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The relative positions and proper motions of components for 32 triple stars from HIPPARCOS input catalogue.
Orlov, V. V.; Anosova, Zh. P.; Todua, M. M.
A statistical study of the astrometric data for 32 triple stars has been carried out in the frame of the program of the International working group "Double and Multiple Stars HIPPARCOS". The relative positions and proper motions of the components have been made more accurate, uncertainties of their determinations have been analysed.
Analyses of Wolf-Rayet Stars.
Schmutz, W.; Hamann, W. -R.; Koesterke, L. +5 more
Current ideas about the production of the electroglow of Uranus
Clarke, J. T.
A process known as ``electroglow'' was identified by Broadfoot et al. /1/ shortly after the Voyager Uranus encounter as soft charged particle excitation of atmospheric gas in the presence of sunlight and in excess of the available photoelectron energy. Localized aurora and diffuse H and H2 band emissions have been observed from Uranus, …
Gamma rays and interstellar gas in the Cepheus region: A new gamma-ray source?
Grenier, I. A.; Lebrun, F.
A recent CO survey of the Cepheus Flare region (100°<=1<=141°, 8°<=b<=22°) has allowed a detailed study of the diffuse gamma-ray emission and the gas content of this nearby region. The comparison of the HI and CO observations with the COS-B gamma-ray data yields estimates of the N(H2)/WCO ratio in this molecular complex and …
Variability of GX 3+1 observed with EXOSAT.
Frontera, F.; Stella, L.; Robba, N. R. +1 more
The authors report results from an observation of the X-ray source GX 3+1 carried out with the EXOSAT satellite on 1983, October 23. The source showed a strong X-ray variability in excess of the counting statistics noise. This variability increased toward low frequencies ("red noise") and was different in different energy bands, with the lower ene…
First ultraviolet observations of the transition regions of X-ray bright solar-type stars in the Pleiades
Linsky, J. L.; Caillault, J. -P.; Vilhu, O.
Nearby clusters, such as Ursa Major, the Hyades, and the Pleiades, have been extensively studied in the X-ray regime. The first two clusters have also been studied with the IUE. However, the younger, fainter Pleiades cluster, which contains the youngest, and presumably most active, main sequence stars in the solar vicinity, had not been observed i…
X-Ray Observations of Gamma-Ray Burst Sources
Hurley, K.; Boer, Michel; Pizzichini, G. +1 more
We report on preliminary results of EXOSAT observations of three gamma-ray burst error boxes. No source was detected down to a limit of 10‑10 erg cm‑2s‑1, assuming a black-body spectrum for the burst counterpart. Results are interpreted in the framework of current theoretical models.
Highlights from the COS-B mission
Hermsen, W.
The European Space Agency's high-energy (E>50 MeV) gamma-ray observatory COS-B was operational from August 1975 to April 1982 and in that time made 65 observations of about 1 month duration and with a field-of-view of approximately 0.4 sr each. The high counting statistics achieved over the total mission allowed, for the first time, a detailed …
Gamma-ray constraints on the Galactic halo
Bloemen, J. B. G. M.
Some findings from recent COS-B analyses of the diffuse Galactic γ-ray emission are briefly summarized, with emphasis on their impact for our understanding of the Galactic cosmic-ray halo.
Gamma rays from dark clouds.
Feitzinger, J. V.; Stuewe, J. A.
The distribution of dark clouds and the COS-B X-ray observations of the local interstellar medium at intermediate galactic latitudes are compared. The dark cloud catalog of Lynds (1962) is combined with the complementary work of Feitzinger & Stuewe (1986) to obtain a uniform coverage of the medium-latitude sky. A good correlation between the e…