. Spitzer combines the intrinsic sensitivity achievable with a cryogenic telescope in space with the great imaging and spectroscopic power of modern detector arrays to provide the user community with huge gains in capability for exploration of the cosmos in the infrared. The observatory systems are largely performing as expected, and the projected cryogenic lifetime is about five years. Spitzer is thus both a scientific and a technical precursor to the infrared astronomy missions of the future. This very brief paper refers interested readers to several sets of recent publications which describe both the scientific and the technical features of Spitzer in detail. Note that, until 2003 December, Spitzer was known as the Space Infrared Telescope Facility (SIRTF).

  8. Scientific management of Space Telescope

    NASA Technical Reports Server (NTRS)

    Odell, C. R.

    1981-01-01

    A historical summay is given on the science management of the Space Telescope, the inception of which began in 1962, when scientists and engineers first recommended the development of a nearly diffraction limited substantial-size optical telescope. Phase A, the feasibility requirements generation phase, began in 1971 and consisted largely of NASA scientists and a NASA design. Phase B, the preliminary design phase, established a tiered structure of scientists, led by the Large Space Telescope operations and Management Work Group. A Mission Operations Working Group headed six instrument definition teams to develop the essential instrument definitions. Many changes took place during Phase B, before design and development, which began in 1978 and still continues today.

  9. Quantum telescope: feasibility and constraints.

    PubMed

    Kurek, A R; Pięta, T; Stebel, T; Pollo, A; Popowicz, A

    2016-03-15

    The quantum telescope is a recent idea aimed at beating the diffraction limit of spaceborne telescopes and possibly other distant target imaging systems. There is no agreement yet on the best setup of such devices, but some configurations have already been proposed. In this Letter we characterize the predicted performance of quantum telescopes and their possible limitations. Our extensive simulations confirm that the presented model of such instruments is feasible and the device can provide considerable gains in the angular resolution of imaging in the UV, optical, and infrared bands. We argue that it is generally possible to construct and manufacture such instruments using the latest or soon to be available technology. We refer to the latest literature to discuss the feasibility of the proposed QT system design.

  10. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew

    2008-01-01

    The James Webb Space Telescope is being developed by NASA in partnership with the European and Canadian space agencies for launch during 2013. This mission is expected to carry the legacy of discovery of the Hubble Space Telescope through the next decade, and is designed with unique capability to address key questions about formation of the first galaxies after the Big Bang, their subsequelet volution, and the formation of stars and planets within our own galaxy. This talk will present an overview of the mission science objectives and the status of the mission development.

  11. Superconductor lunar telescopes --Abstract only

    NASA Technical Reports Server (NTRS)

    Chen, P. C.; Pitts, R.; Shore, S.; Oliversen, R.; Stolarik, J.; Segal, K.; Hojaji, H.

    1994-01-01

    We propose a new type of telescope designed specifically for the lunar environment of high vacuum and low temperature. Large area UV-Visible-IR telescope arrays can be built with ultra-light-weight replica optics. High T(sub c) superconductors provide support, steering, and positioning. Advantages of this approach are light-weight payload compatible with existing launch vehicles, configurable large area optical arrays, no excavation or heavy construction, and frictionless electronically controlled mechanisms. We have built a prototype and will be demonstarting some of its working characteristics.

  12. Wide field of view telescope

    DOEpatents

    Ackermann, Mark R.; McGraw, John T.; Zimmer, Peter C.

    2008-01-15

    A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8.degree. to approximately 6.5.degree.. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

  13. Analysis of OH, CN, and C2 Gas Jets in Comet Hale-Bopp through Monte Carlo Modeling

    NASA Astrophysics Data System (ADS)

    Lederer, S. M.; Campins, H.; Lisse, C. M.

    2000-10-01

    We present an analysis of OH, CN, and C2 jets observed in Comet Hale-Bopp during April 22-26, 1997. We conclude that an extended source, which does not peak in productivity at the nucleus, is responsible for the observed morphology in all three species. Sub-micron organic CHON grains are the favored candidate for the extended source. Our model indicates that approximately 40% of the OH, 50% of the C2, and 75% of the CN is produced by the extended source. The balance for each is created by a nuclear gas source. Compared with the nuclear gas source, the composition of the extended source is depleted in OH by a factor of ~4-7, and depleted in C2 by a factor of ~2. We have constrained the number (5) and the locations of the gas jets necessary to reproduce the observed coma morphology on these dates, for all three species. Four of the five active areas on the comet's surface appear to be emitting the same relative mixture of OH, CN and C2. The fifth area (located at ~12S latitude) is richer in OH than the other active areas. This suggests that the composition of the nucleus is not entirely homogeneous. A high thermal inertia, which would allow production of the radicals throughout the cometary night, is not necessary to explain the existence of the anti-sunward gas jets. Instead, active areas that exist in near-twilight conditions throughout the comet's rotation period produce the bulk of the anti-sunward morphology. This work was supported by NASA.

  14. Silicate Mineralogy of C/1995 O1 (Hale-Bopp) and its Implications to the Study of Pre-Main Sequence Stars and the Origins of Solar Systems

    NASA Astrophysics Data System (ADS)

    Harker, David

    1999-12-01

    The evolution of the gas chemistry and dust mineralogy in disks surrounding newly forming stars is fundamental to elucidating processes associated with the origins of solar systems. In particular, silicate mineralogy now can be deduced from the 10 \\micron\\ and 18 -- 33 \\micron \\ resonances. As reservoirs of pristine solar nebula materials, comets are one of the best sources for investigating early solar nebula dust properties that currently would be observable in the optically thin dust in external PMS objects. Observation and analysis of the silicate features of solar system comets provide a direct probe of the chemical and physical conditions in these potentially planet-forming environments, the condensation of dust from the gas-disk, and the aggregation and accretion of these solids into planetesimals and comets. Mid-infrared spectrophotometry of comet C/1995 O1 (Hale-Bopp) was obtained with the NASA/Ames HIFOGS at four pre- and post-perihelion epochs from 1996 October through 1997 June. Synthetic spectra calculated from Mie Scattering Theory and the most recent optical constants are fit to the observed 10 \\micron\\ spectral feature of Hale-Bopp. Our analysis suggests that the observed spectra can be modeled with the Hanner grain size distribution (Hanner 1983) peaked at ap = 0.2 \\micron\\ of fractal porous grains with porosity parameter D = 2.5. This model spectrum also fits photometry points in the 3 -- 5 \\micron\\ region. Comparison with the ISO SWS spectrum of Hale-Bopp obtained 1996 October suggests that the crystalline olivine grains must be at a temperature hotter than computed from Mie theory. This work was supported by grants from the NASA Graduate Student Research Program NGT2-52218, the NSF (AST94--53354), NASA (GRSP NGT2--52218, NAG5--7906), and the Office of Research, University of Wyoming.

  15. Hubble Space Telescope prescription retrieval.

    PubMed

    Redding, D; Dumont, P; Yu, J

    1993-04-01

    Prescription retrieval is a technique for directly estimating optical prescription parameters from images. We apply it to estimate the value of the Hubble Space Telescope primary mirror conic constant. Our results agree with other studies that examined primary-mirror test fixtures and results. In addition they show that small aberrations exist on the planetary-camera repeater optics.

  16. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  17. Push-To Telescope Mathematics

    ERIC Educational Resources Information Center

    Teets, Donald

    2012-01-01

    Two coordinate systems are related here, one defined by the earth's equator and north pole, the other by the orientation of a telescope at some location on the surface of the earth. Applying an interesting though somewhat obscure property of orthogonal matrices and using the cross-product simplifies this relationship, revealing that a surprisingly…

  18. NEAT: a microarcsec astrometric telescope

    NASA Astrophysics Data System (ADS)

    Shao, M.; Nemati, B.; Zhai, C.; Goullioud, R.; Malbet, F.; Leger, A.

    2011-10-01

    NEAT, Nearby Exo-Earth Astrometric Telescope is a medium-small telescope ~ 1m in diameter that is designed to make ultra precise < 1 uas (microarcsec) astrometric measurements of nearby stars in a ~ 1hr observation. Four major error sources prevent normal space telescopes from obtaining accuracies close to 1 uas. Even with a small 1m telescope, photon noise is usually not a problem for the bright nearby target stars. But in general, the reference stars are much fainter. Typically a field of view of ~0.5 deg dia is needed to obtain enough bright reference stars. The NEAT concept uses a very simple but unusual design to avoid optically induced astrometric errors. The third source of error is the accuracy and stability of the focal plane. A 1uas error over a ~2000 arcsec field of view implies the focal plane is accurate or at least stable to 5 parts in 1010 over the lifetime of the mission (~5yrs). The 4th class of error has to do with our knowledge of the PSF and how that PSF is sampled by an imperfect detector. A Nyquist sampled focal plane would have > 2 pixels per λ/D, and centroiding to 1uas means centroiding to 10-5 pixels. This paper describes the mission concept, and an overview of the technology needed to perform 1uas astrometry with a small telescope, and how we overcome problems 1 and 2. A companion paper will describe the technical progress we've made in solving problems 3 and 4.

  19. Eclipse Photographs Through a Small Telescope

    NASA Astrophysics Data System (ADS)

    Kramer, Bill

    1999-08-01

    Results of previous eclipse photography using a small telescope (Questar 90mm x 1200mm EFL) and camera. During the presentation of images, tips and ideas for getting good pictures through a telescope will be discussed.

  20. FORCAST Camera Installed on SOFIA Telescope

    NASA Video Gallery

    Cornell University's Faint Object Infrared Camera for the SOFIA Telescope, or FORCAST, being installed on the Stratospheric Observatory for Infrared Astronomy's 2.5-meter telescope in preparation f...

  1. Optical Telescope Assembly Concept for Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Wallace, N.; Krim, M.; Horner, G.

    1996-12-01

    A recent study by a TRW/HDOS/GSFC/LaRC/Swales team produced a conceptual design for an eight-meter diameter Next Generation Space Telescope (NGST). This space telescope would have a deployed primary mirror with active figure control of the mirror petals to give diffraction limited performance at one micron wavelength. The High Accuracy Reflector Development (HARD) scheme, utilizing special translation-rotation mechanisms and precision latches, would deploy and lock the primary mirror segments into place. Thin mirror faceplates on stiff, lightweight backing structure would allow the extremely low weight at moderate cost. The telescope would produce images and spectra from radiation in the 0.5 micron to 10 micron spectral interval, have a 10 arc-minute circular field of view, weigh about 1000 kg, and fit within the shroud of an Atlas II AS launch vehicle. A deployable sunshield and an L2 Lissajous orbit would give passive cooling to 30 K. This paper describes the baseline optics, structures, and control systems of the Optical Telescope Assembly design produced in the study. The associated technologies are discussed, with emphasis on the optics and mechanisms for the primary mirror. For the optics, different mirror materials, fabrication processes, structural configurations, controls configurations, and verification techniques were studied, and a preliminary wavefront error budget was produced. For mechanisms, concepts were produced for high resolution actuators with a large operating range and for active vibration suppression. The state-of-the-art of all these technologies is presented, the technological advances needed, and some preliminary plans for their development.

  2. Alignment of the James Webb Space Telescope optical telescope element

    NASA Astrophysics Data System (ADS)

    Glassman, Tiffany; Levi, Joshua; Liepmann, Till; Hahn, Walter; Bisson, Gary; Porpora, Dan; Hadjimichael, Theo

    2016-07-01

    The optical telescope element (OTE) of the James Webb Space Telescope has now been integrated and aligned. The OTE comprises the flight mirrors and the structure that supports them - 18 primary mirror segments, the secondary mirror, and the tertiary and fine steering mirrors (both housed in the aft optics subsystem). The primary mirror segments and the secondary mirror have actuators to actively control their positions during operations. This allows the requirements for aligning the OTE subsystems to be in the range of microns rather than nanometers. During OTE integration, the alignment of the major subsystems of the OTE structure and optics were controlled to ensure that, when the telescope is on orbit and at cryogenic temperatures, the active mirrors will be within the adjustment range of the actuators. Though the alignment of this flagship mission was complex and intricate, the key to a successful integration process turned out to be very basic: a clear, concise series of steps employing advanced planning, backup measurements, and cross checks that this multi-organizational team executed with a careful and methodical approach. This approach was not only critical to our own success but has implications for future space observatories.

  3. The Next Generation Space Telescope

    NASA Technical Reports Server (NTRS)

    Bely, Pierre-Yves (Editor); Burrows,, Christopher J. (Editor); Illingworth,, Garth D.

    1989-01-01

    In Space Science in the Twenty-First Century, the Space Science Board of the National Research Council identified high-resolution-interferometry and high-throughput instruments as the imperative new initiatives for NASA in astronomy for the two decades spanning 1995 to 2015. In the optical range, the study recommended an 8 to 16-meter space telescope, destined to be the successor of the Hubble Space Telescope (HST), and to complement the ground-based 8 to 10-meter-class telescopes presently under construction. It might seem too early to start planning for a successor to HST. In fact, we are late. The lead time for such major missions is typically 25 years, and HST has been in the making even longer with its inception dating back to the early 1960s. The maturity of space technology and a more substantial technological base may lead to a shorter time scale for the development of the Next Generation Space Telescope (NGST). Optimistically, one could therefore anticipate that NGST be flown as early as 2010. On the other hand, the planned lifetime of HST is 15 years. So, even under the best circumstances, there will be a five year gap between the end of HST and the start of NGST. The purpose of this first workshop dedicated to NGST was to survey its scientific potential and technical challenges. The three-day meeting brought together 130 astronomers and engineers from government, industry and universities. Participants explored the technologies needed for building and operating the observatory, reviewed the current status and future prospects for astronomical instrumentation, and discussed the launch and space support capabilities likely to be available in the next decade. To focus discussion, the invited speakers were asked to base their presentations on two nominal concepts, a 10-meter telescope in space in high earth orbit, and a 16-meter telescope on the moon. The workshop closed with a panel discussion focused mainly on the scientific case, siting, and the

  4. World atlas of large optical telescopes

    NASA Technical Reports Server (NTRS)

    Meszaros, S. P.

    1979-01-01

    By 1980 there will be approximately 100 large optical telescopes in the world with mirror or lens diameters of one meter (39 inches) and larger. This atlas gives information on these telescopes and shows their locations on continent-sized maps. Observatory locations considered suitable for the construction of future large telescopes are also shown.

  5. The Hubble Space Telescope: Problems and Solutions.

    ERIC Educational Resources Information Center

    Villard, Ray

    1990-01-01

    Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)

  6. Telescoping Space-Station Modules

    NASA Technical Reports Server (NTRS)

    Witcofski, R. D.

    1986-01-01

    New telescoping-space-station design involves module within a module. After being carried to orbit within payload bay of Space Shuttle orbiter, outer module telescopically deployed to achieve nearly twice as much usable space-station volume per Space Shuttle launch. Closed-loop or "race-track" space-station configurations possible with this concept and provide additional benefits. One benefit involves making one of modules double-walled haven safe from debris, radiation, and like. Module accessible from either end, and readily available to all positions in space station. Concept also provides flexibility in methods in which Space Shuttle orbiter docked or berthed with space station and decrease chances of damage.

  7. THE OPTIMAL GRAVITATIONAL LENS TELESCOPE

    SciTech Connect

    Surdej, J.; Hanot, C.; Sadibekova, T.; Delacroix, C.; Habraken, S.; Coleman, P.; Dominik, M.; Le Coroller, H.; Mawet, D.; Quintana, H.; Sluse, D.

    2010-05-15

    Given an observed gravitational lens mirage produced by a foreground deflector (cf. galaxy, quasar, cluster, ...), it is possible via numerical lens inversion to retrieve the real source image, taking full advantage of the magnifying power of the cosmic lens. This has been achieved in the past for several remarkable gravitational lens systems. Instead, we propose here to invert an observed multiply imaged source directly at the telescope using an ad hoc optical instrument which is described in the present paper. Compared to the previous method, this should allow one to detect fainter source features as well as to use such an optimal gravitational lens telescope to explore even fainter objects located behind and near the lens. Laboratory and numerical experiments illustrate this new approach.

  8. Focusing X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  9. Synchronous network of distant telescopes

    NASA Astrophysics Data System (ADS)

    Zhilyaev, B.; Svyatogorov, O.; Verlyuk, I.; Andreev, M.; Sergeev, A.; Lovkaya, M.; Antov, A.; Konstantinova-Antova, R.; Bogdanovski, R.; Avgoloupis, S.; Seiradakis, J.; Contadakis, M. E.

    The Synchronous Network of distant Telescopes (SNT) represents an innovative approach in observational astrophysics. The authors present an unique existing realization of the SNT-conception. It was founded within the international collaboration between astronomical observatories of Ukraine, Russia, Bulgaria and Greece. All the telescopes of the Network are equipped with standardized photometric systems (based on photo-multipliers). The unified timing systems (based on GPS-receivers) synchronize all the apertures to UTC with an accuracy of 1 microsecond and better. The essential parts of the SNT are the original software for operating and data processing. The described international Network successfully works for more than 10 years. The obtained unique observational data made it possible to discover new fine-scale features and flare-triggered phenomena in flaring red dwarfs, as well as the recently found high-frequency variability in some chromospherically active stars.

  10. Hubble Space Telescope Servicing begins.

    NASA Astrophysics Data System (ADS)

    1993-12-01

    The day's work began when astronauts Story Musgrave and Jeff Hoffman stepped out into the cargo bay at 9h41 pm CST, Saturday (4h41 am CET, Sunday). They immediately set to work replacing two gyroscope assemblies, known as the Rate Sensor Units, two associated electronics boxes, called Electronic Control Units, and eight electrical fuse plugs. The work was completed ahead of schedule, but the astronauts had trouble closing the doors of the compartment housing the gyros and took over an hour to get them shut. The astronauts also prepared equipment for the replacement of the solar arrays. "The feeling down here is one of great satisfaction for a tremendous job today" said spacecraft communicator Greg Harbaugh in mission control. "We are very proud of the work that you all did and we are very confident in the continued success of the mission. Everything is going great and tomorrow is going to be another great day". ESA astronaut Claude Nicollier played a vital role during the spacewalk moving the astronauts and their equipment around the cargo bay with the shuttle's robot arm. The Hubble Space Telescope servicing mission features more robot arm operations than any other shuttle flight. The telescope's left-hand solar array was rolled up successfully at 6h24 am CST (1h24 pm CET). The 11-tonne observatory was rotated 180 degrees on its turntable before commands were sent to retract the second array at 8h23 am CST (3h23 pm CET). The crew stopped the retraction when it appeared the system may have jammed. Mission control instructed the crew to jettison the array, a procedure that they have trained for. Tomorrow astronauts Kathy Thornton and Tom Akers will make a six-hour spacewalk to jettison the troublesome wing, store the other in the cargo bay, and install two new panels supplied by ESA. The second set of arrays feature thermal shields and a modified thermal compensation system to prevent the flexing that affected the first pair. The Hubble Space Telescope was plucked

  11. Workshop on Mars Telescopic Observations

    NASA Technical Reports Server (NTRS)

    Bell, J. F., III (Editor); Moersch, J. E. (Editor)

    1995-01-01

    The Mars Telescopic Observations Workshop, held August 14-15, 1995, at Cornell University in Ithaca, New York, was organized and planned with two primary goals in mind: The first goal was to facilitate discussions among and between amateur and professional observers and to create a workshop environment fostering collaborations and comparisons within the Mars observing community. The second goal was to explore the role of continuing telescopic observations of Mars in the upcoming era of increased spacecraft exploration. The 24 papers presented at the workshop described the current NASA plans for Mars exploration over the next decade, current and recent Mars research being performed by professional astronomers, and current and past Mars observations being performed by amateur observers and observing associations. The workshop was divided into short topical sessions concentrating on programmatic overviews, groundbased support of upcoming spacecraft experiments, atmospheric observations, surface observations, modeling and numerical studies, and contributions from amateur astronomers.

  12. Space infrared telescope facility project

    NASA Technical Reports Server (NTRS)

    Cruikshank, Dale P.

    1988-01-01

    The functions undertaken during this reporting period were: to inform the planetary science community of the progress and status of the Space Infrared Telescope Facility (SIRTF) Project; to solicit input from the planetary science community on needs and requirements of planetary science in the use of SIRTF at such time that it becomes an operational facility; and a white paper was prepared on the use of the SIRTF for solar system studies.

  13. TOML - Telescope Observation Markup Language

    NASA Astrophysics Data System (ADS)

    de Witt, S.; Jenness, T.; Economou, F.; Folger, M.

