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  • 1
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    The High Resolution Spectrograph for the Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2009-11-16
    Beschreibung: The High Resoltuion Spectrograph (HRS) in conjunction with the Space Telescope (ST), extends ultraviolet astronomical spectroscopy to higher spectra, spatial, and time resolutions than previously achieved, as well as to fainter and more distant celestial objects. Other significant advances inherent in the instrument are high photometric accuracy and efficient operation via exposure meter control and real time rejection of bad data. These capabilities are provided to accomplish the scientific programs of the HRS investigation definition team, which concern the interstellar medium, stellar winds, and evolutionary aspects of stellar atmosphere studies; the determination of chemical abundances relevant to stellar evolution; the investigation of quasars and Seyfert galaxy nuclei; and the analysis of the atmospheres of solar system objects, including comets.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 76-105
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  • 2
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    Reflections on the Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The significance of the Space Telescope for the advancement of astronomy and astrophysics is described. The current state of knowledge in astronomy and cosmology is summarized and unanswered questions in those fields discussed. The rapid evolution of modern astronomy and the need for systematic observations are stressed.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 121-134
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  • 3
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    Astrometric observations with the Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: Astrometry with the Space Telescope (ST) is performed using one of the fine guidance sensors (FGS). The FGS, which is based on a pair of Koester's prism interferometers, one for each axis, is capable of measuring the position of one object relative to another with an accuracy of 0.002 arcseconds. Astrometric Data Reduction Software (ADRS) available to the astrometric user of ST is described. The kinds of problems the space telescope astrometry team plans to investigate using ST are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 114-120
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  • 4
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    The wide field/planetary camera (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: A wide site of potential astronomical and solar system scientific studies using the wide field planetary camera on space telescope are described. The expected performance of the camera as it approaches final assembly and testing is also detailed.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 28-39
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  • 5
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    European astronomy and the Space Telescope: The Space Telescope European Coordinating Facility (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The role of the European Coordinating Facility is described. European participation in the Space Telescope Science Institute and the relation of Space Telescope to ground-based astronomy in Europe are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 16-19
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  • 6
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    The High Speed Photometer for the Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: An overview of the high speed photometer (HSP), its optics and detectors, its electronics, its mechanical structure, and some observational considerations are presented. The capabilities and limitations of the HSP are outlined.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 106-113
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  • 7
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    The Faint Object Camera (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The Faint Object Camera fully exploits the spatial resolution capability of the Space Telescope on the very faintest detectable objects over a broad wavelength range. A full complement of filters, objective prisms and polarizers, a choice of coronograhic masks, and a variety of scan formats extend the scientific versatility of the direct imaging mode. In addition, the Faint Object Camera provides the unique facility of long-slit spectroscopy to Space Telescope observers.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 40-54
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  • 8
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    Ray tracing studies of Jupiter's magnetosphere (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: Raypaths for decametric wavelength radiation in Jupiter's magnetosphere were calculated. The model-dependent raypaths with the Voyager observations were compared. Characteristics of the source regions and the influence of propagation effects were deduced. A three dimensional ray tracing program was employed to calculate the raypaths. Families of rays were launched at particular angles with respect to the magnetic field lines to generate conical sheets of radiation for various frequencies and various source locations. As the planet's magnetic field rotates, these warped sheets of radiation sweep past the observer, producing signatures in frequency versus time plots. These signatures match some of those found in the Voyager data. The greatest propagation effects occur in and around the source regions in the Io auroral oval.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Alabama Univ. in Huntsville The 1981 NASA(ASEE Summer Fac. Fellowship Program; 16 p
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  • 9
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    Astronomical capabilities of the Faint Object Spectrograph on Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: Examples of scientific observing programs planned with the Faint Object Spectrograph on Space Telescope are presented. An overview of the spectrograph design and operation is presented. The expected astronomical performance of the instrument is described in some detail.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 55-75
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  • 10
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    The Space Telescope Observatory (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The history of the observatory is briefly described, as is the overall system design. The principal design features that are important to the scientific user are described. The present status of preparation for launch in the spring of 1985 is summarized.
    Schlagwort(e): ASTRONOMY
    Materialart: Space Telescope Science Inst. The Space Telescope Obs.; p 20-27
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  • 11
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    Science operations with Space Telescope (1982)
    In:  CASI
    Details
    Publikationsdatum: 2006-02-14
    Beschreibung: The operation, instrumentation, and expected contributions of the Space Telescope are discussed. Space Telescope capabilities are described. The organization and nature of the Space Telescope Science Institute are outlined, including the allocation of observing time and the data rights and data access policies of the institute.
    Schlagwort(e): ASTRONOMY
    Materialart: The Space Telescope Obs.; p 1-15
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  • 12
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    Interaction of large meteoroids with the atmosphere (1982)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-19
    Beschreibung: Disturbances of the atmosphere at heights of 120 to 40 km by penetration of meteroids of meter and decameter dimensions were examined. Unbiased data on atmospheric penetration of large meteroids was acquired, and their supply of gas and dust components to the middle atmosphere and their connection with the noctilucent clouds were determined.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: International Council of Scientific Unions Middle Atmosphere Program. Handbook for MAP, Vol. 4; p 153-154
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  • 13
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    Anomalies within the system - Rochechouart target rock meteorite (1982)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Contaminated impact crater formations are pertinent to the study of meteoritic contamination at the Cretaceous-Tertiary boundary and other Ir-enriched layers. Target mixing considerations and volumetric estimates of Rochechouart breccias are presently combined with the geochemistry of both major and siderophile trace elements, to evaluate how the chemistry of the preserved target rock-projectile mixture evolved since deposition. Over 99 percent of the mass of extraterrestrial Ir and Os in preserved formations at Rochechouart is located in suevite-like breccias and impact melts. Hydrothermal alteration and/or weathering are the most likely processes to explain both major and trace element redistribution in Rochechouart formations.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 14
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    Solar system history as recorded in the Saturnian ring structure (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Holberg's analysis of the Voyager Saturn photographs in reflected and transparent light, and occultation data of stars seen through the rings are discussed. A hyperfine structure with 10,000 ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interpret them as fossils which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas and Janus and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase. The shadows are not simple void regions but exhibit a characteristic signature. Parts of the fine structure, explained by Holberg as resonances with satellites, are interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. Analysis of ring data can reconstruct the plasma-planetesimal transition with an accuracy of a few percent. Previously announced in STAR as N84-12013
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Astrophysics and Space Science (ISSN 0004-640X); 97; 1, No; 79-94
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  • 15
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    Stability of streams and lakes on Mars (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The freezing of small Martian streams is modelled for a variety of climatic conditions, on the supposition that the Martian atmosphere may have been considerably thicker in the past, at the time of the formation of the valley networks. This model examines the energy balance at the upper and lower surfaces of ice on streams, in order to determine the rate at which ice thickens with time. Results indicate that freezing rates are not strongly dependent on atmospheric pressure, and, under windy conditions, dependence on atmospheric pressure is even weaker. It is noted that the main problem in valley formation is in initiating the flow. Groundwater seepage alone is inadequate, due to the difficulty of groundwater system replenishment.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 56; 476-495
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  • 16
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    Detection of silicate emission features in the 8- to 13-micron spectra of main belt asteroids (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: A presentation is given of 8.0-13.0 micron spectra (Delta lambda/lambda = 0.02-0.03) for six main belt asteroids, which range from 58 to 220 km in diameter and sample the five principal taxonomic classes (C, S, M, R and E). Narrow, well-defined silicate emission features are present on two of the asteroids, the C-type 19 Fortuna and the M-type 21 Lutetia. No comparable emission features are observed on the S-types 11 Parthenope and 14 Irene, the R-type 349 Dembowska or the E-type 64 Angelina.
