Stellar Variability in a Survey of Field Stars

We present results from a 5 night wide-field time-series photometric survey that detects variable field stars. We find that the fraction of stars whose light curves show variations depends on color and magnitude, reaching 17% for the brightest stars in this survey ( ) for which the photometric precision is best. The V ∼ 14 fraction of stars found to be variable is relatively high at colors bluer than the Sun and relatively low at colors similar to the Sun and increases again for stars redder than the Sun. We present light curves for a sample of the pulsating and eclipsing variables. Most of the stars identified as pulsating variables have low amplitudes ( ), relatively blue colors, and multiple periods. There are 13 stars we identify as either SX DV p 0.01-0.05 Phoenicis or d Scuti stars. These classes represent a significant contribution to the total number of blue variables found in this survey. Another 17 stars are identified as eclipsing variables, which have a wide range in color, magnitude, and amplitude. Two variable giants are observed, and both show night-to-night ∼1% variations. We present data for 222 variables in total, most of which are not classified. Implications of surveys for stellar variability and interferometry are briefly discussed.