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500 3200 Å observations of the interacting binary stars V356 Sgr and β Lyr
Polidan, R. S.
In this paper we present new results from the Voyager ultraviolet spectrometers and the IUE spacecraft on V356 Sgr and β Lyr. The V356 Sgr observations cover, in detail, two eclipses and include one IUE high dispersion SWP image. During both eclipses the total strength of the UV emission lines were found to be invariant. Also, an uneclipsed UV con…
EXO 032957-2606.9 : a new long-period probable AM Herculis binary.
Tagliaferri, G.; Beuermann, K.; Giommi, P. +2 more
The identification of the serendipitous Exosat X-ray source EXO032957-2606.9 with a new probable long-period AM Herculis binary is reported. The orbital period is (228 + or - 1) min (1-sigma error). The classification as an AM Herculis binary is based on the very soft X-ray spectrum and the characteristics of the high-excitation optical spectrum. …
On the Possible Detection of Organic Dust-borne C 3H + Ions in the Coma of Comet Halley
Reme, H.; Korth, A.; Lin, R. P. +4 more
The heavy ion analyzer (PICCA) on board the Giotto spacecraft was used to determine the composition of positively charged ions in the environment of Comet Halley. Here it is argued that a distinct peak at 37 amu, observed in the mass spectrum inside the ionopause, is due to C3H(+). It is further argued that the dominant source of this ion, as well…
Complex organic ions in the atmosphere of Comet Halley
Anderson, K. A.; Reme, H.; Korth, A. +7 more
The ordered series of broad mass groups observed in thermal ion mass spectra taken in the coma of Comet Halley by the RPA2-PICCA instrument aboard the Giotto spacecraft is shown to be characteristic of molecules rich in hydrogen, carbon, nitrogen, and oxygen, and does not imply the presence of a long chain polymer such as polyoxymethylene. Inside …
IUE Observations of Wolf-Rayet Binary Systems in the Small Magellanic Cloud
Moffat, Anthony F. J.; Koenigsberger, Gloria; Auer, Lawrence H.
The results of IUE observations of three SMC W-R binary systems at various orbital phases are presented. Selective atmospheric eclipse effects are evident in HD 5980 (WN 4 + O7 I:) and Sk 188 (W04 + O4 V), and are very weak or absent in Sk 108 (WN 3 + O6.5 I:). The difference in heavy-metal content between the SMC and Galactic objects is especiall…
Non-Planckian behaviour of burst spectra : dependence of the blackbodyradius on the duration of bursts.
van Paradijs, J.; Jansen, F.; Oosterbroek, T. +3 more
Exosat observations indicate a strong correlation between X-ray burst duration and the blackbody temperature measured at the moment when the flux has decayed to 10 percent of the Eddington flux. No correlation is observed between the persistent flux near the burst and this temperature. Burst spectra reveal deviations from a Planckian spectrum whic…
Deuterium content of the Venus atmosphere
Bertaux, J. -L.; Clarke, J. T.
THERE is no liquid water on Venus. The water vapour in its atmosphere would, if condensed, form a layer only 20 cm deep which means, in contrast to the 3-km-deep oceans that cover its sister planet Earth, that Venus is very dry indeed. It is not known with certainty whether Venus has lacked water since its formation, or if water once present has b…
Properties of plasma electrons in the magnetic pile-up region of comet Halley.
Anderson, K. A.; Rème, H.; Korth, A. +6 more
In the environment of comet P/Halley, a sharp transition, named the cometopause, was detected by the VEGA and GIOTTO spacecraft around 170000 km from the nucleus. In electron measurements, a clear discontinuity was detected 20% closer to the nucleus, than the cometopause as seen in the ion measurements. Significant changes in the electron distribu…
On the Signal-to-Noise Ratio in IUE High-Dispersion Spectra
Adelman, Saul J.; Leckrone, David S.
An observational and data reduction technique for fixed pattern noise (FPN) and random noise (RN) in fully extracted IUE high-dispersion spectra is described in detail, along with actual empirical values of signal-to-noise ratio (S/N) achieved. A co-addition procedure, involving SWP and LWR cameras observations of the same spectrum at different po…
The first decade of envelope formation of 59 Cygni in the far UV and optical regions. II.
Doazan, V.; Thomas, R. N.; Barylak, M. +3 more
Coordinated far-UV and optical observations of 59 Cygni are presented which, together with earlier results, describe the behavior of the entire atmosphere of the star during the first decade of formation and evolution of a new cool H-alpha emitting envelope. The data delineate an entire episode composed of a series of organized changes in the size…