    Schlagwort(e): ASTRONOMY
    Materialart: Icarus (ISSN 0019-1035); 56; 393-397
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  • 17
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    Large amplitude MHD waves upstream of the Jovian bow shock (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Observations of large amplitude MHD waves upstream of Jupiter's bow shock are analyzed. The waves are found to be right circularly polarized in the solar wind frame, which suggests that they are propagating in the fast magnetosonic mode. A complete spectral and minimum variance eigenvalue analysis of the data was performed. The power spectrum of the magnetic fluctuations contains several peaks. The fluctuations at 2.3 MHz have a direction of minimum variance anti-parallel to the direction of the average magnetic field. Several harmonics at 6, 9, and 12 MHz are also present. The direction of minimum variance of these fluctuations lies at approximately 40 deg to the magnetic field. It is argued that these fluctuations are waves excited by protons reflected off the Jovian bow shock. The inferred speed of the reflected protons is about two times the solar wind speed in the solar wind frame. A linear instability analysis is presented that suggests an explanation for many of the observed features of the observations. The fluctuations apparently contain a significant fraction of magnetic energy that is linearly polarized and in the Alfven mode.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 9989-999
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  • 18
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    The evolution of the infrared emission from the Type II supernova 1980k in NGC 6946 - The dust formation model (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: The paper presents 1-4 micron photometry of supernova 1980 k in NGC 6946 obtained over a period of 1 year following the outburst. During the period between 1980 November 1 and December 19, the infrared emission probably originated from the extended atmosphere of the expanding star. The JHKL colors and a 1.3-2.6-micron spectrum observed during this period correspond to those of a blackbody with an average temperature of about 5000 K. Observations around 1981 May 31 showed that the supernova developed an infrared excess after 1980 December. This infrared excess persisted through 1981 October and is consistent with the appearance of thermal emission from about 700 to 900 K dust in addition to a hotter photosphere. The similarity of this behavior to that of the infrared evolution of some novae suggests that dust formation may be occurring in the supernova ejecta. The hypothesis, that the emission arises from preexisting grains in a circumstellar shell which are heated by the supernova outburst, is also consistent with the data.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal, Part 1 (ISSN 0004-637X); 274; 168-174
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  • 19
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    Light element geochemistry and spallogenesis in lunar rocks (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Abundance and isotopic compositions are measured for the very volatile elements carbon, nitrogen and sulfur in 11 lunar rocks representing a wide spectrum of textures and compositions. Samples were combusted sequentially at three temperatures in order to remove terrestrial contaminants before melting the lunar rock and liberating lunar volatiles. The combustion results indicate very little terrestrial sulfur contamination, with sulfur contents correlated with the TiO2 contents of the basalts analyzed. Sulfur isotopic compositions are remarkably uniform and similar to the Canon Diablo meteorite standard. Nitrogen levels are found to be no greater than those obtained with procedural blanks, corresponding to abundances less than 0.1 microg/g. Stable nitrogen isotope measurements indicate a spallogenic N-15 production rate of 4.1 x 10 to the -6th microg N-15/g sample/million years, in agreement with previous estimates. No indigenous carbon in excess of procedural blank levels of about 0.7 microg/g is found in lunar basalts. Levels of 1 to 5 microg/g found in highland rocks may derive from meteoritic or terrestrial sources. The average measured spallogenic C-13 production rate is 4.1 x 10 to the -6th microg C-13/g sample/million years.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta (ISSN 0016-7037); 47; 1769-178
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  • 20
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    Ultraviolet and optical studies of binaries with luminous cool primaries and hot companions. III - Reticon radial velocities (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Radial velocities for 72 stars, most of them known or suspected binaries with F - K giant-supergiant primaries, are derived from Reticon spectra in the region 6005-6235 A at a scale of 7 km/s per diode. Cross-correlation of the spectra normally produces results accurate to better than 1.0 km/s. Eight new radial velocity variables are found (HR 2786, R Pup, HR 3291, HR 4451, HD 114520, HR 5667, HR 7014, and Nu1 Sgr). Improved orbits are determined for 15 known spectroscopic binaries, and provisional orbits are obtained for seven new spectroscopic binaries.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal Supplement Series (ISSN 0067-0049); 53; 553-571
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  • 21
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    Infrared observations of RS CVn stars (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The paper presents infrared photometry of the RS CVn binary stars AR Lac (1.2-10 microns) and MM Her (1.2-3.5 microns) as they egressed from their primary and secondary eclipses; of the eclipsing systems RS CVn and Z Her at maximum light (1.2-10 microns) and of the non-eclipsing systems UX Ari and HR 1099 (1.2-10 microns). An analysis of these and published V data based on flux ratio diagrams (linear analogues of color-color diagrams) shows that G and K stars supply the infrared light of these systems. In AR Lac, the combined light of a G5-K0 subgiant and either a late F dwarf or an early F subgiant can account for the observed visual and infrared light curves. None of these systems shows infrared emission from circumstellar matter. This result is simply understood: dust grains would not be expected to form in the physical conditions surrounding the subgiant, and the corona and chromosphere (whose properties have been deduced from spectroscopic X-ray observations) should not produce appreciable infrared emission.
    Schlagwort(e): ASTRONOMY
    Materialart: Royal Astronomical Society, Monthly Notices (ISSN 0035-8711); 205; 859-873
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  • 22
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    The flux and source of energetic protons in Saturn's inner magnetosphere (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The flux of energetic protons in Saturn's inner magnetosphere was observed in two channels from 48 to 63 and 63 to 160 MeV. Absorption features due to the G ring and the satellites Enceladus and Mimas were easily identifiable. The flux observed in the absorption slot of Mimas can be maintained by the decay of a cosmic ray albedo neutron flux of 0.007/sq cm/s/sr. This flux is entirely consistent with calculations of the neutron flux produced by galactic cosmic ray interactions with the rings of Saturn. The omnidirectional proton flux of 0.0082/sq cm/s at 2.734 R sub s requires a residence time of 30 years. Both the residence time and the energy spectrum are comparable to those found in the inner radiation belt of the Earth. The angular distribution is nearly isotropic in the Mimas slot and beyond 4R sub s. Otherwise the pitch angle distribution is pancake and is approximated by sin(n)theta with n in the range 2 to 7. This distribution is consistent with an isotropic neutron source in the ring plane. Previously announced in STAR as N83-22084
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 8923-893
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  • 23
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    Survey of low-energy plasma electrons in Saturn's magnetosphere - Voyagers 1 and 2 (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The low energy plasma electron environment within Saturn's magnetosphere was surveyed by the Plasma Science Experiment (PLS) during the Voyager encounters with Saturn. Over the full energy range of the PLS instrument (10 eV to 6 keV) the electron distribution functions are clearly non-Maxwellian in character; they are composed of a cold (thermal) component with Maxwellian shape and a hot (suprathermal) non-Maxwellian component. A large scale positive radial gradient in electron temperature is observed, increasing from less than 1 eV in the inner magnetosphere to as high as 800 eV in the outer magnetosphere. Three fundamentally different plasma regimes were identified from the measurements: (1) the hot outer magnetosphere, (2) the extended plasma sheet, and (3) the inner plasma torus. Previously announced in STAR as N83-34872
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 8847-887
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  • 24
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    The Z3 zonal harmonic model of Saturn's magnetic field Analyses and implications (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The planetary magnetic field of Saturn has been studied by the spacecraft Pioneer 11 in 1979, Voyager 1 in 1980, and Voyager 2 in 1981. The field is found to be primarily dipolar and axially coincident with the rotation axis, but with significant quadrupole and octupole moments. The harmonic terms are g1(0) = 21535 nT, g2(0) = 1642 nT, and g3(0) = 2743 nT. This model field, Z3, in conjunction with a model for an equatorial ring current, represents very precisely the in situ magnetic-field measurements and data on charged-particle absorption by satellites and rings within 8 Saturn radii of the planet. However, this axisymmetric model fails to explain the periodic modulation of Saturn's kilometric radiation or Saturn's electrostatic discharges. This enigma of Saturn's magnetosphere remains unsolved in spite of extensive reconsideration of all available data bearing on this issue.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 8771-877
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  • 25
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    Photometry and polarimetry of Saturn at 2640 and 7500 A (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Voyager 2 photometric and polarimetric data are reduced and tabulated, with spatially resolved limb-to-terminator scans across Saturn's equatorial zone providing information on the altitude distribution of UV-absorbing hazes, together with the phase function and polarizing properties of stratospheric and tropospheric aerosols. It is found that the UV photometry and polarimetry are best fit by Rayleigh's phase matrix. A stratospheric haze of small particles is allowed as long as the optical depth is near unity or less, and the center of the haze layer is in the 30 to 70 mbar region. The altitudes presently derived for three latitudes agree with those obtained by ground-based methane band studies and analyses from Pioneer 11. A high altitude absorber is abundant in the polar regions.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 8679-869
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  • 26
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    Ultraviolet high-resolution spectroscopy from the Space Telescope (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The High Resolution Spectrograph is one of five scientific instruments which will be part of the Space Telescope observatory. The spectrograph was designed to take advantage of the imaging and pointing capabilities of the telescope to obtain ultraviolet spectra with spectral resolution comparable to large, ground-based coudeinstruments. Some of the results of the ground-based testing program will be described, along with applications of these properties to future science programs.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific, Publications (ISSN 0004-6280); 95; 543-549
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  • 27