    2005-12-01

    Telescope Observation Markup Language (TOML) has been developed by the Joint Astronomy Centre as a means of expressing an astronomical observing program in XML. It provides a means of encoding a program developed using a graphical tool in a language neutral format which can be sent over the web to a database or a colleague who is also working on the same project. This can then be loaded into any tool capable of accepting TOML.

  14. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  15. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  16. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2011-01-01

    The James Webb Space Telescope is the scientific successor to the Hubble and Spitzer Space Telescopes, and is currently the largest scientific project under construction in the United States. It will be a large (6.6m) cold (50K) telescope launched in about 5 years into orbit around the second Earth-Sun Lagrange point. It is a partnership of NASA with the European and Canadian Space Agencies. Science with the James Webb Space Telescope falls into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and black holes within them evolved from the epoch of reionization to the present. The Birth of Stars and Proto planetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. Webb will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I will conclude the talk with a description of recent technical progress in the construction of the observatory.

  17. India's National Large Solar Telescope

    NASA Astrophysics Data System (ADS)

    Hasan, S. S.

    2012-12-01

    India's 2-m National Large Solar Telescope (NLST) is aimed primarily at carrying out observations of the solar atmosphere with high spatial and spectral resolution. A comprehensive site characterization program, that commenced in 2007, has identified two superb sites in the Himalayan region at altitudes greater than 4000-m that have extremely low water vapor content and are unaffected by monsoons. With an innovative optical design, the NLST is an on-axis Gregorian telescope with a low number of optical elements to reduce the number of reflections and yield a high throughput with low polarization. In addition, it is equipped with a high-order adaptive optics to produce close to diffraction limited performance. To control atmospheric and thermal perturbations of the observations, the telescope will function with a fully open dome, to achieve its full potential atop a 25 m tower. Given its design, NLST can also operate at night, without compromising its solar performance. The post-focus instruments include broad-band and tunable Fabry-Pérot narrow-band imaging instruments; a high resolution spectropolarimeter and an Echelle spectrograph for night time astronomy. This project is led by the Indian Institute of Astrophysics and has national and international partners. Its geographical location will fill the longitudinal gap between Japan and Europe and is expected to be the largest solar telescope with an aperture larger than 1.5 m till the ATST and EST come into operation. An international consortium has been identified to build the NLST. The facility is expected to be commissioned by 2016.

  18. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2009-01-01

    The scientific capabilities of the James Webb Space Telescope (JWST) fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. To enable these for science themes, JWST will be a large (6.6m) cold (50K) telescope launched to the second Earth-Sun Lagrange point early in the next decade. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I review the status and capabilities of the observatory and instruments in the context of the major scientific goals.

  19. First light for space telescope

    NASA Astrophysics Data System (ADS)

    Tresch-Fienberg, Richard

    1986-12-01

    The launch of the 2.4-m Hubble Space Telescope (HST) by the Space Shuttle Atlantis in late 1988 is discussed. Only after a commissioning period will the observatory begin routine scientific operations. After circling the globe in tandem for two days, Atlantis and space telescope will part and a one-to-two month Orbital Verification period will begin. 'First light' will involve the detection of an anonymous star by the spacecraft's pointing and control system. Three fine-guidance sensors permit the telescope to find a particular object and remain pointed at it to within 0.007 arc second for as long as 24 hours. Magnitude 28 stars will be detected routinely and magnitude 31 stars in the longest exposures. Objects that will be used to test the functioning of the various scientific instruments are noted: NGC 188 for the wide-field/planetary camera, 30 Doradus (Tarantula nebula) for the high-resolution spectrograph, the triple quasar PG 1115 + 80A, B, C in Leo for the faint-object spectrograph. In a Science verification period, the scientific instruments will be calibrated so as to remove their signatures as much as possible from the data. Kapteyn's Selected Area 95, the Orion nebula, and the 'Egg nebula' in Cygnus are candidate calibration objects.

  20. QUIJOTE telescope design and fabrication

    NASA Astrophysics Data System (ADS)

    Gomez, Alberto; Murga, Gaizka; Etxeita, Borja; Sanquirce, Rubén; Rebolo, Rafael; Rubiño-Martin, Jose Alberto; Herreros, José-Miguel; Hoyland, Roger; Gomez, Francisca; Génova-Santos, Ricardo T.; Piccirillo, Lucio; Maffei, Bruno; Watson, Robert

    2010-07-01

    The QUIJOTE CMB experiment aims to characterize the polarization of the CMB in the frequency range 10-30 GHz and large angular scales. It will be installed in the Teide Observatory, following the projects that the Anisotropy of the Cosmic Microwave Background group has developed in the past (Tenerife experiment, IAC-Bartol experiment...) and is running at the present time (VSA, Cosmosomas). The QUIJOTE CMB experiment will consist of two telescopes which will be installed inside a unique enclosure, which is already constructed. The layout of both telescopes is based on an altazimuth mount supporting a primary and a secondary mirror disposed in a offset Gregorian Dragon scheme. The use of industrial-like fabrication techniques, such as sand-mould casting, CNC machining, and laser tracker measuring for alignment, provided the required performances for microwave observation. A fast-track construction scheme, altogether with the use of these fabrication techniques allowed designing and manufacturing the opto-mechanics of the telescope in 14 months prior to delivery for final start-up in December 2008.

  1. The NASA Spitzer Space Telescope.

    PubMed

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  2. NEWS: Hands-on telescopes!

    NASA Astrophysics Data System (ADS)

    2000-05-01

    As part of the International Astronomical Union Meeting taking place in Manchester in August, the Education Committee of the Royal Astronomical Society is organizing a day conference on using robotic telescopes in schools. `Astronomy research projects for schools and university students' will commence at 10.30 on Friday 18 August 2000. This discussion meeting will explore ways in which students at school and university can participate in research projects, and at the same time increase their understanding of astronomy and develop useful skills. The increase in access to robotic telescopes and to astronomy databases is making research by school and undergraduate students ever more feasible. In addition, useful research can be done with very modest telescope systems, of the sort a school could afford. A range of international speakers will describe and demonstrate the possibilities, as well as leading the discussion. This meeting is being organized by the Education Committee of the Royal Astronomical Society and by Commission 46 of the International Astronomical Union. It is being held at the end of the IAU General Assembly. Those who pay the registration fee for the General Assembly need pay no further fee for attending the discussion meeting; otherwise there is a fee of £10. Refreshments will be provided at no charge. To obtain a registration form for this discussion meeting please contact Alan Pickwick (Alan_C_Pickwick@compuserve.com).

  3. EUSO-TA prototype telescope

    NASA Astrophysics Data System (ADS)

    Bisconti, Francesca

    2016-07-01

    EUSO-TA is one of the prototypes developed for the JEM-EUSO project, a space-based large field-of-view telescope to observe the fluorescence light emitted by cosmic ray air showers in the atmosphere. EUSO-TA is a ground-based prototype located at the Telescope Array (TA) site in Utah, USA, where an Electron Light Source and a Central Laser Facility are installed. The purpose of the EUSO-TA project is to calibrate the prototype with the TA fluorescence detector in presence of well-known light sources and cosmic ray air showers. In 2015, the detector started the first measurements and tests using the mentioned light sources have been performed successfully. A first cosmic ray candidate has been observed, as well as stars of different magnitude and color index. Since Silicon Photo-Multipliers (SiPMs) are very promising for fluorescence telescopes of next generation, they are under consideration for the realization of a new prototype of EUSO Photo Detector Module (PDM). The response of this sensor type is under investigation through simulations and laboratory experimentation.

  4. The NASA Spitzer Space Telescope.

    PubMed

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/. PMID:17503900

  5. Educational activities with the Faulkes Telescopes

    NASA Astrophysics Data System (ADS)

    Roberts, S.; Roche, P.; Ross, R.

    2008-06-01

    Las Cumbres Observatory Global Telescope Network (LCOGTN) will eventually provide access to a global network of robotic telescopes for research-based science education. Here we present the educational projects that have been undertaken using the 2-m Faulkes Telescopes in Hawaii and Australia in both the UK and Europe. These include themed observing days in which schools collaborate in their telescope sessions, the development of science portals where schools can upload and share their telescope data, and other innovative projects. Public access to these facilities will increase as IYA2009 approaches.

  6. Equal-Curvature X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Saha, Timo T.; Zhang, William

    2002-01-01

    We introduce a new type of x-ray telescope design; an Equal-Curvature telescope. We simply add a second order axial sag to the base grazing incidence cone-cone telescope. The radius of curvature of the sag terms is the same on the primary surface and on the secondary surface. The design is optimized so that the on-axis image spot at the focal plane is minimized. The on-axis RMS (root mean square) spot diameter of two studied telescopes is less than 0.2 arc-seconds. The off-axis performance is comparable to equivalent Wolter type 1 telescopes.

  7. Cost Modeling for Space Optical Telescope Assemblies

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Henrichs, Todd; Luedtke, Alexander; West, Miranda

    2011-01-01

    Parametric cost models are used to plan missions, compare concepts and justify technology investments. This paper reviews an on-going effort to develop cost modes for space telescopes. This paper summarizes the methodology used to develop cost models and documents how changes to the database have changed previously published preliminary cost models. While the cost models are evolving, the previously published findings remain valid: it costs less per square meter of collecting aperture to build a large telescope than a small telescope; technology development as a function of time reduces cost; and lower areal density telescopes cost more than more massive telescopes.

  8. Twin-Telescope Wettzell (TTW)

    NASA Astrophysics Data System (ADS)

    Hase, H.; Dassing, R.; Kronschnabl, G.; Schlüter, W.; Schwarz, W.; Lauber, P.; Kilger, R.

    2007-07-01

    Following the recommendations made by the VLBI2010 vision report of the IVS, a proposal has been made to construct a Twin Telescope for the Fundamental Station Wettzell in order to meet the future requirements of the next VLBI generation. The Twin Telescope consists of two identical radiotelescopes. It is a project of the Federal Agency for Cartography and Geodesy (BKG). This article summarizes the project and some design ideas for the Twin-Telescope. %ZALMA (2005). Technical Specification for Design, Manufacturing, Transport and Integration on Site of the ALMA ANTENNAS, Doc. ALMA-34.00.00.00.006-BSPE. Behrend, D. (2006). VLBI2010 Antenna Specs, Data sheet. DeBoer, D. (2001). The ATA Offset Gregorian Antenna, ATA Memo #16, February 10. Imbriale, W.A. (2006). Design of a Wideband Radio Telescope, Jet Propulsion Laboratory and S. Weinreb and H. Mandi, California Institute of Technology. Kilger, R. (2007). TWIN-Design studies, Presentation for the IVS board members (internal document),Wettzell. Kronschnabl, G. (2006). Subject: Memo from Bill Petrachenko, E-mail to the Twin-Working Group (in German), July. Lindgren, ETS-Lindgren (2005). The Model 3164-05 Open Boundary Quadridge Horn, Data Sheet. Niell, A., A. Whitney, W. Petrachenko, W. Schlüter, N. Vandenberg, H.Hase, Y. Koyama, C. Ma, H. Schuh, G. Tucari (2006). in: IVS Annual Report 2005, pg. 13-40, NASA/TP-2006-214136, April. Olsson, R., Kildal, P.-S., and Weinreb, S. (2006). IEEE Transactions on Antennas and Propagation, Vol. 54, No. 2, February. Petrachenko, B. (2006). The Case For and Against Multiple Antennas at a Site, IVS Memorandum, 2006-019v01. Petrachenko, B. (2006). IVS Memorandum, 2006-016v01. RFSpin (2004). Double Ridged Waveguide Horn-Model DRH20, Antenna Specifications, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Crossed Log- Periodic Antennas HL024A1/S1, Data Sheet. Rohde&Schwarz (2004). SHF Antennas Log-Periodic Antennas HL050/HL050S1, Data Sheet. Rogers, A.E.E. (2006). Simulations of broadband

  9. Wavefront Analysis of Adaptive Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Hillman, Lloyd

    1997-01-01

    The motivation for this work came from a NASA Headquarters interest in investigating design concepts for a large space telescope employing active optics technology. Current and foreseeable launch vehicles will be limited to carrying around 4-5 meter diameter objects. Thus, if a large, filled-aperture telescope (6-20 meters in diameter) is to be placed in space, it will be required to have a deployable primary mirror. Such a mirror may be an inflatable membrane or a segmented mirror consisting of many smaller pieces. In any case, it is expected that the deployed primary will not be of sufficient quality to achieve diffraction-limited performance for its aperture size. Thus, an active optics system will be needed to correct for initial as well as environmentally-produced primary figure errors. Marshall Space Flight Center has developed considerable expertise in the area of active optics with the PAMELA test-bed. The combination of this experience along with the Marshall optical shop's work in mirror fabrication made MSFC the logical choice to lead NASA's effort to develop active optics technology for large, space-based, astronomical telescopes. Furthermore, UAH's support of MSFC in the areas of optical design, fabrication, and testing of space-based optical systems placed us in a key position to play a major role in the development of this future-generation telescope. A careful study of the active optics components had to be carried out in order to determine control segment size, segment quality, and segment controllability required to achieve diffraction-limited resolution with a given primary mirror. With this in mind, UAH undertook the following effort to provide NASA/MSFC with optical design and analysis support for the large telescope study. All of the work performed under this contract has already been reported, as a team member with MSFC, to NASA Headquarters in a series of presentations given between May and December of 1995. As specified on the delivery

  10. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    NASA Astrophysics Data System (ADS)

    1999-11-01

    Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

  11. Aligning Astronomical Telescopes via Identification of Stars

    NASA Technical Reports Server (NTRS)

    Whorton, Mark

    2010-01-01

    A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate the need for an initial estimate of the aiming direction. The method does not require any equipment other than a digital imaging device such as a charge-coupled-device digital imaging camera and control computers of the telescope and camera, all of which are standard components in professional astronomical telescope systems and in high-end amateur astronomical telescope systems. The method could be implemented in software running in the telescope or camera control computer or in an external computer communicating with the telescope pointing mount and camera control computers.

  12. Palomar AO Observations During the Uranian Equinox

    NASA Astrophysics Data System (ADS)

    Bauer, James M.; Goguen, J. D.; Buratti, B. J.; Hibbitts, C. A.; Young, L.; Young, E. F.; Baines, K. H.; Hammel, H. B.; Fitzsimmons, A.; Lainey, V.; Arlot, J. E.; Hicks, M. D.

    2007-10-01

    In December of 2007, the planet Uranus will pass through its northern hemisphere spring equinox. The northernmost latitudes of the planet and regular satellites will be exposed to sunlight for the first time in 42 years, when the planet's atmosphere may undergo an active seasonal change during the time surrounding this equinox. Unique circumstances during the equinoctial event also concerning the viewing geometries of the rings and satellites provide rare opportunities to determine the physical nature of these elements of the Uranian system and to study the short-term and evolutionary effects of seasonal insolation in the outer solar system. Furthermore, the approaching perspective affords us opportunities to characterize details of surfaces that have not been viewable, even by Voyager-2, since the advent of modern instrumentation. We present preliminary results from the first of these observations made over several nights during the 2006B and 2007A observing semesters. Our imaging using the Palomar adaptive optics system on the observatory's 200-inch telescope has been used to obtain high-resolution images. These observations will provide constraints on the planet's atmospheric dynamics and structure by monitoring the storms that already appear to be arising. These same images also provide unique photometric information regarding the ring-system particles by viewing the system from its dark side, accessible only during the 2007 season. Spectral and spectro-photometric observations of the newly exposed surfaces of the major satellites have also been obtained from the IRTF and Palomar 200-inch, including observations of some mutual event phenomena. Acknowledgements: These results are based in part on observations obtained at the Hale Telescope, Palomar Observatory, as part of a collaborative agreement between Caltech, JPL and Cornell University. Some observations were also obtained at the Infrared Telescope Facility, which is operated by the University of Hawaii

  13. The James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2007-01-01

    The scientific capabilities of the James Webb Space Telescope (JWST) fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to unravel the birth and early evolution of stars, from infall onto dust-enshrouded protostars, to the genesis of planetary systems. The Planetary Systems and the Origins of Life theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. To enable these four science themes, JWST will be a large (6.6m) cold (50K) telescope launched to the second Earth-Sun Lagrange point early in the next decade. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In this paper, the status and capabilities of the observatory and instruments in the context of the major scientific goals are reviewed.

  14. The Northwest Indiana Robotic Telescope

    NASA Astrophysics Data System (ADS)

    Slavin, Shawn D.; Rengstorf, A. W.; Aros, J. C.; Segally, W. B.

    2011-01-01

    The Northwest Indiana Robotic (NIRo) Telescope is a remote, automated observing facility recently built by Purdue University Calumet (PUC) at a site in Lowell, IN, approximately 30 miles from the PUC campus. The recently dedicated observatory will be used for broadband and narrowband optical observations by PUC students and faculty, as well as pre-college students through the implementation of standards-based, middle-school modules developed by PUC astronomers and education faculty. The NIRo observatory and its web portal are the central technical elements of a project to improve astronomy education at Purdue Calumet and, more broadly, to improve science education in middle schools of the surrounding region. The NIRo Telescope is a 0.5-meter (20-inch) Ritchey-Chrétien design on a Paramount ME robotic mount, featuring a seven-position filter wheel (UBVRI, Hα, Clear), Peltier (thermoelectrically) cooled CCD camera with 3056 x 3056, square, 12 μm pixels, and off-axis guiding. It provides a coma-free imaging field of 0.5 degrees square, with a plate scale of 0.6 arcseconds per pixel. The observatory has a wireless internet connection, local weather station which publishes data to an internet weather site, and a suite of CCTV security cameras on an IP-based, networked video server. Control of power to every piece of instrumentation is maintained via internet-accessible power distribution units. The telescope can be controlled on-site, or off-site in an attended fashion via an internet connection, but will be used primarily in an unattended mode of automated observation, where queued observations will be scheduled daily from a database of requests. Completed observational data from queued operation will be stored on a campus-based server, which also runs the web portal and observation database. Partial support for this work was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0736592.

  15. Camp Hale Study Act

    THOMAS, 112th Congress

    Sen. Udall, Mark [D-CO

    2011-02-03

    05/11/2011 Committee on Energy and Natural Resources Subcommittee on National Parks. Hearings held. With printed Hearing: S.Hrg. 112-124. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  16. Las Cumbres Observatory Global Telescope Network

    NASA Astrophysics Data System (ADS)

    Brown, T. M.; Baliber, N.; Bianco, F. B.; Bowman, M.; Burleson, B.; Conway, P.; Crellin, M.; Depagne, É.; De Vera, J.; Dilday, B.; Dragomir, D.; Dubberley, M.; Eastman, J. D.; Elphick, M.; Falarski, M.; Foale, S.; Ford, M.; Fulton, B. J.; Garza, J.; Gomez, E. L.; Graham, M.; Greene, R.; Haldeman, B.; Hawkins, E.; Haworth, B.; Haynes, R.; Hidas, M.; Hjelstrom, A. E.; Howell, D. A.; Hygelund, J.; Lister, T. A.; Lobdill, R.; Martinez, J.; Mullins, D. S.; Norbury, M.; Parrent, J.; Paulson, R.; Petry, D. L.; Pickles, A.; Posner, V.; Rosing, W. E.; Ross, R.; Sand, D. J.; Saunders, E. S.; Shobbrook, J.; Shporer, A.; Street, R. A.; Thomas, D.; Tsapras, Y.; Tufts, J. R.; Valenti, S.; Vander Horst, K.; Walker, Z.; White, G.; Willis, M.

    2013-09-01

    Las Cumbres Observatory Global Telescope (LCOGT) is a young organization dedicated to time-domain observations at optical and (potentially) near-IR wavelengths. To this end, LCOGT is constructing a worldwide network of telescopes, including the two 2 m Faulkes telescopes, as many as 17 × 1 m telescopes, and as many as 23 × 40 cm telescopes. These telescopes initially will be outfitted for imaging and (excepting the 40 cm telescopes) spectroscopy at wavelengths between the atmospheric UV cutoff and the roughly 1-μm limit of silicon detectors. Since the first of LCOGT's 1 m telescopes are now being deployed, we lay out here LCOGT's scientific goals and the requirements that these goals place on network architecture and performance, we summarize the network's present and projected level of development, and we describe our expected schedule for completing it. In the bulk of the paper, we describe in detail the technical approaches that we have adopted to attain desired performance. In particular, we discuss our choices for the number and location of network sites, for the number and sizes of telescopes, for the specifications of the first generation of instruments, for the software that will schedule and control the network's telescopes and reduce and archive its data, and for the structure of the scientific and educational programs for which the network will provide observations.

