Showing results 201 to 204 of 204
  The ultraviolet spectrum of the Be star HD 50138Hutsemekers, Damien  in Astronomy and Astrophysics. Supplement Series (1985), 60 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 ... [more ▼] 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 for the Mg II doublet, similar to that seen in the star AB Aur. A few Fe II emission lines are also detected. The slowly expanding envelope surrounding HD 50138 appears to be decelerated outward with a decreasing ionization. The physical state of this envelope seems to suffer strong variations: a double structure was detected for some of the absorption lines in 1978-1979, and is interpreted as due to an outburst. A net increase of the excitation in 1980 is also observed and vanishes in 1982. In order to explain the unusual profiles of the Mg II lines, a possible fluorescence mechanism driven by Ly-beta is discussed. An accurate list of line identification is also provided. [less ▲] Detailed reference viewed: 12 (5 ULg)The structure and physical conditions characterizing the emission-line galaxy He 2-10Hutsemekers, Damien ; Surdej, Jean in Astronomy and Astrophysics (1984), 133 Direct plates taken through interference (Halpha+[N II] and [O III]) and broad band (B, R) filters at the prime focus of the ESO 3.6 m telescope reveal the structure of the emission-line galaxy He 2-10 ... [more ▼] Direct plates taken through interference (Halpha+[N II] and [O III]) and broad band (B, R) filters at the prime focus of the ESO 3.6 m telescope reveal the structure of the emission-line galaxy He 2-10. The authors confirm that the broad emission band at lambda4660 Å first reported by Allen et al. (1976) essentially originates from the bright central nucleus. They estimate that the number of Wolf-Rayet (WC+WN) stars contributing to this feature is approximately 3.3×10[SUP]3[/SUP] and that the number of early-type stars (mainly O-type) necessary to account for the observed ionization of the emitting gas is of the same order. This result is compared to the stellar content derived for a few other galaxies and giant H II regions known to contain a large population of Wolf-Rayet stars. [less ▲] Detailed reference viewed: 7 (1 ULg)The UV spectrum of the Be star HD 50138.Hutsemekers, Damien in Be Star Newsletter (1983), 8 Not Available Detailed reference viewed: 7 (5 ULg)Supergéantes O et B dans le Grand Nuage de MagellanHutsemekers, Damien Master's dissertation (1982) Detailed reference viewed: 13 (7 ULg) |
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