Search Publications
Missions
Journals
Publication Years
The old nova GK Per : discovery of the X-ray pulse period.
King, A. R.; Watson, M. G.; Osborne, J.
EXOSAT observations of GK Per during an optical outburst are reported. The hard X-ray emission (greater than 2 keV) shows a strong coherent modulation at a period of 351 s, identifying GK Per as the latest member of the 'intermediate polar' subclass of magnetic cataclysmic variables. The X-ray pulse profile has a quasi-sinusoidal shape with mean a…
The Structure of Low-Mass X-Ray Binaries
White, N. E.; Mason, K. O.
The present knowledge of the structure of low-mass X-ray binary systems is reviewed. We examine the orbital period distribution of these sources and discuss how the orbital periods are measured. There is substantial observational evidence that the accretion disks in low-mass X-ray binaries are thick and structured. In a number of highly inclined s…
The discovery of 4.4 second X-ray pulsations from the rapidly variable X-ray transient V 0332+53.
Stella, L.; Parmar, A. N.; White, N. E. +3 more
Using the EXOSAT Observatory, three outbursts from the transient X-ray source V0332 + 53 have been observed between November 1983 and January 1984. It is found that in addition to the rapid Cyg X-1-like variability previously reported by Tanaka et al. (1983), this source also displays stable pulsations with a period of 4.4 s. Doppler variations in…
EXOSAT observations of broad iron K line emission from Scorpius X-1.
White, N. E.; Taylor, B. G.; Peacock, A.
Using the Exosat Gas Scintillation Proportional Counter a broad iron K emission line is found to be present in the X-ray spectrum of Sco X-1. The line full width half-maximum (FWHM) is 0.7 keV, independent of the source intensity state. During flaring intervals the line intensity remains constant such that the equivalent width, decreases from 50 e…
The apsidal motion of the eccentric eclipsing binary DI Herculis - an apparent discrepancy with general relativity.
Guinan, E. F.; Maloney, F. P.
DI Her is an important system for studying relativistic apsidal motion because of the large masses and small fractional radii of its components, the large orbital eccentricity and its relatively short period, and the favorable orientation of its orbital plane to our line of sight producing deep eclipses. In addition, the long history of eclipse ti…
An X-ray study of AM Herculis. I. Discovery of a new mode of soft X-ray emission.
Stella, L.; Heise, J.; King, A. R. +4 more
The discovery of a new mode of soft X-ray emission of the magnetic cataclysmic variable AM Her is reported. AM Her has been observed in June, August and September 1983 with EXOSAT in both hard (1-30 keV) and soft (40-120 A) X-rays. Hard X-rays were seen to be partially eclipsed and periodic with the white dwarf rotation period. The eclipse phases …
Ultraviolet spectral evolution and heavy element abundances in nova Coronae Austrinae 1981.
Williams, R. E.; Truran, J. W.; Wyckoff, S. +3 more
Nova CrA 1981, a moderately fast galactic nova, was systematically observed over a period of seven months with the IUE satellite. The initial evolution of the UV spectrum was similar to that of previously observed novae; however, several months after maximum, weak emission due to very high ionizating forbidden lines of Na, Mg, Al, and Si appeared,…
IUE observations of beta Pictoris : an IRAS candidate for a proto-planetary system.
Kondo, Y.; Bruhweiler, F. C.
The authors have obtained new IUE observations of β Pic, which was identified from IRAS observations as one of the several candidate stars associated with proto-planetary systems (reported by Aumann and colleagues) and whose near-infrared imagery by Smith and Terrile showed an edge-on disk surrounding the star. New high-resolution spectra, when co…
Interstellar dust in the Large Magellanic Cloud.
Martin, P. G.; Clayton, G. C.
This paper presents extensive observations of the properties of interstellar dust in the Large Magellanic Cloud. Extinction and polarization analysis of 12 reddened stars spread across the LMC shows that in the optical and infrared the dust characteristics are remarkably similar to the Galaxy. The wavelength dependence of the polarization and the …
TT ARIETIS : the low state.
Szkody, P.; Shafter, A. W.; Bond, H. E. +3 more
A comprehensive photometric and spectroscopic study of the low state of the novalike variable TT Ari has been made with observations spanning the UV to IR spectral regions. The roughly 5 mag drop in the system's luminosity from the high state indicates that the mass-transfer rate decreased by more than two orders of magnitude. The drastic reductio…