  17. History of Robotic and Remotely Operated Telescopes

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.

    2011-03-01

    While automated instrument sequencers were employed on solar eclipse expeditions in the late 1800s, it wasn't until the 1960s that Art Code and associates at Wisconsin used a PDP minicomputer to automate an 8-inch photometric telescope. Although this pioneering project experienced frequent equipment failures and was shut down after a couple of years, it paved the way for the first space telescopes. Reliable microcomputers initiated the modern era of robotic telescopes. Louis Boyd and I applied single board microcomputers with 64K of RAM and floppy disk drives to telescope automation at the Fairborn Observatory, achieving reliable, fully robotic operation in 1983 that has continued uninterrupted for 28 years. In 1985 the Smithsonian Institution provided us with a suburb operating location on Mt. Hopkins in southern Arizona, while the National Science Foundation funded additional telescopes. Remote access to our multiple robotic telescopes at the Fairborn Observatory began in the late 1980s. The Fairborn Observatory, with its 14 fully robotic telescopes and staff of two (one full and one part time) illustrates the potential for low operating and maintenance costs. As the information capacity of the Internet has expanded, observational modes beyond simple differential photometry opened up, bringing us to the current era of real-time remote access to remote observatories and global observatory networks. Although initially confined to smaller telescopes, robotic operation and remote access are spreading to larger telescopes as telescopes from afar becomes the normal mode of operation.

  18. Hubble Space Telescope battery background

    NASA Technical Reports Server (NTRS)

    Standlee, Dan

    1991-01-01

    The following topics are presented in viewgraph form and include the following: the MSFC Hubble Space Telescope (HST) Nickel-Hydrogen Battery Contract; HST battery design requirements; HST nickel-hydrogen battery development; HST nickel-hydrogen battery module; HST NiH2 battery module hardware; pressure vessel design; HST NiH2 cell design; offset non-opposing vs. rabbit ear cell; HST NiH2 specified capacity; HST NiH2 battery design; and HST NiH2 module design.

  19. The Large Millimeter Telescope (LMT)

    NASA Astrophysics Data System (ADS)

    Baars, J. W. M.; Carrasco, L.; Schloerb, F. P.

    1999-05-01

    The University of Massachusetts at Amherst, through the FCRAO, and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Puebla, Mexico, are collaborating in the design, construction and joint operation of the Large Millimeter Telescope (LMT). The LMT is a full aperture telescope of 50 m diameter for operation to a shortest wavelength of 1 mm. First generation facility instruments include a 32-channel spectroscopy receiver for the 85-115 GHz band and a 144-channel bolometer system at 250 GHz. A joint institute, the LMT Observatory, will operate the telescope for the astronomers from the participating institutes and outside observers. Commissioning of the LMT is scheduled to start in 2001. The LMT is expected to contribute in particular to the study of the Universe at high redshifts. Its size and southern location also make it a powerful member of the growing mm-wavelength VLBI activity. The LMT is located on Cerro la Negra in Central Mexico at 4600 m altitude and a latitude of 19 degrees. The site is 100 km east of Puebla. The opacity shows median tau-values of less than 0.15 at 230 GHz from Sep through May, good for operation to 300 GHz. Site preparation and installation of utilities is under way. Work on the telescope foundation will begin in Spring 1999 with steel assembly expected to commence in early 2000. The LMT is being designed by MAN Technologie. It is an exposed, alt-azimuth antenna with a wheel-on-track azimuth drive and double bull-gear elevation drive. An advanced servo-system will aid in achieving the pointing accuracy of 1''. A spacious receiver cabin behind the reflector, allows the deployment of and easy access to several receiver systems. The reflector is a space-frame structure, supporting 130 reflector subframes of about 5x3 m2 which carry the reflector surface panels. The subframes are supported on actuators to enable real-time correction of the reflector surface for deformations, caused by gravity, temperature gradients and

  20. Apollo Telescope Mount Thermal Unit

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The Apollo Telescope Mount (ATM) was designed and developed by the Marshall Space Flight Center (MSFC) and served as the primary scientific instrument unit aboard Skylab (1973-1979). The ATM consisted of eight scientific instruments as well as a number of smaller experiments. This image is of the ATM thermal unit being tested in MSFC's building 4619. The thermal unit consisted of an active fluid-cooling system of water and methanol that was circulated to radiators on the outside of the canister. The thermal unit provided temperature stability to the ultrahigh resolution optical instruments that were part of the ATM.

  1. Silicate Mineralogy of the Dust in the Inner Coma of Comet C/1995 01 (Hale-Bopp) Pre- and Post-Perihelion

    NASA Technical Reports Server (NTRS)

    Wooden, Diane H.; Harker, David E.; Woodward, Charles E.; Butner, Harold M.; Koike, Chiyoe; Witteborn, Fred C.; McMurtry, Craig M.

    1998-01-01

    We present 7.6 - 13.3 microns infrared (IR) spectrophotometry (R approx. = 180 - 350) of the 10 microns silicate emission from dust in the inner coma (i.e., within a diameter of 3in.) of comet C/1995 O1 (Hale-Bopp) at four temporal epochs from 1996 October through 1997 June during Hale-Bopp s approach to, arrival at, and recession from perihelion. The HIFOGS spectra at large heliocentric distances exhibit strong emission peaks from 9.9 - 10.1 microns and at 11.2 microns. The HIFOGS spectra of Hale-Bopp taken 1996 October 07 - 14 UT are identical in shape to the ISO SWS spectrum at 2.8 AU obtained on 1996 October 06 UT. Magnesium-rich olivine was unambiguously identified due to presence of the expected 11.2 microns peak along with the matching far-IR 18 microns, 23 microns, and 33 microns peaks in the ISO SWS spectrum. In contrast, to large heliocentric distances, we find that the silicate feature at small heliocentric distances (tau(sub lambda) less than or = 1.7 AU) exhibits strong peaks at 9.3 microns, 9.9 - 10.1 microns, and 11.2 microns, and weak at 10.5 microns and 11.8 microns. We will show that the dramatic increase of the 9.3 microns and 10.0 microns peaks close to perihelion leads to the hypothesis that there are two crystalline grain components with significantly different temperatures. The hotter mineral species (including olivines) radiate over a large range of heliocentric distances at detectable leve!s. The cooler mineral species (pyroxenes) radiate on the Wien side of the blackbody, too faint to detect in the mid-infrared spectra, until close to the sun when this species radiates on the Reyleigh-Jeans tail and becomes apparent. Decomposition of the observed silicate emission features into mineral components through comparison of the height and shape of the silicate feature ("Flux/cont") derived from the cometary spectra, to optical extinctions (Qext) derived from laboratory measurements of terrestrial silicate minerals and interplanetary dust

  2. Mars Telescopic Observations Workshop II

    NASA Technical Reports Server (NTRS)

    Sprague, A. L. (Editor); Bell, J. F., III (Editor)

    1997-01-01

    Mars Telescopic Observations Workshop E convened in Tucson, Arizona, in October 1997 by popular demand slightly over two years following the first successful Mars Telescopic Observations Workshop, held in Ithaca, New York, in August 1995. Experts on Mars from the United Kingdom, Japan, Germany, and the United States were present. Twenty-eight oral presentations were made and generous time allotted for useful discussions among participants. The goals of the workshop were to (1) summarize active groundbased observing programs and evaluate them in the context of current and future space missions to Mars, (2) discuss new technologies and instrumentation in the context of changing emphasis of observations and theory useful for groundbased observing, and (3) more fully understand capabilities of current and planned Mars missions to better judge which groundbased observations are and will continue to be of importance to our overall Mars program. In addition, the exciting new discoveries presented from the Pathfinder experiments and the progress report from the Mars Global Surveyor infused the participants with satisfaction for the successes achieved in the early stages of these missions. Just as exciting was the enthusiasm for new groundbased programs designed to address new challenges resulting from mission science results. We would like to thank the National Aeronautics and Space Administration as well as Dr. David Black, director of the Lunar and Planetary Institute, and the staff of the Institute's Publications and Program Services Department for providing logistical, administrative, and publication support services for this workshop.

  3. ALMA telescope reaches new heights

    NASA Astrophysics Data System (ADS)

    2009-09-01

    of the Array Operations Site. This means surviving strong winds and temperatures between +20 and -20 Celsius whilst being able to point precisely enough that they could pick out a golf ball at a distance of 15 km, and to keep their smooth reflecting surfaces accurate to better than 25 micrometres (less than the typical thickness of a human hair). Once the transporter reached the high plateau it carried the antenna to a concrete pad - a docking station with connections for power and fibre optics - and positioned it with an accuracy of a few millimetres. The transporter is guided by a laser steering system and, just like some cars today, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 18.5 km and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. "Transporting our first antenna to the Chajnantor plateau is a epic feat which exemplifies the exciting times in which ALMA is living. Day after day, our global collaboration brings us closer to the birth of the most ambitious ground-based astronomical observatory in the world", said Thijs de Graauw, ALMA Director. This first ALMA antenna at the high site will soon be joined by others and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimetre and submillimetre wavelengths, between infrared light and radio waves in

  4. Holographic spectrograph for space telescope

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas D.; Lysenko, Sergiy; Crenshaw, Melissa

    2013-09-01

    A spectrograph is described which is made with dual Holographic Optical Elements (HOEs) which are identical and parallel to each other. Both optics are collimating transmission HOEs with focal points that are at equal and opposite distances from each other. The identical HOEs are formed by the interference of a plane wave parallel to the grating plane with an off-axis spherical wave originating in the near-field. In playback, a spectrum can be formed from a point source radiator placed at the position of the recording spherical wave. If played back at an arbitrary wavelength other than the recording wavelength, the image exhibits coma. This spectrograph is intended for an unusual configuration where many nearly monochromatic sources of known wavelengths are separately positioned relative to the first HOE. The special application is in a space telescope capable of resolving spectra from habitable planets within 10 pc. HOEs of this type could be fabricated on membrane substrates with a low areal mass and stowable on rolls for insertion into the second Lagrange point. The intended application is for a 50 x 10 meter class primary objective holographic space telescope with 50 x 10 m HOEs in the spectrograph. We present a computer model of the spectrograph.. Experimental results are compared with predictions from theory. A single HOE is shown to perform over a wider bandwidth and is demonstrated.

  5. Large aperture diffractive space telescope

    DOEpatents

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  6. Edwin Hubble's Silence

    NASA Astrophysics Data System (ADS)

    Lago, D.

    2013-04-01

    In late 1928 Edwin Hubble was right in the middle of using V. M. Slipher's redshift data to prove that the universe is expanding, when Hubble's boss, George Hale, directed him to drop everything and rush to the Grand Canyon and test it as a possible site for Hale's planned 200-inch telescope. On his way, Hubble stopped at Lowell Observatory and met with V. M. Slipher. The letters both men wrote about this visit suggest that Hubble never said a word about his being in the middle of using Slipher's research to transform the universe. At the least, this silence is symbolic of the silence with which astronomical history has often treated Slipher's work. A survey of the historical literature suggests several reasons for this. Theorists and observers in astronomy (and other sciences) have long had different perspectives about how science works, and those who place more importance on theory have tended to credit the idea of the expanding universe to the theorists. Also, many sources indicate that Edwin Hubble was not a modest man or generous about sharing credit.

  7. JWST Telescope Integration and Test Progress

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Whitman, Tony L.; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Keski-Kuha, Ritva

    2016-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. The JWST Optical Telescope Element (Telescope) integration and test program is well underway. The telescope was completed in the spring of 2016 and the cryogenic test equipment has been through two optical test programs leading up to the final flight verification program. The details of the telescope mirror integration will be provided along with the current status of the flight observatory. In addition, the results of the two optical ground support equipment cryo tests will be shown and how these plans fold into the flight verification program.

  8. JWST telescope integration and test progress

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Whitman, Tony L.; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Keski-Kuha, Ritva

    2016-07-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. The JWST Optical Telescope Element (Telescope) integration and test program is well underway. The telescope was completed in the spring of 2016 and the cryogenic test equipment has been through two optical test programs leading up to the final flight verification program. The details of the telescope mirror integration will be provided along with the current status of the flight observatory. In addition, the results of the two optical ground support equipment cryo tests will be shown and how these plans fold into the flight verification program.

  9. Review of lunar telescope studies at MSFC

    NASA Astrophysics Data System (ADS)

    Hilchey, John D.; Nein, Max E.

    1993-09-01

    In the near future astronomers can take advantage of the lunar surface as the new 'high ground' from which to study the universe. Optical telescopes placed and operated on the lunar surface would be successors to NASA's Great Observatories. Four telescopes, ranging in aperture from a 16-m, IR/Vis/UV observatory down to a 1-m, UV 'transit' instrument, have been studied by the Lunar Telescope Working Group and the LUTE (lunar telescope ultraviolet experiment) Task Team of the Marshall Space Flight Center (MSFC). This paper presents conceptual designs of the telescopes, provides descriptions of the telescope subsystem options selected for each concept, and outlines the potential evolution of their science capabilities.

  10. Optical aperture synthesis with electronically connected telescopes.

    PubMed

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D

    2015-04-16

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths.

  11. Telescope Systems for Balloon-Borne Research

    NASA Technical Reports Server (NTRS)

    Swift, C. (Editor); Witteborn, F. C. (Editor); Shipley, A. (Editor)

    1974-01-01

    The proceedings of a conference on the use of balloons for scientific research are presented. The subjects discussed include the following: (1) astronomical observations with balloon-borne telescopes, (2) orientable, stabilized balloon-borne gondola for around-the-world flights, (3) ultraviolet stellar spectrophotometry from a balloon platform, (4) infrared telescope for balloon-borne infrared astronomy, and (5) stabilization, pointing, and command control of balloon-borne telescopes.

  12. Optical photometry using Bradford robotic telescope

    NASA Astrophysics Data System (ADS)

    Seal Braun, P.; Baruch, J. E. F.

    2009-06-01

    The Bradford Robotic Telescope (BRT) is located on Mount Teide at Tenerife and is working, taking observations since 2003. It is a fully automated telescope. The hardware and software used for the working of the telescope are described here. Twenty four BL Lac objects are observed since 2005 and magnitudes of the objects are calculated. We describe in this paper the working of BRT and optical BVR photometry of BL Lac objects, observed during 2005-2007.

  13. ANTARES: The first undersea neutrino telescope

    NASA Astrophysics Data System (ADS)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Assis Jesus, A. C.; Astraatmadja, T.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Cârloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th.; Charvis, Ph.; Chauchot, P.; Chiarusi, T.; Circella, M.; Compère, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; de Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J.-J.; di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J.-L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J.-F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatá, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gómez-González, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernández-Rey, J. J.; Herold, B.; Hößl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J.-C.; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Levansuu, A.; Lefèvre, D.; Legou, T.; Lelaizant, G.; Lévéque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazéas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Palioselitis, D.; Papaleo, R.; Păvălaş, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J.-F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; van Wijk, R.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

    2011-11-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the design, the construction and the installation of the telescope in the deep sea, offshore from Toulon in France. An illustration of the detector performance is given.

  14. A cooled telescope for infrared balloon astronomy

    NASA Technical Reports Server (NTRS)

    Frederick, C.; Jacobson, M. R.; Harwit, M. O.

    1974-01-01

    The characteristics of a 16 inch liquid helium cooled Cassegrain telescope with vibrating secondary mirror are discussed. The telescope is used in making far infrared astronomical observations. The system houses several different detectors for multicolor photometry. The cooled telescope has a ten to one increase in signal-to-noise ratio over a similar warm version and is installed in a high altitude balloon gondola to obtain data on the H2 region of the galaxy.

  15. Design of Galilean-type telescope systems.

    PubMed

    Menchaca, C; Malacara, D

    1988-09-01

    In this paper we present the design of three Galilean-type telescope systems with magnifications of 2.2x, 4x, and 5x. These systems are free of the large weight and length as well as the reduced field of view, which are frequent undesirable properties of Galilean telescopes. These designs have a moderate field of view and a short length, with reasonably good aberration correction, and may be used as binocular telescopes or magnifiers with a large working distance.

  16. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    NASA Astrophysics Data System (ADS)

    1999-11-01

    Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

  17. Unravelling dropsy: from Marcello Malpighi's discovery of the capillaries (1661) to Stephen Hales' production of oedema in an experimental model (1733).

    PubMed

    Andreae, L; Fine, L G

    1997-01-01

    A modern understanding of oedema formation traditionally begins with Starling's description in 1898 of hydrostatic and oncotic forces acting on the capillary membrane. Clearly, hypotheses of oedema formation predating the knowledge of the existence of capillaries must have been incomplete. Marcello Malpighi first described capillaries in 1661, but although he displayed a good grasp of the principles of the Harveian circulation and believed that oedema fluid (the clinical entity dropsy) was derived from the blood rather than the tissues, we have found no evidence that he realised the central role played by his discovery. However, only 60 years later, Stephen Hales' Haemastaticks reveals the creation of an experimental model for dropsy which led him towards an understanding of oedema formation not far behind Starling.

  18. The spectrum of comet Hale-Bopp (C/1995 O1) observed with the Infrared Space Observatory at 2.9 astronomical units from the sun.

    PubMed

    Crovisier, J; Leech, K; Bockelée-Morvan, D; Brooke, T Y; Hanner, M S; Altieri, B; Keller, H U; Lellouch, E

    1997-03-28

    Comet Hale-Bopp (C/1995 O1) was observed at wavelengths from 2.4 to 195 micrometers with the Infrared Space Observatory when the comet was about 2.9 astronomical units (AU) from the sun. The main observed volatiles that sublimated from the nucleus ices were water, carbon monoxide, and carbon dioxide in a ratio (by number) of 10:6:2. These species are also the main observed constituents of ices in dense interstellar molecular clouds; this observation strengthens the links between cometary and interstellar material. Several broad emission features observed in the 7- to 45-micrometer region suggest the presence of silicates, particularly magnesium-rich crystalline olivine. These features are similar to those observed in the dust envelopes of Vega-type stars.

  19. Weather Requirements and Procedures for Step 1: High Altitude Long Endurance (HALE) Unmanned Aircraft System (UAS) Flight Operations in the National Air Space (NAS)

    NASA Technical Reports Server (NTRS)

    2007-01-01

    This cover sheet is for version 2 of the weather requirements document along with Appendix A. The purpose of the requirements document was to identify and to list the weather functional requirements needed to achieve the Access 5 vision of "operating High Altitude, Long Endurance (HALE) Unmanned Aircraft Systems (UAS) routinely, safely, and reliably in the National Airspace System (NAS) for Step 1." A discussion of the Federal Aviation Administration (FAA) references and related policies, procedures, and standards is provided as basis for the recommendations supported within this document. Additional procedures and reference documentation related to weather functional requirements is also provided for background. The functional requirements and related information are to be proposed to the FAA and various standards organizations for consideration and approval. The appendix was designed to show that sources of flight weather information are readily available to UAS pilots conducting missions in the NAS. All weather information for this presentation was obtained from the public internet.

  20. Unravelling dropsy: from Marcello Malpighi's discovery of the capillaries (1661) to Stephen Hales' production of oedema in an experimental model (1733).

    PubMed

    Andreae, L; Fine, L G

    1997-01-01

    A modern understanding of oedema formation traditionally begins with Starling's description in 1898 of hydrostatic and oncotic forces acting on the capillary membrane. Clearly, hypotheses of oedema formation predating the knowledge of the existence of capillaries must have been incomplete. Marcello Malpighi first described capillaries in 1661, but although he displayed a good grasp of the principles of the Harveian circulation and believed that oedema fluid (the clinical entity dropsy) was derived from the blood rather than the tissues, we have found no evidence that he realised the central role played by his discovery. However, only 60 years later, Stephen Hales' Haemastaticks reveals the creation of an experimental model for dropsy which led him towards an understanding of oedema formation not far behind Starling. PMID:9189256

  1. Preliminary Cost Model for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Prince, F. Andrew; Smart, Christian; Stephens, Kyle; Henrichs, Todd

    2009-01-01

    Parametric cost models are routinely used to plan missions, compare concepts and justify technology investments. However, great care is required. Some space telescope cost models, such as those based only on mass, lack sufficient detail to support such analysis and may lead to inaccurate conclusions. Similarly, using ground based telescope models which include the dome cost will also lead to inaccurate conclusions. This paper reviews current and historical models. Then, based on data from 22 different NASA space telescopes, this paper tests those models and presents preliminary analysis of single and multi-variable space telescope cost models.

