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Optical spectroscopy and photometry of the periodic X-ray transient AO 538-66 ( X 0535-668) during an outburst and an OFF state.
Parmar, A. N.; Branduardi-Raymont, G.; Mason, K. O. +2 more
Optical spectroscopy and photometry of the periodic X-ray transient A0538 - 66 are presented. Extensive spectroscopy performed in March 1982 follows the evolution of the multi-component line profiles through an outburst. Particularly distinctive are the broad, asymmetric emission lines which are interpreted as arising in an extensive stellar wind.…
The ultraviolet spectrum of the Be star HD 50138.
Hutsemekers, D.
The ultraviolet spectrum of the B8 Ve star HD 50138, recorded during the December 1978-January 1982 period with IUE, is analyzed. The spectrum is found to be crowded by absorption lines, mostly those of singly ionized iron peak elements. In addition there are broad lines essentially due to superionized species (Si IV, C IV) and a P Cygni profile f…
Line identifications, line strengths and continuum flux measurements in the ultraviolet spectrum of Arcturus.
Carpenter, K. G.; Stencel, R. E.; Wing, R. F.
The ultraviolet spectrum of Arcturus has been observed at high resolution with the IUE satellite. Line identifications, mean absolute 'continuum' flux measurements, integrated absolute emission-line fluxes, and measurements of selected absorption line strengths are presented for the 2250-2930 A region. In the 1150-2000 A region, identifications ar…
Carbon IV absorption troughs in the ultraviolet spectra of Be stars :gone with the wind ?
Marlborough, J. M.; Barker, P. K.
IUE observations of five Be stars reveal striking and previously unrecognized forms of stellar wind variability. Broad C IV double-lambda 1548,1550 absorption troughs, which underlie shortward-shifted narrow absorption components, may disappear or reappear. The C IV equivalent width can vary by a factor approximately equal to or greater than 5 on …
UV and optical observations of variability in the WR+compact candidate HD 96548.
Smith, L. J.; Lloyd, C.; Walker, E. N.
The present IUE SWP high resolution spectra of the WR+ compact candidate HD 96548 exhibit significant variability in the P Cygni and emission line profiles. A reanalysis of previously published visible photometry in light of new data shows that all the photometry is periodic, with a period of 5.879 d or its one-day aliases at 0.855 and 1.204 d. Th…
The ultraviolet spectrum of the symbiotic star HM Sge.
Nussbaumer, H.; Mueller, B. E. A.
The authors present IUE fluxes of the symbiotic star HM Sge, extracted from IUE observations made during the years 1978 - 1983. They argue in favour of an accretion disc model. They suggest that the sudden flux increase in He II and the more highly ionized atoms were due to a decrease from a high mass accretion rate, leading to a luminosity above …
IUE observations of amorphous hot galaxies.
Hunter, D. A.; Lamb, S. A.; Gallager, J. S., III +1 more
Blue amorphous galaxies are star-forming, irregularlike systems which lack the spatially distinct OB stellar groups that are characteristic of most late-type galaxies. In order to better understand the nature of star-formation processes in these unusual galaxies, short-wavelength IUE spectra of the amorphous galaxies NGC 1705 and NGC 1800 have bee…
Closed coronal structures. VI. Far-ultraviolet and X-ray emission from active late-type stars and the applicability of coronal loop models.
Golub, L.; Peres, G.; Vaiana, G. S. +2 more
We present far-ultraviolet line fluxes of prominent transition region emission lines, as obtained with the International Ultraviolet Explorer satellite, for a sample of solar-type stars. We combine the ultraviolet observations with existing soft X-ray measurements obtained by the Einstein Observatory (HEAO 2). We utilize the resulting data set and…
On the nature of the UX Ursa Majoris-type nova-like variables : CPD -48 1577.
Sion, E. M.
A series of low-dispersion spectra and one high-dispersion spectrum have been obtained of the catacylsmic variable CPD-48 deg 1577. Like other UX UMa stars, this variable exhibits the flat continuum of a luminous, thick, steady state accretion disk dominating its light from the far UV to the infrared. A wind mass loss rate of less than about 10 to…
HD 160538 and HD 185510 : two active-chromosphere stars with hot companions.
Fekel, F. X.; Simon, T.
Short-wavelength ultraviolet spectra of two active-chromosphere giants, HD 160538 and HD 185510, show hot stellar continua and Lα absorption features. The hot companion of HD 160538 is a white dwarf whose ultraviolet spectrum is matched best to the energy distribution of a Teff = 30000K and log g = 8 model atmosphere. The ultraviolet sp…