Variable Stars Observed in the Galactic Disk by AST3-1 from Dome A, Antarctica

TL;DR

This study reports the discovery and classification of 560 variable stars, including 339 new discoveries, from a time-series survey of a Galactic disk field using the AST3-1 telescope at Dome A, Antarctica.

Contribution

First wide-field optical survey from Dome A identifying and classifying a large sample of variable stars, including many new discoveries, using the AST3-1 telescope.

Findings

560 variable stars detected, 339 new discoveries

Identified various types including eclipsing binaries and pulsating stars

Detected complex binary system with RS CVn-like light curve

Abstract

AST3-1 is the second-generation wide-field optical photometric telescope dedicated to time domain astronomy at Dome A, Antarctica. Here we present the results of $i$ band images survey from AST3-1 towards one Galactic disk field. Based on time-series photometry of 92,583 stars, 560 variable stars were detected with $i$ magnitude $\leq$ 16.5 mag during eight days of observations; 339 of these are previously unknown variables. We tentatively classify the 560 variables as 285 eclipsing binaries (EW, EB, EA), 27 pulsating variable stars ($\delta$~Scuti, $\gamma$~Doradus, $\delta$~Cephei variable and RR Lyrae stars) and 248 other types of variables (unclassified periodic, multi-periodic and aperiodic variable stars). Among the eclipsing binaries, 34 show O'Connell effects. One of the aperiodic variables shows a plateau light curve and another one shows a secondary maximum after peak brightness. We also detected a complex binary system with RS CVn-like light curve morphology; this object is being followed-up spectroscopically using the Gemini South telescope.