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    Morphology and chemistry of projectile residue in small experimental impact craters (1983)
    In:  Other Sources
    Details
    Publikationsdatum: 2011-08-18
    Beschreibung: Small-scale impact craters (5-7 mm in diameter) were produced with a light gas gun in high purity Au and Cu targets using soda lime glass (SL) and man-made basalt glass (BG) as projectiles. Maximum impact velocity was 6.4 km/s resulting in peak pressures of approximately 120-150 GPa. Copious amounts of projectile melts are preserved as thin glass liners draping the entire crater cavity; some of this liner may be lost by spallation, however. SEM investigations reveal complex surface textures including multistage flow phenomena and distinct temporal deposition sequences of small droplets. Inasmuch as some of the melts were generated at peak pressures greater than 120 GPa, these glasses represent the most severely shocked silicates recovered from laboratory experiments to date. Major element analyses reveal partial loss of alkalis; Na2O loss of 10-15 percent is observed, while K2O loss may be as high as 30-50 percent. Although the observed volatile loss in these projectile melts is significant, it still remains uncertain whether target melts produced on planetary surfaces are severely fractionated by selective volatilization processes.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B353-B36
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  • 28
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    The production curve for agglutinates in planetary regoliths (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Models for the production of agglutinates are developed that can be applied to the lunar surface or to any planetary or asteroidal body lacking an atmosphere. Models are developed using rate equations for progressively more complex situations and range from Model 1, which is a simple linear increase of agglutinate content with time, to Model 4, which includes provision for recycling of existing agglutinates and replenishment and burial of exposed soil. Model 4 has some aspects of a steady state because, depending on the rate constants, agglutinate content may be limited to an intermediate value, even for long exposure times. In an extreme case, agglutinate content may be limited to a value near zero. These models predict that agglutinates should be low in abundance in areas of thin regolith, such as the Lunokhod-2 site on the moon, and on asteroids. The models may also help explain the apparent low agglutinate abundances of lunar regolith breccias and meteorite regolith breccias.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B193-B19
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  • 29
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    Ancient crustal components in the Fra Mauro breccias (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Texturally pristine clasts preserve primary petrographic relationships and mineral compositions, yielding insights into igneous processes of the early lunar crust that cannot be gained from highly shocked and brecciated 'chemically pristine' samples. The use of texture as a prime criterion allows for expansion of the data base derived solely from chemical criteria, and provides complementary data. Texturally pristine clasts from the Apollo 14 site studied here include anorthosite, troctolites, gabbronorites, and basalts. Alkali anorthosites are plagioclase orthocumulates and may form by flotation in Mg-suite plutons. Ferroan anorthosite was cataclastically deformed and metamorphosed to granulite facies. Troctolites include both 01 + Plg and 01 + En + Plg cumulates. Major and trace element analyses of two troctolites reveal 'eastern' geochemical affinities that contrast other 'western' troctolites. Gabbronorites are Pig + Plg + or - Sp cumulates whose parent magmas may range from high-Al to intermediate-Ti mare basalt. At least three varieties of mare basalt are found at Apollo 14: high-Al, low-Ti; low-Al, intermediate-Ti; and low-Al, Ti VHK basalt. VHK (Very High Potassium) basalt is a new variety indigenous to Apollo 14.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B177-B19
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  • 30
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    An upper bound on the radius of a highly electrically conducting lunar core (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Parker's (1980) nonlinear inverse theory for the electromagnetic sounding problem is converted to a form suitable for analysis of lunar day-side transfer function data by: (1) transforming the solution in plane geometry to that in spherical geometry; and (2) transforming the theoretical lunar transfer function in the dipole limit to an apparent resistivity function. The theory is applied to the revised lunar transfer function data set of Hood et al. (1982), which extends in frequency from 10 to the -5th to 10 to the -3rd Hz. On the assumption that an iron-rich lunar core, whether molten or solid, can be represented by a perfect conductor at the minimum sampled frequency, an upper bound of 435 km on the maximum radius of such a core is calculated. This bound is somewhat larger than values of 360-375 km previously estimated from the same data set via forward model calculations because the prior work did not consider all possible mantle conductivity functions.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research, Supplement (ISSN 0148-0227); 88; B97-B102
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  • 31
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    Theoretical studies of the effects of grain noise on photographic stellar astrometry and photometry (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: A method of incorporating the effects of photographic emulsion grain noise into digital image centering algorithms is presented which improves the accuracy of the derived stellar positions and magnitudes. Theoretical formulae are then derived for the limiting error of the center, and the photometric parameters. For IIIa-J, this error is 0.2-0.3 mu for bright unsaturated images, which agrees quite well with measurements made with the Yale PDS microdensitometer. It is expected that, with further improvements in the positional accuracy of the PDS, it should be possible to reach the emulsion grain noise limit, providing that emulsion shifts or other large scale errors do not dominate. It is also shown that, with appropriate trimming, marginal distribution image centering algorithms can yield an accuracy only slightly poorer than that obtained with two-dimensional distributions.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal (ISSN 0004-6256); 88; 1683-168
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  • 32
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    Atmospheric tides on Venus. III - The planetary boundary layer (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Diurnal solar heating of Venus' surface produces variable temperatures, winds, and pressure gradients within a shallow layer at the bottom of the atmosphere. The corresponding asymmetric mass distribution experiences a tidal torque tending to maintain Venus' slow retrograde rotation. It is shown that including viscosity in the boundary layer does not materially affect the balance of torques. On the other hand, friction between the air and ground can reduce the predicted wind speeds from about 5 to about 1 m/sec in the lower atmosphere, more consistent with the observations from Venus landers and descent probes. Implications for aeolian activity on Venus' surface and for future missions are discussed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus (ISSN 0019-1035); 56; 165-175
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  • 33
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    Structure and dynamics of Saturn's outer magnetosphere and boundary regions (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: In 1979-1981, the three USA spacecraft Pioneer 11 and Voyagers 1 and 2 discovered and explored the magnetosphere of Saturn to the limited extent possible on flyby trajectories. Considerable variation in the locations of the bow shock (BS) and magnetopause (MP) surfaces were observed in association with variable solar wind conditions and, during the Voyager 2 encounter, possible immersion in Jupiter's distant magnetic tail. The limited number of BS and MP crossings were concentrated near the subsolar region and the dawn terminator, and that fact, together with the temporal variability, makes it difficult to assess the three dimensional shape of the sunward magnetospheric boundary. The combined BS and MP crossing positions from the three spacecraft yield an average BS-to-MP stagnation point distance ratio of 1.29 +/- 0.10. This is near the 1.33 value for the Earth's magnetosphere, implying a similar sunward shape at Saturn. Study of the structure and dynamical behavior of the outer magnetosphere, both in the sunward hemisphere and the magnetotail region using combined plasma and magnetic field data, suggest that Saturn's magnetosphere is more similar to that of Earth than that of Jupiter. Previously announced in STAR as N83-30346
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research (ISSN 0148-0227); 88; 8791-880
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  • 34
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    Channels and valleys on Mars (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Tentative conclusions about the origins of channels and valleys on Mars based on the consensus of investigators who have studied the problem are presented. The morphology of outflow channels is described in detail, and the morphology, distribution, and genesis of Martian valleys are addressed. Secondary modification of channels and valleys by mass-wasting phenomena, eolian processes, cratering, and mantling by lava flows is discussed. The physics of the flows needed to account for the immense volumes of Martian outflow channels is considered in detail, including the possible influence of debris flows and mudflows, glaciers, and ice sheets. It is concluded that Mars once probably possessed an atmosphere with higher temperatures and pressures than at present which played an essential role in an active hydrological cycle.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geological Society of America, Bulletin (ISSN 0016-7606); 94; 1035-105
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  • 35
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    Three Mars years - Viking Lander 1 imaging observations (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The Mutch Memorial Station (Viking Lander 1) on Mars acquired imaging and meteorological data over a period of 2245 martian days (3.3 martian years). This article discusses the deposition and erosion of thin deposits (ten to hundreds of micrometers) of bright red dust associated with global dust storms, and the removal of centimeter amounts of material in selected areas during a dust storm late in the third winter. Atmospheric pressure data acquired during the period of intense erosion imply that baroclinic disturbances and strong diurnal solar tidal heating combined to produce strong winds. Erosion occurred principally in areas where soil cohesion was reduced by earlier surface sampler activities. Except for redistribution of thin layers of materials, the surface appears to be remarkably stable, perhaps because of cohension of the undisturbed surface material.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science (ISSN 0036-8075); 222; 463-468
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  • 36
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    An improved celestial radio reference frame: JPL 1982-4 (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: In the development of a celestial radio reference frame, there are now over 100 sources whose relative positions are known with an average uncertainty less than 5 milliarcseconds. These sources are fairly uniformly distributed over the celestial sphere north of -40 deg declination. Their positions are expressed in the new IAU system. This presentation describes the analysis involved in obtaining these results, as well as future plans for linking this system to the JPL planetary ephemerides.
