Extinction and Abundance Properties of Alpha Scorpii Circumstellar Grains
Abstract
The authors have investigated the ultraviolet extinction and element depletions in the circumstellar envelope of the M supergiant binary system, α Sco, by using IUE, Copernicus, and ANS data of the B dwarf companion, α Sco B, which can be seen in absorption through the cool-star envelope. After assessing the interstellar, circumstellar, and atmospheric column densities toward α Sco B, the authors estimated the circumstellar reddening, the circumstellar depletions, and the circumstellar spectral extinction toward α Sco B. It is found that the circumstellar grains in this oxygen-rich environment are larger than 0.05 μm and siliceous in composition, yet contain less depleted elements than the diffuse-interstellar grains in the Scorpius region or the general Galactic diffuse-interstellar grains.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1987
- DOI:
- 10.1086/165685
- Bibcode:
- 1987ApJ...321..921S
- Keywords:
-
- Abundance;
- Binary Stars;
- Interstellar Matter;
- M Stars;
- Stellar Envelopes;
- Supergiant Stars;
- Hydrogen;
- Interstellar Extinction;
- Iue;
- Spectral Resolution;
- Stellar Spectrophotometry;
- Ultraviolet Spectra;
- Astrophysics;
- INTERSTELLAR: GRAINS;
- STARS: CIRCUMSTELLAR SHELLS;
- STARS: INDIVIDUAL CONSTELLATION NAME: ALPHA SCORPII