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  • ASTRONOMY
  • 1985-1989  (218)
  • 1980-1984
  • 1975-1979
  • 1985  (218)
  • 1
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    Institutional arrangements for the space telescope: A mid-term review (1985)
    In:  CASI
    Details
    Publikationsdatum: 2005-03-01
    Schlagwort(e): ASTRONOMY
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  • 2
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    The identification of H2311 + 77 with HD220140, a probable RS CVn star (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: H2311 + 77, one of the bright soft X-ray sources in the sky originally detected with HEAO 1, has been identified in an Exosat imaging observation with a 7.7-mag late-type star, HD220140. The X-ray luminosity and the optical characteristics of this star indicate that it is probably an RS CVn binary system.
    Schlagwort(e): ASTRONOMY
    Materialart: Royal Astronomical Society, Monthly Notices (ISSN 0035-8711); 215; 11P-13P
    Format: text
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  • 3
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    Optical detection of large meteoroids in space (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: CCD sensors placed across the focal plane of large Schmidt telescopes have great potential for detecting and measuring the very low flux in space of meteoroids with diameters larger than 1 meter. With the Palomar 'Big Schmidt', a detection rate of 1.4 per hour is obtained for meteoroids between 0.6 and 200 meters in diameter. For the Baker-Nunn 'Satellite Tracking Camera', the corresponding rate is about 0.8 per hour. The key to obtaining such high detection rates derives from approximately setting the sensor integration time equal to the time it takes a meteoroid to cross a pixel field of view. This minimizes signal to noise problems and is accomplished, in practice, by multiple summing of short integration time data records to obtain data records of longer effective integration times.
    Schlagwort(e): ASTRONOMY
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  • 4
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    On the orientation of ephemeris reference frames (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Precession corrections, equinox motions and locations, and obliquities for the FK4 are determined from laser-ranging data only by the ephemeris-fitting method of Standish (1982) and compared with those calculated by Fricke (1971 and 1982) from optical observations. The theoretical basis of the comparison is explained, and the results are presented in a table. No significant differences are found in the equinox offset and equinox motion values, and good agreement is found in the equinox location. The ephemeris-fitting obliquity values are shown to be consistent to within 10 marcsec and to be about 20 marcsec lower than the optical values.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics (ISSN 0008-8714); 37; 239-242
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  • 5
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    The evolution of adopted values for precession (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The history of astronomical longitude precession determination is reviewed. Consideration is given to the work of Hipparchus and Ptolemy, the definition of rotation axes, the major 19th-century determinations, and 20th-century studies (using the data of Newcomb; based on PGC, GC, and McCormick/Cape catalogs; using FK3, FK4, and AGK3; involving galaxies; and using the dynamical method). Laser ranging and VLBI are seen as the most promising techniques for future precession measurements. Diagrams, graphs, and tables of numerical data are provided.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics (ISSN 0008-8714); 37; 209-238
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  • 6
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    Protoplanetary material around nearby stars (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A statistical analysis of IRAS observations indicates that about 20 percent of the nearby main sequence stars, and probably a similar fraction of main sequence stars not detectable by IRAS, shows evidence of significant infrared excess beyond 12 microns. Spectral type A dwarfs are predominant, but not exclusive in showing large 60-micron excesses. The solar system, when viewed from sufficient distance, appears to have, in contrast to this, less than 1 percent of cool infrared excess. These observational facts are consistent with the working hypothesis that cold infrared excess in stable main sequence stars is due to protoplanetary material, observable during the accretion phase in the evolution of a solar system.
    Schlagwort(e): ASTRONOMY
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  • 7
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    Layered synthetic microstructures for solar EUV telescopes (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The application of layered synthetic microstructures (LSMs) to figured mirrors suitable for normal incidence solar EUV telescopes is considered, and initial studies for a single mirror telescope consisting of an f/18, 200-cm focal length off-axis paraboloid demonstrate the feasibility of LSM coatings for moderate sized mirrors. Analytical studies on broadband designs comprised of five layers show a seven percent reflectance at 256 A and reflectivities of over 12 percent for wavelengths above 300 A. Deposition considerations are also discussed.
    Schlagwort(e): ASTRONOMY
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  • 8
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    The status of low-energy gamma-ray astronomy and the Gamma-Ray Observatory (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A brief sketch of the objectives and status of the various subdisciplines in gamma-ray astronomy (below 10 GeV) are presented. The Gamma-Ray Observatory planned for launch in 1988 is described. This NASA observatory and several planned French-Soviet spacecraft are expected to elevate gamma-ray astronomy into a mature observational science for the Space Station era.
    Schlagwort(e): ASTRONOMY
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  • 9
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    Pedestal features in dark clouds - A search for radio emission (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Radio emission associated with broad-winged CO sources in B335, L1527, L1455, and L732 was searched for. No detections were made in three of the sources, B335, L1527, and L732. A nonthermal double radio source was found near the focus of the L1455 flow. This source is probably associated with the flow, and may represent a new aspect of the molecular flow phenomenon.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 295; 89-93
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  • 10
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    Cometary impacts, molecular clouds, and the motion of the sun perpendicular to the galactic plane (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The stochastic nature of the mass extinction model of Rampino and Stothers (1984), based on the vertical oscillation of the solar system about the plane of the Galaxy, can accommodate a few events with large phase discrepancies. The degree of modulation is crucial in that it depends on the scale height of the population of molecular clouds relative to the amplitude of the solar system and tends to zero if this ratio is large and encounters are entirely random. Here data are presented here from CO surveys of molecular clouds both within and beyond the solar circle which permit explicit calculation of the strength of the modulation. The cloud layer near the sun it too extended and, as a consequence, the modulation of cloud encounters is too weak for a statistically significant period to be extracted from the nine extinctions analyzed by Rampino and Stothers.
    Schlagwort(e): ASTRONOMY
    Materialart: Nature (ISSN 0028-0836); 314; 73-75
    Format: text
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  • 11
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    Tail phenomena (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: An overview of tail phenomena is presented based on worldwide submissions to the Large-Scale Phenomena Discipline Specialist Team of the International Halley Watch. Examples of tail phenomena and science are presented along with estimates of total expected yield from the Network. The archive of this material will clearly be very valuable for studying the solar-wind/comet interaction during the 1985-1986 apparition of Halley's Comet.
    Schlagwort(e): ASTRONOMY
    Materialart: Advances in Space Research (ISSN 0273-1177); 5; 12, 1
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  • 12
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    8.3 and 12.4 micron imaging of the Galactic Center source complex with the Goddard infrared array camera (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-19
    Beschreibung: A 30 x 30 arcsec field at the Galactic Center (1.5 x 1.5 parsec) was mapped at 8.3 microns and 12.41 microns with high spatial resolution and accurate relative astrometry, using the 16 x 16 Si:Bi accumulation mode charge injection device Goddard infrared array camera. The design and performance of the array camera detector electronics system and image data processing techniques are discussed. Color temperature and dust opacity distributions derived from the spatially accurate images indicate that the compact infrared sources and the large scale ridge structure are bounded by warmer, more diffuse material. None of the objects appear to be heated appreciably by internal luminosity sources. These results are consistent with the model proposing that the complex is heated externally by a strong luminosity source at the Galactic Center, which dominates the energetics of the inner few parsecs of the galaxy.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 299; 1007-101
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  • 13
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    The Broad Band X-ray telescope (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The Broad-Band X-ray Telescope (BBXRT) has been designed to perform high sensitivity, moderate resolution spectrophotometry of X-ray sources in the 0.3-12 keV band from the Shuttle. It consists of a coaligned pair of high throughput conical X-ray imaging mirrors, with a cryogenically cooled multiple element Si(Li) spectrometer at the focus of each. On axis, BBXRT will have an effective area of 580 sq cm at 2 keV and 250 sq cm at 7 keV, and a spectral resolution of 110 eV at 2 keV and 150 eV at 7 keV. A 10,000-s observation with BBXRT will allow a determination of the continuum spectral shape for sources near the Einstein deep survey limit.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Science Reviews (ISSN 0038-6308); 40; 707-713
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  • 14
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    The determination of physical and dynamical parameters of Pluto/Charon and binary asteroids by least-square formation of a matched filter for a time series of images. I - The operational theory (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A theory is derived for the determination of the masses, radii, and orbital elements of the Pluto/Charon, or similar, system based on the prediction of an image distribution over space and time and its comparison with observation. The comparison may be ultimately through the theory of least squares or the application of a matched filter to the observations as a three-dimensional signal stream at an initial or intermediate state. The theory is an approximation correct to fifth order in the diameters of celestial bodies. The theory of astronomical seeing that is used is based on Kolmogorov turbulence in the long-exposure limit. The images must be photometric. Linear tracking errors that can be removed are preferable to either automatic or manual guiding, in the collection of candidate observations.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 1883-189
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  • 15
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    A VLBI survey at 2.29 GHz (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: VLBI observations at 2.29 GHz with fringe spacings of about 3 milliarcsec have been performed on 1398 radio sources spread over the entire sky. 917 sources were detected, including 93 percent of the identified BL Lacertae objects, 86 percent of the quasars, and 36 percent of the galaxies. The resulting catalog of compact radio sources is useful for various astrophysical studies and in the formation of VLBI celestial reference frames.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 1599-164
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  • 16
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    The brightest high-latitude 12-micron IRAS sources (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The Infrared Astronomical Satellite (IRAS) Point Source catalog was searched for sources brighter than 28 Jy (0 mag) at 12 microns with absolute galactic latitude greater than 30 deg excluding the Large Magellanic Cloud. The search resulted in 269 sources, two of which are the galaxies NGC 1068 and M82. The remaining 267 sources are identified with, or have infrared color indices consistent with late-type stars some of which show evidence of circumstellar dust shells. Seven sources are previously uncataloged stars. K and M stars without circumstellar dust shells, M stars with circumstellar dust shells, and carbon stars occupy well-defined regions of infrared color-color diagrams.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 616-633
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  • 17
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    A new luminosity component in 3C 48 (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The infrared emission from the quasar 3C48 has a luminosity L approximately 5 x 10 to the 12th power solar luminosity and dominates the power output of the quasar system. It is shown that the infrared emission, unlike that of most radio loud quasars, is most likely not an extension of the radio emission of the quasar. It is argued that the infrared emission in 3C48 is probably thermal radiation arising in a highly luminous galaxy surrounding the quasar.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 295; L27-L31
    Format: text
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  • 18
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    On the trail of Comet G-Z (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The International Cometary Explorer (ICE) is to investigate the magnetic and electric fields, plasmas, and particles in the Comet Giacobini-Zinner (G-Z) and to study its interaction with solar wind. The ICE can pass through the comet only once and it will take 90 minutes to cross from one side of the tail to the other. Since the Comet G-Z often changes its orbit due to nongravitational forces changing its direction and velocity, ICE's position needs to be adjusted. The probe is aimed 10,000 km from the nucleus in order to be provided the best passage through the Comet G-Z. The 64-meter dishes of JPL's Deep-Space Network (DSN) will receive data transmitted on two adjacent S-band frequencies at the rate of 1024 bits per second. Also NASA has arranged for the radio telescope at Arecibo to record the transmission. The Japanese 64-meter tracking antenna at Usada, equipped with an ultrasensitive receiver for one ICE frequency, will provide pre-encounter and post-encounter tracking. The ICE data may provide information about the dust tail in the Comet G-Z which could be compared to previous research.