    Schlagwort(e): ASTRONOMY
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  • 37
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    Stability and capture of asteroids (1983)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The problem of stability of asteroids is treated from the point of view of Hill's stability-concept and using Lyapunov's Characteristic Numbers. The quantitative measure of stability (S) introduced earlier is evaluated for over 300 asteroids and a surprisingly simple relation is established between the semi-major axes of some of the asteroids' orbits and S. A detailed analysis is presented of the Lyapunov Characteristic Numbers for two minor planets and the time-variation of these numbers is discussed. The technology of capture of asteroids is vitally dependent on their orbital stability, therefore, these two problems, i.e., capture and stability, are closely related. In fact, some predictable instabilities may be properly utilized to capture and/or change asteroidal orbits to accomplish collisions with the Earth.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Sao Paulo Univ. The Motion of Planets and Nat. and Artificial Satellites, Volume 2; p 39-46
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  • 38
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    A Sr and Nd isotopic study of five Yamato polymict eucrites and a comparison to other Antarctic and ordinary eucrites (1983)
    In:  Other Sources
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    Publikationsdatum: 2011-08-19
    Beschreibung: Sr and Nd isotopic analysis of five Yamato polymict eucrites indicate that these samples formed at about 4.6 Ga ago with initial Sr and Nd ratios essentially the same as the analyzed non-Antarctic eucrites. The Yamato eucrites have Sr, Sm, and Nd concentrations that consistently lie among the highest found in eucritic samples. This characteristic identifies these Yamato samples as a closely related group. Comparisons between these Yamato samples and other Antarctic polymict eucrites clearly estabishes that they all share some characteristic trace element features. Comparisons of Antarctic polymict eucrites with non-Antarctic ordinary eucrites reveal consistent differences. The most obvious is an enrichment of Rb in the polymict eucrites. These comparisons suggest that the Antarctic polymict eucrites belong to a single large family of material that is itself fairly diverse and distinct from the non-Antarctic eucrites.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: National Institute of Polar Research, Memoirs, Special Issue (ISSN 0386-0744); 30, D
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  • 39
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    Condensation of chondrules (1983)
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    Publikationsdatum: 2011-08-19
    Beschreibung: Analysis of current experimental results concerned with the kinetic constraints on chondrule formation showed that the major physical properties of chondrules could have been produced by direct condensation of metastable liquid silicates droplets from a hot gas in the primordial nebula. It is argued that such a condensation process would have to be followed by crystallization, accretion, and partial comminution of the droplets. The chemical mechanisms driving this process are described, including: nucleation constraints on comminution and crystallization; slow transformations and chemical reactions in chain silicates; and the slow diffusion of ions. It is shown that the physical mechanisms for chondrule condensation are applicable to a broad spectrum of chondrule sources.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 40
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    External control of planetary radio emission (1983)
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    Publikationsdatum: 2011-08-19
    Beschreibung: Recent studies using data from Voyagers 1 and 2 to correlate variations in the Saturn kilometric radiation (SKR) with changes in solar-wind properties are summarized and illustrated with graphs. Best SKR correlations have been obtained with the solar-wind ram pressure and the related kinetic energy flux. It is pointed out that the related phenomenon on earth, the auroral kilometric radiation, occurs mainly in the nightside auroral region (as opposed to the dayside cleft region for SKR) and is best correlated with solar-wind velocity and inverted-V electron-precipitation events, implying a different stimulation process. The evidence for solar-wind control of the non-Io-related decametric radiation of Jupiter is also reviewed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Oesterreichische Akademie der Wissenschaften, mathematisch-naturwissenschaftliche Klasse, Sitzungsberichte, Abteilung 2 (ISSN 0723-9319); 192; 8-10,
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  • 41
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    Submillimetre astronomy from space platforms (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The scientific need and the technical feasibility of a 10-m class far infrared telescope in space were studied and culminated in the recommendation of the large deployable reflector (LDR). The scientific considerations for such a project are described and the general characteristics of LDR are derived. A scientific program culminating in LDR is suggested.
    Schlagwort(e): ASTRONOMY
    Materialart: ESA The Sci. Importance of Submillimetre Observations ap 91-96 (SEE N83-22034 11-88)
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  • 42
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    The spectrum of comets as derived from IUE observations (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Eight comets were observed with the IUE at various-heliocentric and geocentric distances. Their UV spectra are remarkably similar despite the large differences in the dust to gas ratios. Since all the dominant atomic species (except N) radicals and ions of the coma are detected in this spectral region, the total gaseous output of the nucleus can be estimated. The abundance of the carbon atom-bearing species is still not very well known and there are indications that the CO content of the coma could vary from comet to comet.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: ESA 3rd European IUE Conf.; p 445-449
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  • 43
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    Analysis of photometric spectra of 17 meteors (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The initial phase of the photometry which involved 17 meteor spectra consisting of eight Geminid spectra, six Orionid spectra and three Eta Aquarid spectra is discussed. Among these 17 spectra it is found that the Geminid spectra are of the best quality and are used for the identification of the atomic lines and molecular bands that normally appear on video tape spectra. The data from the Geminid records are used for developing calibration techniques in photometry. The Orionid and Eta Aquarid spectra are chosen for early analysis because of the current interest in all physical and chemical data relating to Comet Halley.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Meteors and Meteor Spectra Anal.; 9 p
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  • 44
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    Morphology of volcanoes (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The effects of chemical composition of the lava, physical processes of volcanic formation, and lava flow lengths on the morphology of Earth volcanoes were investigated. Difficulties in investigating volcanic morphology are discussed.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA, Washington Advan. in Planetary Geol.; p 565-568
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  • 45
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    A simple criterion for determining the dynamical stability of three-body systems (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Coplanar, prograde three-body systems (TBS) are discussed, emphasizing the specification of general criteria for determining whether such systems are dynamically stable. It is shown that the Graziani-Black (1981) criteria provide a quantitatively accurate characterization of the onset of dynamic instability for values of the dimensionless mass ranging from one millionth to one million. Harrington's (1977) general criterion and the Graziani-Black criterion are compared with results from analytic work that spans a 12-orders-of-magnitude variation in the mass ratios of the TBS components. Comparison of the Graziani-Black criteria with data for eight well-studied triple-star systems indicates that the observed lower limit for the ratio of periastron distance of the tertiary orbit to the semimajor axis of the binary orbit is due to dynamical instability rather than to cosmogonic processes.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal; 87; Sept
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  • 46
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    Chemistry and evolution of Titan's atmosphere (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The chemistry and evolution of Titan's atmosphere are reviewed, in light of the scientific findings from the Voyager mission. It is argued that the present N2 atmosphere may be Titan's initial atmosphere, rather than one photochemically derived from an original NH3 atmosphere. The escape rate of hydrogen from Titan is controlled by photochemical production from hydrocarbons. CH4 is irreversibly converted to less hydrogen-rich hydrocarbons, which over geologic time accumulate on the surface to a layer thickness of about 0.5 km. Magnetospheric electrons interacting with Titan's exosphere may dissociate enough N2 into hot, escaping N atoms to remove about 0.2 of Titan's present atmosphere over geologic time. The energy dissipation of magnetospheric electrons exceeds solar EUV energy deposition in Titan's atmosphere by an order of magnitude, and is the principal driver of nitrogen photochemistry. The environmental conditions in Titan's upper atmosphere are favorable to building up complex molecules, particularly in the north polar cap region.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 47
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    Production of nitric oxide by lightning on Venus (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The first measurements of the production of nitric oxide (NO) by a laboratory discharge in a simulated Venus atmosphere are presented. The average NO yield over a range of energies was found to be 3.7 + or - 0.7 x 10 to the 15th molecules/joule. Simultaneous measurements of carbon monoxide (CO) resulting from the lightning-induced dissociation of carbon dioxide (CO2) indicated a CO yield of about 4 x 10 to the 17th molecules/joule. These measurements suggest that at and below cloud level, a region where solar ultraviolet radiation cannot penetrate, the dissociation of CO2 by lightning may be a significant source of oxygen atoms. Depending on the assumed value for the total energy dissipated by lightning on Venus, the production of NO by lightning may be a significant sink of atmospheric nitrogen over the history of Venus.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 9; Aug. 198
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  • 48
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    Evidence for a distant /greater than 8,700 R sub J/ Jovian magnetotail - Voyager 2 observations (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: (Previously announced in STAR as N82-18106)
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geophysical Research Letters; 9; Aug. 198
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  • 49
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    Quasi-periodic climate changes on Mars - A review (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The current understanding of the manner in which astronomical variations modulate the Martian climate and thereby lead to the occurrence of laminated polar terrain is considered. The seasonal cycles of dust, carbon dioxide and water, and their responses to astronomical variations, are studied. After an assessment of the way in which these cycles presently operate, for which pertinent spacecraft and ground-based observations are extant, attempts to predict how these cycles may differ under conditions of high and low obliquity and eccentricity are discussed. Attention is given not only to those areas in which there is broad agreement, but also to the controversial and speculative. Key questions include the proportion of dust and water ice in the laminae and its variations within individual layers, the relative importance of older laminae and lower-latitude material as sources of new laminae, and the factors responsible for the youth of the laminated terrain.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 50
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    Photoclinometric determination of the topography of the Martian north polar cap (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Photoclinometry is useful for the determination of topography for areas which have a uniform albedo. The technique is applied to early spring Viking images of the Martian north polar cap, taken when the surface was covered by a nearly uniform frost cover. Unlike earlier approaches, the topographic profiling can be used for surfaces with any photometric function, but the strike of the planetary surface relative to the illumination angle must be specified along the profile. The resultant profiles are relatively insensitive to misestimation of the photometric function and slope orientation, but are quite sensitive to the assumed values of the reflectance of an equivalent level surface and the atmospheric opacity (if it is large).
