A new RR Lyrae Star in Segue 2

Type Conference Paper
Names Erin Boettcher, B. Willman, R. Fadely, J. Strader
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #221, #316.02
Volume 221
Date January 1, 2013
URL http://adsabs.org/2013AAS.22131602B
Library Catalog labs.adsabs.harvard.edu
Abstract We present a newly discovered fundamental mode (RRab) RR Lyrae star in the ultra-faint Milky Way dwarf galaxy companion Segue 2 (L ˜ 830 Lsun). We perform a near complete search for RR Lyrae in Segue 2 using Harris B and V band imaging taken at Kitt Peak National Observatory's 0.9 meter WIYN telescope. A very low metallicity for the RRab star ([Fe/H] <˜ -2.5) is hinted at by the length of the RRab star's period (Pab = 0.749 days). The RRab star as well as spectroscopically confirmed blue horizontal branch stars belonging to Segue 2 allow us to rigorously determine the distance to this object. Assuming a low metallicity ([Fe/H] = -2.5) for both the RRab and BHB stars, we find distances consistent within one standard deviation of dRRL = 37.9+2.8-2.7 kpc and dBHB = 35.2 ± 2.6 kpc. We gratefully acknowledge NSF AST-0908193 for support.
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