  2. Enthusiasm for Europe's space telescope ISO

    NASA Astrophysics Data System (ADS)

    1996-11-01

    down 75 per cent of the proposed observations. Nevertheless the allocations announced this month will meet the wishes of most groups of applicants at least in part. ISO is now about half way through its operating life. An Ariane 44P launcher put it into orbit on 17 November 1995. ISO's superfluid helium which keeps the telescope and instruments cold, will last about six months longer than required in the specification. Operations are expected to continue until December 1997, with the benefit that the chemically rich and starmaking clouds of the important Orion region of the sky will be observable by ISO. Tracing the origin of planets Observations of the Antennae galaxies, and some of the other ISO results now described in full technical detail in Astronomy and Astrophysics, were outlined in earlier ESA Information Notes, 02-96 and 14-96. These include examinations of star formation in many galaxies and within dust clouds in our own Galaxy, the Milky Way. ISO has also given a big boost to astrochemistry by identifying infrared signatures of many materials, which play a physical as well as a chemical role in the evolution of galaxies and stars. The materials seen by ISO include ionized carbon atoms, sooty carbon compounds, hydrogen molecules, water molecules, and frozen carbon dioxide and methane. The latest results tell of mineral crystals, which may shed light on the origin of the Earth itself. Disks of dust around some stars, of the kind from which planets might evolve, were a major discovery in infrared astronomy by ISO's predecessor, the Dutch US UK satellite IRAS (1983). The prototype was the bright northern star Vega. It showed excess emissions of long-wavelength infrared rays, which could not come from the star itself. Subsequent studies confirmed the dust disks of Vega and a few other stars, and the search for more such disks is a major programme for ISO, relying particularly on measurements by the photometer ISOPHOT across a wide range of infrared wavelengths

  3. Diffractive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  4. The Giant Metrewave Radio Telescope

    NASA Astrophysics Data System (ADS)

    Nityananda, R.

    2003-05-01

    The Giant Metrewave Radio Telescope (GMRT) of the National Centre of Radio Astrophysics (NCRA) of the Tata Institute of Fundamental Research (TIFR) at Khodad, India, has been operational in the band 0.2 to 2 metres for the last two and a half years. The system characteristics and performance and recent results from the group will be presented. Details of use over the last six months by scientists from other observatories under the GMRT Time Allocation Committee (GTAC) and future plans will be also be reviewed in this paper. Areas which have been studied include observations made in the GMRT band of neutral hydrogen, nearby galaxies, supernova remnants, the Galactic Centre, pulsars, the Sun and others.

  5. Unparticle effects in neutrino telescopes

    SciTech Connect

    Gonzalez-Sprinberg, G.; Martinez, R.; Sampayo, Oscar A.

    2009-03-01

    Recently H. Georgi has introduced the concept of unparticles in order to describe the low energy physics of a nontrivial scale invariant sector of an effective theory. We investigate its physical effects on the neutrino flux to be detected in a kilometer cubic neutrino telescope such as IceCube. We study the effects, on different observables, of the survival neutrino flux after through the Earth, and the regeneration originated in the neutral currents. We calculate the contribution of unparticle physics to the neutrino-nucleon interaction and, then, to the observables in order to evaluate detectable effects in IceCUbe. Our results are compared with the bounds obtained by other nonunderground experiments. Finally, the results are presented as an exclusion plot in the relevant parameters of the new physics stuff.

  6. Recent results from telescope array

    NASA Astrophysics Data System (ADS)

    Fukushima, Masaki

    2015-08-01

    The Telescope Array (TA) is an experiment to observe Ultra-High Energy Cosmic Rays (UHECRs). TA's recent results, the energy spectrum and anisotropy based on the 6-year surface array data, and the primary composition obtained from the shower maximum (XMAX) are reported. The spectrum demonstrates a clear dip and cutoff. The shape of the spectrum is well described by the energy loss of extra-galactic protons interacting with the cosmic microwave background (CMB). Above the cutoff, a medium-scale (20∘ radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 σ. The measured ⟨XMAX⟩ is consistent with the primary being proton or light nuclei for energies 1018.2 eV-1019.2 eV.

  7. SLAC Cosmic Ray Telescope Facility

    SciTech Connect

    Va'vra, J.

    2010-02-15

    SLAC does not have a test beam for the HEP detector development at present. We have therefore created a cosmic ray telescope (CRT) facility, which is presently being used to test the FDIRC prototype. We have used it in the past to debug this prototype with the original SLAC electronics before going to the ESA test beam. Presently, it is used to test a new waveform digitizing electronics developed by the University of Hawaii, and we are also planning to incorporate the new Orsay TDC/ADC electronics. As a next step, we plan to put in a full size DIRC bar box with a new focusing optics, and test it together with a final SuberB electronics. The CRT is located in building 121 at SLAC. We anticipate more users to join in the future. This purpose of this note is to provide an introductory manual for newcomers.

  8. Adaptive Optics for Large Telescopes

    SciTech Connect

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  9. The Large Synoptic Survey Telescope

    NASA Astrophysics Data System (ADS)

    Ivezic, Zeljko

    2007-05-01

    The Large Synoptic Survey Telescope (LSST) is currently by far the most ambitious proposed ground-based optical survey. With initial funding from the US National Science Foundation (NSF), Department of Energy (DOE) laboratories and private sponsors, the design and development efforts are well underway at many institutions, including top universities and leading national laboratories. The main science themes that drive the LSST system design are Dark Energy and Matter, the Solar System Inventory, Transient Optical Sky and the Milky Way Mapping. The LSST system, with its 8.4m telescope and 3,200 Megapixel camera, will be sited at Cerro Pachon in northern Chile, with the first light scheduled for 2014. In a continuous observing campaign, LSST will cover the entire available sky every three nights in two photometric bands to a depth of V=25 per visit (two 15 second exposures), with exquisitely accurate astrometry and photometry. Over the proposed survey lifetime of 10 years, each sky location would be observed about 1000 times, with the total exposure time of 8 hours distributed over six broad photometric bandpasses (ugrizY). This campaign will open a movie-like window on objects that change brightness, or move, on timescales ranging from 10 seconds to 10 years, and will produce a catalog containing over 10 billion galaxies and a similar number of stars. The survey will have a data rate of about 30 TB/night, and will collect over 60 PB of raw data over its lifetime, resulting in an incredibly rich and extensive public archive that will be a treasure trove for breakthroughs in many areas of astronomy and astrophysics.

  10. The Onsala Twin Telescope Project

    NASA Astrophysics Data System (ADS)

    Haas, R.

    2013-08-01

    This paper described the Onsala Twin Telescope project. The project aims at the construction of two new radio telescopes at the Onsala Space Observatory, following the VLBI2010 concept. The project starts in 2013 and is expected to be finalized within 4 years. Z% O. Rydbeck. Chalmers Tekniska Högskola, Göteborg, ISBN 91-7032-621-5, 407-823, 1991. B. Petrachenko, A. Niell, D. Behrend, B. Corey, J. Böhm, P. Charlot, A. Collioud, J. Gipson, R. Haas, Th. Hobiger, Y. Koyama, D. MacMillan, Z. Malkin, T. Nilsson, A. Pany, G. Tuccari, A. Whitney, and J. Wresnik. Design Aspects of the VLBI2010 System. NASA/TM-2009-214180, 58 pp., 2009. R. Haas, G. Elgered, J. Löfgren, T. Ning, and H.-G. Scherneck. Onsala Space Observatory - IVS Network Station. In K. D. Baver and D. Behrend, editors, International VLBI Service for Geodesy and Astrometry 2011 Annual Report, NASA/TP-2012-217505, 88-91, 2012. H.-G. Scherneck, G. Elgered, J. M. Johansson, and B. O. Rönnäng. Phys. Chem. Earth, Vol. 23, No. 7-8, 811-823, 1998. A. R. Whitney. Ph.D. thesis, Dept. of Electrical engineering, MIT Cambridge, MA., 1974. B. A. Harper, J. D. Kepert, and J. D. Ginger. Guidelines for converting between various wind averaging periods in tropical cyclone conditions. WMO/TD-No. 1555, 64 pp., 2010 (available at \\url{http://www.wmo.int/pages/prog/www/tcp/documents/WMO_TD_1555_en.pdf})

  11. Proposed Integrated Radio-Telescope Network

    NASA Technical Reports Server (NTRS)

    Cohen, M. H.; Ewing, M. S.; Levy, G. S.; Mallis, R. K.; Readhead, A. C. S.; Smith, J. R.; Backer, D. C.

    1982-01-01

    Proposed network of radio telescopes, controlled by a central computer and managed by a single organization, offer potential for research on a scale that could not be matched by present privately and publicly-owned radio telescopes. With 10 antenna sites, network would establish base lines thousands of miles long. Antennas will be linked to computer center by telephone circuits.

  12. Milestone reached for James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Banks, Michael

    2016-03-01

    The primary mirror for the James Webb Space Telescope (JWST) - the successor to the Hubble Space Telescope - is complete after engineers at NASA's Goddard Space Flight Center in Maryland, US, put in place the craft's 18th and final mirror segment.

  13. Telescopes in Education: the Little Thompson Observatory

    NASA Astrophysics Data System (ADS)

    Schweitzer, A.; Vanlew, K.; Melsheimer, T.; Melsheimer, L.; Rideout, C.; Patterson, T.

    1997-12-01

    A second observatory of the Telescopes in Education (TIE) project is in the planning stages, with hopes to be in use by fall 1998. The Little Thompson Observatory will be located adjacent to Berthoud High School in northern Colorado. TIE has offered the observatory a Tinsley 18" Cassegrain telescope on a 10-year loan. Local schools and youth organizations will have prioritized access to the telescope until midnight; after that, the telescope will be open to world-wide use by schools via the Internet. The first TIE observatory is a 24" telescope on Mt. Wilson, already booked through July 1998. That telescope has been in use every clear night for the past four years by up to 50 schools per month. Students remotely control the telescope over the Internet, and then receive the images on their local computers. The estimated cost of the Little Thompson Observatory is roughly \\170,000. However, donations of labor and materials have reduced the final price tag closer to \\40,000. Habitat for Humanity is organized to construct the dome, classrooms, and other facilities. Tom and Linda Melsheimer, who developed the remote telescope control system for the University of Denver's Mount Evans Observatory, are donating a similar control system. The formally-trained, all-volunteer staff will be comprised of local residents, teachers and amateur astronomers. Utilities and Internet access will be provided by the Thompson School District.

  14. A Mechanical Analogue of the Refracting Telescope

    ERIC Educational Resources Information Center

    Vannoni, Maurizio; Molesini, Giuseppe; Sordini, Andrea; Straulino, Samuele

    2011-01-01

    The recent celebration of the discoveries made by Galileo four centuries ago has attracted new attention to the refracting telescope and to its use as an instrument for the observation of the night sky. This has offered the opportunity for addressing in the classroom the basic principles explaining the operation of the telescope. When doing so, a…

  15. Longer-baseline telescopes using quantum repeaters.

    PubMed

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2012-08-17

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines. PMID:23006349

  16. Galaxies, quasars, and beyond - The Space Telescope

    NASA Astrophysics Data System (ADS)

    Bahcall, J. N.

    1983-03-01

    The overall NASA plans for the Space Telescope are described. A brief history of the development of the Space Telescope is presented and the major characteristics of the ST Observatory are summarized. The astronomical instruments that will be used in the first few years are described and some of the important scientific projects are outlined.

  17. Adaptive compensation for an optical tracking telescope

    NASA Technical Reports Server (NTRS)

    Gilbart, J. W.; Winston, G. C.

    1974-01-01

    The application of model referenced adaptive control theory to an optical tracking telescope is discussed. The capability of the adaptive technique to compensate for mount irregularities such as inertial variations and bearing friction is demonstrated via field test results on a large tracking telescope. Results are presented which show a 6 to 1 improvement in tracking accuracy for a worst-case satellite trajectory.

  18. Software controls for the ATST Solar Telescope

    NASA Astrophysics Data System (ADS)

    Goodrich, Bret D.; Wampler, Stephen B.

    2004-09-01

    The Advanced Technology Solar Telescope (ATST) is intended to be the premier solar observatory for experimental solar physics. The ATST telescope control software is designed to operate similar to current nighttime telescopes, but will contain added functionality required for solar observations. These additions include the use of solar coordinate systems, non-sidereal track rates, solar rotation models, alternate guide signal sources, the control of thermal loads on the telescope, unusual observation and calibration motions, and serendipitous acquisition of transient objects. These requirements have resulted in a design for the ATST telescope control system (TCS) that is flexible and well-adapted for solar physics experiments. This report discusses both the classical design of the ATST TCS and the modifications required to observe in a solar physics environment. The control and servo loops required to operate both the pointing and wavefront correction systems are explained.

  19. James Webb Space Telescope Project (JWST) Overview

    NASA Technical Reports Server (NTRS)

    Dutta, Mitra

    2008-01-01

    This presentation provides an overview of the James Webb Space Telescope (JWST) Project. The JWST is an infrared telescope designed to collect data in the cosmic dark zone. Specifically, the mission of the JWST is to study the origin and evolution of galaxies, stars and planetary systems. It is a deployable telescope with a 6.5 m diameter, segmented, adjustable primary mirror. outfitted with cryogenic temperature telescope and instruments for infrared performance. The JWST is several times more sensitive than previous telescope and other photographic and electronic detection methods. It hosts a near infrared camera, near infrared spectrometer, mid-infrared instrument and a fine guidance sensor. The JWST mission objection and architecture, integrated science payload, instrument overview, and operational orbit are described.

  20. Optical design of a rotating eyepiece telescope

    NASA Astrophysics Data System (ADS)

    Siddique, M.; Nasim, F.; Khan, A. N.; Gul, A.

    2016-08-01

    Flexible eyepiece telescope has been designed and verified. The rotating eyepiece of telescope will facilitate viewing of objects in a remote or out of sight target. Eyepiece arm of telescope can be rotated upto 360o keeping objective and reticule unchanged and ensuring zero deviation in reticule inclination. Main application of this scope is off axis viewing of objects. Image inversion has been carried out by using pair of mirrors and length of telescope is controlled by using relay lenses. The optical design, simulation and image analysis has been carried out by using ZEMAX®. Magnification of telescope is between 10∼⃒12 times with FOV of 60. Experiment has been carried out using uncoated Edmund Optics and optical tool box of Micro Series Kit, NEWPORT.

  1. Las Cumbres Observatory Global Telescope 1-meter Telescope Project: Design, Deployment Plans, Status

    NASA Astrophysics Data System (ADS)

    Brown, Timothy M.; Burleson, B.; Crellin, M.; De Vera, J.; Dubberly, M.; Greene, R.; Falarski, M.; Haldeman, B.; Hausler, S.; Haynes, R.; Hjelstrom, A.; Hygelund, J.; Johnson, D.; Lobdill, R.; Martinez, J.; Mullins, D.; Pickles, A.; Posner, V.; Rosing, W.; Tufts, J.; Vander Horst, K.; Vanderhyden, B.; Walker, Z.

    2010-01-01

    Las Cumbres Observatory Global Telescope (LCOGT) is a privately-funded observatory dedicated to time-domain astronomy. Our main observing tool will be a homogeneous world-wide network of 12 x 1m optical telescopes, each equipped for both imaging and spectroscopy. Here we describe the LCOGT 1m telescope design, its development status, and our plans for deploying a dozen or so such telescopes in a worldwide network capable of continuous observing. We also describe the 80 cm Sedgwick telescope, which is now in regular operation as a research instrument, and which has served as a prototype for many of the 1m mechanical and control systems.

  2. ALMA Telescope Reaches New Heights

    NASA Astrophysics Data System (ADS)

    2009-09-01

    ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array

  3. The Large Millimeter Telescope (LMT)

    NASA Astrophysics Data System (ADS)

    Young, J. S.; Carrasco, L.; Schloerb, F. P.

    2002-05-01

    The Large Millimeter Telescope (LMT) project is a collaboration between the University of Massachusetts (UMass) in the USA and the Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Mexico to build a 50m-diameter millimeter-wave antenna which will operate with good efficiency at wavelengths as short as 1 mm. The LMT is being built at an altitude of 4600 m atop Volcan Sierra Negra, an extinct volcanic peak in the state of Puebla, Mexico, approximately 100 km east of the city of Puebla. At 18 degrees 59' N latitude, the site offers an excellent view of the Galactic Center and good sky coverage of both hemispheres. Construction of the telescope is now well underway, and it is expected to be completed in late 2004. The LMT specifications call for an overall effective surface accuracy of 75 microns rms and a pointing accuracy of 1" rms. The strategy for meeting these performance goals supplements conventional antenna designs with various "active" systems to bring the final performance within the requirements. For surface accuracy, the LMT will rely on an open loop active surface which includes 180 moveable surface segments. For pointing accuracy, we will use traditional approaches supplemented by measurements to characterize the behavior of the structure, including inclinometers and temperature sensors which may be used with finite element models to determine structural deformations and predict pointing behavior. The initial complement of instruments will include a 32 element, heterodyne focal plane array at 3mm; a large format, focal plane bolometer array; a unique wide band receiver and spectrometer to determine the redshifts of primordial galaxies; and a 4 element receiver for the 1mm band. With its excellent sensitivity and angular resolution, the LMT will enable unique studies of the early universe and galaxy evolution, the interstellar medium and star formation in galaxies, and planetary science. In particular, with nearly 2000 m2 of collecting

  4. The One-Hectare Telescope

    NASA Astrophysics Data System (ADS)

    Welch, William J.; Dreher, John W.

    2000-07-01

    The 1HT will be a large area telescope whose novel characteristics will be a wide field of view, continuous frequency coverage from .500 - 11 Ghz, multibeam capability, and provision for RFI mitigation built in. Its scientific motivation includes deep SETI searches, pulsar detection and investigation, galactic magnetic field mapping through many Zeemann transitions, mapping of the decrement in the cosmic background radiation seen toward galaxy clusters, observation of HI absorption toward quasars at redshifts up to z equals 2, and deep mapping of the HI distributions in the Milky Way and nearby galaxies. The array will use economies of scale to keep the costs down. It will consist of 500 - 1000 dishes of diameters in the range 3.6 m - 5 m. The dishes will be TV satellite style with wideband MMIC chip front-end amplifiers. Substantial prototype activity is under way. The feed, dish, and front-end MMIC designs are well along. A seven element test array is nearing completion. It will be used for studying RFI mitigation. By 2002, a 12 element array (PTA) which will be made up of all the final components will be operational. Final construction of the full array is expected by 2005.

  5. Spitzer Space Telescope proposal process

    NASA Astrophysics Data System (ADS)

    Laine, S.; Silbermann, N. A.; Rebull, L. M.; Storrie-Lombardi, L. J.

    2006-06-01

    This paper discusses the Spitzer Space Telescope General Observer proposal process. Proposals, consisting of the scientific justification, basic contact information for the observer, and observation requests, are submitted electronically using a client-server Java package called Spot. The Spitzer Science Center (SSC) uses a one-phase proposal submission process, meaning that fully-planned observations are submitted for most proposals at the time of submission, not months after acceptance. Ample documentation and tools are available to the observers on SSC web pages to support the preparation of proposals, including an email-based Helpdesk. Upon submission proposals are immediately ingested into a database which can be queried at the SSC for program information, statistics, etc. at any time. Large proposals are checked for technical feasibility and all proposals are checked against duplicates of already approved observations. Output from these tasks is made available to the Time Allocation Committee (TAC) members. At the review meeting, web-based software is used to record reviewer comments and keep track of the voted scores. After the meeting, another Java-based web tool, Griffin, is used to track the approved programs as they go through technical reviews, duplication checks and minor modifications before the observations are released for scheduling. In addition to detailing the proposal process, lessons learned from the first two General Observer proposal calls are discussed.

  6. The earliest telescope preserved in Japan

    NASA Astrophysics Data System (ADS)

    Nakamura, Tsuko

    2008-11-01

    This paper describes the antique telescope owned by one of Japan's major feudal warlords, Tokugawa Yoshinao. As he died in 1650, this means that this telescope was produced in or before that year. Our recent investigation of the telescope revealed that it is of Schyrlean type, consisting of four convex lenses, so that it gives erect images with a measured magnifying power of 3.9 (± 0.2-0.3). This also implies that Yoshinao's telescope could be one of the earliest Schyrlean telescopes ever. The design, fabrication technique, and the surface decoration of the telescopic tube and caps all suggest that it is not a Western make at all, but was produced probably under the guidance of a Chinese Jesuit missionary or by the Chinese, in Suzhou or Hangzhou in Zhejiang province, China, or in Nagasaki. Following descriptions in the Japanese and Chinese historical literature, we also discuss the possibility that production of Schyrlean-type telescopes started independently in the Far East nearly simultaneously with the publication of Oculus Enoch et Eliae by Anton Maria Schyrle in 1645.

