Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I
Abstract
We have identified 23 RR Lyrae stars and 3 possible Anomalous Cepheids among 84 candidate variables in the recently discovered Canes Venatici I dwarf spheroidal galaxy. The mean period of 18 RRab type stars is <Pab> = 0.60 +/-0.01 days. This period, and the location of these stars in the period-amplitude diagram, suggest that Canes Venatici I is likely an Oosterhoff-intermediate system. The average apparent magnitude of the RR Lyrae stars <V> = 22.17 +/-0.02 is used to obtain a precision distance estimate of 210 +7/-5 kpc, for an adopted reddening E(B-V)=0.03 mag. We present a B,V color-magnitude diagram of Canes Venatici I that reaches V about 25 mag, and shows that the galaxy has a mainly old stellar population with a metal abundance near [Fe/H] = -2.0 dex. The width of the red giant branch and the location of the candidate Anomalous Cepheids on the color-magnitude diagram may indicate that the galaxy hosts a complex stellar population with stars from about 13 Gyr to as young as about 0.6 Gyr.
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Cite
@article{arxiv.0709.3281,
title = {Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I},
author = {Charles Kuehn and Karen Kinemuchi and Vincenzo Ripepi and Gisella Clementini and Massimo Dall'Ora and Luca Di Fabrizio and Christopher T. Rodgers and Claudia Greco and Marcella Marconi and Ilaria Musella and Horace A. Smith and Márcio Catelan and Timothy C. Beers and Barton J. Pritzl},
journal= {arXiv preprint arXiv:0709.3281},
year = {2009}
}
Comments
13 pages, 5 figures, typos in abstract and paper have been corrected, paper has been submitted to APJLetters