Variable Stars in the Newly Discovered Milky Way Dwarf Spheroidal Satellite Canes Venatici I

We have Identified 23 RR Lyrae stars and three possible anomalous Cepheids (ACs) among 84 candidate variables in the recently discovered Canes Venatici I (CVn I) dwarf spheroidal galaxy. The mean period of 18 RRab type stars, (P sub(ab)) = 0.60 plus or minus 0.01 days, and the location of these stars in the period-amplitude diagram suggest that CVn I is likely an Oosterhoff-lntermediate system. The average apparent magnitude of the RR Lyrae stars, (V) = 22.17 plus or minus 0.02 mag, gives a distance of 210 super(+) sub(-) super(7) sub(5) kpc, for an adopted reddening E(B - V) = 0.03 mag. We present a B, V color-magnitude diagram (CMD) of CVn I that reaches V similar to 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 ACs on the CMD may indicate that the galaxy hosts a complex stellar population with stars from similar to 13 Gyr to as young as similar to 0.6 Gyr.