  7. NLST: the Indian National Large Solar Telescope

    NASA Astrophysics Data System (ADS)

    Hasan, S. S.; Soltau, D.; Kärcher, H.; Süss, M.; Berkefeld, T.

    2010-07-01

    India is planning a new solar telescope with an aperture of 2-m for carrying out high resolution studies of the Sun. Site characterization is underway at high altitude locations in the Himalayan mountains. A detailed concept design for NLST (National Large Solar Telescope) has been completed. The optical design of the telescope is optimized for high optical throughput and uses a minimum number of optical elements. A high order AO system is integrated part of the design that works with a modest Fried's parameter of 7-cm to give diffraction limited performance. The telescope will be equipped with a suite of post-focus instruments including a high resolution spectrograph and a polarimeter. NLST will also be used for carrying out stellar observations during the night. The mechanical design of the telescope, building, and the innovative dome is optimized to take advantage of the natural air flush which will help to keep the open telescope in temperature equilibrium. After its completion (planned for 2014), NLST will fill a gap in longitude between the major solar facilities in USA and Europe, and it will be for years the largest solar telescope in the world

  8. Reproduction Of William Herschel's Metallic Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Okamura, N.; Hirabayashi, S.; Isida, A.; Komori, A.; Nishitani, M.

    2006-08-01

    Following the reproduction of Cassini's open-air telescope, which took us almost three years to complete, our club decided to reproduce the metallic mirror telescope invented by William Herschel, which is a telescope of the subsequent generation. We based our design on the 7-foot telescope by which he used to discover Uranus in 1781. The metallic mirror was casted and blended copper and tin in the ratio of seven to three, exactly like the mirrors in those days. The surface of the casted mirror had many imperfections such as hollow portions and bubbles. These were removed by using the rock grinder at our school and the mirror was later polished at the Hidaka Optical Institute. The tube of the mirror was also made up of eight polygons just like the original. When we observed the stars with the metallic mirror telescope, they were a little bit dark, but it was possible to observe them well and to observe the gap between Saturn and Cassini. We also succeeded in observing Uranus with this telescope last September. Reproduction of the telescope mount is being made in a nearly the same design as the original one. We have learned through the reproduction that the unique design of the mount allows us to make observations with precise tracking accuracy in a comfortable observing position.

  9. Parametric Cost Models for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtney

    2010-01-01

    Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

  10. Ground-Based Telescope Parametric Cost Model

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Rowell, Ginger Holmes

    2004-01-01

    A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

  11. General surface equations for glancing incidence telescopes.

    PubMed

    Saha, T T

    1987-02-15

    A generalized set of equations are derived for two mirror glancing incidence telescopes using Fermat's principle, a differential form of the law of reflection, the generalized sine condition, and a ray propagation equation described in vector form as a theoretical basis. The resulting formulation groups the possible telescope configurations into three distinct classes which are the Wolter, Wolter-Schwarzschild, and higherorder telescopes in which the Hettrick-Bowyer types are a subset. Eight configurations are possible within each class depending on the sign and magnitude of the parameters. PMID:20454195

  12. NASA capabilities roadmap: advanced telescopes and observatories

    NASA Technical Reports Server (NTRS)

    Feinberg, Lee D.

    2005-01-01

    The NASA Advanced Telescopes and Observatories (ATO) Capability Roadmap addresses technologies necessary for NASA to enable future space telescopes and observatories collecting all electromagnetic bands, ranging from x-rays to millimeter waves, and including gravity-waves. It has derived capability priorities from current and developing Space Missions Directorate (SMD) strategic roadmaps and, where appropriate, has ensured their consistency with other NASA Strategic and Capability Roadmaps. Technology topics include optics; wavefront sensing and control and interferometry; distributed and advanced spacecraft systems; cryogenic and thermal control systems; large precision structure for observatories; and the infrastructure essential to future space telescopes and observatories.

  13. Hubble Space Telescope Primer for Cycle 21

    NASA Astrophysics Data System (ADS)

    Gonzaga, S.; et al.

    2012-12-01

    The Hubble Space Telescope Primer for Cycle 21 is a companion document to the HST Call for Proposals1. It provides an overview of the Hubble Space Telescope (HST), with basic information about telescope operations, instrument capabilities, and technical aspects of the proposal preparation process. A thorough understanding of the material in this document is essential for the preparation of a competitive proposal. This document is available as an online HTML document and a PDF file. The HTML version, optimized for online browsing, contains many links to additional information. The PDF version is optimized for printing, but online PDF readers have search capabilities for quick retrieval of specific information.

  14. The Thirty Meter Telescope (TMT) Project

    NASA Astrophysics Data System (ADS)

    Sanders, G.; TMT Project

    2004-12-01

    The Thirty Meter Telescope (TMT) Project is engaged in a design and development phase. TMT is proposed as a private-public partnership of the California Institute of Technology and the University of California (partners in the earlier CELT design study), AURA (designers of the earlier GSMT concept), and the Canadian ACURA consortium (designers of the VLOT concept). The partners are developing a 30 meter diameter, finely segmented filled aperture telescope with seeing-limited and diffraction-limited capabilities to address the broad range of GSMT science goals. The paper will present the status of the project development and telescope and instrument design.

  15. Passive Cooling For Large Infrared Telescopes

    NASA Technical Reports Server (NTRS)

    Lin, Edward I.

    1993-01-01

    Conceptual passive-cooling technique enables very large infrared telescope in vacuum of outer space cooled to below 20 K without using cryogen. Telescope orbiting Earth at high altitude of around 100,000 km. Scheme also offers very small gradient of temperature across primary telescope reflector, so thermal distortions smaller; accuracy of surface figure of reflector significantly enhanced. Passive-cooling technique also applied to building of very large cryostats and to development of very large sun shields in traditional manner, and some elements of technique adapted for current small observatories.

  16. Telescoping cylindrical piezoelectric fiber composite actuator assemblies

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G. (Inventor); Shams, Qamar A. (Inventor); Fox, Robert L. (Inventor); Fox, legal representative, Christopher L. (Inventor); Fox Chattin, legal representative, Melanie L. (Inventor)

    2010-01-01

    A telescoping actuator assembly includes a plurality of cylindrical actuators in a concentric arrangement. Each cylindrical actuator is at least one piezoelectric fiber composite actuator having a plurality of piezoelectric fibers extending parallel to one another and to the concentric arrangement's longitudinal axis. Each cylindrical actuator is coupled to concentrically-adjacent ones of the cylindrical actuators such that the plurality of cylindrical actuators can experience telescopic movement. An electrical energy source coupled to the cylindrical actuators applies actuation energy thereto to generate the telescopic movement.

  17. Dual-Channel Multi-Purpose Telescope

    NASA Technical Reports Server (NTRS)

    Howard, Joseph M.; Content, David

    2009-01-01

    A dual-channel telescope allows for a wide-field telescope design wit h a good, narrow field channel of fewer surfaces for shorter-wavelen gth or planet-finding applications. The design starts with a Korsch three-mirror-anastigmat (TMA) telescope that meets the mission criter ia for image quality over a wide field of view. The internal image a t the Cassegrain focus is typically blurry due to the aberration bala ncing among the three mirrors. The Cassegrain focus is then re-optim ized on the axis of the system where the narrow field channel instru ment is picked off by bending the primary mirror.

  18. Support structures for large infrared telescopes

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1984-01-01

    An infrared telescope requires an accuracy of its reflecting surfaces of less than a micrometer. Future missions may require such accuracy from telescopes that are 20 meters or larger in diameter. The structure for supporting such a telescope will most probably take the form of a deep truss. Various approaches for constructing the primary mirror in space are illustrated. One that employs automated deployment of interconnected reflector-structure modules was described in detail. Estimates were made of the precision obtainable with properly configured truss structures and the required ability of active control systems for achieving the desired accuracy.

  19. Measuring Neutrinos with the ANTARES Telescope

    SciTech Connect

    Reed, Corey

    2009-12-17

    The ANTARES underwater neutrino telescope has been taking data since construction began in 2006. The telescope, completed in May of 2008, detects the Cerenkov radiation of charged leptons produced by high energy neutrinos interacting in or around the detector. The lepton trajectory is reconstructed with high precision, revealing the direction of the incoming neutrino. The performance of the detector will be discussed and recent data showing muons, electromagnetic showers and atmospheric neutrinos will be presented. Studies have been underway to search for neutrino point sources in the ANTARES data since 2007. Results from these studies will be presented, and the sensitivity of the telescope will be discussed.

  20. California Extremely Large Telescope : conceptual design for a thirty-meter telescope

    NASA Astrophysics Data System (ADS)

    Following great success in the creation of the Keck Observatory, scientists at the California Institute of Technology and the University of California have begun to explore the scientific and technical prospects for a much larger telescope. The Keck telescopes will remain the largest telescopes in the world for a number of years, with many decades of forefront research ahead after that. Though these telescopes have produced dramatic discoveries, it is already clear that even larger telescopes must be built if we are to address some of the most profound questions about our universe. The time required to build a larger telescope is approximately ten years, and the California community is presently well-positioned to begin its design and construction. The same scientists who conceived, led the design, and guided the construction of the Keck Observatory have been intensely engaged in a study of the prospects for an extremely large telescope. Building on our experience with the Keck Observatory, we have concluded that the large telescope is feasible and is within the bounds set by present-day technology. Our reference telescope has a diameter of 30 meters, the largest size we believe can be built with acceptable risk. The project is currently designated the California Extremely Large Telescope (CELT).

  1. The ALMA Telescope Control System

    NASA Astrophysics Data System (ADS)

    Farris, A.; Marson, Ralph; Kern, Jeff

    2005-10-01

    The Atacama Large Millimeter Array (ALMA) is a joint project between North America, Europe and Japan. ALMA is an aperture synthesis radio telescope consisting of 50 12-meter antennas located at an elevation of 5,000 meters in Llano de Chajnantor, Chile. These antennas will operate at frequencies ranging from 31.3 GHz to 950 GHz. The antennas can be moved and placed in different configurations, with baselines between the antennas varying from 150 meters to 20 km. The 50 antennas are supplemented by sixteen additional ones, known as the ALMA Compact Array (ACA): 12 7-meter antennas and 4 12-meter antennas. The ALMA control system will consist of over 70 computers separated by distances of over 20 km. Two aspects of the system are apparent: its distributed nature and its need to accurately synchronize events across many computers separated by large distances. In this paper we describe key features of the architecture of the ALMA Control System, focusing on its properties as a distributed system and on the mechanisms employed to achieve its time synchronization goals. This control system is a distributed system that uses the ALMA Common Software (ACS) as a middleware system layered on top of CORBA. The architecture of the control system extensively employs the component/container model in ACS. In addition, the use of CORBA allows us to employ Java in the higher levels of the control system, leaving C++ to the lower time-critical levels. Python as a scripting language is used by astronomers, to craft standard observing programs, and engineers, in a testing and debugging mode. Key to the concept of an aperture synthesis telescope is a special purpose hardware system known as a correlator, responsible for making various delay model corrections and correlating the signals from the antennas. There are two correlators in ALMA, one for the array of 50 antennas and one for the ACA. This entire system operates under a control system that must synchronize events across the

  2. Cosmology with liquid mirror telescopes

    NASA Astrophysics Data System (ADS)

    Hogg, David W.; Gibson, Brad K.; Hickson, Paul

    1993-01-01

    Liquid mirrors provide an exciting means to obtain large optical telescopes for substantially lower costs than conventional technologies. The liquid mirror concept has been demonstrated in the lab with the construction of a diffraction limited 1.5 m mirror. The mirror surface, using liquid mercury, forms a perfect parabolic shape when the mirror cell is rotated at a uniform velocity. A liquid mirror must be able to support a heavy mercury load with minimal flexure and have a fundamental resonant frequency that is as high as possible, to suppress the amplitude of surface waves caused by small vibrations transmitted to the mirror. To minimize the transmission of vibrations to the liquid surface, the entire mirror rests on an air bearing. This necessitates the mirror cell being lightweight, due to the limited load capabilities of the air bearing. The mirror components must also have physical characteristics which minimize the effects of thermal expansion with ambient temperature fluctuations in the observatory. In addition, the 2.7 m mirror construction is designed so that the techniques used may be readily extended to the construction of large mirrors. To attain the goals of a lightweight, rigid mirror, a composite laminant construction was used. The mirror consists of a foam core cut to the desired parabolic shape, with an accuracy of a few mm. An aluminum hub serves as an anchor for the foam and skin, and allows precise centering of the mirror on the air bearing and drive system. Several plys of Kevlar, covered in an epoxy matrix, are then applied to the foam. A final layer of pure epoxy is formed by spin casting. This final layer is parabolic to within a fraction of a mm. An aluminum ring bonded to the circumference of the mirror retains the mercury, and incorporates stainless-steel hard-points for the attachment of balance weights.

  3. The associate principal astronomer telescope operations model

    NASA Technical Reports Server (NTRS)

    Drummond, Mark; Bresina, John; Swanson, Keith; Edgington, Will; Henry, Greg

    1994-01-01

    This paper outlines a new telescope operations model that is intended to achieve low operating costs with high operating efficiency and high scientific productivity. The model is based on the existing Principal Astronomer approach used in conjunction with ATIS, a language for commanding remotely located automatic telescopes. This paper introduces the notion of an Associate Principal Astronomer, or APA. At the heart of the APA is automatic observation loading and scheduling software, and it is this software that is expected to help achieve efficient and productive telescope operations. The purpose of the APA system is to make it possible for astronomers to submit observation requests to and obtain resulting data from remote automatic telescopes, via the Internet, in a highly-automated way that minimizes human interaction with the system and maximizes the scientific return from observing time.

  4. Apollo Telescope Mount of Skylab: an overview.

    PubMed

    Tousey, R

    1977-04-01

    This introductory paper describes Skylab and the course of events that led to this complex space project. In particular it covers the Apollo Telescope Mount and its instruments and the method of operation of the ATM mission.

  5. Theoretical contamination of cryogenic satellite telescopes

    NASA Technical Reports Server (NTRS)

    Murakami, M.

    1978-01-01

    The state of contaminant molecules, the deposition rate on key surfaces, and the heat transfer rate were estimated by the use of a zeroth-order approximation. Optical surfaces of infrared telescopes cooled to about 20 K should be considered to be covered with at least several deposition layers of condensible molecules without any contamination controls. The effectiveness of the purge gas method of contamination controls was discussed. This method attempts to drive condensible molecules from the telescope tube by impacts with a purge gas in the telescope tube. For this technique to be sufficiently effective, the pressure of the purge gas must be more than 2 x .000001 torr. The influence caused by interactions of the purged gas with the particulate contaminants was found to slightly increase the resident times of the particulate contaminants within the telescope field of view.

  6. Compound catadioptric telescopes with all spherical surfaces.

    PubMed

    Sigler, R D

    1978-05-15

    Catadioptric, all spherical Cassegrainian and Gregorian telescopes with one and two full aperture corrector lenses are investigated. Appropriate closed form third-order aberration equations are presented, and a variety of aplanatic and anastigmatic solutions are indicated. PMID:20198015

  7. Improving the Blanco Telescope's delivered image quality

    NASA Astrophysics Data System (ADS)

    Abbott, Timothy M. C.; Montane, Andrés; Tighe, Roberto; Walker, Alistair R.; Gregory, Brooke; Smith, R. Christopher; Cisternas, Alfonso

    2010-07-01

    The V. M. Blanco 4-m telescope at Cerro Tololo Inter-American Observatory is undergoing a number of improvements in preparation for the delivery of the Dark Energy Camera. The program includes upgrades having potential to deliver gains in image quality and stability. To this end, we have renovated the support structure of the primary mirror, incorporating innovations to improve both the radial support performance and the registration of the mirror and telescope top end. The resulting opto-mechanical condition of the telescope is described. We also describe some improvements to the environmental control. Upgrades to the telescope control system and measurements of the dome environment are described in separate papers in this conference.

  8. Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets coronagraphic operations: lessons learned from the Hubble Space Telescope and the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Debes, John H.; Ygouf, Marie; Choquet, Elodie; Hines, Dean C.; Perrin, Marshall D.; Golimowski, David A.; Lajoie, Charles-Phillipe; Mazoyer, Johan; Pueyo, Laurent; Soummer, Rémi; van der Marel, Roeland

    2016-01-01

    The coronagraphic instrument (CGI) currently proposed for the Wide-Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets (WFIRST-AFTA) mission will be the first example of a space-based coronagraph optimized for extremely high contrasts that are required for the direct imaging of exoplanets reflecting the light of their host star. While the design of this instrument is still in progress, this early stage of development is a particularly beneficial time to consider the operation of such an instrument. We review current or planned operations on the Hubble Space Telescope and the James Webb Space Telescope with a focus on which operational aspects will have relevance to the planned WFIRST-AFTA CGI. We identify five key aspects of operations that will require attention: (1) detector health and evolution, (2) wavefront control, (3) observing strategies/postprocessing, (4) astrometric precision/target acquisition, and (5) polarimetry. We make suggestions on a path forward for each of these items.

  9. Hunting Spinning Asteroids with the Faulkes Telescopes

    NASA Astrophysics Data System (ADS)

    Miles, Richard

    2008-08-01

    The Faulkes telescopes are proving a dab hand at allowing schools and amateurs to do real science. The author discusses the latest Faulkes research project, and his record-breaking discovery that was pert of it.

  10. Wind loads on ground-based telescopes.

    PubMed

    MacMynowski, Douglas G; Vogiatzis, Konstantinos; Angeli, George Z; Fitzsimmons, Joeleff; Nelson, Jerry E

    2006-10-20

    One of the factors that can influence the performance of large optical telescopes is the vibration of the telescope structure due to unsteady wind inside the telescope enclosure. Estimating the resulting degradation in image quality has been difficult because of the relatively poor understanding of the flow characteristics. Significant progress has recently been made, informed by measurements in existing observatories, wind-tunnel tests, and computational fluid dynamic analyses. We combine the information from these sources to summarize the relevant wind characteristics and enable a model of the dynamic wind loads on a telescope structure within an enclosure. The amplitude, temporal spectrum, and spatial distribution of wind disturbances are defined as a function of relevant design parameters, providing a significant improvement in our understanding of an important design issue.

  11. Compound catadioptric telescopes with all spherical surfaces.

    PubMed

    Sigler, R D

    1978-05-15

    Catadioptric, all spherical Cassegrainian and Gregorian telescopes with one and two full aperture corrector lenses are investigated. Appropriate closed form third-order aberration equations are presented, and a variety of aplanatic and anastigmatic solutions are indicated.

  12. The Hubble Space Telescope (HST) Transportation Operation

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Ready for transportation to the Kennedy Space Center, the Hubble Space Telescope (HST) is pictured onboard the strongback dolly at the Vertical Processing Facility (VPF) at the Lockheed assembly plant upon completion of final testing and verification.

  13. The misalignment induced aberrations of TMA telescopes.

    PubMed

    Thompson, Kevin P; Schmid, Tobias; Rolland, Jannick P

    2008-12-01

    The next major space-borne observatory, the James Webb Space Telescope, will be a 6.6M field-biased, obscured, three-mirror anastigmat (TMA). Over the used field of view, the performance of TMA telescopes is dominated by 3(rd) order misalignment aberrations. Here it is shown that two dominant 3(rd) order misalignment aberrations arise for any TMA telescope. One aberration, field constant 3(rd) order coma is a well known misalignment aberration commonly seen in two-mirror Ritchey Chretien telescopes. The second aberration, field-asymmetric, field-linear, 3(rd) order astigmatism is a new and unique image orientation dependence with field derived here for the first time using nodal aberration theory.