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 51
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    Stability of negatively charged dust grains in Saturn's ring plane (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: The boundary between the inner and outer parts of Saturn's B ring is located at the theoretical limit of stability of dust grains with large negative charge to mass ratio. A grain inside of this stability limit will move along magnetic field lines and strike Saturn if given a slight velocity component normal to the ring plane. Outside of this marginal stability radius, a perturbed grain merely oscillates back and forth through the ring plane. The theoretical location of the marginal stability radius is at 1.625 Saturn radius. Observations by Pioneer 11 and Voyager 2 in the infared see the boundary as a prominent change in ring brightness at this radius. The occultation of delta-Scorpii by the rings in the ultraviolet seen by Voyager 2 shows about a factor of two change in optical depth beginning very close to this radius.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 87; Aug. 1
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  • 52
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    The Lappajarvi meteorite crater, Finland - Petrography, Rb-Sr, major and trace element geochemistry of the impact melt and basement rocks (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Geochimica et Cosmochimica Acta; 46; July 198
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  • 53
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    A 1400-MHz survey of 1478 Abell clusters of galaxies (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: Observations of 1478 Abell clusters of galaxies with the NRAO 91-m telescope at 1400 MHz are reported. The measured beam shape was deconvolved from the measured source Gaussian fits in order to estimate the source size and position angle. All detected sources within 0.5 corrected Abell cluster radii are listed, including the cluster number, richness class, distance class, magnitude of the tenth brightest galaxy, redshift estimate, corrected cluster radius in arcmin, right ascension and error, declination and error, total flux density and error, and angular structure for each source.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal; 87; Aug. 198
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    IUE observations of proto-planetary and variable planetary nebulae. I - V1016 Cygni, HM Sagittae, and HBV 475. II - A search for variability in IC 4997 and NGC 6905 (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The IUE satellite has undertaken UV observations of the proto-planetary nebulae V1016 Cyg, HM Sge, and HBV 475, yielding emission line fluxes, line ratios, line profiles, electron densities, and distances from these objects. While levels of increasing excitation and ionization as a function of time are shown by the data for the first two nebulae, the trend for HBV 475 is found to lead in the opposite direction. The formation of a shell is suggested by dramatic changes in the HM Sge UV line profiles over the last four years, including the disappearance of W-R features and the incipient splitting of the semi-forbidden C III 1909 A line. An additional IUE search for UV variability in the planetary nebulae IC 4997 and NGC 6905 has yielded emission line fluxes, line ratios and profiles, and central star temperatures, as well as stratification effects data for several ions in NGC 6905
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal; vol. 258
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  • 55
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    On the location of acid-hydrolysable carbon in lunar soil fines (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Soil fines exposed on the lunar surface accumulate small metallic iron particles and solar wind-derived carbon. In previous work, it has been suggested that an intimate association exists between one particular carbon phase, hydrolysable carbon, and very fine iron droplets, where the carbon is in solid solution in the iron. The earlier hypothesis of a constant carbon in iron concentration across a broad range of droplet sizes is testable by combining hydrolysable carbon determinations with a variety of magnetic measurements sensitive to different droplet diameters. New measurements of ferromagnetic resonance response on density and magnetic separates from size fractions of soil 12023 are interpreted as evidence that hydrolysable carbon is preferentially associated with the larger, magnetically stable single-domain iron particles rather than with the smaller superparamagnetic droplets. For the former, there is a quite uniform ratio of iron to carbon both within a series of separates from a single soil, and among soils of widely varying FeO content.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Earth and Planetary Science Letters; 59; 1, Ju; June 198
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  • 56
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    Theory of radio occultation by Saturn's rings (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The radio occultation technique, as applied to Saturn's rings, is developed as a new method for the study of the physical properties of planetary ring systems. The rings are treated as a Doppler-spread radar target composed of an ensemble of discrete scatterers. The mathematical formulation of the received signal as a random-phasor-sum process is carried out following a conventional radar theory approach, providing a convenient starting point for deriving coherent signal parameters. A classical result is rederived for the equivalent refractive index of the medium. The analysis is generalized to include ringlets of arbitrary width and it is shown that when the width is such that two adjacent rays are differentially perturbed in phase, ray bending that causes focusing of the coherent signal may result. The diffuse component is also treated in detail.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 49; Feb. 198
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  • 57
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    Periodic orbits of the elliptic restricted problem for the Sun-Jupiter-Saturn system (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A systematic approach to generate periodic orbits in the elliptic restricted problem of three bodies is introduced. The approach is based on (numerical) continuation from periodic orbits of the first and second kind in the circular restricted problem to periodic orbits in the elliptic restricted problem. Two families of periodic orbits of the elliptic restricted problem are found by this approach. The mass ratio of the primaries of these orbits is equal to that of the Sun-Jupiter system. The sidereal mean motions between the infinitesimal body and the smaller primary are in a 2:5 resonance, so as to approximate the Sun-Jupiter-Saturn system. The lineaar stabilities of these periodic orbits are studied as functions of the eccentricities of the primaries and of the infinitesimal body. The results show that both stable and unstable periodic orbits exist in the elliptic restricted problem that are close to the actual Sun-Jupiter-Saturn system. However, the periodic orbit closest to the actual Sun-Jupiter-Saturn system is (linearly) stable.
    Schlagwort(e): ASTRONOMY
    Materialart: Celestial Mechanics; 27; May 1982
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  • 58
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    Sky input horn for a far-infrared interferometer (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A unique design has been developed whereby a compound parabolic concentrator (CPC) and a compound elliptical concentrator (CEC) are joined at their throats. The CPC serves as the field-defining optics, in that it accepts up to a certain maximum acceptance angle and then concentrates this accepted energy at its throat. Energy incident from angles greater than the acceptance angle is rejected. The CEC takes the energy concentrated at the CPC throat and then redirects this energy into a finite-sized pupil a given distance away. The considered design will be used as the sky input horn for a cryogenic far-infrared polarizing interferometer to be flown on NASA's Cosmic Background Explorer satellite. The interferometer will operate at 2 K and measure the 3-K cosmic background radiation of the universe in the 100-micrometer-1-cm spectral range.