    Schlagwort(e): ASTRONOMY
    Materialart: Sky and Telescope (ISSN 0037-6604); 70; 198-203
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  • 19
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    Periodic orbits of the general three-body problem for the sun-Jupiter-Saturn system (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Two families of symmetric periodic orbits of the planar, general, three-body problem are presented. The masses of the three bodies include ratios equal to the sun-Jupiter-Saturn system and the periods of the orbits of Jupiter and Saturn are in a 2:5 resonance. The (linear) stability of the orbits are studied in relation to eccentricity and mass variations. The generation of the two families of periodic orbits follows a systematic approach and employs (numerical) continuation from periodic orbits of the first and second kind in the circular restricted problem to the elliptic restricted problem and from the circular and elliptic problems to the general problem through bifurcation phenomena relating the three dynamical systems. The approach also provides insight into the evolutionary process of periodic orbits continued from the restricted problems to the general problem.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics (ISSN 0008-8714); 35; 289-303
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  • 20
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    Submilliarcsecond VLBI observations of the close pair GC 1342 + 662 and GC 1342 + 663 (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Differential VLBI was simultaneously performed on the source pair GC 1342 + 662 and GC 1342 + 663 (4.4-arcminute separation) using S-band on the Goldstone/Madrid baseline. These measurements were acquired on two separate observing sessions: 30 December 1982 and 14 May 1983. The change in separation of GC 1342 + 662 relative to GC 1342 + 663 between the two epochs was 0.03 + or - 0.08 milliarcsecond. The differences of the relative position measurements between epochs of GC 1342 + 662 relative to GC 1342 + 663 were -0.29 + or - 0.05 milliarcsecond in right ascension and 0.14 + or 0.09 milliarcsecond in declination. These measurements demonstrate submilliarcsecond accuracy and repeatability. The discrepancies outside of the formal uncertainties could be attributed to the intrinsic properties of the sources such as structure and to a lesser probability, proper motion. These discrepancies could also be attributed to excursions in UT1-UTC of about four times the quoted BIH uncertainty.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 1004-100
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  • 21
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    A transformation of the two-body problem (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A transformation of the differential equations of motion of the two-body problem in the spherical coordinates to oscillator form is derived. It is shown that the independent variable transformation dt/ds = r squared is a transformation which makes the oscillator form possible.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics (ISSN 0008-8714); 35; 1-7
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  • 22
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    Epsilon Aurigae (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: In April 1984, fourth contact ended the two year long eclipse of Epsilon Aurigae. An astrometric study of the study of the system was carried out by Van de kamp (1978) leading to the conclusion that the orbit is seen very close to edge on. The eclipse was monitored by a number of groups from the ground and from spacecraft such as the IUE. Ultraviolet observations of the system from IUE have thrown new light on the nature of the system that led to the conclusion that the secondary object is probably a cold, dusty accretion disk surrounding a star that is completely hidden inside the disk.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysics and Space Science (ISSN 0004-640X); 110; 1, Ma
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  • 23
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    Absolute calibration of photometry at 1 through 5 microns (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The solar-analog method is used to determine the absolute calibration of photometry in the J, H, K, L, and M bands to an accuracy of 3 percent, (5 percent at M). This calibration agrees well with the direct calibration obtained by Blackwell et al. (1983); this agreement gives confidence that the calibration is known to an accuracy of 2 percent to 3 percent. The agreement also implies that the behavior of solar type stars is well understood in the infrared and that such stars make reliable standards for calibration of nonstandard photometric bands and for planetary reflectance studies. Both methods indicate that Vega is slightly brighter than indicated by atmospheric models.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 896-899
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  • 24
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    An absolute photometric system at 10 and 20 microns (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Two new direct calibrations at 10 and 20 microns are presented in which terrestrial flux standards are referred to infrared standard stars. These measurements give both good agreement and higher accuracy when compared with previous direct calibrations. As a result, the absolute calibrations at 10 and 20 microns have now been determined with accuracies of 3 and 8 percent, respectively. A variety of absolute calibrations based on extrapolation of stellar spectra from the visible to 10 microns are reviewed. Current atmospheric models of A-type stars underestimate their fluxes by about 10 percent at 10 microns, whereas models of solar-type stars agree well with the direct calibrations. The calibration at 20 microns can probably be determined to about 5 percent by extrapolation from the more accurate result at 10 microns. The photometric system at 10 and 20 microns is updated to reflect the new absolute calibration, to base its zero point directly on the colors of A0 stars, and to improve the accuracy in the comparison of the standard stars.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 900-906
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  • 25
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    Surface photometry of comet P/Encke (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A scheme to clean cometary digital images from offending background-star trails, and this technique has been applied to a pair of deep Kitt Peak 4-m plates of comet P/Encke, taken in October 1980. Simultaneous and subsequent digital spectra have been obtained at Lick Observatory. The non-polluted coma images show a strong asymmetric sunward-oriented fan/jet, and an extended and rounder (mostly gaseous) main coma, out to approximately 100,000 km radius. The stellar-trail point-spread function has a narrow width (sigma approximately 0.6 arcsec), so that spatial resolution better than approximately 300 km is achieved at the comet. The photometric gradient near the nucleus is very steep, strongly suggesting an icy-grain component which evaporates quickly (at radii equal to or less than 500 km) in the sunlight. Further from the nucleus, the profile becomes shallower, bluer, and more gas dominated. The effect of solar radiation pressure on C2, CN, and other molecules is probably responsible for the rounding of the outer, fainter isophotes. The source of the molecules is likely to be larger than the nucleus itself, and a substantial fraction may originate in the jet. The technique described here may also be applicable in surface photometry of galaxies, in cases where the heavy image pollution by foreground stars is present.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 869-876
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  • 26
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    Astometry at La Silla (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Astronomy of comets and minor planets is done regularly at ESO, La Silla, Chile. Plates are obtained with the 1 m Schmidt telescope and the 40 cm GPO, and CCD frames with the Danish 1.5 m telescope. Reductions are carried out by microdensitometer scanning and image processing at ESO, Garching, FRG. P/Halley will be observed intensively during the interval from perihelion passage on 9 February 1986 until the middle of March 1986. Almost real-time, accurate positions will be made in support of the spacecraft missions.
