The First Historical Standstill of WW Ceti

Volume 39 number 1 (2011)

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Mike Simonsen

AAVSO, 49 Bay State Road, Cambridge, MA, 02138; mikesimonsen@aavso.org

Rod Stubbings

Tetoora Observatory, 2643 Warragul-Korumburra Road, Tetoora Road 3821, Victoria, Australia; stubbo@sympac.com.au

Abstract

Z Cam dwarf novae are distinguished from other dwarf novae based on the appearance of so called "standstills" in their long-term optical light curves. It has been suggested previously that WW Cet might be a Z Cam type dwarf nova, but this classification was subsequently ruled out, based on its long-term light curve behavior. Forty years of historical data for WW Cet has shown no evidence of standstills. WW Cet is therefore classified as a UG type dwarf nova in the General Catalogue of Variable Stars (GCVS, Samus et al. 2007-2009) and the International Variable Star Index (VSX, Watson et al. 2006). Beginning in the 2010 observing season, WW Cet has been observed to be in a standstill, remaining more or less steady in the 12th magnitude range. Based on this first ever, historical standstill of WW Cet, we conclude that it is indeed a bona fide member of the Z Cam class of dwarf novae.