The distance modulus of the Small Magellanic Cloud based on double-mode Cepheids

Abstract

We employ the very recent photometric data of the OGLE project together with stellar atmosphere and linear pulsation models to determine the distance modulus of the Small Magellanic Cloud from its double-mode Cepheids. Based on the requirement of obtaining the same distance modulus DM from the two types of variables (fundamental & first overtone and first & second overtone), we get DM=19.05 mag, with a very small statistical error (standard deviation) of 0.017 mag. Various systematic and zero point ambiguities (primarily those of the color - temperature transformation) lead to an error of +/-0.13 mag (estimated 3 sigma deviation). This result is in very good agreement with the distance modulus of the Large Magellanic Cloud of 18.5 mag, derived earlier from cluster double-mode RR Lyrae stars.