    Schlagwort(e): ASTRONOMY
    Materialart: JPL Cometary Astometry; p 60-65
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  • 27
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    High dispersion observations of Epsilon Aur from Sept. 1982 to March 1983 (1985)
    In:  CASI
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    Publikationsdatum: 2016-06-07
    Beschreibung: Between September 1982 and March 1983 I obtained high dispersion spectra of epsilon Aur in selected regions using the Palomar 200-inch coude spectrograph and the Dominion Astrophysical Observatory 48-coude spectrograph. All spectra were taken with the 90-mm ITT image tube and IIa-D emulsion. Radial velocities are listed for the sodium D lines, KI lines, H alpha, and a few other features. While most of the sodium and potassium features are surely circumstellar there is certainly an interstellar component present. In the direction of epsilon Aur interstellar gas is seen mostly with radial velocities between +5 and +10 km s(-1). The sodium D lines and potassium lines show incipient resolution which may involve the interstellar components. The equivalent widths of the sodium and potassium lines are given. For potassium, blending with atmospheric O2 makes the line at lambda 7664 unmeasurable on the dates of these observations. The increase in equivalent widths already noted by Pathasarathy and Lambert is evident. Blending and partial resolution of the circumstellar and interstellar features may account for much of the velocity structure which is only partially discernable at the available resolution.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 99-102
    Format: application/pdf
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  • 28
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    Astronomical research at the Hopkins Phoenix Observatory (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: After trying astrophotography and radio astronomy it was decided that the best way to do meaningful astronomical research at a small private observatory was by doing photoelectric photometry. Having the observatory located in the back yard of a private residence affors the luxury of observing any time the sky conditions permit. Also modest equipment is all that is needed to do accurate UBV photometry of stars 8th magnitude and brighter. Since beginning in 1980 the Hopkins Phoenix Observatory has published papers on several RS CVn star systems, 31 Cygni, 22 Vul, 18 Tau Per, and has followed the 1982-1984 eclipse of Epsilon Aurigae from its start to the present with over 1000 UBV measurements. In addition the Hopkins Phoenix Observatory has developed several pieces of photometry equipment including the HPO PEPH-101 photometer head and photon counting electronics.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 93-97
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  • 29
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    Micron CO in the eclipse spectrum of Epsilon Aur (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: Two micrometer spectrum of epsilon Aur was observed at high resolution (lambda/delta lambda approx. 40000) with the KPNO 4m telescope and FTS approximately every 100 days during the recent eclipse. CO delta v=2 lines appeared in the spectrum only after mid-totality. No CO features were present JD 2445478 but weak absorption lines were present on 2445592. The CO strengthened in the spectrum and remained present until at least 2445812. CO was again absent after forth contact when the spectrum was observed on 2445912. The CO appears to originate in a cool (approx. 1000 K), turbulent region. Excitation temperatures, velocities, and column densities is presented.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 80
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  • 30
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    Modelling Epsilon Aurigae without solid particles (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: Three components can be expected to contribute to the emission of epsilon Aurigae. There is a primary F star. There is an opaque disk which occults it, and there is a gas stream which is observed to produce absorption lines. Evidence that the disk is not responsible for the gas stream lines comes both from the radial velocities, which are too small, and from the IR energy distribution out of eclipse, which shows free-free emission that would produce inadequate optical depth in electron scattering. The color temperature of the IR excess can give misleading indications of low temperature material. Free-free emission at 10,000 K between 10 and 20 microns has a color temperature of 350 K. Attempts to mold the system are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 91
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  • 31
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    Spectrophotometry of Epsilon Aur, 3295-8880 A (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: Spectrophotometric scans were obtained at 8 A resolution from 3295 to 8880 A on twenty nights before, during, and after the recent eclipse of epsilon Aurigae, beginning with a pre-eclipse observation on 5 March 1982 U.T. The observations were reduced to absolute flux using the standard stars 109 Vir or xi(2) Ceti. The data confirm that the eclipse is essentially gray over the entire visible spectrum, as others have noted from broadband photometry. High resolution echellograms (450 to 6700 A) made through mid-eclipse and the scans show changes in the equivalent widths of H alpha, Na D, and O I as large as a factor of two.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 79
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  • 32
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    Intermediate and narrow band photometry of Epsilon Aurigae (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: Intermediate band blue (4530A), far red (7790A) and H-alpha intermediate and narrow band photoelectric observations of the peculiar, 27 year eclipsing binary, Epsilon Aurigae were made from December 1981 through the present (December 1984). BD +42 1170 served as the primary comparison star because of its angular proximity to the variable star. The analysis of this data along with other available photometry was undertaken to study the characteristics of the low amplitude, semi-regular light variations that appear inside and outside of eclipse. It appears that these short term light variations arise from nonradial pulsations of the luminous f supergiant in the system. Furthermore, the semi-regular light variations found for Epsilon Aurigae are similar to those found for other luminous A-F supergiants. Also, the preliminary results from the analyses of the light variations produced by the eclipse of the F-supergiant by the mysterious cooler component is discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 77-78
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  • 33
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    UBV photometry of the 1982-4 eclipse of Epsilon Aurigae: A discussion of the observed light curves (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: At least 29 observers in nine countries have contributed photometric measurements of Epsilon Aurigae during the recent observational campaign. The present discussion is limited to data submitted by J. L. Hopkins of the Hopkins Phoenix Observatory and S. I. Ingvarsson of the Tjornisland Astronomical Observatory. Both sources are on the UBV system, with no significant systematic differences. Combined, these two sources cover the entire eclipse, from pre-ingress up to the present (April 1985). It should be noted that this eclipse is the first to have complete photometric coverage in all three broadband filters U, B, and V.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 67-74
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  • 34
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    Photometric support for future astonomical research (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: The I.A.P.P.P. is described and how that organization can provide photometric support for future astronomical research projects such as the 1982-1984 eclipse of epsilon Aurigae discussed at this workshop. I.A.P.P.P., International Amateur-Professional Photoelectric Photometry, is an organization founded in Fairborn, Ohio by the authors in 1980. Its purpose is to encourage contact between amateur and professional astronomers interested in photoelectric photometry, for their mutual benefit and for the benefit of astronomical research. Aspects dealt with include instrumentation, electronics, computer hardware and software, observing techniques, data reduction, and observing programs. Starting with the June 1980 issue, I.A.P.P.P. has published the quarterly I.A.P.P.P. Communications. The Communications contain articles dealing with all the above aspects of photoelectric photometry, although it does not publish observational results as such. Photoelectric photometry obtained by amateurs is published in the same journals which publish photometry obtained by professionals.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 61-64
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  • 35
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    The eclipse of Epsilon Aurigae visible spectroscopy and ultraviolet activity (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: The preliminary results of the study of several high resolution spectrograms (lambda 3500 - lambda 7000 A), obtained at the Haute Provence Observatory (OHP) in France, at different epochs before, during and after the eclipse are reported. Some of these spectrograms are compared with corresponding IUE high resolution observations, in order to study the effects of the intrinsic UV activity, towards the longer wavelengths.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 43-48
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  • 36
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    Evidence for Non-radiative Activity in Hot Stars (1985)
    In:  CASI
    Details
    Publikationsdatum: 2014-09-16
    Beschreibung: Indications of non-radiative activity in hot stars were investigated. Data used as evidence of non-radiative activity includes: (1) evidence for high temperature regions, especially regions that are too hot to be explained by shocks that can be initiated and driven by radiative forces; (2) evidence for multi-plume flow. Non-spherically symmetric flow can be diagnosed by the effect it can have on the polarization of the light from a star; and (3) direct evidence for stellar magnetic fields.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center The Origin of Nonradiative Heating(Momentum in Hot Stars; p 2-23
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  • 37
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    Nonradial Pulsation and Mass Loss in Early B Stars (1985)
    In:  CASI
    Details
    Publikationsdatum: 2014-09-16
    Beschreibung: It has been firmly established that nonradial pulsation (NRP) probably occurs in nearly all sharp-lined early B stars near the main sequence. A recent breakthrough occurred with the discovery of quasi emission/absorption bumps moving across the line profiles of the rapid rotators zeta Oph and alpha Vir. It was found that an intermediate-1 (1=8) NRP mode is responsible for these features in zeta Oph. Some 20 Be and Bn stars were monitored and convincing evidence for NRP in 13 of them was found. Line profile variations suggestive of NRP in the other 7 were also discovered. A search for line profile variables among moderate rotators has turned up NRP in epsilon and eta Lep, with v sin i's of 140 and 70 km/sec, respectively. It now seems that NRP can be present at all rotational velocities with equal frequency (near 100%! . However, at most 20% of these stars exhibit detectable photometric variations.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center The Origin of Nonradiative Heating(Momentum in Hot Stars; p 53-56
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  • 38
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    Coronal Temperatures (1985)
    In:  CASI
    Details
    Publikationsdatum: 2014-09-16
    Beschreibung: The solid state spectrometer (SSS) on the Einstein Observatory (HEAO 2) was sensitive in the energy range 0.5 to 4.5 keV to fluxes as low as 4x10 to the 12th power ergs/cu cm/s. Good spectra were obtained for 19 stars, including Algol, 7 RS CVn systems, 2 dMe stars, 2 W UMa binaries, 1 GV single star, and 3 0B supergiants, 2 BV stars and 1 07 binary. This is a very incomplete survey of stellar coronae, but it does include coverage of several late and early types and usually more than 1 sample of the class. The results for these stars suggest two generalizations despite the small numbers: (1) there is a broad variety of X-ray spectra of stellar coronae; and (2) there probably are X-ray spectral types (X-ray coronae of stars of similar other properties have similar temperatures). Evidence indicating that some emission distributions are bimodal is discussed. Finally, some remarks are made concerning the spectra of the early type stars and constraints on the presence of very high temperatures.
