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

Abstract

We have conducted a deep (15 ≲ r ≲ 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 BVICKS 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⊙. © 2008. The American Astronomical Society. All rights reserved.