    Schlagwort(e): ASTRONOMY
    Materialart: Optics Letters; 7; May 1982
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  • 59
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    Infrared, optical, and ultraviolet observations of hydrogen line emission from Seyfert galaxies (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Nearly simultaneous observations are reported of P-alpha, H-alpha, and H-beta emission from 18 Seyfert galaxies and of Ly-alpha from eight of these galaxies. In many cases, P-alpha is stronger relative to the Balmer lines than is predicted by recombination calculations; reddening appears to be required. Dispersion in the P-alpha/H-alpha/H-beta ratios orthogonal to the reddening track indicates that high densities or optical depths also affect the line flux ratios. Several galaxies, notably NGC 1275, have very low P-alpha/H-alpha ratios. High densities, large optical depths, and reddening probably all contribute to the low observed Ly-alpha/H-beta ratios.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal; vol. 256
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  • 60
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    Structure of the Venus mesosphere and lower thermosphere from measurements during entry of the Pioneer Venus probes (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Data on the thermal structure of the nightside middle atmosphere of Venus, from 84 to 137 km altitude, have been obtained from analysis of deceleration measurements from the third Pioneer Venus small probe, the night probe, which entered the atmosphere near the midnight meridian at 27 deg S latitude. Comparison of the midnight sounding with the morning sounding at 31 deg S latitude indicates that the temperature structure is essentially diurnally invariant up to 100 km, above which the nightside structure diverges sharply from the dayside toward lower temperatures. Very large diurnal pressure differences develop above 100 km with dayside pressure ten times that on the nightside at 126 km altitude. This has major implications for upper atmospheric dynamics. The data are compared with the measurements of Keating et al. (1980) above 140 km, with theoretical thermal structure models of Dickinson, and with data obtained by Russian Venera spacecraft below 100 km. Midnight temperatures are approximately 130 K, somewhat warmer than those reported by Keating et al.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Icarus; 49; Jan. 198
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  • 61
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    Ultraviolet images of M101 - Observations of dust and inferences on the metallicity (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Since extreme Population I dominates three rocketborne telescope UV images of the Sc I galaxy NGC 5457, the delineation of the spiral structure is sharper than that of ground photographs. The UV pictures, in which the H II regions appear as reflection nebulae and illumine the nearby dust, reveal faint arms which, although correlated with the 21 cm H I radiograph, are only marginally detectable on deep visual photographs. The surface brightness of the arms is explainable in terms of UV light scattering off dust from hot stars and bright H II regions, in which case the dust would have extinction properties and a dust-to-gas ratio similar to that in the solar neighborhood and would in addition suggest that the NGC 5457 outer arm metal content is similar to that of the galaxy.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal; vol. 255
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  • 62
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    The Mars reference atmosphere (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A nominal atmospheric model of Mars is presented, with detailed consideration being given to the various sources of variability in the Martian atmosphere. A basic model for the midlatitude summer is outlined for the northern and southern hemispheres. Attention is given to meteorological variability due to winds, diurnal and seasonal pressure variations, temperature changes, and the effects of dust opacity, particularly on temperature stratification. Viking lander IR thermal mapper data are examined in terms of diurnal and latitudinal temperature variations, and cloud and haze formation and locations are discussed. Mass spectrometry of the atmosphere is used to describe the molecular abundances, and water vapor measurements are reviewed. Finally, radio occultation, UV airglow, and mass spectrometry of the Martian upper atmosphere are investigated, along with the temperature structure of the upper atmosphere.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
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  • 63
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    Venus - Chemical weathering of igneous rocks and buffering of atmospheric composition (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Data from the Pioneer Venus radar mapper, combined with measurements of wind velocity and atmospheric composition, suggest that surface erosion on Venus varies with altitude. Calcium- and magnesium-rich weathering products are produced at high altitudes by gas-solid reactions with igneous minerals, then removed into the hotter lowlands by surface winds. These fine-grained weathering products may then rereact with the lower atmosphere and buffer the composition of the observed gases carbon dioxide, water vapor, sulfur dioxide, and hydrogen fluoride in some regions of the surface. This process is a plausible mechanism for the establishment in the lowlands of a calcium-rich mineral assemblage, which had previously been found necessary for the buffering of these species.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Science; 216; Apr. 9
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  • 64
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    VI photometry of selected SAO stars (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Johnson V- and I-band photoelectric photometry has been obtained for 158 SAO stars in a continuing program in support of the Near Infrared Photographic Sky Survey. These data are utilized in the calibration of the survey photographs and are presented here to assist other programs reliant upon access to photometry in the photographic infrared.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Society of the Pacific; vol. 94
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  • 65
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    The double structure of W3-IRS 5 as determined from high-resolution spatial scans (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Slit scans over the infrared source W3-IRS 5, from 4.8 to 12.7 microns are interpreted in terms of two sources of luminosity separated by 0.9 arcsec in declination. The data, as a function of wavelength, show that the two sources must have remarkably similar properties.
    Schlagwort(e): ASTRONOMY
    Materialart: Astronomical Journal; 87; Feb. 198
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  • 66
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    Balloon observations of galactic high-energy X-ray sources (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A number of X-ray sources were observed with the Naval Research Laboratory hard X-ray observatory during balloon flights on 1976 May 11 and 1977 November 24. The primary objective of the observations was to characterize the temporal and spectral behavior of the sources in the energy range from 20 to 250 keV. Special emphasis was placed on the determination of spectrum versus phase for periodic sources and on the search for spectral features such as the reported 60 keV line in the X-ray spectrum of Her X-1. Results of the observations include: evidence for possible phase-dependent spectral variations in the emission from GX 1+4; flaring in the emission from GX 301-2; detection of unmodulated X-ray emission up to approximately 35 keV from GX 304-1; and an unexpectedly hard spectrum above 20 keV from Cyg X-2.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal; vol. 254
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  • 67
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    The induced magnetosphere of Titan (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: No evidence was found for an intrinsic magnetic field, nor for the development of a bow shock wave, as the corotating Saturnian magnetoplasma convected past Titan during the Voyager 1 close encounter of November 12, 1980. The observation of a well-developed, induced bipolar magnetic tail is evidence, however, of a strong electrodynamic interaction. Three thin, current-carrying regions were crossed which correspond to the inbound and outbound tail magnetopause and an imbedded tail neutral sheet. The interaction is unique among those observed to date in the solar system, in that it is intermediate with respect to sonic and Alfvenic Mach numbers by comparison with Titan in the solar wind and Io in the Jovian magnetosphere. The draping of the Saturnian magnetic field around the ionosphere of Titan is suggested by results of the analysis of magnetic field data.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Journal of Geophysical Research; 87; Mar. 1
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  • 68
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    PKS 2155-304 - Relativistically beamed synchrotron radiation from a BL Lacertae object (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The previously reported variability by a factor of two in less than a day is confirmed for the newly discovered BL Lac object PKS 2155-304, by means of the HEAO 1 A-2 experiment's medium- and high-energy detectors. An interpretation of the overall spectrum from radio through X-rays in terms of a synchrotron self-Compton model yields a good description of the data if relativistic beaming is allowed for. The presence of jets is inferred without their direct observation through consideration of the spectrum, combined with an estimate of the size of the source.
    Schlagwort(e): ASTRONOMY
    Materialart: Astrophysical Journal; vol. 253
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  • 69
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    The Allan Hills icefield and its relationship to meteorite concentration (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The Allan Hills icefield is described by as a limited icefield that has large concentrations of meteorites. The meteorites appear to be concentrated on the lower limb of an ice monocline with other finds scattered throughout the field. In an attempt to understand the mechanisms of meteorite concentration, a triangulation chain was established across the icefield. This chain is composed of 20 stations, two of which are on bedrock, and extends westward from the Allan Hills a distance of 15 kilometers. The triangulation chain and its relationship to the meteorite concentrations is shown.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Smithsonian Astrophysical Observatory Catalog of Meteorites from Victoria Land, Antarctica, 1978 - 1980; p 12-18
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  • 70
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    Mass loss from the central star of the planetary nebulae IC 3568 (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Low resolution IUE spectra of IC 3568 show several stellar P Cygni features. A high resolution spectrum was obtained which shows a saturated N V lambda 1240 profile from which we find the terminal velocity of the tellar wind to be v = 1840 km/s. The P Cygni features due to C IV lambda 1549, O V lambda 1371 and N IV lambda 1719 are also observed. The unsaturated O V lambda 1371 line seems best for determination of the mass loss rate. It is found that the level of ionization in the stellar wind appears to increase outwards. The possible effects of such stellar winds from central stars on surrounding nebulae are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 610-614
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    The peculiar, luminous early-type emission line stars of the Magellanic clouds: A preliminary taxonomy (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A sample of some 20 early type emission supergiants in the Magellanic clouds was observed with both the SWP and LWR low resolution mode of IUE. All stars have strong H-emission, some showing P-Cygni structure as well with HeI, HeII, FeII and other ions also showing strong emission. It is found that the stars fall into three distinct groups on the basis of the HeII/HeI and HeI/HI strengths: (1) HeII strong, HeI, HI; (2) HeII absent, HeI, HI strong; (3) HeI absent, HI, FeII, FeII, strong in addition to low excitation ions. The two most extreme emission line stars found in the Clouds S 134/LMC and S 18/SMC are discussed. Results for the 2200A feature in these supergiants, and evidence for shells around the most luminous stars in the clouds are also described.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 602-605
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    Magnetospheres and winds of the helium strong stars: Dependence on rotation (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Large aperture, low resolution spectra of 24 stars of types 05, 04, and 03 were obtained, and from these the energy distribution between 1200 and 3200 angstrom was derived in absolute units. The energies were combined with energies deduced from uvby and UBV photometry and corrected for interstellar extinction. Angular diameters and effective temperatures are also derived. The effective temperatures range from 24800K to 63000K. There is no correlation between effective temperature and spectral type or luminosity class for the early 0 stars. The size of the expected errors are also studied.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 589-592
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    The chromospheric rotation activity relation in late type close binary systems (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The IUE data on 36 late type close binary stars are presented. It is shown that the chromospheric and TR line fluxes increase with decreasing stellar rotation period, though not as rapidly as does the X-ray flux. There is an increasing dependence upon rotation with increasing line temperature. The data are consistent with the hypothesis that there exists a critical rotation rate, which depends on temperature, below which the emission flux is independent of rotation and above which it increases linearly with increasing angular velocity omega.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 566-569
