Recent Data on IU Cygni

Volume 20 number 1 (1991)

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Deborah C. Banks
Maria Mitchell Observatory, Nantucket, MA 02554

Abstract

IU Cygni is a 31-day Cepheid with a period that varies strongly. The Maria Mitchell data for 1978-1990 are satisfied by these elements: JD_max = 2446129.322 + 31.183 E + 0.00066E^2. This implies a period increasing at an average rate of 0.00049+-0.00009 cycle per year. Representation by one or more abrupt changes during these years is also possible.