Variables in Sextans dSph galaxy

We have identified 44 variables: 36 RR Lyr star, 6 anomalous Cepheids, one long-period red variable, all probable members of Sextans, and one foreground contact binary. We have used the pulsating stars to derive a true distance modulus of 19.67+/-0.15 for Sextans (or D=86+/-6kpc), where the error is primarily due to uncertainties in the luminosity-metallicity relation for RR Lyr stars.

Based on our new data we conclude that [Fe/H]_Sex=-1.6+/-0.2, somewhat higher than the value from Suntzeff et al. (1993ApJ...418..208S) obtained from the analysis of fiber spectroscopy of the near-IR Calcium triplet. We present a new deep color-magnitude diagram for Sextans which reveals the presence of anomalous Cepheids in the galaxy. This young population may represent as much as 25% of the total stellar content of Sextans.