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The beta Pictoris circumstellar disk. IV. Redshifted UV lines.
Ferlet, R.; Vidal-Madjar, A.; Lagrange, A. M.
Several new and archive observations with the International Ultraviolet Explorer have confirmed the variability of the UV circumstellar absorption lines of Fe II and Mg II toward β Pic. The authors furthermore show that all these variations take place on the red wing of the lines, in material which is moving toward the star. Tentative scenarios ar…
The radio to X-ray continuum emission of the quasar 3C 273 and its temporal variations.
Bouchet, P.; Falomo, R.; Gear, W. K. +7 more
Quasi-simultaneous multifrequency observations from radio to X-rays of the bright quasar 3C273 for several epochs between December 1983 and March 1986 are presented. The light curves in the different wavebands and the overall spectral energy distribution are analyzed. The NIR and optical fluxes showed small variations during the period considered,…
A detailed analysis of the high energy gamma-ray emission from the Crab pulsar and nebula.
Grenier, I. A.; Hermsen, W.; Bennett, K. +4 more
The gamma-ray emissions from the Crab pulsar and nebula are analyzed. The data were collected from 1975-1982 in the Galactic anticenter region by COS-B in the energy range 50-3000 MeV. The temporal behavior of the pulsed gamma-ray flux from PSR 0531 + 21 and the unpulsed gamma-ray emissions from the Crab region are examined. It is determined that …
EXOSAT observations of X-rays from classical novae during the outburst stage.
Beuermann, K.; Krautter, J.; Oegelman, H.
Soft X-ray light curves of the classical novae Nova Muscae 1983 and Nova Vulpeculae 1984 No. 1 and No. 2 from optical maximum to about 900 days after maximum were sampled with the Exosat satellite, and the implications of the results for models of nova outbursts are considered. The observations seem best explained by the constant bolometric lumino…
Systematics of the CHON and Other Light Element Particle Populations in Comet p/ Halley
Kissel, J.; Clark, B. C.; Mason, L. W.
Based on chemical signatures measured by the PIA experiment during the Giotto flyby of comet P/Halley, a number of particle classifications have been designated. In addition to silicate-like grains and particles of mixed (cosmic) composition, there appear to be several light-element rich populations including the CHON, (H,C), (H, C, O), and (H,C,N…
First statistical analysis of 5000 mass spectra of cometary grains obtained by PUMA 1 (Vega 1) and PIA (Giotto) impact ionization mass spectrometers in the compressed modes
Langevin, Y.; Bertaux, J. -L.; Kissel, J. +1 more
Impact ionization mass spectrometers have been flown on board the space vehicles Giotto (instrument PIA), Vega 1 and Vega 2 (instruments PUMA 1 and 2). All three instruments obtained a large collection of mass spectra of individual cometary dust particles in the mass range 3×10-16 - 3×10-10g. Spectra from PUMA 2 are still bei…
The D/h Ratio in Water from Comet p/ Halley
Berthelier, J. J.; Eberhardt, P.; Krankowsky, D. +6 more
The neutral gas mass spectrometer on the Giotto spacecraft made neutral and ion composition measurements with a high mass resolution. From a preliminary evaluation of the ion data within the contact surface the authors obtain for the water in Halley an 18O abundance of 18O/16O = 0.0023±0.0006 and for the D/H ratio …
Rotational modulation and flares on RS CVn and BY DRA stars. VI. Physical parameters of the chromospheres/transition regions of V711 Tau (HR 1099), II Peg and AR Lac during october 1981.
Doyle, J. G.; Linsky, J. L.; Rodono, M. +2 more
Ground-based optical and IUE satellite-ultraviolet observations of three RS CVn stars are combined with density sensitive line ratios and differential emission measure curves to describe the physical conditions in their outer atmospheres. Solar-like densities are found to be representative of average conditions on two of the stars, V 711 Tau and A…
General Features of Comet p/ Halley - Solar Wind Interaction from Plasma Measurements
Anderson, K. A.; Reme, H.; Korth, A. +8 more
The Giotto RPA-COPERNIC plasma experiment identified several regions in which the solar wind interaction with the cometary plasma displayed characteristic features: (1) Beginning ∼4.6×106km from the comet there is an upstream region with sporadic connection to the comet, (2) An electron foreshock is present up to 2.5×105km aw…
Ion Temperature and Flow Profiles in Comet p/ Halley's Close Environment
Schwenn, R.; Balsiger, H.; Goldstein, R. +5 more
The HIS instrument of the ion mass spectrometer on board the Giotto spacecraft identified the contact surface at 4800 km distance from the comet nucleus. This boundary is clearly seen by a drastic drop in the temperatures of different ion species from about 2000 K outside to values as low as 300 K inside. Also, inside the contact surface an outflo…