Publications 9-2000 The White Dwarf Cooling Age of the Open Cluster NGC 2420 Ted von Hippel Embry-Riddle Aeronautical University,
[email protected] Gerard Gilmore Institute of Astronomy, Cambridge,
[email protected] Follow this and additional works at: https://commons.erau.edu/publication Part of the Stars, Interstellar Medium and the Galaxy Commons Scholarly Commons Citation von Hippel, T., & Gilmore, G. (2000). The White Dwarf Cooling Age of the Open Cluster NGC 2420. The Astronomical Journal, 120(3). Retrieved from https://commons.erau.edu/publication/217 This Article is brought to you for free and open access by Scholarly Commons. It has been accepted for inclusion in Publications by an authorized administrator of Scholarly Commons. For more information, please contact
[email protected]. THE ASTRONOMICAL JOURNAL, 120:1384È1395, 2000 September ( 2000. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE WHITE DWARF COOLING AGE OF THE OPEN CLUSTER NGC 24201 TED VON HIPPEL Gemini Observatory, 670 North AÏohoku Place, Hilo, HI 96720; ted=gemini.edu AND GERARD GILMORE Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK; gil=ast.cam.ac.uk Received 2000 April 14; accepted 2000 June 1 ABSTRACT We have used deep HST WFPC2 observations of two Ðelds in NGC 2420 to produce a cluster color- magnitude diagram down to V B 27. After imposing morphological selection criteria we Ðnd eight candi- date white dwarfs in NGC 2420. Our completeness estimates indicate that we have found the terminus of the WD cooling sequence. We argue that the cluster distance modulus is likely to be close to 12.10 with E(B[V ) \ 0.04.