    Schlagwort(e): ASTRONOMY
    Materialart: The Origin of Nonradiative Heating(Momentum in Hot Stars; p 86-90
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  • 39
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    The peculiar A star HD 43819 - A photographic region line-identification study (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A line identification study of the sharp-lined silicon star HD 43819 has been performed for the photographic region 3759-4924 A. Comparison of this star's spectrum with those of other silicon stars shows that it shares many of their apparent abundance anomalies. The TiII, CrII, FeI, and FeII spectra are well represented while the singly ionized rare earths are represented by at best a few lines per species.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 976-989
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  • 40
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    20-micron transparency and atmospheric water vapor at the Wyoming Infrared Observatory (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The atmospheric transparency at 19.5 and 23 microns from the Wyoming Infrared Observatory over the past six years has been examined. It is found that the transparency is largely controlled by the season. Four months: June, July, August, and September have very poor 20-micron transparency. During the rest of the year the transparency is usually quite good at 19.5 microns and moderately good at 23 microns. Using rawinsonde data and theoretical calculations for the expected infrared transparency, the measures of 20-micron transparency were calibrated in terms of atmospheric water-vapor content. The water vapor over the Wyoming Infrared Observatory is found to compare favorably with that above other proposed or developed sites: Mauna Kea, Mount Graham, and Wheeler Peak.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 1013-101
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  • 41
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    Radar observations of asteroids and comets (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Radar techniques for the observation of asteroids and comets are reviewed, emphasizing the logical basis for inferring physical properties from radar measurements. Results to date are reviewed, focusing on some recent highlights of the research to demonstrate the synergism between radar and other ground-based techniques. Particular attention is given to the asteroids 2 Pallas, 16 Psyche, 2101 Adonis, and the comet IRAS-Araki-Alcock.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 877-884
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  • 42
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    Aperture synthesis using orbiting telescopes (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A study was carried out to determine the feasibility, with current technology, of performing aperture synthesis using two telescopes orbiting the earth in coordinated orbits separated by approximately 10 m to 1 km. The objective was to determine whether there is a practical alternative to a very large, deployed, servo-controlled submillimeter telescope (i.e., the Large Deployable Reflector) for obtaining high-resolution submillimeter images of astronomical sources. It is found that suitable classes of orbits exist which can provide good UV coverage over the entire sky and the real-time correlation of wideband signals can be performed in orbit using current technology. The most difficult task appears to be the real-time determination of the orientation of the baseline vector in a stable coordinate system. A plausible scheme has been identified for the determination of an arbitrary direction to within 0.003 arcsec in an astrometric coordinate system. This scheme not only makes submillimeter interferometric image reconstruction possible but should also have numerous other applications.
    Schlagwort(e): ASTRONOMY
    Materialart: Radio Science (ISSN 0048-6604); 20; 1105-111
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  • 43
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    Terrestrial record of the solar system's oscillation about the galactic plane (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A new study is presented of the observational evidence pertaining to the theory which attributes the episodic component of the earth's impact cratering record over the past 600 Myr to gravitational encounters between the solar system and interstellar clouds that cause comets to fall into the solar system and impact the earth. Contrary to a claim by Thaddeus and Chanan (1985), the vertical scale height of the clouds seems to be sufficently small and the sun's vertical trajectory sufficiently large for the modulating effect of the sun's galactovertical motion to be detectable in the terrestrial record of impact cratering with at least a 50 percent a priori probability.
    Schlagwort(e): ASTRONOMY
    Materialart: Nature (ISSN 0028-0836); 317; 338-341
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  • 44
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    IRAS observations of matter around nearby stars (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A systematic search of the IRAS point-source catalog has led to the identification of eight new nearby stars that are Vega-like in terms of their large 60-micron excess. These stars are distinguished by the predominance of spectral type A and the absence of double stars in the Vega-like group. Both effects are intuitively consistent with the interpretation that the 60-micron excess radiation is due to a disk of protoplanetary material, suggesting an early phase in the evolution of a planetary system; however, this distribution can also be due to luminosity and brightness selection effects.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 885-891
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  • 45
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    The invariance of the restricted problem of three bodies (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The restricted problem of three bodies in sidereal coordinates is investigated using Lie theoretical methods of extended groups. The application of the theory results in a single scalar generator with an associated invariant - the integral of the motion attributed to Jacobi.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics (ISSN 0008-8714); 36; 287-298
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  • 46
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    The dust coma of periodic Comet Churyumov-Gerasimenko (1982 VIII) (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: IR emission from the dust comet of Comet C-G was monitored at 1-20 microns with the 3-m NASA Infrared Telescope Facility at Mauna Kea, Hawaii during its perihelion passage from September 1982 to March 1983. The maximum dust production rate of approximately 200,000 g/sec was found to occur approximately one month after perihelion. It was also found that no obvious 1-micron silicate feature was present at 1.33 AU preperihelion, and that the ratio of dust/gas production was higher in other short-period comets observed in the infrared, particularly preperihelion. The low albedos derived for the dust grains (less than 0.05 micron) are noted to be plausible for mineral mixtures expected in cometary grains.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 64; 11-19
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  • 47
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    C2 imagery of the inner coma of Comet IRAS-Araki-Alcock (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: May 10, 1983 observations of the comet IRAS-Araki-Alcock are analyzed to determine the spatial molecular abundance of C2 in the inner coma, via the Delta-v = +1 Swan band sequence near 4690 A. The observations indicate a deficiency of C2 emission across a projected diameter of about 2000 km that is centered on the peak of continuum emission. Comet imagery indicates a sunward-pointing coma that suggests an outburst of subsurface volatile ices through a nonvolatile surface crust, as predicted for periodic comets. These results are discussed in the framework of instrumental and observational constraints.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 63; 339-346
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  • 48
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    Photometric lightcurves of 21 asteroids (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Forty-three light curves of 21 asteroids obtained during 1968-1978 are presented and briefly discussed. The light curves were obtained to increase the data base for studies in shapes, spin periods, and the orientation of the rotation axes.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 64; 37-52
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  • 49
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    Optical spectroscopy of the filamentary halo that surrounds HD 148937 and NGC 6164-65 (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Optical spectra have been obtained for the recently-discovered faint filamentary halo that surrounds both the extremely young star HD 148937 and the peculiar S-shaped nebula NGC 6164-65. This halo, interpreted to be a wind-generated interstellar bubble, has a spectrum which appears to result from both shock-wave heating and photoionization.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 97; 780-783
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  • 50
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    New developments at the NASA Astronomical Data Center (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The need for a compilation catalog containing a large variety of astronomical data for the Astronomical Data Base of NASA is considered. It is suggested that the catalog should be prepared directly from the SIMBAD data base by processing through a single software program and made available for distribution on magnetic tape or microfilm. Annual updating is recommended to ensure the quality of the catalog. Data recommended for inclusion in the compilation catalog are listed in a table.
    Schlagwort(e): ASTRONOMY
    Materialart: Abastumanskaia Astrofizicheskaia Observatoriia, Biulleten' (ISSN 0375-6644); 59, 1; 31-39; D
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  • 51
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    The generation of infrared and ultraviolet astronomical data bases and retrieval systems (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Observations with the Infrared Astronomy Satellite (IRAS) and with the International Ultraviolet Explorer (IUE) satellite have stimulated the need for machine-readable data bases at infrared and ultraviolet wavelengths along with associated software. This paper describes the generation of three such data sets at the Astronomical Data Center (ADC) of the NASA-Goddard Space Flight Center (GSFC): the Catalog of Infrared Observations, the Combined List of Astronomical Sources, and the Bibliographical Index of Objects Observed by IUE 1978-82. The discussion is divided by spectral regime and includes summaries of the data products developed in each category.
    Schlagwort(e): ASTRONOMY
    Materialart: Abastumanskaia Astrofizicheskaia Observatoriia, Biulleten' (ISSN 0375-6644); 59, 1
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  • 52
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    Orbital motion, nucleus precession, and splitting of periodic Comet Brooks 2 (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Results of ten nongravitational orbital solutions are given for Comet Brooks 2, based on observations from the apparitions 1889-1980. The time history of the nongravitational parameters, including the transverse component A-sub-2, is vital for modeling the nucleus precession. The comet is obviously a fragment of a once larger object that split during a close encounter with Jupiter in 1886. Factors possibly responsible for the breakup are examined. A similarity between the orbital histories of P/Brooks 2 and P/Wild 2 is noted.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 2335-235
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  • 53
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    A signal detection strategy for the SETI All Sky Survey (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A source detection strategy for the SETI All Sky Survey is described. The method is designed to detect continuous wave (or very narrowband) sources transitting an antenna beam. The short-time spectra of the received signal are accumulated, and candidate extraterrestrial sources are recognized by the recognized by the presence of narrowband power exceeding a threshold function. The threshold function is derived using a Neyman-pearson hypothesis test.
