view Abstract Citations (44) References (38) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS BV CCD Photometry of the Old Open Cluster NGC 2243 Bergbusch, Peter A. ; Vandenberg, Don A. ; Infante, L. Abstract The photometry of NGC 2243 is presented, which reaches approximately 4 mag below the turnoff point calibrated independently of studies of the cluster. The color-magnitude diagram (CMD) and luminosity function (LF) are calibrated by utilizing stars from the lists of Landolt and Graham. A strong binary sequence is noted in the CMD which contributes approximately 30 percent of the stars, a gap is observed in the turnoff region, and a clump of HB stars is located. The CMD data are compared to those for the cluster 47 Tuc and are found to match well, although a slightly higher metal abundance accounts for the redder giant branch of the NGC 2243. The distance modulus and the cluster age are calculated, and the Fe/H = -0.47, O/Fe = +0.23 isochrones are the only isochrones that reproduce the location of the giant branch. A flat mass spectrum characterizes the LF, and a small gap is found where V is 16.1. Convective overshooting in the cores of moderate mass stars is theorized as the cause of the gap, and other models of the structure are shown to provide inadequate descriptions. Publication: The Astronomical Journal Pub Date: June 1991 DOI: 10.1086/115832 Bibcode: 1991AJ....101.2102B Keywords: Astronomical Photometry; Color-Magnitude Diagram; Open Clusters; Abundance; Astronomical Models; Charge Coupled Devices; Metallicity; Stellar Mass; Astrophysics; CLUSTERS: OPEN full text sources ADS | data products SIMBAD (20)