Photometry of Variable Stars from Dome A, Antarctica

TL;DR

This study presents high-cadence photometry of 10,000 stars from Dome A, Antarctica, revealing 157 variable stars and demonstrating the site's excellent observing conditions during the polar winter.

Contribution

First high-cadence, long-duration photometric survey from Dome A, providing valuable site statistics and significantly increasing known variable stars in the region.

Findings

Detected 157 variable stars, 55% unclassified.

Found 27% likely binaries, 17% likely pulsators.

Identified potential transiting exoplanet candidate.

Abstract

Dome A on the Antarctic plateau is likely one of the best observing sites on Earth thanks to the excellent atmospheric conditions present at the site during the long polar winter night. We present high-cadence time-series aperture photometry of 10,000 stars with i<14.5 mag located in a 23 square-degree region centered on the south celestial pole. The photometry was obtained with one of the CSTAR telescopes during 128 days of the 2008 Antarctic winter. We used this photometric data set to derive site statistics for Dome A and to search for variable stars. Thanks to the nearly-uninterrupted synoptic coverage, we find 6 times as many variables as previous surveys with similar magnitude limits. We detected 157 variable stars, of which 55% are unclassified, 27% are likely binaries and 17% are likely pulsating stars. The latter category includes delta Scuti, gamma Doradus and RR Lyrae variables. One variable may be a transiting exoplanet.