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  • 74
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    Observations of the May 1979 outburst of Centaurus X-4 (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The IUE spectra of the X-ray transient/X-ray burst source Cen X-4 at three intervals during the peak and decline of the May 1979 transient event were studied. The spectrum is characterized by a blue continuum and strong emission lines of N V lambda 1240, Si IV lambda 1398 and C IV lambda 1550. The origin of these emission components in the context of an X-ray dwarf nova model is investigated. It is suggested that an accretion disk plays a prominent role in the generation of the continuum emission and that X-ray heating of the accretion disk and the companion star may be important in the formation of the emission lines.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 558-562
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    Model fitting of the Algol binaries (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Energy distribution of the component stars of the Algol type semidetached binaries were studied by combining IUE low dispersion spectra with optical scans made with the same resolution. In most cases the flux distributions are matched by Kuruz model atmospheres with normal solar composition. Deviations from normal atmospheres which indicate a higher level of activity and interaction in the binaries are examined. Eclipse observations in U Cep and V356 Sgr reveal emission lines of the W serpentis type.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 538-541
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    Observations of mass accretion in binary stars (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Results from high resolution observations of eight close binary stars (TX UMa, U CrB, CX Dra, TT Hya, AU Mon, KX And, HR 2142, and phi Per) are presented. Variable absorption lines, indicative of mass flow, are observed in all systems expect phi Per. Emission lines are seen in KX And and phi Per. Variable high ionization features (NV, SiIV, and CIV) are seen in TX UMa, UCrB, CX Dra, and AU Mon. The observations are modeled using the calculations of Lubow and Shu.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 534-537
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    Line-profile and continuum variations of the contact binary SV Centauri (1982)
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    Publikationsdatum: 2011-08-18
    Beschreibung: A total of five high and ten low dispersion UV spectra of the interacting contact binary SV Centauri obtained between 1979 and 1982 are analyzed. The low resolution observations cover the whole phase range, while a few selected phases were observed in high dispersion. The UV data were complemented with optical photometric and spectroscopic observations, in order to determine the tructure and absolute dimensions of the system. The profiles of prominent UV resonance and metastable lines undergo drastic changes with phase angle and time. Their overall appearance indicates relatively strong mass loss from the system, exhibiting pronounced variations of the stellar wind. The far UV continuum distribution suggests the presence of a luminous hot radiation source with maximum emission in the soft X-ray range, which is most apparently seen during the first quadrature phase, while it is weakest close to primary minimum. The case exchange and mass loss process as well as the evolutionary stage of SV Centauri are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: Advan. in Ultraviolet Astron.; p 521-525
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    IUE spectroscopy, visible-band polarimetry, and radiometry of V641 Mon (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: This hot, double line, ellipsoidal variable member of NGC 2264 has been shown previously to be either a semi-detached or contact close binary. Low-resolution IUE spectra are best fitted to a Kurucz model atmosphere for very small (approximately 0.08 mag) E(B-V). The familiar interstellar absorption dip near lambda 2200 is apparently absent. A suitable model atmosphere can be fitted to the IUE fluxes, but flux excesses (compared to the model) appear for all the published U through L magnitudes. The spectrum of the B through L excess appears to follow a .0001 lambda dependence. It is shown that this cannot be interpreted as arising from another star fortuitously observed in the visible band or IR. Ground based polarization measures indicate V641 Mon to be a polarization variable. Previous and new V light curves show the amplitude of light variability itself to be variable by about a factor of 2. It is suggested that all these observed characteristics are best explained by postulating "third light" and identifying part of it with Rayleigh scattered starlight very near to the stars. From this same region there arise circumstellar absorptions which give rise to nontheoretical strengths for Si II and Si III lines.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 513-516
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    IUE observations of the 1981 outburst of nova Cr A (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Low dispersion spectrum observations are analyzed. The light curve of nova Cr A, indicating a moderately fast nova, is presented. Flux calibrated, merged spectrum graphs of April 21, 1981 and September 13, 1981 are presented, demonstrating very strong lines of Al and Si. Additional strong C, Ni, O, and Ne emission lines were identified. Emission lines due to highly ionized species such as Mg VII and Al Vl were observed for short times in May and June 1981. Preliminary analysis of spectra obtained 200 days after maximum indicate that the nebula is still in transition and has not yet reached the nebula state. An over abundance of N and Ne are suggested.
    Schlagwort(e): ASTRONOMY
    Materialart: Advan. in Ultraviolet Astron.; p 478-481
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  • 80
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    Observations and analysis of the R Aquarii jet (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Ultraviolet, optical and radio observations of the symbiotic star R Aquarii are discussed in the light of the discovery of a bright radio and optical jet from this star. The star is probably a binary with a period of 44 years. The VLA maps of the jet reveal a protruding structure extending approximately 10 arc sec from the central radio source with a position angle virtually identical to that of the optical jet observed at Lick. The observations of R Aqr are interpreted as indicating the existence of an accretion disk around an unseen companion. The hot subdwarf has effective temperature approximately 65,000 K. It is suggested that the Mira primary and the hot secondary are in orbit around each other with a high eccentricity. At periastron the hot subdwarf accretes at super critical rates and a jet forms. It is difficult to understand how an accretion disk would have eclipsed the Mira in 1928-1935 and 1974-1980. The suppression of maximum light in these two periods is interpreted as due to a distortion of the Mira envelope at periastron by the tidal interaction with the secondary. The jet may help to explain the excitation of the R Aqr nebula. It is possible that R Aqr flared up as a nova approximately 1000 years ago forming the nebula.
    Schlagwort(e): ASTRONOMY
    Materialart: Advan. in Ultraviolet Astron.; p 452-455
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  • 81
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    The high velocity symbiotic star AG Draconis after its 1980 outburst (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: High and low resolution spectra of AG Dra taken in 1981 are analyzed. The UV spectrum of AG Dra is characterized by prominent high ionization emission lines superimposed on a strong continuum. At high resolution, several intense absorption lines of interstellar origin are seen, in spite of the low interstellar extinction. A similar situation is displayed by the high galactic latitude sd0 stars. The radial velocity difference between the emission lines and the i.s. lines is about -105 Km/sec in agreement with the optical observations. The He II 1640 A line appears much stronger than in other symbiotic stars and suggests the presence of a hot source which is variable according to the activity of the star. The line also exhibits broad emission wings which could be formed in a rotating disk. The NV resonance doublet displays a P Cygni profile and is probably formed in a warm wind. Two components in the UV continuum are identified: a steep component dominating the far UV probably associated with the hot source, and a flatter continuum in the near UV which cannot be accounted for by f-f and f-b emission alone, but which is probably emitted by an optically thick region or disk.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 446-447
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  • 82
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    Ultraviolet spectra of R Coronae Borealis stars (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: An analysis of the International Ultraviolet Explorer spectra of the R CrB-type variables R CrB, RY Sgr, XX Cam, and MV Sgr suggests that: (1) it should be possible to construct useful models for the atmospheres of these hydrogen deficient, carbon rich stars if present standards of metallic line blanketing are used; and (2) the observed wavelength dependence of the circumstellar extinction is primarily due to circumstellar grains.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 429-432
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  • 83
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    The UV emission line spectrum of NGC 6572 (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Ultraviolet spectra of the medium excitation planetary nebula NGC 6572 were obtained with IUE both in the low and in the high resolution mode. These spectra reveal a superposition of emission lines arising in the expanding atmosphere of the central star, evidenced e.g., by their P Cygni profiles, and features arising in the planetary nebula proper. The latter were analyzed in order to determine C, N, O abundances.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 389-392
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  • 84
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    The violet interstellar medium associated with the Carina Nebula (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The interstellar spectrum of HD 93205, an 03V star in the cluster Tr16, located inside the most active part of the Great Carina Nebula was analyzed using data extracted directly from raw IUE images. From the analysis of 67 lines of 25 atoms, ions and molecules, up to six discrete absorption components spanning a maximum velocity range of approximately 375 km 5/1 were identified. The component structure for different species is tabulated and sample absorption lines, indicating at the top the positions of the six components, labelled A to F are shown. Ion column densities appropriate to each component which can be resolved in at least one line were derived by constructing empirical curves of growth and by fitting the observations with corresponding theoretical absorption line profiles. The most important results concerning each component are discussed.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 38-384
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  • 85
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    Small scale structure in the interstellar medium: Orion's threadbare cloak (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The interstellar medium in the central portion of the Orion Cloak dynamical feature was examined for evidence of fine structure. Four stars in the Ori OB I association, HD 37017, 37468, 37479, and 37776 bracket the stars in the lower belt region that were studied previously. Two are members of the sigma Ori subcluster. A lower limit to the scale inhomogeneity can be set using these at 0.1 pc, while on a scale of about 10 pc, the high velocity component of the second spectrum ions shows optical depth variation of more than a factor of 5. Neutral lines do not display the high velocity component. Some preliminary abundances are also given.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 370-373
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  • 86
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    MAGELLAN: High resolution spectroscopy at FUV and EUV wavelengths (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The aim of ESA's MAGELLAN mission is to provide high resolution spectra of celestial sources down to sixteenth magnitude over the extreme ultraviolet wavelength range (between 50 and 140 nm). This range extends from studies of interstellar matter in the disc and halo of this and other galaxies, to stellar envelopes, hot and evolved stars, clusters, intergalactic matter, nuclei of galaxies, quasars, and, finally, planets and satellites. The instrument has a nonconventional optical design using only one reflecting surface; a high groove density concave grating collects the star light, diffracts it and focuses its spectrum into a bidimensional windowless detector operated in a photon counting mode. The slitless configuration provides the spectra of all the sources (point like and extended) in the field of view of the grating. This field of view is limited by a grid collimator to reduce the diffuse background, the stray light and the probability of overlapping spectra in crowded fields.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 347-354
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  • 87
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    Spectral anomalies in low dispersion SWP images (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Physical interpretation of IUE spectra obtained with the SWP camera may be significantly affected by artificial spectral features of several types. In low dispersion large aperture SWP exposures of sources with nominally featureless spectra, a spectral imprint which alters the shape of the continuum, several spurious "emission features" which recur at fixed locations on the camera target, and fixed pattern noise which can result in illusory emission and absorption features were identified. The anomalies appear in spectra extracted from line by line files generated by IUESIPS at all epochs, regardless of the ITF or rectification scheme used for processing.
