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

TL;DR

This study presents detailed observations and analysis of the open cluster M37, including its stellar content, dynamical state, and fundamental parameters, based on a deep transit survey and multi-method data analysis.

Contribution

It provides new, precise measurements of M37's age, metallicity, distance, and mass function, and describes the survey methodology and data reduction procedures.

Findings

Cluster age estimated at 485 Myr without overshooting

Mass function determined down to 0.3 solar masses

Total cluster mass estimated at 3640 solar masses

Abstract

We have conducted a deep ($15 \la r \la 23$), 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 6.5m Multiple Mirror Telescope (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 $BVI_{C}K_{S}$ and new $gri$ color magnitude diagrams we determine the fundamental cluster parameters: $t = 485 \pm 28$ Myr without overshooting ($t = 550 \pm 30 {\rm Myr}$ with overshooting), $E(B-V) = 0.227 \pm 0.038$, $(m-M)_{V} = 11.57 \pm 0.13$ and $[M/H] = +0.045 \pm 0.044$ which are in good agreement with, though more precise than, previous measurements. We determine the mass function down to $0.3 M_{\odot}$ and use this to estimate the total cluster mass of $3640 \pm 170 M_{\odot}$.