    Schlagwort(e): ASTRONOMY
    Materialart: The Telecommunications and Data Acquisition Report; p 191-208
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  • 54
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    Low altitude, one centimeter, space debris search at Lincoln Laboratory's (M.I.T.) experimental test system (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The majority of work performed by the Lincoln Laboratory's Space Surveillance Group, at the request of NASA, to define the near-earth population of man-made debris is summarized. Electrooptical devices, each with a 1.2 deg FOV, were employed at the GEODSS facility in New Mexico. Details of the equipment calibration and alignment procedures are discussed, together with implementation of a synchronized time code for computer controlled videotaping of the imagery. Parallax and angular speed data served as bases for distinguishing between man-made debris and meteoroids. The best visibility was obtained in dawn and dusk twilight conditions at elevation ranges of 300-2000 km. Tables are provided of altitudinal density distribution of debris. It is noted that the program also yielded an extensive data base on meteoroid rates.
    Schlagwort(e): ASTRONOMY
    Materialart: Advances in Space Research (ISSN 0273-1177); 5; 2, 19; 35-45
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  • 55
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    Clarifications concerning the definition and determination of the celestial ephemeris pole (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The precise meaning and consequences of the introduction beginning in 1984 of the 1980 IAU theory of nutation (Wahr, 1980; Seidelmann, 1982) based on the celestial ephemeris pole (CEP) rather than the instantaneous pole of rotation (IPR) of the previous theory (Woolard, 1953) are analyzed and discussed. The CEP implicitly accounts for the forced diurnal polar motion and thus implies a fixed change of 0.0087 arcsec in the mean celestial pole. It is pointed out that past determinations of the obliquity and the celestial pole which were assumed to be referred to the IPR were actually referred to the CEP. A number of clarified formulations of the new theory are proposed.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomy and Astrophysics (ISSN 0004-6361); 146; 2, Ma
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    The rotation period and pole orientation of asteroid 4 Vesta (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: In 1971 asteroid Vesta was observed in a region of the sky in which it had never been observed before. Its photometric lightcurve had two distinct maxima. Those observations have been the only strong evidence to support a rotation period of about 10 hr 41 min. Lightcurves made in 1982, when Vesta was at the same aspect as 1971, do not show two different maxima. It is concluded that there was a systematic error in the 1971 observations. At this time a definitive statement cannot be made about the true period of Vesta, although the 5 hr 20 min period does appear more plausible. Radar echoes in 1988 and 1992 should resolve the problem. The shorter rotation period was assumed and the photometric astrometry method applied. The sidereal period is 5 hr 20 min 31.68 sec (0.2225889 + or 0.0000002 days), the rotation is prograde, and the coordinates of the north pole are 103 deg longitude and + 43 deg latitude with an uncertainty of about 6 deg.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 62; 298-304
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  • 57
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    Detectability of extrasolar planetary transits (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Precise stellar photometry can be used to detect other planetary systems. However, the intrinsic variability of stellar luminosity imposes a fundamental limit on the sensitivity of this method. Based on recent precise solar observations made from the Solar Maximum Mission satellite, it appears that the detection of earth-sized planets will be marginal during periods of high stellar activity. However, with a suitable photometer larger planets should be readily detectable even in the presence of stellar activity equal to that of the sun at the peak of its sunspot cycle. The high precision, multiple-star photometric system required to detect planets in other stellar systems could be used to monitor flares, starspots, and global oscillations.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 291; 852-854
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  • 58
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    Seeing Comet IRAS with a radar eye (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: IRAS data in April 1983 held evidence for the approach of a comet which would pass close enough to earth to bounce radar signals off the cometary nucleus. The closest pass was calculated to be 450,000 km. Ephemerides were prepared for the object while radio observatory tracking schedules were arranged. S-band observations were selected for the JPL 64 m antenna to obtain 2.7 arcmin resolution. A 400 kW signal was generated. Two 4 hr observational periods were achieved, revealing a rough, faceted surface by using S-band in the first run and the X-band in the second. The comet was concluded irregularly shaped and roughly elliptical, with a 2 d period.
    Schlagwort(e): ASTRONOMY
    Materialart: Spaceflight (ISSN 0038-6340); 27; 221-224
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  • 59
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    The pole orientation of asteroid 433 Eros determined by photometric astrometry (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 61; 490-496
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  • 60
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    The enigma of the Uranian satellites' orbital eccentricities (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The eccentricity decay times for the Uranian satellites are calculated using recent observations (Brown et al., 1982) of the diameters and orbital elements of the satellites and assuming reasonable dissipation functions and rigidities for icy satellites. For the outer two satellites, Titania and Oberon, the decay times are found to be very long, whereas the inner three satellites, Miranda, Ariel, and Umbriel, have decay times on the order of 10 to the 7th to 10 to the 8th years and have a near-commensurability in their mean motions that cannot force their eccentricities. There are several possible solutions for the lack of resonant forcing: (1) the reported eccentricities are incorrect, and are very nearly zero, (2) the reported mean motions are incorrect, and an exact commensurability exists, (3) the physical properties assumed for the satellites are grossly in error, and (4) the system is evolving rapidly, perhaps from a previous state of higher eccentricity. A new lower bound of about 17,000 on the dissipation function of Uranus is calculated from the mass of Ariel and its proximity to Uranus.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 61; 218-223
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    Strong source VLBI observations at 22 GHz (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Twenty-six strong high-frequency radio sources have been observed at 22.3 GHz on interferometer baselines of approximately 500 million wavelengths. Twenty-five were detected, and 14 have mean visibilities over 50 percent. The strongest sources as a group are more heavily resolved than the weaker sources.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 296; 458-460
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    The X-ray spectroscopy of active galactic nuclei (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: The scientific goals of X-ray spectroscopy of active galactic nuclei are discussed. The underlying energy source, the regions responsible for the optical emission lines, the different types of active galaxies, and cosmology are considered. The requirements for an X-ray mission of broad band width, large collecting area, modest spatial resolution and good spectral resolution are outlined. It is concluded that the ESA XMM mission meets these requirements.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Proceedings of ESA Workshop on a Cosmic X-Ray Spectroscopy Mission; p 19-23
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    Observation of a possible optical burst of the double star Beta Camelopardalis (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: An intensified SEC Vidicon observation of a brightening of the image of Beta Cam for a duration of about 0.25 sec at 0932 UT on December 4, 1969 is described. The observation was made during airborne observations of meteors over Canada between latitudes of 50 and 60 deg N.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 295; 171-174
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    IRAS observations of Seyfert galaxies (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Infrared Astronomy Satellite measurements at 25, 60 and 100 microns were used to analyze the infrared properties of Seyfert galaxies from the Markarian and NGC Catalogs. One hundred and sixteen of 186 Seyfert galaxies were detected. About 50 percent of all Seyfert galaxies in the sample have 60 micron luminosities in excess of 10 to the 10th power solar luminosity, and the mean 60 micron luminosity increase with the optical B absolute magnitude. The luminosity functions of the Seyfert 1 and Seyfert 2 galaxies appear quite similar. It is possible, however, to statistically separate the two types of galaxies in color-color plots. The 100- to 60-micron energy distributions flatten systematically with increasing 60-micron luminosity. The infrared measurements provide a measure of the bolometric luminosity of the Seyfert galaxies, but do not discriminate between the physical processes involved.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 293; L11-L14
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    Optical and radio observations for the BL Lacertae objects 1219 + 28, 0851 + 202, and 1400 + 162 (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Radio- and visible-wavelength observations for the BL Lac object 1219 + 28 (ON 231, W Com) are reported along with optical observations of 0851 + 202 (OJ 287), and radio data for 1400 + 162 (4C 16.39, OQ 100). The obtained data consist of imaging and surface photometry for both 1219 + 28 and 0851 + 202, as well as spectra for 1219 + 28, and Very Long Baseline Interferometry (VLBI) observations for 1219 + 28 and 1400 + 162. Two emission features have been observed in the spectrum of 1219 + 28. Radio observations of 1219 + 28 in three frequencies reveal the presence of a radio jet with at least three components. The obtained results for 1219 + 28 support previous conclusions that at least some BL Lac objects are located at the center of elliptical galaxies.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 292; 614-619
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  • 66
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    Spectroscopic orbits for 16 more binaries in the Hyades field (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: A photoelectric survey of the radial velocities of Hyades candidates has provided data for 16 spectroscopic binary orbits, in addition to the 11 known binaries in the Hyades field. The majority of photoelectric observations in the survey were carried out at the Cambridge and Palomar Observatories using different data reduction techniques for determining radial velocities. It is found that two of the objects, vB 164 and J336, are definitely not members of the Hyades cluster; two other objects, HD 16909 and J301, appear to be located far from the center of the cluster, but still deserve classification as Hyades members. The gamma-velocity of HD 16909 differed slightly from the value expected for a member of the Hyades cluster. An additional twelve systems were definitely identified as members of the Hyades. The radial velocity values for all the candidate stars are given in a series of tables.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 609-642
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  • 67
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    Arcsecond positions for milliarcsecond VLBI nuclei of extragalactic radio sources. III - 74 sources (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: VLBI measurements at 2290 and 8420 MHz on baselines of 10,000 km have been used to determine the positions of the milliarcsecond nuclei in 74 extragalactic radio sources. Estimated accuracies range from 0.1 to 4.3 arcsec in both right ascension and declination with typical accuracies of about 0.3 arcsec. The observed sources are part of an all-sky VLBI catalog of milliarcsecond radio sources. Arcsecond positions have been determined for 819 sources. These positions are presently being used to identify optical counterparts in the southern hemisphere.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 90; 590-594
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    Detecting supernova remnants in external galaxies (1985)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Identification of supernova remnants (SNR) in external galaxies through the combined use of radio, optical and X-ray surveys is discussed. Some 24 likely distant galaxy SNR have been found in the past six years, though confirmation is often difficult. Radio surveys of other galaxies are restricted by background object contamination in the field, and confirmation of these candidates requires other techniques. Optical measurement of the ratio of the forbidden SII doublet at .6717 and .6731 microns to H-alpha, followed by spectroscopic or radio confirmation, has successfully identified SNR in the LMC and other galaxies, though few in number. Most of the SNR in the Magellanic Clouds have been detected as X-ray emitters, but towards M31 there are no coincidences between the lists of optical SNR and X-ray sources. An increase in SNR identifications should result from use of the Space Telescope and continued use of the VLA.
