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IUE: un observatoire en orbite.
Gry, Cecile
The acquisition of ultraviolet data by the geosynchronous IUE satellite since its launch in 1978 is discussed, with emphasis on the procedure for obtaining IUE data from the Vilspa station near Madrid. Images are obtained by IUE every two hours on the average, with exposures lasting from 0.4 sec to 21 hours. UV spectra are derived from the images …
Ireland's contribution to deep space missions
McKenna-Lawlor, Susan M. P.
Irish contributions to the Giotto mission, the Phobos mission, and the planned International Solar Terrestrial Physics (ISTP) program are discussed. Results are presented from the Energetic Particle Onset Admonitor (Epona) experiment, which flew on the Giotto mission. The Epona instruments detected electrons, protons, alpha particles, and pickup i…
Quasi-periodic oscillations in celestial X-ray sources
van der Klis, Michiel
Exosat observations of the X-ray sources and the discovery of QPOs of GX5-1 are discussed. Recent developments in X-ray astronomy are reviewed. Also, possible models to explain QPOs in X-ray sources are examined.
Simulataneous X-ray and optical observations of LMC X-2
Motch, C.; Beuermann, K.; Pakull, M. +3 more
The X-ray source LMC X-2 was observed with EXOSAT for -8hours on February 2nd, 1984 with simultaneous photometric and spectroscopic optical coverage. The source was seen at a luminosity of Lx ~ 1.5 1038erg.s-1 with a mean X-ray spectrum which can be described equally well by either a superposition of a thermal emis…
Happy birthday, IUE
Coles, Peter
Two new results on PSR 0833-45: (1) optical data on its birthplace, and (2) possible polarization in its high energy gamma-ray emission
Bignami, G. F.
Two new and completely different results are presented, both related to the Vela pulsar PSR 0833-45. In Part I, recent ESO optical images of the pulsar and its starfield are compared to the discovery plates, and used to set stringent upper limits on its proper motion and thus on its birthplace. Consequences are briefly explored. Part 2 refers to a…
Ground-Based and On-Satellite Observations of BE and B Stars
Jeong, Jang-Hae
Gamma Cassiopeae has been observed at Yonsei University Observatory(YUO) for 31 nights in the period 1983-1987 and a total of 312 UBV observations(104 in each colour) was secured. Light curves of ¥ã Cas in V, B-V, and U-B have been constructed with YUO data; among them we present selected light curves of 5 different long nights. Discussed are the …
Spectroscopic Determinations of Surface Gravities of Giant Stars and Ultraviolet Observations of RR Lyrae and X ARIETIS
Bonnell, Jeremiah Tighe