Search Publications
The Variable Iron Line in CYGNUS-X-3
van der Klis, M.; Manzo, G.; Smith, A. +3 more
Cygnus X-3 was observed with the GSPC on board EXOSAT on several occasions, one observation lasting for 7 orbital cycles. The width W and centroid energy E of the iron emission feature near 6.7 keV show a smooth, correlated, sinusoidal-type modulation, the iron line being widest and E being lowest just before X-ray maximum. The line profile may sh…
Spectral variability of scorpius X-1, as observed with EXOSAT
Mewe, R.; Heise, J.; Brinkman, A. C. +3 more
EXOSAT measurements of Sco X-1 have been carried out with the 500 l/mm and 1000 l/mm grating spectrometers and simultaneously with the gas scintillation proportional counter (GSPC) on two occasions in August 1983. The first observing period, part of the instrument performance verification phase, on August 7 and 8, 1983, lasted for about twenty two…
Exosat observations of the galactic bulge X-ray source GX17+2
Sztajno, M.; Truemper, J.; Langmeier, A. +1 more
We have measured the X-ray flux of the bright galactic bulge source GX17+2 in the energy range 1-20 keV using the EXOSAT ME experiment. During 8 hours of continuous observation an X-ray flare was observed (lasting ~1 hr) followed by an intensity increase. The data show intensity dips with a quasiperiod of ~1.4 hours and quasi-periodic oscillations…
The August 1984 eclipse of 22 Vulpeculae.
Ake, T. B.; Parsons, S. B.; Hopkins, J. L.
The newly discovered eclipsing binary 22 Vul (G3 Ib-II + B9) was observed in and around the 1984 eclipse both with the IUE satellite and by photometrists at various ground-based observatories. The depth of total eclipse of the hot component was 0.05 mag in the V band, 0.14 in B, and 0.35 in U. Time of mideclipse is now established at JD2445942.3 (…
A survey of MG II H and K emission in near-solar-type stars.
Doherty, L. R.
IUE measurements of Mg II h and k emission fluxes are presented for 30 F and G stars that are on or near the main sequence and compared with Wilson's measurements of the Ca II H and K fluxes in these stars. The survey includes a large proportion of stars with very low chromospheric activity as well as 111 Tau, χ1Ori and other examples o…
Discovery of the hot companion to the two-day cepheid HD 129708.
Arellano Ferro, A.; Madore, B. F.
The Cepheid HD 129708 has been observed with the International Ultraviolet Explorer satellite, and a hot companion star (B4-5) has been discovered. Comparison of the observed energy distribution with theoretical atmosphere models gives Te = 16,000±1000K and log g = 4.0±0.5 for the hot companion. A visual magnitude difference ΔV = 2…
The ultraviolet absorption spectrum of NGC 4151.
Tarenghi, M.; Veron, P.; Veron-Cetty, M. P.
The analysis of all available low dispersion, short wavelength, large aperture IUE spectra of NGC 4151 taken prior to March 1982 shows a linear correlation between the depth of the absorption lines and the strength of the underlying emission; the absorption lines vanish while the continuum is still measurable. This is interpreted as being due to a…
The final COS-B database now publicly available
Caraveo, P. A.; Bignami, G. F.; Hermsen, W. +7 more
The data obtained by the gamma-ray satellite COS-B have been processed, condensed and integrated together with the relevant mission and experiment parameters into the "Final COS-B Database". The database contents and the access programs available with the database are outlined. The final sky coverage and a presentation of the large-scale distribut…
On the coronae of rapidly rotating star. V. The other stars.
Walter, F. M.
Results of Einstein X-ray observations of 25 stellar systems are presented. The systems observed include 15 spectroscopic binaries of which eleven were detected; nine were serendipitous detections, three of which may be new RS CVn systems. Coronal activity levels and their implications for these stars are discussed.
Properties of dust in the Orion nebula.
Patriarchi, P.; Perinotto, M.
New observations of the Orion nebula very close to the Trapezium stars have been taken with the IUE satellite in order to improve knowledge of the dust properties in the nebula. The new data have been interpreted together with previous observations using multiscattering models with various distributions of the dust-to-gas ratio. The main result is…