  14. Goldstone Apple Valley Radio Telescope Project.

    ERIC Educational Resources Information Center

    Ibe, Mary; MacLaren, Dave

    2003-01-01

    Describes the Goldstone Apple Valley Radio Telescope (GAVRT) project as a way of teaching astronomy concepts to middle school students. The project provides students opportunities to work with professional scientists. (SOE)

  15. Solar Rejection Filter for Large Telescopes

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Lesh, James

    2009-01-01

    To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the telescope, and a large-diameter filter located in the front of the main aperture. Two types of large filters are viable: reflectance mode and transmittance mode. In the case of reflectance mode, a dielectric coating on a suitable substrate (e.g. a low-thermal-expansion glass) is arranged to reflect only a single, narrow wavelength and to efficiently transmit all other wavelengths. These coatings are commonly referred to as notch filter. In this case, the large mirror located in front of the telescope aperture reflects the received (signal and background) light into the telescope. In the case of transmittance mode, a dielectric coating on a suitable substrate (glass, sapphire, clear plastic, membrane, and the like) is arranged to transmit only a single wavelength and to reject all other wavelengths (visible and near IR) of light. The substrate of the large filter will determine its mass. At first glance, a large optical filter with a diameter of up to 10 m, located in front of the main aperture, would require a significant thickness to avoid sagging. However, a segmented filter supported by a structurally rugged grid can support smaller filters. The obscuration introduced by the grid is minimal because the total area can be made insignificant. This configuration can be detrimental to a diffraction- limited telescope due to diffraction effects at the edges of each sub-panel. However, no discernable degradation would result for a 20 diffraction-limit telescope (a photon bucket). Even the small amount of sagging in each subpanel should have minimal effect in the performance of a non-diffraction limited telescope because the part has no appreciable optical power. If the

  16. Productivity and Impact of Optical Telescopes

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia; Zaich, Paul; Bosler, Tammy

    2005-01-01

    In 2001, about 2100 papers appearing in 18 journals reported and/or analyzed data collected with ground-based optical and infrared telescopes and the Hubble Space Telescope. About 250 telescopes were represented, including 25 with primary mirror diameters of 3 m or larger. The subjects covered in the papers divide reasonably cleanly into 20 areas, from solar system to cosmology. These papers were cited 24,354 times in 2002 and 2003, for a mean rate of 11.56 citations per paper, or 5.78 citations per paper per year (sometimes called impact or impact factor). We analyze here the distributions of the papers, citations, and impact factors among the telescopes and subject areas and compare the results with those of a very similar study of papers published in 1990-1991 and cited in 1993. Some of the results are exactly as expected. Big telescopes produce more papers and more citations per paper than small ones. There are fashionable topics (cosmology and exoplanets) and less fashionable ones (binary stars and planetary nebulae). And the Hubble Space Telescope has changed the landscape a great deal. Some other results surprised us but are explicable in retrospect. Small telescopes on well-supported sites (La Silla and Cerro Tololo, for instance) produce papers with larger impact factors than similar sized telescopes in relative isolation. Not just the fraction of all papers, but the absolute numbers of papers coming out of the most productive 4 m telescopes of a decade ago have gone down. The average number of citations per paper per year resulting from the 38 telescopes (2 m and larger) considered in 1993 has gone up 38%, from 3.48 to 4.81, a form, perhaps, of grade inflation. And 53% of the 2100 papers and 38% of the citations (including 44% of the papers and 31% of the citations from mirrors of 3 m and larger) pertain to topics often not regarded as major drivers for the next generation of still larger ground-based telescopes.

  17. New optical telescope projects at Devasthal Observatory

    NASA Astrophysics Data System (ADS)

    Sagar, Ram; Kumar, Brijesh; Omar, Amitesh; Pandey, A. K.

    2012-09-01

    Devasthal, located in the Kumaun region of Himalayas is emerging as one of the best optical astronomy site in the continent. The minimum recorded ground level atmospheric seeing at the site is 0.006 with median value at 1.001. Currently, a 1.3-m fast (f/4) wide field-of-view (660) optical telescope is operating at the site. In near future, a 4-m liquid mirror telescope in collaboration with Belgium and Canada, and a 3.6-m optical telescope in collaboration with Belgium are expected to be installed in 2013. The telescopes will be operated by Aryabhatta Research Institute of Observational Sciences. The first instruments on the 3.6-m telescope will be in-house designed and assembled faint object spectrograph and camera. The second generation instruments will be including a large field-of-view optical imager, high resolution optical spectrograph, integral field unit and an optical near-infrared spectrograph. The 1.3-m telescope is primarily used for wide field photometry imaging while the liquid mirror telescope will see a time bound operation to image half a degree wide strip in the galactic plane. There will be an aluminizing plant at the site to coat mirrors of sizes up to 3.7 m. The Devasthal Observatory and its geographical importance in between major astronomical observatories makes it important for time critical observations requiring continuous monitoring of variable and transient objects from ground based observatories. The site characteristics, its expansions plans and first results from the existing telescope are presented.

  18. Development of a clean optical telescope

    NASA Technical Reports Server (NTRS)

    Brown, R. A.

    1983-01-01

    Particulate contamination on astronomical mirrors degrades performance in two ways: by information loss by extinction of light; and background and noise from scattering, especially forward or Fraunhofer scattering. These effects were not generally understood, and an ambitious pilot program was outlined to measure particulate effects on telescope optical performance; develop prophylactic and cleaning procedures suitable for groundbased observatories; investigate by computational modelling the effects on telescopes in space; and communicate the results and concerns within the astronomical community.

  19. Hubble Space Telescope (HST) Primary Mirror Inspection

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Prior to installation, technicians inspect the primary mirror of the Hubble Space Telescope (HST). The first in a series of great observatories launched by NASA, the HST was designed to last approximately 15 years. The Marshall Space Flight Center had management responsibility for the development of the HST and played a major role in ground tests and orbital checkout of the telescope. The HST was launched April 24, 1990 aboard Space Shuttle Discovery's STS-31 mission.

  20. Improvements to the CTIO Blanco Telescope

    NASA Astrophysics Data System (ADS)

    Walker, Alistair

    2011-01-01

    The V. M. Blanco 4-m telescope at Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, is undergoing a number of improvements prior to the delivery of the Dark Energy Camera. These include improved slewing and tracking performance resulting from a new telescope control system plus new encoders, and upgrades to the primary mirror support system and the environmental control system that have potential to improve both image quality and stability. I will describe the status of the upgrades.

  1. Zone generator for Large Space Telescope technology

    NASA Technical Reports Server (NTRS)

    Erickson, K. E.

    1974-01-01

    A concept is presented for monitoring the optical adjustment and performance of a Large Space Telescope which consists of a 1.2m diameter turntable with a laser stylus to operate at speeds up to 30 rpm. The focus of the laser stylus is under closed loop control. A technique for scribing zones of suitable depth, width, and uniformity applicable to large telescope mirrors is also reported.

  2. Holographic Optical Elements as Scanning Lidar Telescopes

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

    2003-01-01

    We have investigated and developed the use of holographic optical elements (HOE) and holographic transmission gratings for scanning lidar telescopes. By rotating a flat HOE in its own plane with the focal spot on the rotation axis, a very simple and compact conical scanning telescope is possible. We developed and tested transmission and reflection HOES for use with the first three harmonics of Nd:YAG lasers, and designed, built, and tested two lidar systems based on this technology.

  3. Commissioning Results on the JWST Testbed Telescope

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H.; Acton, D. Scott

    2006-01-01

    The one-meter 18 segment JWST Testbed Telescope (TBT) has been developed at Ball Aerospace to facilitate commissioning operations for the JWST Observatory. Eight different commissioning activities were tested on the TBT: telescope focus sweep, segment ID and Search, image array, global alignment, image stacking, coarse phasing, fine phasing, and multi-field phasing. This paper describes recent commissioning results from experiments performed on the TBT.

  4. Utrecht and the European Solar Telescope

    NASA Astrophysics Data System (ADS)

    Bettonvil, F. C. M.; EST Team

    2013-01-01

    In 2008, in the quest towards large solar facilities, a pan-European project was started to study a 4-m European Solar Telescope (EST). As one of the major partners, Utrecht played a significant role in the design, in particular in relation to the intended open design, its enclosure, telescope mechanics as well its polarimetric properties. Mid-2011 the work did result in an innovative conceptual design for EST.

  5. Range-balancing the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Rakich, A.; Thompson, D.; Kuhn, O. P.

    2011-10-01

    The Large Binocular Telescope (LBT) consists of two 8.4 m telescopes mounted on a common alt-az gimbal. The telescope has various modes of operation, including prime-focus, bent- and direct-Gregorian modes. The telescopes can feed independent instruments or their light can be combined in one of two interferometric instruments, giving an interferometric baseline of over 22 m. With all large telescopes, including the LBT, collimation models or modeled values for hexapod positions, are required to maintain reasonable optical alignment over the working range of temperatures and telescope elevations. Unlike other telescopes, the LBT has a highly asymmetric mechanical structure, and as a result the collimation models are required to do a lot more "work", than on an equivalent aperture monocular telescope that are usually designed to incorporate a Serurrier truss arrangement. LBT has been phasing in science operations over the last 5 years, with first light on the prime-focus cameras in 2006, and first light in Gregorian mode in 2008. In this time the generation of collimation models for LBT has proven to be problematic, with large departures from a given model, and large changes in pointing, being the norm. A refined approach to generating collimation models, "range balancing", has greatly improved this situation. The range-balancing approach to generating collimation models has delivered reliable collimation and pointing in both prime focus and Gregorian modes which has led to greatly increased operational efficiency. The details of the range-balancing approach, involving the removal of pointing "contamination" from collimation data, are given in this paper.

  6. The Faulkes Telescope Optical Spectrographs and Swift

    NASA Astrophysics Data System (ADS)

    O'Brien, Paul

    The Faulkes Telescope project funded primarily by the Dill Faulkes Educational Trust is currently constructing two 2-m robotic telescopes to be located in Hawaii and Australia. These will be the largest and most powerful telescopes ever built dedicated for use by schools and colleges. We have been awarded funding to build two optical spectrographs to be permanently mounted on these telescopes by the end of 2003. At this time an astronomical satellite called Swift will be launched by NASA. Swift is dedicated to the study of gamma-ray bursts the most powerful explosive events in the Universe. The Department of Physics and Astronomy at the University of Leicester has provided the X-ray camera for Swift and is a partner in the Faulkes Telescopes project. To enhance both projects we intend to use the Faulkes Telescope optical spectrographs to study the gamma-ray bursts identified by Swift. These data will also be made available to schools thereby raising the profile of physics and astronomy in the educational community.

  7. Thermal analysis of the TMT telescope structure

    NASA Astrophysics Data System (ADS)

    Cho, Myung; Corredor, Andrew; Vogiatzis, Konstantinos; Angeli, George

    2010-07-01

    Thermal performances of the Thirty Meter Telescope (TMT) structure were evaluated by finite element thermal models. The thermal models consist of the telescope optical assembly systems, instruments, laser facility, control and electronic equipments, and structural members. Temporal and spatial temperature distributions of the optical assembly systems and the telescope structure were calculated under various thermal conditions including air convections, conductions, heat flux loadings, and radiations. In order to capture thermal responses faithfully, a three-consecutive-day thermal environment data was implemented. This thermal boundary condition was created by CFD based on the environment conditions of the corresponding TMT site. The thermo-elastic analysis was made to predict thermal deformations of the telescope structure at every hour for three days. The line of sight calculation was made using the thermally induced structural deformations. Merit function was utilized to calculate the OPD maps after repositioning the optics based on a best fit of M1 segment deformations. The goal of this thermal analysis is to establish creditable thermal models by finite element analysis to simulate the thermal effects with the TMT site environment data. These thermal models can be utilized for estimating the thermal responses of the TMT structure. Thermal performance prediction of the TMT structure will guide us to assess the thermal impacts, and enables us to establish a thermal control strategy and requirements in order to minimize the thermal effects on the telescope structure due to heat dissipation from the telescope mounted equipment and systems.

  8. Analysis of space telescope data collection systems

    NASA Technical Reports Server (NTRS)

    Ingels, F. M.

    1984-01-01

    The Multiple Access (MA) communication link of the Space Telescope (ST) is described. An expected performance bit error rate is presented. The historical perspective and rationale behind the ESTL space shuttle end-to-end tests are given. The concatenated coding scheme using a convolutional encoder for the outer coder is developed. The ESTL end-to-end tests on the space shuttle communication link are described. Most important is how a concatenated coding system will perform. This is a go-no-go system with respect to received signal-to-noise ratio. A discussion of the verification requirements and Specification document is presented, and those sections that apply to Space Telescope data and communications system are discussed. The Space Telescope System consists of the Space Telescope Orbiting Observatory (ST), the Space Telescope Science Institute, and the Space Telescope Operation Control Center. The MA system consists of the ST, the return link from the ST via the Tracking and Delay Relay Satellite system to White Sands, and from White Sands via the Domestic Communications Satellite to the STOCC.

  9. Optical aperture synthesis with electronically connected telescopes

    PubMed Central

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D.

    2015-01-01

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths. PMID:25880705

  10. Adaptive-optics performance of Antarctic telescopes.

    PubMed

    Lawrence, Jon S

    2004-02-20

    The performance of natural guide star adaptive-optics systems for telescopes located on the Antarctic plateau is evaluated and compared with adaptive-optics systems operated with the characteristic mid-latitude atmosphere found at Mauna Kea. A 2-m telescope with tip-tilt correction and an 8-m telescope equipped with a high-order adaptive-optics system are considered. Because of the large isoplanatic angle of the South Pole atmosphere, the anisoplanatic error associated with an adaptive-optics correction is negligible, and the achievable resolution is determined only by the fitting error associated with the number of corrected wave-front modes, which depends on the number of actuators on the deformable mirror. The usable field of view of an adaptive-optics equipped Antarctic telescope is thus orders of magnitude larger than for a similar telescope located at a mid-latitude site; this large field of view obviates the necessity for multiconjugate adaptive-optics systems that use multiple laser guide stars. These results, combined with the low infrared sky backgrounds, indicate that the Antarctic plateau is the best site on Earth at which to perform high-resolution imaging with large telescopes, either over large fields of view or with appreciable sky coverage. Preliminary site-testing results obtained recently from the Dome Concordia station indicate that this site is far superior to even the South Pole. PMID:15008551

  11. Retention force measurement of telescopic crowns.

    PubMed

    Bayer, Stefan; Stark, Helmut; Mues, Sebastian; Keilig, Ludger; Schrader, Anja; Enkling, Norbert

    2010-10-01

    This study deals with the determination of the retentive force between primary and secondary telescopic crowns under clinical conditions. Forty-three combined fixed-removable prostheses with a total of 140 double crowns were used for retention force measurement of the telescopic crowns prior to cementation. The crowns had a preparation of 1-2°. A specifically designed measuring device was used. The retentive forces were measured with and without lubrication by a saliva substitute. The measured values were analyzed according to the type of tooth (incisors, canines, premolars, and molars). Additionally, a comparison between lubricated and unlubricated telescopic crowns was done. As maximum retention force value 29.98 N was recorded with a telescopic crown on a molar, while the minimum of 0.08 N was found with a specimen on a canine. The median value of retention force of all telescopic crowns reached 1.93 N with an interquartile distance of 4.35 N. No statistically significant difference between lubricated and unlubricated specimens was found. The results indicate that retention force values of telescopic crowns, measured in clinical practice, are often much lower than those cited in the literature. The measurements also show a wide range. Whether this proves to be a problem for the patient's quality of life or not can however only be established by a comparison of the presented results with a follow-up study involving measurement of intraoral retention and determination by e.g. oral health impact profile.

  12. Sardinia Radio Telescope: the new Italian project

    NASA Astrophysics Data System (ADS)

    Grueff, Gavril; Alvito, Giovanni; Ambrosini, Roberto; Bolli, Pietro; Maccaferri, Andrea; Maccaferri, Giuseppe; Morsiani, Marco; Mureddu, Leonardo; Natale, Vincenzo; Olmi, Luca; Orfei, Alessandro; Pernechele, Claudio; Poma, Angelo; Porceddu, Ignazio; Rossi, Lucio; Zacchiroli, Gianpaolo

    2004-10-01

    This contribution gives a description of the Sardinia Radio Telescope (SRT), a new general purpose, fully steerable antenna proposed by the Institute of Radio Astronomy (IRA) of the National Institute for Astrophysics. The radio telescope is under construction near Cagliari (Sardinia) and it will join the two existing antennas of Medicina (Bologna) and Noto (Siracusa) both operated by the IRA. With its large antenna size (64m diameter) and its active surface, SRT, capable of operations up to about 100GHz, will contribute significantly to VLBI networks and will represent a powerful single-dish radio telescope for many science fields. The radio telescope has a Gregorian optical configuration with a supplementary beam-waveguide (BWG), which provides additional focal points. The Gregorian surfaces are shaped to minimize the spill-over and the standing wave between secondary mirror and feed. After the start of the contract for the radio telescope structural and mechanical fabrication in 2003, in the present year the foundation construction will be completed. The schedule foresees the radio telescope inauguration in late 2006.

  13. Telescopes Lofted to Space: An Historical Chronology

    NASA Astrophysics Data System (ADS)

    Abrahams, Peter

    2005-01-01

    To become airborne was an early dream of humanity. It was a profound dream because of the meaningfulness of the perspective from aloft: the subject was able to observe the Earth and to become closer to heaven. In this context, a telescope is the most basic augmentation of the airborne experience: it expands the new perspective, allows measurement and analysis, and provides new forms of beauty. The first telescopes in space were anticipated by imaginative authors and by exacting engineers, whose dreams and proposals have a part in this story. The earliest telescopes to achieve space, the rocket-launched suborbital missions, both successes and failures, will be described, along with the effect they had on science and culture. Telescopes in orbit and in space probes are the current generation of instruments, a prelude to a future of lunar and planetary telescopes. Every success can be seen to have had a direct effect on the widening of horizons provided by the telescope. This paper will serve as an introduction to a very extensive subject.

  14. Optical aperture synthesis with electronically connected telescopes.

    PubMed

    Dravins, Dainis; Lagadec, Tiphaine; Nuñez, Paul D

    2015-01-01

    Highest resolution imaging in astronomy is achieved by interferometry, connecting telescopes over increasingly longer distances and at successively shorter wavelengths. Here, we present the first diffraction-limited images in visual light, produced by an array of independent optical telescopes, connected electronically only, with no optical links between them. With an array of small telescopes, second-order optical coherence of the sources is measured through intensity interferometry over 180 baselines between pairs of telescopes, and two-dimensional images reconstructed. The technique aims at diffraction-limited optical aperture synthesis over kilometre-long baselines to reach resolutions showing details on stellar surfaces and perhaps even the silhouettes of transiting exoplanets. Intensity interferometry circumvents problems of atmospheric turbulence that constrain ordinary interferometry. Since the electronic signal can be copied, many baselines can be built up between dispersed telescopes, and over long distances. Using arrays of air Cherenkov telescopes, this should enable the optical equivalent of interferometric arrays currently operating at radio wavelengths. PMID:25880705

  15. Astronomy in Hawaii: Telescopes, Research, and Libraries

    NASA Astrophysics Data System (ADS)

    Robertson, A. K.

    2012-08-01

    Since early Polynesian way-finding combined observations of sky and ocean and allowed voyagers to locate and se ttle the far-flung islands of the Pacific, astronomy has impacted the islands of Hawaii. The Twentieth Century saw telescope development on both Haleakala on Maui and Mauna Kea on Hawaii Island. These complexes have developed libraries and information services to support and enhance their research. The University of Hawaii established the Institute for Astronomy (IfA). The IfA Library serves researchers and instrument developers at each of its three locations. Canada-France-Ha waii Telescope, the Joint Astronomy Center, the W. M. Keck Observatory, Gemini Northern Telescope and Subaru Telescope have each developed library services to respond to their unique needs. The librarians at these organizations have formed Astronomy Libraries of HAwaii (A LOHA) to share resources. As electronic research has developed, each library has responded to capitalize on these new capabilities. In coming years, projects such as the Advanced Technology Solar Telescope on Maui and the Thirty Meter Telescope on Hawaii Island have the promise of enlarging our understanding of the Universe. Astronomy libraries in Hawaii will con tinue to enhance their expertise to match the evolution of astronomy technologies and maximize research impact.

  16. Wind responses of Giant Magellan telescope

    NASA Astrophysics Data System (ADS)

    Irarrazaval, Benjamin; Buleri, Christine; Johns, Matt

    2014-08-01

    The Giant Magellan Telescope (GMT) is 25 meter diameter extremely large ground based infrared/optical telescope being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory in Chile. The GMT primary mirror consists of seven 8.4 meter diameter borosilicate mirror segments. Two seven segment Gregorian secondary mirror systems will be built; an Adaptive Secondary Mirror (ASM) to support adaptive optics modes and a Fast-steering Secondary Mirror (FSM) with monolithic segments to support natural seeing modes when the ASM is being serviced. Wind excitation results in static deformation and vibration in the telescope structure that affects alignment and image jitter performance. The telescope mount will reject static and lower frequency windshake, while each of the Faststeering Secondary Mirror (FSM) segments will be used to compensate for the higher frequency wind-shake, up to 20 Hz. Using a finite element model of the GMT, along with CFD modeling of the wind loading on the telescope structure, wind excitation scenarios were created to study the performance of the FSM and telescope against wind-induced jitter. A description of the models, methodology and results of the analyses are presented.

