2008ApJ...675L..73G

We report on the detection of variable stars in the Canes Venatici II (CVn II) dwarf spheroidal galaxy, a new satellite of the Milky Way recently discovered by the Sloan Digital Sky Survey. We also present a V, B-V color-magnitude diagram that reaches V∼25.5 mag, showing the galaxy's main-sequence turnoff at V∼24.5 mag and revealing several candidate blue straggler stars. Two RR Lyrae stars have been identified within the half-light radius of CVn II, a fundamental-mode variable (RRab) with period P_ab= 0.743 days, and a first-overtone (RRc) RR Lyrae star with P_c= 0.358 days. The rather long periods of these variables along with their position on the period-amplitude diagram support an Oosterhoff type II classification for CVn II. The average apparent magnitude of the RR Lyrae stars, <V≥21.48±0.02 mag, is used to obtain a precision distance modulus of µ₀=21.02±0.06 mag and a corresponding distance of 160⁺⁴_–5kpc, for an adopted reddening E(B-V)=0.015 mag.