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Updating the Period of V Comae Berenices

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Janet Johnston

Maria Mitchell Observatory, Nantucket, Massachusetts

Abstract

In AAVSO Abstracts, 19 October 1968, Jean Jackson pointed out that the period of V COm is changing. Since then additional observations have been acquired from Harvard, Nantucket, and Yale plates, and more published observations have been compiled. All this material was turned over to Janet Johnston for re-evaluation of the period. Her results, based on some 450 miscellaneous observations, mainly between JD 18443 and 42188, indicate that he observed phases, 0, are satisfactorily represented by the relation, ?????. It is noted that he basic period, P?, agrees with the period as given in the Genral Catalogue of Variable Stars. The correction term implies a progressive shortening ofthe period (dP/ dn = 2kP?) amounting to 1.6x10? day/cycle. This is reasonably consistent with the difference between the basic periods given in the GCVS and by Miss Jackman, which refer to different basic epochs, JD?.