  17. Seismic analysis of the 4-meter telescope SST-GATE for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Dournaux, Jean-Laurent; Huet, Jean-Michel; Amans, Jean-Philippe; Dumas, Delphine; Blake, Simon; Sol, Hélène

    2014-07-01

    The Cherenkov Telescope Array (CTA) project aims to create a next generation Very High Energy (VHE)γ-ray telescope array, devoted to the observation in a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky, with the main one in the Southern Hemisphere where about 100 telescopes of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are 4-meter telescopes and are devoted to the highest energy region, from 1 TeV to beyond 100 TeV. Some of these sites considered for CTA exhibit strong seismic constraints. At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which was never before implemented in the design of a Cherenkov telescope. The integration of this telescope on the site of the Observatoire de Paris is currently in progress. Technical solutions exist in the literature to protect structures from dynamic loads caused by earthquakes without increasing the mass and cost of the structure. This paper presents a state of the art of these techniques by keeping in mind that the operational performance of the telescope should not be compromised. The preliminary seismic analysis of SSTGATE performed by the finite element method is described before.

  18. The Lunar Configurable Array Telescope (LCAT)

    NASA Technical Reports Server (NTRS)

    Meinel, Aden B.; Meinel, Marjorie P.

    1989-01-01

    The desire for a much larger space telescope than HST by astronomers is clearly demonstrated by the attendance at this Workshop. The reality is that a much larger space telescope than the HST collides with cost scaling reality. Coupled with this reality is the fact that any multi-billion dollar science project must have broad-based support from the science community and solid political support at both Presidential and Congressional levels. The HST successor is certainly in the same multi-billion dollar class as the Super Collider of the physics community, a project that has finally achieved the broad support base necessary for funding to follow. Advocacy of a bigger HST on the general grounds that 'bigger is better' will not be sufficient. A new concept needs to be developed that clearly diverges from scaling up of a traditional HST-type space telescope. With these realities in mind we have a few comments regarding the nature of a possible space telescope that may depart from what the organizers of this Workshop had in mind. The national goal declared by the President is Space Station, the Moon and Mars, in that order. Space Station is a potential location where a large system could be assembled prior to being sent into a high orbit. It is not a desirable environment for a large space telescope. Mars is not relevant as an observatory site. The Moon is very relevant for reasons we will address. Our comments are based on the premise of a permanent Lunar Outpost. One of the main arguments for a lunar telescope is a degree of permanency, that is, as long as a Lunar Outpost is maintained. In contrast, the relatively short lifetime of an orbiting telescope is a disadvantage, especially as a cost penalty. Access to a telescope in a 100,000 km orbit for refurbishment and resupply is a major problem with no solution in the present NASA planning. A telescope in conjunction with a Lunar Outpost means the possibility for continual upgrading or modifying the telescope to meet

  19. The Lunar Configurable Array Telescope (LCAT)

    NASA Astrophysics Data System (ADS)

    Meinel, Aden B.; Meinel, Marjorie P.

    1990-01-01

    The desire for a much larger space telescope than HST by astronomers is clearly demonstrated by the attendance at this Workshop. The reality is that a much larger space telescope than the HST collides with cost scaling reality. Coupled with this reality is the fact that any multi-billion dollar science project must have broad-based support from the science community and solid political support at both Presidential and Congressional levels. The HST successor is certainly in the same multi-billion dollar class as the Super Collider of the physics community, a project that has finally achieved the broad support base necessary for funding to follow. Advocacy of a bigger HST on the general grounds that 'bigger is better' will not be sufficient. A new concept needs to be developed that clearly diverges from scaling up of a traditional HST-type space telescope. With these realities in mind we have a few comments regarding the nature of a possible space telescope that may depart from what the organizers of this Workshop had in mind. The national goal declared by the President is Space Station, the Moon and Mars, in that order. Space Station is a potential location where a large system could be assembled prior to being sent into a high orbit. It is not a desirable environment for a large space telescope. Mars is not relevant as an observatory site. The Moon is very relevant for reasons we will address. Our comments are based on the premise of a permanent Lunar Outpost. One of the main arguments for a lunar telescope is a degree of permanency, that is, as long as a Lunar Outpost is maintained. In contrast, the relatively short lifetime of an orbiting telescope is a disadvantage, especially as a cost penalty. Access to a telescope in a 100,000 km orbit for refurbishment and resupply is a major problem with no solution in the present NASA planning. A telescope in conjunction with a Lunar Outpost means the possibility for continual upgrading or modifying the telescope to meet

  20. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Wood, M.; Jogler, T.; Dumm, J.; Funk, S.

    2016-01-01

    We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies-Cotton (DC) and Schwarzchild-Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30-40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. We attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  1. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    DOE PAGES

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parametersmore » including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.« less

  2. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    SciTech Connect

    Wood, M. D.; Jogler, T.; Dumm, J.; Funk, S.

    2015-06-07

    In this paper, we present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies–Cotton (DC) and Schwarzchild–Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30–40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. Finally, we attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  3. Hubble Space Telescope Deployment-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This artist's concept depicts the Hubble Space Telescope after being released into orbit, with the high gain anternas and solar arrays deployed and the aperture doors opened. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  4. Hubble Space Telescope Deployment-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This artist's concept depicts the Hubble Space Telescope (HST) being raised to a vertical position in the cargo bay of the Space Shuttle orbiter. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13-meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  5. Hubble Space Telescope Deployment-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This artist's concept depicts the Hubble Space Telescope (HST) being positioned for release from the Space Shuttle orbiter by the Remote Manipulator System (RMS). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is 42.5-feet (13- meters) long and weighs about 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  6. TALON - The Telescope Alert Operation Network System : intelligent linking of distributed autonomous robotic telescopes

    SciTech Connect

    White, R. R.; Wren, J.; Davis, H. R.; Galassi, M. C.; Starr, D. L.; Vestrand, W. T.; Wozniak, P. R.

    2004-01-01

    The internet has brought about great change in the astronomical community, but this interconnectivity is just starting to be exploited for use in instrumentation. Utilizing the internet for communicating between distributed astronomical systems is still in its infancy, but it already shows great potential. Here we present an example of a distributed network of telescopes that performs more efficienfiy in synchronous operation than as individual instruments. RAPid Telescopes for Optical Response (RAPTOR) is a system of telescopes at LANL that has intelligent intercommunication, combined with wide-field optics, temporal monitoring software, and deep-field follow-up capability all working in closed-loop real-time operation. The Telescope ALert Operations Network (TALON) is a network server that allows intercommunication of alert triggers from external and internal resources and controls the distribution of these to each of the telescopes on the network. TALON is designed to grow, allowing any number of telescopes to be linked together and communicate. Coupled with an intelligent alert client at each telescope, it can analyze and respond to each distributed TALON alert based on the telescopes needs and schedule.

  7. SST-GATE telescope: an innovative dual-mirror prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Dumas, Delphine; Huet, Jean-Michel; Dournaux, Jean-Laurent; Laporte, Philippe; Amans, Jean-Philippe; Fasola, Gilles; Zech, Andreas; Rulten, Cameron; Sol, Hélène; Blake, Simon; Schmoll, Jurgen

    2014-07-01

    The Observatoire de Paris is involved in the Cherenkov Telescope Array (CTA) project by designing and constructing on the site of Meudon a Small Size Telescope prototype, named SST-GATE, in collaboration with the CHEC team (Compact High Energy Camera) which is providing the camera. The telescope structure is based on the Schwarzschild- Couder optical design which has never been adopted before in the design of a ground-based telescope. This concept allows a larger field of view and cheaper and smaller telescope and camera design with improved performance compared to the Davies-Cotton design traditionally used in very high energy gamma-ray telescopes. The SST-GATE telescope has been designed with the prime objectives of being light, versatile and simple to assemble with a minimal maintenance cost. This papers aims at reviewing the SST-GATE telescope structure from mechanics to optics along with the control command architecture; several innovative developments implemented within the design are discussed. Updates of the project status and perspectives are made.

  8. Active optics control of VST telescope secondary mirror.

    PubMed

    Schipani, Pietro; D'Orsi, Sergio; Fierro, Davide; Marty, Laurent

    2010-06-01

    In telescopes based on active optics, defocus and coma are usually compensated for by secondary mirror movements. They are performed at the Very Large Telescope Survey Telescope (VST) with a hexapod--a parallel robot with six degrees of freedom positioning capability. We describe the application of the two-mirror telescope theory to the VST case and the solutions adopted for the hexapod control. We present the results of performance and reliability tests performed both in the laboratory and at the telescope.

  9. Introduction to the Chinese Giant Solar Telescope

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Deng, Y.; Ji, H.

    2012-12-01

    In order to detect the fine structures of solar magnetic field and dynamic field, an 8 meter solar telescope has been proposed by Chinese solar community. Due to the advantages of ring structure in polarization detection and thermal control, the current design of CGST (Chinese Giant Solar Telescope) is an 8 meter ring solar telescope. The spatial resolution of CGST is equivalent to an 8 meter diameter telescope, and the light-gathering power equivalent to a 5 meter full aperture telescope. The integrated simulation of optical system and imaging ability such as optical design, MCAO, active maintenance of primary mirror were carried out in this paper. Mechanical system was analyzed by finite element method too. The results of simulation and analysis showed that the current design could meet the demand of most science cases not only in infrared band but also in near infrared band and even in visible band. CGST was proposed by all solar observatories in Chinese Academy of Sciences and several overseas scientists. It is supported by CAS (Chinese Academy of Sciences) and NSFC (National Natural Science Foundation of China) as a long term astronomical project.

  10. Introduction to the Chinese Giant Solar Telescope

    NASA Astrophysics Data System (ADS)

    Liu, Zhong; Deng, Yuanyong; Jin, Zhenyu; Ji, Haisheng

    2012-09-01

    In order to detect the fine structures of solar magnetic field and dynamic field, an 8 meter solar telescope has been proposed by Chinese solar community. Due to the advantages of ring structure in polarization detection and thermal control, the current design of CGST (Chinese Giant Solar Telescope) is an 8 meter ring solar telescope. The spatial resolution of CGST is equivalent to an 8 meter diameter telescope, and the light-gathering power equivalent to a 5 meter full aperture telescope. The integrated simulation of optical system and imaging ability such as optical design, MCAO, active maintenance of primary mirror were carried out in this paper. Mechanical system was analyzed by finite element method too. The results of simulation and analysis showed that the current design could meet the demand of most science cases not only in infrared band but also in near infrared band and even in visible band. CGST was proposed by all solar observatories in Chinese Academy of Sciences and several overseas scientists. It is supported by CAS and NSFC (National Natural Science Foundation of China) as a long term astronomical project.

  11. The Telescope: Outline of a Poetic History

    NASA Astrophysics Data System (ADS)

    Stocchi, M. P.

    2011-06-01

    Amongst the first editions of Galileo's books, only the Saggiatore has on its frontispiece the image of the telescope. Indeed, the telescope is not pictured on the very emphatic frontispieces of the other books in which Galileo was presenting and defending the results achieved by his celestial observations, such as the Sidereus Nuncius. Many contemporary scientists denied the reliability of the telescope, and some even refused to look into the eyepiece. In the 16th and 17th century, the lenses, mirrors, and optical devices of extraordinary complexity did not have the main task of leading to the objective truth but obtaining the deformation of the reality by means of amazing effects of illusion. The Baroque art and literature had the aim of surprising, and the artists gave an enthusiastic support to the telescope. The poems in praise of Galileo's telescopic findings were quite numerous, including Adone composed by Giovanni Battista Marino, one of the most renowned poets of the time. The Galilean discoveries were actually accepted by the poets as ideologically neutral contributions to the "wonder" in spite they were rejected or even condemned by the scientists, philosophers, and theologians.

  12. Science with the Space Infrared Telescope Facility

    NASA Technical Reports Server (NTRS)

    Roellig, Thomas L.

    2003-01-01

    The Space Infrared Telescope Facility (SIRTF), the fourth and final member of NASA's series of Great Observatories, is scheduled to launch on April 15,2003. Together with the Hubbie Space Telescope, the Compton Gamma ray Telescope, and the Chandra X-Ray Telescope this series of observatories offers observational capabilities across the electromagnetic spectrum from the infrared to high-energy gamma rays. SIRTF is based on three focal plane instruments - an infrared spectrograph and two infrared imagers - coupled to a superfluid-helium cooled telescope to achieve unprecedented sensitivity from 3 to 180 microns. Although SIRTF is a powerful general-purpose infrared observatory, its design was based on the capability to address four broad science themes: (1) understanding the structure and composition of the early universe, (2) understanding the nature of brown dwarfs and super-planets, (3) probing protostellar, protoplanetary, and planetary debris disk systems, and (4) understanding the origin and structure of ultraluminous infrared galaxies and active galactic nuclei. This talk will address the design and capabilities of the SIRTF observatory, provide an overview of some of the initial science investigations planned by the SIRTF Guaranteed Time Observers, and give a brief overview of the General Observer proposal process.

  13. Undergraduate Research with a Small Radio Telescope

    NASA Astrophysics Data System (ADS)

    Fisher, P. L.; Williams, G. J.

    2001-11-01

    We describe the construction of a small radio telescope system at ULM and the role of radio astronomy in undergraduate education. The heart of the system is the Small Radio Telescope (SRT), which is a modified satellite TV antenna and custom receiver purchased from MIT Haystack Observatory. This telescope measures the brightness of many celestial objects at wavelengths near 21 cm. The system consists of various components to control dish movement, as well as perform analog to digital conversions allowing analysis of collected data. Undergraduate students have participated in the construction of the hardware and the task of interfacing the hardware to software on two GNU/Linux computer systems. The construction of the telescope and analysis of data allow the students to employ key concepts from mechanics, optics, electrodynamics, and thermodynamics, as well as computer and electronics skills. We will report preliminary results of solar observations conducted with this instrument and with the MIT Haystack Observatory 37m radio telescope. This work was supported by Louisiana Board of Regents grant LEQSF-ENH-UG-16, NASA/LaSPACE LURA R109139 and ULM Development Foundation Grant 97317.

  14. Control challenges for extremely large telescopes

    NASA Astrophysics Data System (ADS)

    MacMartin, Douglas G.

    2003-08-01

    The next generation of large ground-based optical telescopes are likely to involve a highly segmented primary mirror that must be controlled in the presence of wind and other disturbances, resulting in a new set of challenges for control. The current design concept for the California Extremely Large Telescope (CELT) includes 1080 segments in the primary mirror, with the out-of-plane degrees of freedom actively controlled. In addition to the 3240 primary mirror actuators, the secondary mirror of the telescope will also require at least 5 degree of freedom control. The bandwidth of both control systems will be limited by coupling to structural modes. I discuss three control issues for extremely large telescopes in the context of the CELT design, describing both the status and remaining challenges. First, with many actuators and sensors, the cost and reliability of the control hardware is critical; the hardware requirements and current actuator design are discussed. Second, wind buffeting due to turbulence inside the telescope enclosure is likely to drive the control bandwidth higher, and hence limitations resulting from control-structure-interaction must be understood. Finally, the impact on the control architecture is briefly discussed.

  15. Calibration strategies for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Gaug, Markus; Berge, David; Daniel, Michael; Doro, Michele; Förster, Andreas; Hofmann, Werner; Maccarone, Maria C.; Parsons, Dan; de los Reyes Lopez, Raquel; van Eldik, Christopher

    2014-08-01

    The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration efforts of the different telescopes. The latter include LED-based light pulsers, and various methods and instruments to achieve a calibration of the overall optical throughput. On the array level, methods for the inter-telescope calibration and the absolute calibration of the entire observatory are being developed. Additionally, the atmosphere above the telescopes, used as a calorimeter, will be monitored constantly with state-of-the-art instruments to obtain a full molecular and aerosol profile up to the stratosphere. The aim is to provide a maximal uncertainty of 10% on the reconstructed energy-scale, obtained through various independent methods. Different types of LIDAR in combination with all-sky-cameras will provide the observatory with an online, intelligent scheduling system, which, if the sky is partially covered by clouds, gives preference to sources observable under good atmospheric conditions. Wide-field optical telescopes and Raman Lidars will provide online information about the height-resolved atmospheric extinction, throughout the field-of-view of the cameras, allowing for the correction of the reconstructed energy of each gamma-ray event. The aim is to maximize the duty cycle of the observatory, in terms of usable data, while reducing the dead time introduced by calibration activities to an absolute minimum.

  16. Optimal Calibration of the Spitzer Space Telescope

    NASA Technical Reports Server (NTRS)

    Bayard, David; Kang, Bryan; Brugarolas, Paul; Boussalis, Dhemetrio

    2007-01-01

    A document discusses the focal-plane calibration of the Spitzer Space Telescope by use of the instrument pointing frame (IPF) Kalman filter, which was described in Kalman Filter for Calibrating a Telescope Focal Plane (NPO-40798), NASA Tech Briefs, Vol. 30, No. 9 (September 2006), page 62. To recapitulate: In the IPF Kalman filter, optimal estimates of both engineering and scientific focal-plane parameters are obtained simultaneously, using data taken in each focalplane survey activity. The IPF Kalman filter offers greater efficiency and economy, relative to prior calibration practice in which scientific and engineering parameters were estimated by separate teams of scientists and engineers and iterated upon each other. In the Spitzer Space Telescope application, the IPF Kalman filter was used to calibrate 56 frames for precise telescope pointing, estimate >1,500 parameters associated with focal-plane mapping, and process calibration runs involving as many as 1,338 scientific image centroids. The final typical survey calibration accuracy was found to be 0.09 arc second. The use of the IPF Kalman filter enabled a team of only four analysts to complete the calibration processing in three months. An unanticipated benefit afforded by the IPF Kalman filter was the ability to monitor health and diagnose performance of the entire end-to-end telescope-pointing system.

  17. Roughness tolerances for Cherenkov telescope mirrors

    NASA Astrophysics Data System (ADS)

    Tayabaly, K.; Spiga, D.; Canestrari, R.; Bonnoli, G.; Lavagna, M.; Pareschi, G.

    2015-09-01

    The Cherenkov Telescope Array (CTA) is a forthcoming international ground-based observatory for very high-energy gamma rays. Its goal is to reach sensitivity five to ten times better than existing Cherenkov telescopes such as VERITAS, H.E.S.S. or MAGIC and extend the range of observation to energies down to few tens of GeV and beyond 100 TeV. To achieve this goal, an array of about 100 telescopes is required, meaning a total reflective surface of several thousands of square meters. Thence, the optimal technology used for CTA mirrors' manufacture should be both low-cost (~1000 euros/m2) and allow high optical performances over the 300-550 nm wavelength range. More exactly, a reflectivity higher than 85% and a PSF (Point Spread Function) diameter smaller than 1 mrad. Surface roughness can significantly contribute to PSF broadening and limit telescope performances. Fortunately, manufacturing techniques for mirrors are now available to keep the optical scattering well below the geometrically-predictable effect of figure errors. This paper determines first order surface finish tolerances based on a surface microroughness characterization campaign, using Phase Shift Interferometry. That allows us to compute the roughness contribution to Cherenkov telescope PSF. This study is performed for diverse mirror candidates (MAGIC-I and II, ASTRI, MST) varying in manufacture technologies, selected coating materials and taking into account the degradation over time due to environmental hazards.

  18. Pier vibration isolation for lightweight interferometry telescopes

    NASA Astrophysics Data System (ADS)

    Wood, Perry G.; Penado, F. Ernesto; Clark, James H., III; Walton, Joshua P.

    2007-09-01

    The Navy Prototype Optical Interferometer (NPOI) in Flagstaff, Arizona, makes use of separate smaller telescopes spaced along a Y-array and used simultaneously to simulate an equivalent single large telescope. Each telescope is mounted on a massive reinforced concrete pier tied to bedrock. The mass of the pier dampens most, but not all, of the unwanted vibration in the required spectrum. The quality and resolution of a stellar image depends on minimizing movement of the mirrors due to vibration. The main source of pier vibration is due to the soil-pier interaction. Surrounding environmental and man-made vibration propagates through the soil as body and surface waves, and forces the pier to move. In this paper, a novel concept based on a sleeve/air gap system to isolate the soil from the pier is used to minimize the vibration input to the telescope. An example of the concept is presented with respect to the future implementation of a 1.4-m diameter composite telescope at the Navy Prototype Optical Interferometer.

