SIMBAD references

1994A&A...292..213B - Astronomy and Astrophysics, volume 292, 213-220 (1994/12-1)

Ultraviolet and optical spectroscopy of a B supergiant star in M 31.

BIANCHI L., LAMERS H.J.G.L.M., HUTCHINGS J.B., MASSEY P., KUDRITZKI R., HERRERO A. and LENNON D.J.

Abstract (from CDS):

We present and discuss the UV spectrum of the supergiant star in NGC206-277 in M 31, obtained with the Faint Object Spectrograph (FOS) on Hubble Space Telescope. Customised extraction of the data was used to properly correct for the background light in the FOS. An optical blue spectrum taken at KPNO is also shown. From the optical and UV line spectra we classify the star B1.5Ia. We fit the continuum far-UV flux distribution, deriving Teff=20000K, and with this temperature we find log g=2.5 by comparing the Hγ line and HeI lines with predictions from NLTE models. We analyse the stellar UV wind line profiles with the SEI method and derive a terminal velocity of v≃700km/s. We fit the Hα emission line obtained at the WHT with a newly developed (by H.J.G.L.M.L.) code similar to the SEI method for UV lines, and derive {dot}(M)=1.3±0.5x10–6M/yr. We also compare the UV lines with those of Galactic stars of the same type and we find that the P Cygni profiles of the M 31 star have slightly weaker and narrower absorptions, and no emission component. We correct our previously published mass-loss estimate for an O star (NGC206-231) in the same association. The correct value is {dot}(M)≃10–6M/yr, assuming solar abundances.

Abstract Copyright:

Journal keyword(s): stars: mass loss - stars: supergiants - stars: individual: NGC 206-231 (MAC 1 - 231) in M 31 and NGC 206-277 (MAC 1 - 277) in M 31 - galaxies: individual: M 31

CDS comments: stars NGC 206-231 and -277 = [MAC86] 1-231 and 1-277

Simbad objects: 6

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