Search Publications
The Long Period Binary AL Velorum: The Atmospheric Eclipse of a Bright KO Giant
Shore, Steven N.; Kondo, Yoji; Eaton, Joel A. +1 more
The properties of the AL Vel binary system, a Zeta Aur system containing a B dwarf and a bright K0 giant, are reviewed with reference to IUE observations of its atmospheric eclipse and eclipse of the accretion disk around the B-dwarf component. It is found that the conditions in the chromosphere are rather similar to those in the Zeta Aur supergia…
EXOSAT observations of three DA white dwarfs.
Beuermann, K.; Giommi, P.; Koester, D. +3 more
Exosat broad band filter observations, optical and IUE spectra, are presented for three DA white dwarfs. One source is a previously known Hyades white dwarf, the other two are new DA detected by Exosat. The results are consistent with previous observations of other DA white dwarfs and indicate that an absorber other than hydrogen (most probably he…
Ultraviolet Observations of the Enigmatic Bipolar Nebula M1-92
Feibelman, Walter A.; Bruhweiler, Frederick C.
IUE observations of the bipolar nebula M1-92 indicate that this object is an evolved object and possibly a preplanetary nebula. Data acquired in the SWP camera clearly show a flat UV continuum indicative of a relatively unobscured O subdwarf. Data acquired in the long wavelength region of the SWP and in the LWP camera reveal an object which mimics…
Mesures de vitesses radiales. III. Accompagnement AU sol du programmed'observation du satellite Hipparcos. Mesure de la vitesse radiale de391 etoiles dans 12 champs.
Burnage, R.; Fehrenbach, Ch.
The radial velocities of 391 stars, obtained with the Fehrenbach objective prism associated to the Schmidt telescope of the Observatoire de Haute-Provence are presented. These stars belong to fields specially chosen for containing several Hipparcos input catalog star members. Each field is presented independently. The list includes HD and BD ident…
A population synthesis model for the ultraviolet spectrum of the peculiar galaxy NGC 1672
Terlevich, Elena; Diaz, A. I.; Garcia-Vargas, M. L. +1 more
We present a stellar population synthesis model for the UV spectrum of the peculiar galaxy NGC 1672, computed with the use of theIUE Atlas Library of Stellar Spectra.
IUE observations of GL 644 AB (=Wolf 630) in the wavelength region 1150-1950 A, in June 1981.
Doyle, J. G.; Mathioudakis, M.
IUE short wavelength observations of the flare star Gl 644, obtained in June 1981 are presented. A flare was detected in one of the spectra as a strong increase in C IV, He II, and continuum fluxes. The electron density of the flaring plasma, determined using line ratio techniques, is 4 x 10 to the 10th/cu cm, which is an increase by a factor of 2…
UBVRI photometry of G, K, M HIPPARCOS stars.
Jordi, C.; Figueras, F.; Torra, J. +1 more
UBVRI data are presented for a set of 229 late-type stars, most of them being high proper motion stars. All these data are part of the Input Catalog planned observations for the Hipparcos mission.
EXOSAT Observations of the Rapidly Rotating Flare Star Gliese 890
Singh, K. P.; Rao, A. R.
This paper presents the first X-ray observations of the late-type dwarf flare star Gliese 890 using the low-energy (LE) and the medium energy (ME) detectors of the Exosat Observatory. A steady X-ray emission, most probably of coronal origin, is detected. No flaring activity is observed in X-ray observations. A combined spectral fit to the LE and M…
On the Interpretation of the EXOSAT Photometry of Two Hot DA White Dwarfs
Petre, Robert; Vennes, Stephane; Shipman, Harry L.
Exosat photometric observations of the hot DA white dwarfs GD 2 and EG 70 are presented and analyzed using model atmosphere and synthetic spectrum calculations. The numerical accuracy of the calculations and their impact on the reliability of the results are addressed. The optimum atmospheric parameters that explain the complete spectral coverage …
Signal-to-Noise Ratios in IUE SWP-LO Spectra of Chromospheric Emission-Line Sources
Ayres, Thomas R.
The short-wavelength-prime (SWP) detector of the International Ultraviolet Explorer should operate near the photon-counting limit, but the noise levels in flat-field images are several times higher. The exaggerated noise can be traced to the incomplete removal of the pixel-to-pixel granularity of the television frames by the prevailing spectral im…