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Age Dating of Globular Clusters Using UBV(RI) Main-sequence Photometry in the Two-color Diagram: Age of NGC 6397

Published online by Cambridge University Press:  03 August 2017

Valery V. Kravtsov*
Affiliation:
Sternberg Astron. Ins., 13, University Ave., Moscow 119899, Russia

Abstract

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I propose and apply a method for deriving ages of the metal-poor globular clusters (GCs) in a distance-independent way, which is based on an age indicator related to the main sequence in the two-color diagrams using the U-B index. The age of the metal-poor GC NGC 6397 has been estimated, using Yale isochrones of Demarque et al. (1996), to be close to 16 Gyr provided the cluster metallicity is near [Fe/H] = −2.0.

Type
Part 4. Star Cluster Formation and Evolution: Theory and Observation
Copyright
Copyright © Astronomical Society of the Pacific 2002 

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