    Schlagwort(e): ASTRONOMY
    Materialart: Advan. in Ultraviolet Astron.; p 335-338
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  • 88
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    Faint object studies with IUE (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: To push IUE to the limit on faint sources, detector background contributions from the night sky, energetic particle events, detector flaws and calibration errors must be established. Multiple spectra of faint nebular filaments were intercompared with multiple spectra of sky background in a study of the Crab Nebula. Radiation hits dominate the background of any long exposure spectrum but bright spots of the detector can be misconstrued to be radiation hits, or spectral information. The spectra were normalized and then, on a pixel by pixel basis, average and median spectra were constructed. Four data sets (six SWP nebular, six SWP sky, six LWR nebular, and six LWR sky) were processed in parallel. A number of bright and faint background features remain, especially for SWP images. Several features could be misconstrued to be emission from a faint object.
    Schlagwort(e): ASTRONOMY
    Materialart: Advan. in Ultraviolet Astron.; p 331-334
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  • 89
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    Composition of Jupiter (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The chemistry of Jupiter's atmosphere is reviewed. The various molecules that were discovered on Jupiter are summarized. The compounds: methane, ammonia water, ethane, acetylene, carbon monoxide, phosphine, and germane.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA. Goddard Space Flight Center Vibrational-Rotational Spectry. for Planetary Atmospheres, Vol. 1; p 363-385
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  • 90
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    Infrared absorption by OH containing compounds (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The spectroscopy of the species H2O, H2O2, and HO2 are discussed. Their vibration rotation transitions are emphasized, but the pure rotational transitions in the vibrational ground state of H2O are also considered since they contribute to opacity in the middle infrared region.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Vibrational-Rotational Spectry. for Planetary Atmospheres, Vol. 1; p 295-310
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  • 91
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    New theoretical and experimental methods for pressure broadened linewidths and their interpretation (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A review of recent progress in the theory of collisional line broadening, particularly the impact of recent advances in collision dynamics calculations is presented. Some new approaches to the interpretation of experimentally measured linewidths and their impact on planetary atmosphere research are discussed. Experimental techniques which may have some advantage in providing pressure broadening data at very low temperatures are also mentioned.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: NASA. Goddard Space Flight Center Vibrational-Rotational Spectry. for Planetary Atmospheres, Vol. 1; p 125-148
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  • 92
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    Molecular spectroscopy and planetary exploration from space (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Examples of the role which molecular spectroscopy played in the interpretation of the thermal emission spectra of Earth, Mars, and Jupiter are given. Some advantages of molecular spectroscopy from a spacecraft passing close to a planet, or from an orbiter, over ground based techniques are discussed. Specifically the possibility of obtaining spectra over a wide spectral range (1) without the obscuring effect of Earth's atmosphere, (2) at much higher spatial resolution, and (3) from directions and with phase angles inaccessible from Earth.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Vibrational-Rotational Spectry. for Planetary Atmospheres, Vol. 1; p 29-47
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  • 93
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    Global picture of a Be star (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: An attempt is made to synthesize the observational material on Be stars into a empirical pattern of atmospheric structure. The sequence of atmospheric regions is developed and empirical-numerical estimates of location and structure of the regions are described. Inferences are drawn concerning the general stellar structure required to generate the nonthermal fluxes which produce the observed atmospheric pattern. In particular the atmospheric and subatmospheric origins of mass flux are addressed.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA, Washington B Stars With and Without Emission Lines, Parts 1 and 2; p 409-451
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  • 94
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    Channel and physical models of the Jovian subnebula (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: A semiempirical physical model of the Jovian subnebula was developed by analogy with the primitive solar nebula itself. The chemical aspects of this model are developed according to the principles developed in the study of the thermochemistry and gas kinetic behavior of the solar nebula, but with important modifications to take into account the higher pressures and densities in the Jovian subnebula. The bulk compositions and densities of the inner satellites of Jupiter are calculated. It is proposed that Europa differs from Io chiefly in that in has suffered a less severe thermal history. The general features of this model are applicable with minor modification to the systems of Saturn and Uranus.
    Schlagwort(e): LUNAR AND PLANETARY EXPLORATION
    Materialart: Planetary Atmospheres Program; p 4-26
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  • 95
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    On the variability of LSI+61 deg 303 (identical with GT 0236) (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Out of six long and six short wavelength observations, one spectrum exhibits a significant photometric variation: or approximately 20%. Interpreting the continuum as due to superposition of an early B main sequence star plus a gaseous component contributing at lambda 2000 A, the wavelength dependence of the variation suggests that it derives from the latter component. The data indicate that if the observed variation is phase dependent, a minimum should occur between phases 0.8 and 0.2. However, since the variation is observed in only one spectrum, it may well be erratic.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 615-618
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  • 96
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    Empirical atmospheric velocity patterns from combined IUE and visual observations: The Be similar stars (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The velocity pattern which panspectral observations of the Be stars suggest, and an outline of its extension via similar panspectral observations of the Be similar stars are summarized. The time dependent interaction between the stellar mass flux and the local environment produced jointly by the star itself and its original environment are emphasized.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 584-588
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  • 97
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    Mass loss at discrete velocities in Be stars: Evidence for non-radiatively driven wind (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The temporal behavior of the high velocity, relatively narrow absorption components in C IV, Si III, IV observed in the pole-one Be stars psi Ori, 66 Oph, and HR 4009 and what these observations contribute toward our understanding of the Be phenomenon are discussed. Ground based and X-ray data on these stars are compared as well as their UV differences with similarly active Be stars with larger projected rotational velocities.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 575-578
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  • 98
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    continuum and emission lines in eta Lyrae (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: Integral photometric characteristics of beta Lyrae were redetermined using its brightest visual companion, the star HD 174664. It was attempted to separate the fluxes coming from the two components. The flux distributions are badly contaminated by the radiation of the circumstellar hydrogen. Peculiarities seem to be present in both components; in particular, the secondary star cannot be represented by an atmosphere with a unique effective temperature, and best represented by a thick disk.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 550-553
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  • 99
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    A recent time of minimum for and atmospheric-eclipse in the ultraviolet spectrum of the Wolf-Rayet eclipsing binary V444 Cygni (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The 1200-1900 angstrom region and fine error sensor observations in the optical for V444 Cyg were continuously observed. More than half of a primary minimum and almost a complete secondary minimum were observed. It is found that the time of minimum for the secondary eclipse is consistent with that for primary eclipse, and the ultraviolet times of minimum are consistent with the optical ones. The spectrum shows a considerable amount of phase dependence. The general shaps and depths of the light curves for the FES signal and the 1565-1900 angstrom continuum are similar to those for the blue continuum. The FES, however, detected an atmospheric eclipse in line absorption at about the phase the NIV absorption was strongest. It is suggested that there is a source of continuum absorption shortward of 1460 angstrom which exists throughout a large part of the extended atmosphere and which, by implication, must redden considerably the ultraviolet continuua of WN stars. A fairly high degree of ionization for the inner part of the WN star a atmosphere is implied.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 542-545
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    A search for cataclysmic binaries containing strongly magnetic white dwarfs (1982)
    In:  Other Sources
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    Publikationsdatum: 2011-08-18
    Beschreibung: The AM Herculis type binaries which contain accreting white dwarfs with surface magnetic fields of a few times 10 to the seventh power gauss were studied. If white dwarfs in cataclysmic binaries have a range of field strengths similar to that among single white dwarfs. AM Her like systems should exist with fields as high as 3 x 10 to the eighth power gauss. It is suggested that such objects will not have the strong optical polarization of the AM Her variables; however, they exhibit high harmonic cyclotron emission, making them spectacular UV sources. We made IUE observations of seven candidate cataclysmic variables selected for optical similarity to AM Her binaries. Although all seven objects were detected in the UV, none display unusually strong UV continua. It is suggested that the distribution of magnetic field strengths among single white dwarfs may be different from that among binaries.
    Schlagwort(e): ASTRONOMY
    Materialart: NASA. Goddard Space Flight Center Advan. in Ultraviolet Astron.; p 530-533
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