The Optical Gravitational Lensing Experiment. Cepheids in the Magellanic Clouds. I. Double-Mode Cepheids in the Small Magellanic Cloud

Abstract

We present a sample of 93 double-mode Cepheids detected in the 2.4 square degree area in the central part of the SMC. 23 stars from the sample pulsate in the fundamental mode and the first overtone while 70 objects are the first and second overtone pulsators. This is the largest sample of such type Cepheids detected in one environment so far. We analyze period ratio of double-mode Cepheids and Fourier parameters of decomposition of the light curves of these objects. We also present location of different type Cepheids from the SMC in the color-magnitude diagram and show their distribution of V-I color indices. We find one object which is probably a blend, either physical or optical, of two Cepheids pulsating in the fundamental mode.