  19. Debris Collision Warning Sensor (DCWS) telescope design

    NASA Technical Reports Server (NTRS)

    Brown, Robert J.

    1991-01-01

    The 60-cm diameter, f/2 DCWS telescope is a modified Ritchey Chretein configuration which collects radiation in three spectral bands, 0.4 to 0.9/micron (visible), 5.0 to 9.0/microns (MWIR), and 9.0 to 12.0 microns (LWIR). The visible and infrared radiation are separated by a dichroic beamsplitter and focused on to separate focal planes; the MWIR and LWIR radiation share a common focal plane with separate detector arrays residing side-by-side. The conic constants of the primary and secondary mirrors are that of a Ritchey Chretein telescope; to improve the image quality at the edges of the field of view, a set of zero power correcting optics have been introduced to each optical train. The Ritchey Chretein telescope is corrected to have zero third order spherical aberration and zero third order coma; the DCWS telescope is further configured such that the positive power in the primary mirror is approximately equal to the negative power in the secondary mirror, resulting in a telescope with very little field curvature.

  20. The Astronomical Telescope of New York: a new 12-meter astronomical telescope

    NASA Astrophysics Data System (ADS)

    Sebring, T.; Junquist, R.; Stutzki, C.; Sebring, P.; Baum, S.

    2012-09-01

    The Astronomical Corporation of New York has commissioned a study of a 12-meter class telescope to be developed by a group of NY universities. The telescope concept builds on the basic principles established by the Keck telescopes; segmented primary mirror, Ritchey Chretien Nasmyth instrument layout, and light weight structures. New, lightweight, and low cost approaches are proposed for the primary mirror architecture, dome structure and mechanisms, telescope mount approach, and adaptive optics. Work on the design is supported by several NY based corporations and universities. The design offers a substantially larger aperture than any existing Visible/IR wavelength telescope at historically low cost. The concept employs an adaptive secondary mirror and laser guide star adaptive optics. Two First Light instruments are proposed; A High resolution near infrared spectrograph and a near infrared Integral field spectrograph/imager.

  1. The Cherenkov Telescope Array single-mirror small size telescope project: status and prospects

    NASA Astrophysics Data System (ADS)

    Aguilar, J. A.; Bilnik, W.; Bogacz, L.; Bulik, T.; Christov, A.; della Volpe, D.; Dyrda, M.; Frankowski, A.; Grudzińska, M.; Grygorczuk, J.; Heller, M.; Idźkowski, B.; Janiak, M.; Jamrozy, M.; Karczewski, M.; Kasperek, J.; Lyard, E.; Marszalek, A.; Michalowski, J.; Rameez, M.; Moderski, R.; Montaruli, T.; Neronov, A.; Nicolau-Kukliński, J.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Płatos, Ł.; Prandini, E.; Rafalski, J.; Rajda, P. J.; Rataj, M.; Rupiński, M.; Rutkowskai, K.; Seweryn, K.; Sidz, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Tokarz, M.; Toscano, S.; Troyano Pujadas, I.; Walter, R.; Wawer, P.; Wawrzaszek, R.; Wiśniewski, L.; Winiarski, K.; Zietara, K.; Ziółkowski, P.; Źychowski, P.

    2014-07-01

    The Cherenkov Telescope Array (CTA), the next generation very high energy gamma-ray observatory, will consist of three types of telescopes: large (LST), medium (MST) and small (SST) size telescopes. The small size telescopes are dedicated to the observation of gamma-rays with energy between a few TeV and few hundreds of TeV. The single-mirror small size telescope (SST-1M) is one of several SST designs. It will be equipped with a 4 m-diameter segmented mirror dish and a fully digital camera based on Geiger-mode avalanche photodiodes. Currently, the first prototype of the mechanical structure is under assembly in Poland. In 2014 it will be equipped with 18 mirror facets and a prototype of the camera.

  2. An innovative telescope control system architecture for SST-GATE telescopes at the CTA Observatory

    NASA Astrophysics Data System (ADS)

    Fasola, Gilles; Mignot, Shan; Laporte, Philippe; Abchiche, Abdel; Buchholtz, Gilles; Jégouzo, Isabelle

    2014-07-01

    SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) is a 4-metre telescope designed as a prototype for the Small Size Telescopes (SST) of the Cherenkov Telescope Array (CTA), a major facility for the very high energy gamma-ray astronomy of the next three decades. In this 100-telescope array there will be 70 SSTs, involving a design with an industrial view aiming at long-term service, low maintenance effort and reduced costs. More than a prototype, SST-GATE is also a fully functional telescope that shall be usable by scientists and students at the Observatoire de Meudon for 30 years. The Telescope Control System (TCS) is designed to work either as an element of a large array driven by an array controller or in a stand-alone mode with a remote workstation. Hence it is built to be autonomous with versatile interfacing; as an example, pointing and tracking —the main functions of the telescope— are managed onboard, including astronomical transformations, geometrical transformations (e.g. telescope bending model) and drive control. The core hardware is a CompactRIO (cRIO) featuring a real-time operating system and an FPGA. In this paper, we present an overview of the current status of the TCS. We especially focus on three items: the pointing computation implemented in the FPGA of the cRIO —using CORDIC algorithms— since it enables an optimisation of the hardware resources; data flow management based on OPCUA with its specific implementation on the cRIO; and the use of an EtherCAT field-bus for its ability to provide real-time data exchanges with the sensors and actuators distributed throughout the telescope.

  3. Overview of the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Champin, Mark

    2010-01-01

    The James Webb Space Telescope (JWST) is ulxve uperk/rc (6.5 meter), cryogenic space telescope with a suite of near and mid-infrared instruments covering the wavelength range of 0.6 prnio 28 pn). JWS7 s primaryacicoce goal is k) detect and characterize the first galaxies. U will also study the uascrob|y of galaxies, uiur bzcrou1ion, and the formation of evolution of planetary systems. Recent progress in hardware development for the observatory will he presented, including a discussion of the status of JWST's optical system and Beryllium mirror fabrication, progress with sunshield prototypes, and the integration and test configuration. We also review the expected scientific performance of the observatory for observations of exosolar planets by means of transit imaging and spectroscopy. We will review the science goals, the capabilities of each science instrument, and the design and operation of the telescope.

  4. AIROscope: Ames infrared balloon-borne telescope

    NASA Technical Reports Server (NTRS)

    Koontz, O. L.; Scott, S. G.

    1974-01-01

    A balloon-borne telescope system designed for astronomical observations at infrared wavelengths is discussed. The telescope is gyro-stabilized with updated pointing information derived from television, star tracker, or ground commands. The television system furnishes both course and fine acquisition after initial orientation using a pair of fluxgate servo compasses. Command and control is by a UHF link with 256 commands available. Scientific and engineering data are telemetered to the ground station via narrow band F.M. in the L band. The ground station displays all scientific, engineering and status information during the flights and records the command and telemetry digital bit stream for detailed analysis. The AIROscope telescope has a 28-inch diameter primary mirror and Dall-Kirkham optics. The beam is modulated by oscillating a secondary mirror at 11 or 25 Hz with provision for left or right beam fixed positions by command.

  5. A Deployable Primary Mirror for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Phelps, James E.; Dyer, Jack E.; Caudle, David A.; Tam, Anthony

    1999-01-01

    NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (Light direction and ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55- m-diameter, proof-of-concept mirror.

  6. Pulsar prospects for the Cherenkov telescope array

    NASA Astrophysics Data System (ADS)

    Hassan, T.; Bonnefoy, S.; López, M.; Mirabal, N.; Barrio, J. A.; Contreras, J. L.; de los Reyes, R.; Wilhelmi, E. O.; Rudak, B.; CTA Consortium

    2012-12-01

    In the last few years, the Fermi-LAT telescope has discovered over a 100 pulsars at energies above 100 MeV, increasing the number of known gamma-ray pulsars by an order of magnitude. In parallel, imaging Cherenkov telescopes, such as MAGIC and VERITAS, have detected for the first time VHE pulsed gamma-rays from the Crab pulsar. Such detections have revealed that the Crab VHE spectrum follows a power-law up to at least 400 GeV, challenging most theoretical models, and opening wide possibilities of detecting more pulsars from the ground with the future Cherenkov Telescope Array (CTA). In this contribution, we study the capabilities of CTA for detecting Fermi pulsars. For this, we extrapolate their spectra with "Crab-like" power-law tails in the VHE range, as suggested by the latest MAGIC and VERITAS results.

  7. Science with the James Webb Telescope

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan

    2004-01-01

    The James Webb Space Telescope (JWST) will be a large (6.5m) cold (50K) telescope launched to the second Earth-Sun Lagrange point in 2011. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. Its science goals are to detect and identify the first galaxies to form in the universe, to trace the assembly of galaxies, and to study stellar and planetary system formation. JWST will have three instruments: The Near Infrared Camera and the Near Infrared multiobject Spectrometer will cover the wavelength range 0.6 to 5 microns, and the Mid Infrared Instrument will do both imaging and spectroscopy from 5 to 27 microns. In this special session, we review the status and capabilities of the observatory and instruments in the context of these major goals.

  8. On buying a telescope for videolaryngoscopy.

    PubMed

    Painter, C; Komiyama, S

    1987-06-01

    The purpose of this article is to compare aspects of the performance of three widely-used rigid laryngoscopy telescopes. The Nagashima SFT-I, Wolf 4450.57, and Karl Storz 8702 D were used with a JVC GX-N8U camera and Panasonic PV 8600 VCR to make recordings of a one-tenth-inch grid at various distances between the lens and the grid and at two telescope holding angles. Measurements were made of the anteroposterior and mediolateral viewing fields at all distances and holding angles on maximum and minimum zoom. The telescopes were compared for viewing field, lens angle effects, holding angle effects, plane distortion effects, effects due to lens distance, color, edge definition, focus control, light source compatibility, stroboscopic use, cross-sectional diameter, fogging, and cost. An overview enables laryngologists to assess their needs before buying.

  9. The Large Millimeter Telescope (LMT) project

    NASA Astrophysics Data System (ADS)

    Baars, Jacob W.

    1998-07-01

    The LMT is a 50 m diameter telescope for operation to a wavelength of 1 mm from a high mountain site in central Mexico at a latitude of 19 degrees. The telescope is designed to address fundamental questions about the origin and formation of galaxies, clusters of galaxies as well as stars and planets. It is a joint project of the Mexican Instituto Nacional de Astrofisica, Optica y Electronica (INAOE) in Tonantzintla, Puebla and the University of Massachusetts at Amherst. The telescope is in the Critical Design phase and completion of the basic assembly at the site is scheduled for the end of 2000. We describe historical and organizational aspects of the Project and present the major technical specifications and plans for realization.

  10. Telescopic nanotube device for hot nanolithography

    DOEpatents

    Popescu, Adrian; Woods, Lilia M

    2014-12-30

    A device for maintaining a constant tip-surface distance for producing nanolithography patterns on a surface using a telescopic nanotube for hot nanolithography. An outer nanotube is attached to an AFM cantilever opposite a support end. An inner nanotube is telescopically disposed within the outer nanotube. The tip of the inner nanotube is heated to a sufficiently high temperature and brought in the vicinity of the surface. Heat is transmitted to the surface for thermal imprinting. Because the inner tube moves telescopically along the outer nanotube axis, a tip-surface distance is maintained constant due to the vdW force interaction, which in turn eliminates the need of an active feedback loop.

  11. The Wyoming Infrared Observatory telescope software system

    NASA Astrophysics Data System (ADS)

    Spillar, Earl J.; Dumbrill, Daniel; Grasdalen, G. L.; Howell, R. R.

    1993-06-01

    We describe the University of Wyoming telescope control and data- acquisition software system. The software was designed to be maintainable, portable, and inexpensive. Moreover, the software was designed to allow rapid communication between the hardware, the data- acquisition processes, and the tracking processes, while leaving each distinct. We show how the new real-time features embodied in the POSIX.4 standard and implemented in the Unix compatible LynxOS operating system allow us to perform all of our tasks on a single 80486 machine with a standard Unix-like environment, with outstanding real-time performance. We discuss our telescope pointing model, which allows us to point with a root-mean-square error of less than 5 arcsec over the sky with the 2.3-m telescope. For more detailed investigation and use, we will make the software available through anonymous FTP.

  12. Deployable reflector configurations. [for space telescope

    NASA Technical Reports Server (NTRS)

    Meinel, A. B.; Meinel, M. P.; Woolf, N. J.

    1983-01-01

    Both the theoretical reasons for considering a non-circular format for the Large Deployable Reflector, and a potentially realizable concept for such a device, are discussed. The optimum systems for diffraction limited telescopes with incoherent detection have either a single filled aperture, or two such apertures as an interferometer to synthesize a larger aperture. For a single aperture of limited area, a reflector in the form of a slot can be used to give increased angular resolution. It is shown how a 20 x 8 meter telescope can be configured to fit the Space Shuttle bay, and deployed with relatively simple operations. The relationship between the sunshield design and the inclination of the orbit is discussed. The possible use of the LDR as a basic module to permit the construction of supergiant space telescopes and interferometers both for IR/submm studies and for the entire ultraviolet through mm wave spectral region is discussed.

  13. Self-locking telescoping manipulator arm

    NASA Technical Reports Server (NTRS)

    Nesmith, M. F. (Inventor)

    1985-01-01

    A telescoping manipulator arm and pivotable finger assembly are disclosed. The telescoping arm assembly includes a generally T-shaped arm having three outwardly extending fingers guided on grooved roller guides to compensate for environmental variations. The pivotable finger assembly includes four pivoting fingers. Arcuate teeth are formed on the ends of the fingers. A rack having teeth on four sides meshes with each one of the fingers. One surface of the rack includes teeth along its entire surface which mesh with teeth of one of the fingers. The teeth at the remote end of the rack engage teeth of a gear wheel. The wheel includes a worm which meshes with a worn drive shaft of the drive motor providing a ninety degree self-locking drive for locking the fingers in a desired position. A similar drive provides a self-locking drive for positioning the telescoping arm.

  14. Perceptual image quality and telescope performance ranking

    NASA Astrophysics Data System (ADS)

    Lentz, Joshua K.; Harvey, James E.; Marshall, Kenneth H.; Salg, Joseph; Houston, Joseph B.

    2010-08-01

    Launch Vehicle Imaging Telescopes (LVIT) are expensive, high quality devices intended for improving the safety of vehicle personnel, ground support, civilians, and physical assets during launch activities. If allowed to degrade from the combination of wear, environmental factors, and ineffective or inadequate maintenance, these devices lose their ability to provide adequate quality imagery to analysts to prevent catastrophic events such as the NASA Space Shuttle, Challenger, accident in 1986 and the Columbia disaster of 2003. A software tool incorporating aberrations and diffraction that was developed for maintenance evaluation and modeling of telescope imagery is presented. This tool provides MTF-based image quality metric outputs which are correlated to ascent imagery analysts' perception of image quality, allowing a prediction of usefulness of imagery which would be produced by a telescope under different simulated conditions.

  15. Nearby Exo-Earth Astrometric Telescope (NEAT)

    NASA Technical Reports Server (NTRS)

    Shao, M.; Nemati, B.; Zhai, C.; Goullioud, R.

    2011-01-01

    NEAT (Nearby Exo ]Earths Astrometric Telescope) is a modest sized (1m diameter telescope) It will be capable of searching approx 100 nearby stars down to 1 Mearth planets in the habitable zone, and 200 @ 5 Mearth, 1AU. The concept addresses the major issues for ultra -precise astrometry: (1) Photon noise (0.5 deg dia field of view) (2) Optical errors (beam walk) with long focal length telescope (3) Focal plane errors , with laser metrology of the focal plane (4) PSF centroiding errors with measurement of the "True" PSF instead of using a "guess " of the true PSF, and correction for intra pixel QE non-uniformities. Technology "close" to complete. Focal plane geometry to 2e-5 pixels and centroiding to approx 4e -5 pixels.

  16. Accurate Telescope Mount Positioning with MEMS Accelerometers

    NASA Astrophysics Data System (ADS)

    Mészáros, L.; Jaskó, A.; Pál, A.; Csépány, G.

    2014-08-01

    This paper describes the advantages and challenges of applying microelectromechanical accelerometer systems (MEMS accelerometers) in order to attain precise, accurate, and stateless positioning of telescope mounts. This provides a completely independent method from other forms of electronic, optical, mechanical or magnetic feedback or real-time astrometry. Our goal is to reach the subarcminute range which is considerably smaller than the field-of-view of conventional imaging telescope systems. Here we present how this subarcminute accuracy can be achieved with very cheap MEMS sensors and we also detail how our procedures can be extended in order to attain even finer measurements. In addition, our paper discusses how can a complete system design be implemented in order to be a part of a telescope control system.

  17. The James Webb Space Telescope Mission

    NASA Astrophysics Data System (ADS)

    Greenhouse, Matthew

    2015-08-01

    The James Webb Space Telescope (JWST) is the scientific successor to the Hubble Space Telescope. It is a cryogenic infrared space observatory with a 25 m2 aperture telescope that will extend humanities’ high angular resolution view of the universe into the infrared spectrum to reveal early epochs of the universe that the Hubble cannot see. The Webb’s science instrument payload includes four cryogenic near-infrared sensors that provide imagery, coronagraphy, and spectroscopy over the near- and mid-infrared spectrum. The JWST is being developed by NASA, in partnership with the European and Canadian Space Agencies, as a general user facility with science observations to be proposed by the international astronomical community in a manner similar to the Hubble. Construction, integration and verification testing is underway in all areas of the program. The JWST is on schedule for launch during 2018.

  18. A Deployable Primary Mirror for Space Telescopes

    NASA Technical Reports Server (NTRS)

    Lake, Mark S.; Phelps, James E.; Dyer, Jack E.; Caudle, David A.; Tam, Anthony; Escobedo, Javier; Kasl, Eldon P.

    1999-01-01

    NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (light direction and ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55-m-diameter, proof-of-concept mirror.

  19. Fresnel phasing of segmented mirror telescopes.

    PubMed

    Chanan, Gary; Troy, Mitchell; Surdej, Isabelle; Gutt, Gary; Roberts, Lewis C

    2011-11-20

    Shack-Hartmann (S-H) phasing of segmented telescopes is based upon a physical optics generalization of the geometrical optics Shack-Hartmann test, in which each S-H lenslet straddles an intersegment edge. For the extremely large segmented telescopes currently in the design stages, one is led naturally to very large pupil demagnifications for the S-H phasing cameras. This in turn implies rather small Fresnel numbers F for the lenslets; the nominal design for the Thirty Meter Telescope calls for F=0.6. For such small Fresnel numbers, it may be possible to eliminate the lenslets entirely, replacing them with a simple mask containing a sparse array of clear subapertures and thereby also eliminating a number of manufacturing problems and experimental complications associated with lenslets. We present laboratory results that demonstrate the validity of this approach.

  20. Concepts for the Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Margulis, M.; Tenerelli, D.

    1996-12-01

    In collaboration with NASA GSFC, we have examined a wide range of potential concepts for a large, passively cooled space telescope. Our design goals were to achieve a theoretical imaging sensitivity in the near-IR of 1 nJy and an angular resolution at 1 micron of 0.06 arcsec. Concepts examined included a telescope/spacecraft system with a 6-m diameter monolithic primary mirror, a variety of telescope/spacecraft systems with deployable primary mirror segments to achieve an 8-m diameter aperture, and a 12-element sparse aperture phased array telescope. Trade studies indicate that all three concept categories can achieve the required sensitivity and resolution, but that considerable technology development is required to bring any of the concepts to fruition. One attractive option is the system with the 6-m diameter monolithic primary. This option achieves high sensitivity without telescope deployments and includes a stiff structure for robust attitude and figure control. This system capitalizes on coming advances in launch vehicle and shroud technology, which should enable launch of large, monolithic payloads into orbit positions where background noise due to zodiacal dust is low. Our large space telescope study was performed by a consortium of organizations and individuals including: Domenick Tenerelli et al. (Lockheed Martin Corp.), Roger Angel et al. (U. Ariz.), Tom Casey et al. (Eastman Kodak Co.), Jim Gunn (Princeton), Shel Kulick (Composite Optics, Inc.), Jim Westphal (CIT), Johnny Batache et al. (Harris Corp.), Costas Cassapakis et al. (L'Garde, Inc.), Dave Sandler et al. (ThermoTrex Corp.), David Miller et al. (MIT), Ephrahim Garcia et al. (Garman Systems Inc.), Mark Enright (New Focus Inc.), Chris Burrows (STScI), Roc Cutri (IPAC), and Art Bradley (Allied Signal Aerospace).