    Schlagwort(e): ASTRONOMY
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    IUE observations of the 1982-84 eclipse of Epsilon Aurigae (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: The major characteristics in the ultraviolet of the 1982-84 eclipse of Eps Aur as observed with IUE by various workers are summarized. This star can be observed over the entire IUE wavelength range, from 1200 to 3200 A, in low dispersion, allowing eclipse light curves to be obtained in broadband regions, but due to its steep spectral gradient and the sensitivities of IUE cameras, high resolution exposures adequately cover only the regions from 1700-1900 and 2400-3200 A. In many ways, the UV data confirms or expands upon interpretations of the stem made from observations in other wavelength regions, but in other respects the system remains as enigmatic as before.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 37-42
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    Epsilon Aurigae in an evolutionary context (1985)
    In:  CASI
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    Publikationsdatum: 2016-06-07
    Beschreibung: Basic observational data of Epsilon Aurigae are summarized and used as the basis of a discussion of possible evolutionary states of the system. Constraints posed by the presence of a cold disk surrounding the secondary star are also outlined. Possible evolutionary models of the F0 Ia supergiant range from pre-main sequence contraction through shell hydrogen burning, core helium burning, to shell helium burning, depending on the absolute luminosity of the system, for models in which no mass transfer has taken place. Models invoking binary interaction include core and shell helium burning stars, and pre-white dwarfs, again depending on the absolute luminosity of the system. A massive shell helium burning star or a pre-white dwarf mass transfer remnant would appear the most likely of these models at present. Observational tests of these models are briefly outlined.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 49-60
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    The optical polarization of Epsilon Aurigae through the 1982-84 eclipse (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: About 350 nights observations on the 61-cm telescope at Pine Mt. Observatory were made of the variable polarization of Eps. Aurigae during 1982-85, in the U, B, and V color bands. The V data are the most complete and are shown. In terms of the overall features the curves in all three colors are quite similar. The typical errors per nightly point in the V curves are about 0.015% for either of the two normalized, equatorial Stokes parameters Q and U. Note that there is a large background or constant component of some 2.5%, position angle around 135 deg. This is presumably largely interstellar, and the intrinsic polarization probably does not much exceed the amplitude of the variable component, approx. 0.5%. A few field-star polarizations were measured but a very clear pattern was not obtained in this part of the sky.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 33-36
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    Infrared photometry of the 1982-4 eclipse of Epsilon Aurigae (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: The infrared photometry of epsilon Aur performed prior to and during the ingress phase of the recent eclipse allowed the first solid determination of the temperature of the secondary object. The eclipse depth was significantly less at lambda 5 micrometers than in the near-infrared. This is explained by a model of the secondary as an opaque and very cool object with a temperature of approx. 500 K. During eclipse, the secondary blocks approximately 45% of the near infrared radiation from the primary star. At the same time, the radiation from the secondary remains completely unobscured, resulting in a shallower light curve at longer wavelengths. This phenomenon is well known in the study of eclipsing binary stars; if the two stars have different colors, then the net color of the system changes during eclipse. In the case of epsilon Aur, the eclipsing object has a color deep in the infrared, so the effect is only noticeable there.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 23-32
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    Optical photometry of the 1982-1984 eclipse of Epsilon Aurigae (1985)
    In:  CASI
    Details
    Publikationsdatum: 2016-06-07
    Beschreibung: From slightly before the 1982-1984 eclipse of Epsilon Aurigae to the present observers from around the world have been making photoelectric photometry observations of this star system. Over 2000 UBV observations have been reported as well as observations in the R, I, J, H, K, L, M, N, and Q bandpasses plus the y, b, v, and u bandpasses. Twenty nine observers from 9 countries submitted photometry data to the campaign. The data have shown many interesting features of the star system including a Cepheid-like pulsation, flare activity, mid-eclipse brightening, post egress brightening, plus other strange activity.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington The 1982-1984 Eclipse of Epsilon Aurigae; p 7-22
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    Telescope in lunar orbit (1985)
    In:  CASI
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    Publikationsdatum: 2016-06-07
    Beschreibung: The use of a large telescope in high lunar orbit 4000 km above the Moon's equator is proposed. It is recognized that the Hubble Space Telescope (ST), will provide the necessary capabilities if it can be transferred to lunar orbit. The Orbital Transfer Vehicle (OTV), will be able to scan the lunar surface, locate small outcrops of minerals important to base development, support early base operations and undertake detailed geophysical exploration of the whole lunar surface.
    Schlagwort(e): ASTRONOMY
    Materialart: Lunar and Planetary Inst. 16th Lunar and Planetary Sci. Conf.; p 68-70
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    LDR system concepts and technology (1985)
    In:  CASI
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    Publikationsdatum: 2017-10-02
    Beschreibung: The Large Deployable Reflector is a 20 meter diameter infrared/submillimeter telescope planned for the late 1990's. The Astronomy Survey Committee of the National Academy of Sciences (Field Committee) recommended LDR as one of the two space based observatories that should start development in the 80's. LDR's large aperture will give it unequaled resolution in the wavelength range from 30 to 1000 microns. To meet LDR performance goals will call for advances in several technology disciplines including: optics, controls, thermal control, detectors, cryogenic cooling, and large space structures.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Langley Research Center Large Space Antenna Systems Technol., 1984; p 127-138
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    Construction of a multilayered X-ray telescope for solar coronal studies from space (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: The construction and testing of soft x-ray Ritchey-Chretien aplanatic telescope which is to be flown on a NASA sounding rocket in 1986 for very high resolution studies of the solar corona are discussed. Goals include figuring, polishing and measuring the mirror surfaces to tolerances exceding the 5000 A wavelength diffraction limit while achieving a superpolished surface finish, and the development of a structural design to withstand the rigors of the launch. Multilayer coatings are used to achieve usable reflectivity in the soft X-ray regime, and the design goal is for spatial resolution of 1/4 sec. Future applications are discussed.
    Schlagwort(e): ASTRONOMY
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    Ground-based observations of near ecliptic zodiacal light brightness (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: Ground-based observation of the evening zodiacal light taken by Weinberg and Mann (1967) from Mt. Halaekala, Hawaii, during March 1966 are used to derive a table of zodiacal light brightnesses at high spatial resolution (as little as 0.5 deg in differential ecliptic longitude, DEL and 1.0 deg in ecliptic latitude beta) over the DEL region 29.5-56 deg, beta = -30 to +30 deg. Significant differences are found in the brightness distributions above and below the ecliptic plane.
    Schlagwort(e): ASTRONOMY
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    Far-infrared heterodyne spectroscopy (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: A new far-infrared heterodyne spectrometer has been built for ground-based observations at the Cassegrain focus. The receiver, which features a Schottky-diode mixer and a laser local oscillator, was used in January 1984, to detect the 809 GHz fine-structure line of neutral carbon in OMCl. A second-generation version of the spectrometer is now being constructed for airborne observations between 600 and 1500 GHz.
    Schlagwort(e): ASTRONOMY
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    A new objective for the Allegheny Observatory 30-inch refractor (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: As a follow-up to the development of astrometric detectors of sufficient accuracy to detect extrasolar planetary systems, the Allegheny Observatory is modernizing their 30-inch Thaw Refractor. Changes include a new objective lens and the transition of the observational bandpass from blue light to red. The new system will have sufficient accuracy to detect Jovian planets orbiting any of several dozen of the sun's nearest stellar neighbors.
