Deep MMT Transit Survey of the Open Cluster M37. I. Observations and Cluster Parameters

We have conducted a deep (15lesssim rlesssim 23), 20 night survey for transiting planets in the intermediate-age open cluster M37 (NGC 2099) using the Megacam wide-field mosaic CCD camera on the 6.5 m MMT. In this paper we describe the observations and data reduction procedures for the survey and analyze the stellar content and dynamical state of the cluster. By combining high-resolution spectroscopy with existing BVI_CK_s and new gri color-magnitude diagrams, we determine the fundamental cluster parameters: t = 485 +/- 28 Myr without overshooting (t = 550 +/- 30 Myr with overshooting), E(B - V) = 0.227 +/- 0.038, (m - M)_V = 11.57 +/- 0.13, and [ M/H ] = + 0.045 +/- 0.044, which are in good agreement with, although more precise than, previous measurements. We determine the mass function down to 0.3 M_⊙ and use this to estimate the total cluster mass of 3640 +/- 170 M_⊙.

Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.