Discovery and Quantitative Spectral Analysis of an Ofpe/WN9 (WN11) Star in the Sculptor Spiral Galaxy NGC 300
Abstract
We have discovered an Ofpe/WN9 (WN11 following Smith et al.) star in the Sculptor spiral galaxy NGC 300, the first object of this class found outside the Local Group, during a recent spectroscopic survey of blue supergiant stars obtained at the ESO Very Large Telescope. The light curve over a 5 month period in late 1999 displays a variability at the 0.1 mag level. The intermediate-resolution spectra (3800-7200 Å) show a very close resemblance to the Galactic luminous blue variable (LBV) AG Carinae during minimum. We have performed a detailed non-LTE analysis of the stellar spectrum and have derived a chemical abundance pattern that includes H, He, C, N, O, Al, Si, and Fe, in addition to the stellar and wind parameters. The derived stellar properties and the He and N surface enrichments are consistent with those of other Local Group WN11 stars in the literature, suggesting a similar quiescent or post-LBV evolutionary status. Based on observations obtained at the ESO Very Large Telescope [65.N-0389(B) and 67.D-0006(A)].
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 2002
- DOI:
- 10.1086/344241
- arXiv:
- arXiv:astro-ph/0208287
- Bibcode:
- 2002ApJ...577L.107B
- Keywords:
-
- Galaxies: Individual: NGC Number: NGC 300;
- Galaxies: Stellar Content;
- Stars: Wolf-Rayet;
- Astrophysics
- E-Print:
- 9 pages, 4 figures, 2 tables. Accepted for publication in the Astrophysical Journal Letters