The Taiwanese–American occultation survey project stellar variability. ii. detection of 15 variable stars

Abstract

The Taiwanese–American Occultation Survey (TAOS) project has collected more than a billion photometric measurements since 2005 January. These sky survey data—covering timescales from a fraction of a second to a few hundred days—are a useful source to study stellar variability. A total of 167 star fields, mostly along the ecliptic plane, have been selected for photometric monitoring with the TAOS telescopes. This paper presents our initial analysis of a search for periodic variable stars from the time-series TAOS data on one particular TAOS field, No. 151 (R.A. = 17ʰ30 ͫ 6ˢ.7, decl. = 27◦17ʹ30ʺ, J2000), which had been observed over 47 epochs in 2005. A total of 81 candidate variables are identified in the 3 deg² field, with magnitudes in the range 8 < R < 16. On the basis of the periodicity and shape of the light curves, 29 variables, 15 of which were previously unknown, are classified as RR Lyrae, Cepheid, δ Scuti, SX Phonencis, semi-regular, and eclipsing binaries.