    Schlagwort(e): ASTRONOMY
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    Planetary searches using optical astrometric interferometers (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: The detectability of planets is discussed, and observations made with an astrometric interferometer (AI) at Mount Wilson are presented. Planets are detectable as a result of their periodic perturbation of the position of a central observable star. This detection requires relative astrometric accuracies of about 3 x 10 to the -4th for Jovian planets and about 3 x 10 to the -7th arcsec for terrestrial planets. The principles governing astrometric interferometry are explained, and it is conjectured that a two-color optical AI on earth should be capable of about 0.0001 arcsec rms accuracy for stars brighter than magnitude 7-10; small one-color space systems should achieve at least 0.00001 arcsec. Owing to atmospheric turbulence, two-color systems permit correction every few milliseconds for the random wavefront tilt. A 3.4-meter baseline interferometer on Mount Wilson has demonstrated arcsec rms fluctuations of about 0.02 for 1-sec samples. Space-based optical astrometric interferometry is also discussed.
    Schlagwort(e): ASTRONOMY
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    Simultaneous dual-wavelength VLBI observations of the compact radio source near the Galactic center (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: Preliminary results from simultaneous VLBI observations at 3.6 and 13 cm confirm that, in this wavelength range, the size of the compact radio source near the Galactic center varies as lambda-squared, where lambda is the wavelength of observation. These results also establish a flux density upper limit at 3.6 cm of 5 mJy for any source in Sgr A West smaller than 8 mas (80 AU).
    Schlagwort(e): ASTRONOMY
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    Fine pointing of the Solar Optical Telescope in the Space Shuttle environment (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: Instruments requiring fine (i.e., sub-arcsecond) pointing, such as the Solar Optical Telescope (SOT), must be equipped with two-stage pointing devices, coarse and fine. Coarse pointing will be performed by a gimbal system, such as the Instrument Pointing System, while the image motion compensation (IMC) will provide fine pointing. This paper describes work performed on the SOT concept design that illustrates IMC as applied to SOT. The SOT control system was modeled in the frequency domain to evaluate performance, stability, and bandwidth requirements. The two requirements of the pointing control, i.e., the 2 arcsecond reproducibility and 0.03 arcsecond rms pointing jitter, can be satisfied by use of IMC at about 20 Hz bandwidth. The need for this high bandwidth is related to Shuttle-induced disturbances that arise primarily from man push-offs and vernier thruster firings. A block diagram of SOT model/stability analysis, schematic illustrations of the SOT pointing system, and a structural model summary are included.
    Schlagwort(e): ASTRONOMY
    Materialart: AIAA PAPER 85-6086
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    The LAMAR telescope module for high throughput imaging and spectroscopy (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: Kirkpatrick-Baez mirror assemblies for the LAMAR experiment of the Space Shuttle are described. The aperture is 20 cm x 30 cm and the distance from the front of the mirror to the focal plane is 3.4 m. The reflectors are made from 1.8 mm gold coated float glass. A prototype brassboard mirror was constructed with only one-third of the plates. Its angular resolution is 35 arcsec (HPW) in visible light. X-ray tests over small areas indicate very little scattering. The fabrication technique is applicable to larger mirror systems such as those of XMM. The use of flatter material for the reflectors results in better angular resolution.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Proceedings of ESA Workshop on a Cosmic X-Ray Spectroscopy Mission; p 177-182
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  • 84
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    The X-ray spectra and the rotation-activity connection of RS CVN binaries (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Results from a survey of RS CVn binaries which were observed with the Imaging Proportional Counter (IPC) on board the Einstein Observatory are presented. Spectral analyses of the IPC pulse height spectra show that the coronae of RS CVn binaries always contain hot gas with temperatures 10 million K, similar to active late-type main sequence stars, and that at least 2 temperature components are necessary to account for the higher quality IPC spectra (when absorption is unimportant). It is argued that these bimodal temperature distributions indicate true distributions of emission measure vs temperature that are continuous (just as is the case for magnetically-confined coronal plasma loops observed on the Sun). It is shown that none of the derivable X-ray characteristics of RS CVn binaries depend on rotation period, implying that claims of period-activity relationships in RS CVn binaries are unfounded.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Proceedings of ESA Workshop on a Cosmic X-Ray Spectroscopy Mission; p 141-147
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  • 85
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    Soft X-ray maps of the Large Magellanic Cloud (LMC) (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Soft X-ray maps of the Large Magellanic Cloud (LMC) were obtained from scanning-observations with the HEAO-1 low energy detectors. Comparison of the 1/4 keV X-ray observations with the neutral hydrogen column densities in the LMC obtained from a 21 cm line survey, shows no evidence for absorption effects in the 1/4 keV X-ray flux from the LMC due to the neutral matter in the LMC. Instead, faint X-ray emission is detected from the LMC. The extent of this emission is smaller than the size of the halo or the disk of the LMC. Assuming this 1/4 keV emission to be diffuse, it is identified with a supergiant shell of optical nebulosity known as Shapley III, and the bar of the LMC. The X-ray luminosities of the regions are estimated to be 9 times 10 to the 38th power ergs/sec and 1.8 times 10 to the 39th power ergs/sec for the Shapley III region and the bar of the LMC respectively. Shapley III could be an X-ray superbubble.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Proceedings of ESA Workshop on a Cosmic X-Ray Spectroscopy Mission; p 131-136
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  • 86
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    The X-ray properties of normal galaxies. What do we know and what can we learn with the next generation of X-ray telescopes? (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Einstein Observatory results are used to assess the possibilities of spaceborne X-ray astronomy projects such as XMM (ESA) and AXAF (NASA). Einstein observations show that normal galaxies of all morphological types are spatially extended sources of X-ray emission with 0.5 to 3.0 keV X-ray luminosities of 10 to the 39th to 41st power erg/sec. X-ray telescopes can study the end products of stellar evolution in galaxies of different morphological types. Phenomena linked to starburst nuclear activity can best be detected and studied in X-ray. Hot coronae or a hot phase of the interstellar medium can only be studied through their X-ray emission. It is shown that high spatial resolution is essential for studying normal galaxies and identifying different emission regions. Good spectral sensitivity and spectral imaging capability are essential for gaining a deeper understanding of the phenomena at work.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Proceedings of ESA Workshop on a Cosmic X-Ray Spectroscopy Mission; p 33-41
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  • 87
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    Surface analysis of space telescope material specimens (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Qualitative and quantitative data on Space Telescope materials which were exposed to low Earth orbital atomic oxygen in a controlled experiment during the 41-G (STS-17) mission were obtained utilizing the experimental techniques of Rutherford backscattering (RBS), particle induced X-ray emission (PIXE), and ellipsometry (ELL). The techniques employed were chosen with a view towards appropriateness for the sample in question, after consultation with NASA scientific personnel who provided the material specimens. A group of eight samples and their controls selected by NASA scientists were measured before and after flight. Information reported herein include specimen surface characterization by ellipsometry techniques, a determination of the thickness of the evaporated metal specimens by RBS, and a determination of trace impurity species present on and within the surface by PIXE.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-178712 , NAS 1.26:178712
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  • 88
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    Optical and UV spectroscopy of the peculiar RS CVn system, RT Lacertae (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Spectra in the H-alpha and H-beta regions of the peculiar double-lined RS CVn binary, RT Lacertae, were obtained in the fall of 1984. Limited International Ultraviolet Explorer (IUE) long wavelength low and high resolution spectra were obtained concurrently. The ground based spectra have shown an asymmetry with orbital phase in the H-alpha profile. The H-beta profiles were consistent with the same effect. One hemisphere showed excess emission and the other excess absorption, with a broad Gaussian emission component superposed upon the excess H-alpha line. An improved radial velocity curve, giving a better determined mass ratio and geometry was derived. This combined with the radii implied by the rotational broadening of the spectra, showed one component to be 80 to 90% filling the equilibrium Roche surface. The two-faced nature is, therfore, very likely due to mass transfer from the contact component impacting upon its companion. Low resolution ultraviolet data showed that the supposed cooler component is bluer than its companion. High resolution ultraviolet data taken during secondary eclipse showed Mg II emission strength which decreased more slowly than the area visible. The phase behavior of the low resolution data support the former situation, indicating traditional chromospheric activity.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-176525 , NAS 1.26:176525
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  • 89
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    New identifications of bright X-ray sources with the HEAO-1 Scanning Modulation Collimator (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Based on data obtained with the HEAO-1 Scanning Modulation Collimator (MC) experiment, candidate Be star systems and BL Lac objects are reported. Identification of the V = 6.6 star HD91188 as a Be star is confirmed, and X-ray luminosities ranging from 9 x 10 to the 32nd to 1.4 x 10 to the 34th ergs/s are derived. A B2 spectral type with a reddening E(B - V) = 0.42 is deduced for a V = 9.87 star which appears in an MC location diamond for the source 1H0550 + 286. A V = 16.5 ultraviolet excess object in the location 2A1058 - 226 = 3A1057 - 224 = 4U1057 - 21 = H1100 - 230 gave a 20 cm flux of 83 mJy, and a V = 16.2 ultraviolet excess object at 3A1422 + 425 = 1H143 + 423 was found to have a 20 cm flux of 33 mJy, suggesting their classification as BL Lac objects.
