The optical counterpart of Aquila X-1 (3U 1908+00).
Abstract
We have discovered a highly variable star very close to the center of the SAS 3 error circle for the flaring X-ray source Aquila X-1 (3U 1908+00). Photographic photometry over the last 4 years shows covariability; the optical counterpart brightens from B greater than 20 to B approximately 17 mag during times of X-ray outburst, thus establishing the identification. Spectrophotometry of this star during its quiescent state shows spectral features of a K0 star with no obvious peculiarities; its distance must be at least 1.7 kpc.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1978
- DOI:
- 10.1086/182651
- Bibcode:
- 1978ApJ...220L.131T
- Keywords:
-
- Stellar Spectrophotometry;
- Variable Stars;
- X Ray Sources;
- Astronomical Photography;
- Astronomy;
- Variables:X-Ray Sources;
- X-Ray Sources: Optical Counterparts