BV CCD photometry of the old open cluster NGC 2243

Journal Article · Sat Jun 01 04:00:00 EDT 1991 · Astronomical Journal; (United States)

DOI:https://doi.org/10.1086/115832· OSTI ID:5503982

Bergbusch, P A; Vandenberg, D A; Infante, L ^[1]

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1. Regina, University (Canada) Victoria, University (Canada) Pontificia Universidad Catolica de Chile, Santiago (Chile)

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 = {minus}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. 41 refs.

• OSTI ID: 5503982
• Journal Information: Astronomical Journal; (United States), Journal Name: Astronomical Journal; (United States) Vol. 101; ISSN 0004-6256; ISSN ANJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
AGE ESTIMATION
BINARY STARS
CHARGE-COUPLED DEVICES
CHEMICAL COMPOSITION
COLOR
COMPARATIVE EVALUATIONS
DISTANCE
ELEMENT ABUNDANCE
LUMINOSITY
MASS
MASS SPECTRA
MATHEMATICAL MODELS
MORPHOLOGY
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHOTOMETRY
PHYSICAL PROPERTIES
SEMICONDUCTOR DEVICES
SPECTRA
STAR CLUSTERS
STAR MODELS
STARS