Abstract

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, 〈Pab〉 = 0.60 ± 0.01 days, and the location of these stars in the period-amplitude diagram suggest that CVn I is likely an Oosterhoff-intermediate system. The average apparent magnitude of the RR Lyrae stars, 〈V〉 = 22.17 ± 0.02 mag, gives a distance of 210 +7 -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 ∼ 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 ∼13 Gyr to as young as ∼0.6 Gyr. © 2008. The American Astronomical Society. All rights reserved. Printed in U.S.A.