Search Publications
The HIPPARCOS Input Catalogue - a Progress Report from an Astrometric Point of View
Turon, C.; Requieme, Y.
The construction of the Hipparcos satellite is proceeding according to the schedule and should be finished in March 1988. But, due to some problems with the Ariane European booster, the launch has now been postponed until 1989. In practice, this means that the astronomical community may expect delivery of the final Hipparcos Catalog only in 1995. …
Le nouvel astrolabe de l'Observatoire de Paris
Chollet, F.
The new polyvalent astrolabe of the Paris Observatory is described. After some optical modifications this new instrument is able to observe the stars, some planets, and the sun with an internal error less than 0.4 arcsec in the last case. Some new modifications are in progress to obtain better results and stability in the solar observations. This …
Residuals for the Observations of the 62 Selected Minor Planets
Calaf, J.
This paper reports results of the improvement of orbital elements of the 62 minor planets included in the Hipparcos mission. The astrometric observations supplied by the Minor Planet Center and the meridian circles at La Palma and Bordeaux observatories were used by the author. The accuracy reached (RMS O-C) for each minor planet and for La Palma …
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.
Stellar Mass Loss in Late B-Type Supergiants
Dufton, P. L.; Bates, B.; Gilheany, S. +1 more
A study using archive IUE data of time-varying mass loss has been carried out for a sample of 12 supergiants in the spectral range B5–B9. Additionally dedicated IUE velocity-time observations of 'discrete absorption components' (DAC) in the UV resonance lines have been made for one of the stars (βOri), while optical data obtained for this star sho…
The Ultraviolet Spectrum of the Be-Star 88-HERCULIS
Danezis, E.; Theodossiou, E.
In this paper, we give a detailed list and analysis of line identifications of the UV spectrum of the Be star 88 Her in the wavelength range λλ1958–3002 Å recorded in 1984, 23 May with the International Ultraviolet Explorer (IUE). The spectrum is crowded by shell absorptions lines, mostly those of singly ionized iron peak elements. The detailed an…
Multifrequency Behaviour of the Dwarf Nova Ss-Cygni
Rossi, C.; Gaudenzi, S.; Giovannelli, F. +3 more
Several years of coordinated multifrequency observations of the dwarf nova SS Cygni have been performed in order to study the accretion behaviour of this system in particular, and in general to clarify this crucial problem for the cataclysmic variables. From IUE measurements, together with those from optical and IR ground based telescopes, we have…
IUE Spectra of the Four Interacting Binary White Dwarf Stars - Am-Canum PG:1346+082 V803-CENTAURI and Gp-Comae - a Comparative Study
Solheim, J. -E.; Ulla, A. M.
This project is part of a world wide cooperation aimed at investigating properties of white dwarf stars to determine their constitution and evolution. The project is based on two recent developments: -The first is the discovery, of pulsational instabilities in some white dwarf stars, giving rise to non-radial pulsations which can be observed as fl…
Ultraviolet to near-infrared continuum flux distribution in the active binary RS canum venaticorum
Fabregat, J.; Reglero, V.; Gimenez, A.
We present multifrequency observations of the active binary RS CVn. Ultraviolet observations were obtained from the IUE data bank. Optical observations were made at the Observatorio del Roque de los Muchachos (La Palma), while the infrared observations were obtained at the Observatorio del Teide (Tenerife). The continuum of RS CVn shows that both …
Asymmetric winds in be stars
de Freitas Pacheco, J. A.; de Araujo, F. X.
The CIV and SiIV resonance doublets of 43 Be stars are investigated. Measurements of the equivalent widths seem to reveal a correlation between the strenght of the lines and the projected rotational velocity (v sini). it is discussed whether this result indicate that the wind region is not spherically symmetric.