Discovery of a variable star population in NGC 2808
Abstract
We have applied the image subtraction method to images of the peculiar, bimodal-horizontal branch globular cluster NGC 2808, taken over a total of six nights over a range of five months. As a result, we have found, for the first time, a sizeable population of variable stars in the crowded inner regions of the cluster, thus raising the known RR Lyrae population in the cluster to a total of 18 stars. In addition, an eclipsing binary and two other variables with periods longer than 1 day were also found. Periods, positions and (differential) light curves are provided for all the detected variables. The Oosterhoff classification of NGC 2808, which has recently been associated with a previously unknown dwarf galaxy in Canis Major, is briefly discussed.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 2004
- DOI:
- 10.1051/0004-6361:20035944
- arXiv:
- arXiv:astro-ph/0405004
- Bibcode:
- 2004A&A...421..667C
- Keywords:
-
- Galaxy: globular clusters: individual: NGC 2808;
- stars: horizontal-branch;
- stars: variables: RR Lyr;
- Astrophysics
- E-Print:
- 8 pages, 4 figures. A&