The Open Cluster NGC 2437 (Messier 46)

Abstract

The stellar content of the open cluster NGC 2437 (Messier 46) is investigated using moderately deep u*,g', and r' MegaCam images. When compared with solar metallicity isochrones, the (g', u'-g') and (r', g'-r') CMDs are consistent with an age log(t_yr) = 8.35 +/- 0.15, a distance modulus 11.05 +/- 0.05, and a color excess E(B-V) = 0.115 +/- 0.035. The r' luminosity function (LF) of main sequence stars in the magnitude range r' < 17 (i.e. masses > 0.8 solar) has a shape that follows solar neighborhood star counts. However, at fainter magnitudes the cluster LF is flat, in contrast with what would be expected from solar neighborhood counts. The clustering properties of stars in NGC 2437 are investigated by examining the two-point angular correlation functions of main sequence stars in different brightness ranges. Main sequence stars fainter than r' = 17 are less centrally concentrated than brighter stars and are found over a larger area of the sky, suggesting that there is a corona of faint main sequence stars around NGC 2437. Based on the flat LF and extended spatial distribution of faint stars, it is concluded that NGC 2437 is actively shedding stars with masses < 0.8 solar.

To appear in the PASP

References in corpus (8)

• Empirical Color Transformations Between SDSS Photometry and Other Photometric Systems
• Evidence for the Strong Effect of Gas Removal on the Internal Dynamics of Young Stellar Clusters
• Wide Field CCD photometry around nine open clusters
• Fiducial Stellar Population Sequences for the u'g'r'i'z' System
• Mass functions and photometric binaries in nine open clusters
• The Recent Stellar Archeology of M31 - The Nearest Red Disk Galaxy
• The Young Open Clusters King 12, NGC 7788, and NGC 7790: Pre-Main Sequence Stars and Extended Stellar Halos
• AAOmega radial velocities rule out current membership of the planetary nebula NGC 2438 in the open cluster M46

Cited by in corpus (7)

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• Through the magnifying glass: ALMA acute viewing of the intricate nebular architecture of OH231.8+4.2
• Seeing Red in M32: Constraints on the Stellar Content from Near- and Mid-Infrared Observations and Applications for Studies of More Distant Galaxies
• Dissecting the central regions of OH 231.8 + 4.2 with ALMA: a salty rotating disk at the base of a young bipolar outflow
• Galactic astronomy with AO: Nearby star clusters and moving groups