The Identification of RR Lyrae and δ Scutti Stars from Variable Galaxy Evolution Explorer Ultraviolet Sources
Abstract
We identify the RR Lyrae and δ Scuti stars in three catalogs of Galaxy Evolution Explorer (GALEX) variable sources. The NUV amplitude of RR Lyrae stars is about twice that in V, so we find a larger percentage of low-amplitude variables than catalogs such as Abbas et al. Interestingly, the (NUV - V)0 color is sensitive to metallicity and can be used to distinguish between variables of the same period but differing [Fe/H]. This color is also more sensitive to T eff than optical colors and can be used to identify the red edge of the instability gap. We find 8 δ Scuti stars, 17 RRc stars, 1 RRd star, and 84 RRab stars in the GALEX variable catalogs of Welsh et al. and Wheatley et al. We also classify 6 δ Scuti stars, 5 RRc stars, and 18 RRab stars among the 55 variable GALEX sources identified as "stars" or RR Lyrae stars in the catalog of Gezari et al. We provide ephemerides and light curves for the 26 variables that were not previously known.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 2014
- DOI:
- 10.1088/0004-6256/148/6/121
- arXiv:
- arXiv:1408.0808
- Bibcode:
- 2014AJ....148..121K
- Keywords:
-
- stars: horizontal-branch;
- stars: variables: delta Scuti;
- stars: variables: RR Lyrae;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 17 pages, accepted in AJ