    Schlagwort(e): ASTRONOMY
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  • 90
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    The time resolution domain of stellar radio astronomy (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: The high time resolution (HTR) radio observation of late-type stars and RS CVn systems is discussed. Some examples of these sources are addressed, identifying what information HTR observations can provide. HTR can provide important information on flares in late-type stars, and can be used to study coronal structure and the particle acceleration mechanism in these stars. The possible use of HTR to establish the nature of quiescent emission form RS CVn systems is discussed.
    Schlagwort(e): ASTRONOMY
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  • 91
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    Multifrequency observations of dwarf novae outbursts (1985)
    In:  Other Sources
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Studies using EXOSAT and IUE data combined with ground-based optical and IR photometry, spectroscopy and polarimetry of the transition timescales and physical properties of the high accretion rate states of the disks in cataclysmic variables are discussed. Implications for dwarf novae stem from comparison of the timing and amplitude of the optical and IR rise with that of the UV and X-ray; the development of the optical and UV line profile changes as the outburst develops; and the similarity of the outburst flux distributions in different systems and different types of outbursts (standstills and supermaxima). These features of dwarf novae outbursts present interesting comparisons with the outbursts of systems like TV Col and GK Per.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA Recent Results on Cataclysmic Variables; p 39-45
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  • 92
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    The X-ray properties of high redshift, optically selected QSOs (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: In order to study the X-ray properties of high redshift QSOs, grism/grens plates covering 17 deg. of sky previously imaged to very sensitive X-ray flux levels with the Einstein Observatory were taken. Following optical selection of the QSO, the archived X-ray image is examined to extract an X-ray flux detection or a sensitive upper limit.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-176339 , NAS 1.26:176339
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  • 93
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    Detection of [SiLL] (34.8 micron) emission in Orion-KL: A measurement of the silicon abundance in dense interstellar gas (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: The first detection of the ground state fine structure transition of Si+ at a rest wavelength determined to be 34.815 + or - 0.004 micron are reported. These observations were obtained with the facility spectrometer on NASA's Kuiper Airborne Observatory. A 6' NW-SE strip scan across the Orion-KL region shows SiII emission from both the extended photodissociation region surrounding theta 1 Ori C and from the shocked gas NW of BN-KL. The inferred gas-phase silicon elemental abundance relative to hydrogen in the dense 10 to the 5/cc primarily neutral photodissociation region is approximately 2.6 x to the -6, a factor of 0.075 times the solar value and 3.4 times greater than the abundance in the moderate density approx. 10 to the 3/cc cloud toward zeta Oph. The silicon abundance in the shocked gas is approximately solar, indicating that any pre-existing grains have been destroyed in the shock wave or that the preshock gas carries a near solar abundance of gas phase silicon. The shock-excited SiII (34.8 micron) emission may arise from shocked wind material in the outflow around IRc2, with wind velocities approx. 100 km/s.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-TM-86850 , REPT-85433 , NAS 1.15:86850 , PREPRINT-SERIES-43
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  • 94
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    Far infrared and submillimeter brightness temperatures of the giant planets (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: The brightness temperatures of Jupiter, Saturn, Uranus, and Neptune in the range 35 to 1000 micron. The effective temperatures derived from the measurements, supplemented by shorter wavelength Voyager data for Jupiter and Saturn, are 126.8 + or - 4.5 K, 93.4 + or - 3.3 K, 58.3 + or - 2.0 K, and 60.3 + or - 2.0 K, respectively. The implications of the measurements for bolometric output and for atmospheric structure and composition are discussed. The temperature spectrum of Jupiter shows a strong peak at approx. 350 microns followed by a deep valley at approx. 450 to 500 microns. Spectra derived from model atmospheres qualitatively reproduced these features but do not fit the data closely.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-TM-88179 , REPT-86003 , NAS 1.15:88179 , PREPRINT-SERIES-33
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  • 95
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    A mosaic infrared sensor for space astronomy, phase 3 (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: Short wavelength (1 to 3 micron) HgCdTe mosaic detector arrays for space astronomy purposes were fabricated and studied. Honeywell will test and analyze these arrays at moderate temperatures (300-130K). Low temperature testing will be performed at the University of Hawaii. Short wavelength mosaic arrays were fabricated on three wafers and one array from each wafer was tested and analyzed. The p-type base carrier concentration on these wafers was an order of magnitude lower than typically used so far on this program (10 to the 14/cc as compared to 10 to the 15/cc). Tunneling currents are expected to decrease with this decrease in carrier concentration, resulting in improved performance at very low temperatures. The risk with such a low carrier concentration is that fixed charge in the surface passivating layer must be carefully controlled to prevent surface inversion layers.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-176370 , NAS 1.26:176370 , QR-3
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  • 96
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    An unbiased X-ray sampling of stars within 25 parsecs of the Sun (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: A search of all of the Einstein Observatory IPC and HRI fields for untargeted stars in the Woolley, et al., Catalogue of the nearby stars is reported. Optical data and IPC coordinates, flux density F sub x, and luminosity L sub x, or upper limits, are tabulated for 126 single or blended systems, and HRI results for a few of them. IPC luminosity functions are derived for the systems, for 193 individual stars in the systems (with L sub x shared equally among blended components), and for 63 individual M dwarfs. These stars have relatively large X-ray flux densities that are free of interstellar extinction, because they are nearby, but they are otherwise unbiased with respect to the X-ray properties that are found in a defined small space around the Sun.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-178544 , NAS 1.26:178544
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  • 97
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    Detection of Ni 2 lambda 7378 in six Seyfert galaxies (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: A line due to Ni 2 7378 in the Seyfert galaxies NGC 1068, 2110, 3227, 4151, 5506, and Arp 102 B was detected. The average Ni abundance is about 2 times solar, which is 5 times less than in the filaments of the Crab Nebula. This argues for nucleosynthetic processing in the latter. The Ni 2 line is spatially revolved in NGC 1068, and shows at least a factor of 4 enhancement in the Ni abundance away from the nucleus. The off-nuclear abundance of Ni in NGC 1068 approaches that of the Crab, which strongly suggests that type supernovae enriched the off-nuclear gas clouds.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-176358 , NAS 1.26:176358
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  • 98
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    Focal plane optics in far-infrared and submillimeter astronomy (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: The construction of airborne observatories, high mountain-top observatories, and space observatories designed especially for infrared and submillimeter astronomy has opened fields of research requiring new optical techniques. A typical far-IR photometric study involves measurement of a continuum spectrum in several passbands between approx 30 microns and 1000 microns and diffraction-limited mapping of the source. At these wavelengths, diffraction effects strongly influence the design of the field optics systems which couple the incoming flux to the radiation sensors (cold bolometers). The Airy diffraction disk for a typical telescope at submillimeter wavelengths approx 100 microns-1000 microns is many millimeters in diameter; the size of the field stop must be comparable. The dilute radiation at the stop is fed through a Winston nonimaging concentrator to a small cavity containing the bolometer. The purpose of this paper is to review the principles and techniques of infrared field optics systems, including spectral filters, concentrators, cavities, and bolometers (as optical elements), with emphasis on photometric systems for wavelengths longer than 60 microns.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-TM-88186 , REPT-86010 , NAS 1.15:88186
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  • 99
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    The field horizontal-branch star HD 109995: New results with coadded ultraviolet and optical region spectra (1985)
    In:  CASI
    Details
    Publikationsdatum: 2019-06-28
    Beschreibung: A comprehensive ultraviolet and optical region abundance analysis of the field horizontal branch Population 2 A-type star HD 109995 is described. Coaddition of IUE high dispersion images and DAO 6.5 A/mm IIaO spectrograms improved the signal-to-noise ratio of the data. We have identified ultraviolet lines whose analysis will provide more complete and accurate elemental abundances than those obtained from optical region spectra alone. A preliminary elemental abundance analysis of the optical region shows that log Z/Z (solar) approx. = -2. A first attempt to synthesize two Fe 2 ultraviolet resonance lines yields an iron abundance a few tenths of a deg higher than the average obtained from optical region Fe 2 lines.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA-CR-176327 , NAS 1.26:176327
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  • 100
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    Using the ET for gamma-ray astronomy (1985)
    In:  Other Sources
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    Publikationsdatum: 2019-06-28
    Beschreibung: A gamma-ray-telescope design is presented which makes use of the normally spent external tank (ET) of the Space Shuttle as the spacecraft and Cerenkov pressure vessel. The ET would be configured into the telescope once onorbit, using the Space Station as the base of operations for carrying out the assembly activities. The telescope provides a continuation to the NASA program in high-energy astrophysics, providing for follow-on observations to the survey work of the EGRET instrument on GRO. The most important features of the gamma-ray imaging telescope system are its collecting area of 250,000 sq cm per ET (40 times that of the EGRET instrument) and its ability to locate point sources to within several arc minutes.
    Schlagwort(e): ASTRONOMY
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