The identification of the optical/IR counterpart of the 15.8-s transient X--ray pulsar XTE J1946+274
Abstract
We report on the discovery of the optical/IR counterpart of the 15.8 s transient X-ray pulsar XTE J1946+274. We re-analyzed archival BeppoSAX observations of XTE J1946+274 obtaining a new refined position (a circle with 22\arcsec radius at 90% confidence level). Based on this new position we carried out optical and infra-red (IR) follow-up observations. Within the new error circle we found a relatively optical faint (B=18.6) IR bright (H=12.1) early type reddened star (V-R=1.6). The optical spectra show strong Hα and Hβ emission lines. The IR photometric observations of the field confirm the presence of an IR excess for the Hα -emitting star (K=11.6, J-H=0.6) which is likely surrounded by a circumstellar envelope. Spectroscopic and photometric data indicate a B0-1V-IVe spectral-type star located at a distance of 8-10 kpc and confirm the Be-star/X-ray binary nature of XTE J1946+274.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 2002
- DOI:
- 10.1051/0004-6361:20021087
- arXiv:
- arXiv:astro-ph/0207587
- Bibcode:
- 2002A&A...393..983V
- Keywords:
-
- stars: individual:;
- XTE J1946+274;
- GRO J1944+26;
- binaries: general;
- stars: pulsars: general;
- stars: emission-line;
- Be;
- X-rays: stars;
- Astrophysics
- E-Print:
- Accepted for publication on A&