Stellar Flares in the CSTAR Field: Results from the 2008 Data Set

Abstract: The Chinese Small Telescope ARray (CSTAR) is the first Chinese astronomical instrument placed in Antarctica. It is a group of four identical, fully automatic $14.5\,\rm{cm}$ telescopes, with an field of view (FOV) of $20\,\rm{deg^2}$ centered on the South Celestial Pole. Placed at Antarctic Dome A, CSTAR is designed to provide high-cadence photometry for site monitoring and variable sources detection. During the 2008 observing season, CSTAR has taken high-precision photometric data for 18,145 stars around the South Celestial Pole. At $i\,=\,7.5$ and $12$, the photometric precision reaches $\sim 8$ mmag and $\sim 30$ mmag with a cadence of 20s or 30s, respectively. Using robust detection method, we have found 15 stellar flares on 13 sources, including two classified variables. We have also found a linear relation between the decay times and the total durations of the stellar flares. The details of all detected flares along with their stellar properties are presented in this work.