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IUE Observations of Comet p/ Halley - Evolution of the Ultraviolet Spectrum Between 1985SEP and 1986JUL
Feldman, P. D.; A'Hearn, M. F.; Schleicher, D. G. +13 more
The ultraviolet spectrum of comet P/Halley (1982 i) was monitored with the International Ultraviolet Explorer (IUE) satellite observatory between 1985 September 12 and 1986 July 8 (r < 2.6 AU pre- and post-perihelion) at regular time intervals except for a two-month period around the time of perihelion. A complete characterization of the UV spe…
Expansion Velocity and Temperatures of Gas and Ions Measured in the Coma of Comet p/ Halley
Berthelier, J. J.; Eberhardt, P.; Krankowsky, D. +9 more
In situ measurements of flow velocity and temperature in the inner coma were obtained from ram energy spectra of molecules and ions observed by the NMS experiment onboard the Giotto probe to comet Halley. Radial flow speed was (800 ± 50) m s-1 at distances from the nucleus between 1000km and 4000 km. Whereas ions became stagnant just ou…
Soft X-ray transients in quiescence : observations of AQL X-1 and CenX-4.
van Paradijs, J.; Verbunt, F.; Arnaud, K. A. +1 more
The authors observed the soft X-ray transients Aql X-1 and Cen X-4 during quiescence with EXOSAT. For Aql X-1 they obtain a 3σ upper limit to the X-ray luminosity Lx (in the energy range between 0.5 and 4.5 keV) of <3.0×1033erg s-1, Cen X-4 was detected at Lx (0.5 - 4.5 keV) ≅ 1.5 to 4.2×1033
Giotto magnetic-field results on the boundaries of the pile-up region and the magnetic cavity
Neubauer, F. M.
Data from Giotto's magnetometer collected during the encounter at Comet Halley on March 13/14, 1986, were used to investigate the most conspicuous boundaries in the inner plasma region surronding Comet Halley, i.e., the pile-up boundary and the ionopause. The normal vectors at the boundary crossings were determined using the minimum variance techn…
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…