A Luminous Companion to SGR 1806-20
Abstract
We have obtained infrared spectra of the star suggested to be the counterpart of the soft gamma-ray repeater (SGR) 1806-20. We found strong emission lines similar to those seen in the spectra of the rare Luminous Blue Variables and B[e] stars. A He I absorption line is also seen, from which we infer a spectral type O9--B2. This classification, in combination with the minimum distance of $\simgt6$ kpc inferred from its extinction, makes the star one of the most luminous in the Galaxy. We infer that it is a companion to SGR 1806-20, and suggest that the presence of a companion is somehow related to the SGR phenomenon.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 1995
- DOI:
- 10.1086/187853
- arXiv:
- arXiv:astro-ph/9502038
- Bibcode:
- 1995ApJ...444L..33V
- Keywords:
-
- Companion Stars;
- Gamma Ray Bursts;
- Infrared Spectra;
- Line Spectra;
- Stellar Envelopes;
- Stellar Luminosity;
- Stellar Winds;
- Color;
- Interstellar Extinction;
- Red Shift;
- Spectrum Analysis;
- Stellar Spectrophotometry;
- Astronomy;
- GAMMA RAYS: BURSTS;
- STARS: INDIVIDUAL ALPHANUMERIC: SGR 1806-20;
- STARS: NEUTRON;
- X-RAYS: STARS;
- Astrophysics
- E-Print:
- 5 pages, AASTEX text+table and 2 PostScript figures (needs LaTeX style files aaspptwo.sty, epsf.sty and rotate.sty). In case of problems, contact mhvk@astro.caltech.edu. Postscript file of complete article available on request. (Replaced because first version had one wrong reference in it)