Magnitude, color and spectral type of AQL X-1 in quiescence
Abstract
Direct I and V-band imaging of Aql X-1 in quiescence and during outburst maximum shows that the true optical counterpart is the interloper located 0.48'' West of the previously known star. We find for the new counterpart V = 21.6 and V-I = 2.2 in quiescence, when its contribution to the total light was 12% in V and 22% in I. Analysis of this photometry and of low-resolution spectra of the sum of both stars, also taken during quiescence, shows that the likely spectral types for the previously known star and the optical counterpart are late G and late K, respectively, reddened by E(B-V) = 0.5+/-0.1. Based on observations obtained at the European Southern Observatory, La Silla, Chile
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1999
- DOI:
- 10.48550/arXiv.astro-ph/9906278
- arXiv:
- arXiv:astro-ph/9906278
- Bibcode:
- 1999A&A...347L..51C
- Keywords:
-
- STARS: BINARIES: CLOSE;
- STARS: INDIVIDUAL: AQL X-1;
- STARS: NEUTRON;
- X-RAYS: STARS;
- Astrophysics
- E-Print:
- 4 pages + 4 figures, uses aa.cls, accepted by A&