Deep Mmt Transit Survey of the Open Cluster M37. Ii. Variable Stars

We have conducted a deep (15P rP23), 20 night survey for transiting planets in the intermediate-age ( 550Myr) open cluster M37 (NGC 2099) using the Megacam wide-field mosaic CCD camera on the 6.5 mMMT. In this paper we present a catalog and light curves for 1445 variable stars; 1430 (99%) of these are new discoveries. We have discovered 20 new eclipsing binaries and 31 new short-period (P < 1 day) pulsating stars. The bulk of the variables are most likely rapidly rotating young low-mass stars, including a substantial number (k500) that are members of the cluster. We identify and analyze five particularly interesting individual variables, including a previously identified variable that we suggest is probably a hybrid Doradus/ Scuti pulsator, two possible quiescent cataclysmic variables, a detached eclipsing binary (DEB) with at least one Doradus pulsating component (only the second such variable found in an eclipsing binary), and a low-mass (MP MS 0:6 M ) DEB that is a possible cluster member. A preliminary determination of the physical parameters for the DEB+ Doradus system yields MP 1⁄4 1:58 0:04 M , MS 1⁄4 1:58 0:04 M , RP 1⁄4 1:39 0:07 R , and RS 1⁄4 1:38 0:07 R . Subject headinggs: binaries: eclipsing — open clusters and associations: individual (M37) — stars: fundamental parameters — stars: rotation — stars: variables: other — surveys Online material: color figure, machine-readable table