Title: The First Historical Standstill of WW Ceti Authors: Mike Simonsen, Rod Stubbings
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 behaviour. Forty years of historical data for WW Cet has shown no evidence of standstills. WW Ceti is therefore classified as a UG type dwarf nova in the General Catalogue of Variable Stars (GCVS) and the International Variable Star Index (VSX). 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 Ceti, we conclude that it is indeed a bona fide member of the Z Cam class of dwarf novae.
WW Ceti was first mentioned as a variable star by Luyten (1962), who already suspected it's CV nature, which was later confirmed by Herbig (1962). Paczynski (1963) first published a light curve, but could not identify any periodic features. He was also the first to suggest the possibility that the system belongs to the subclass of the Z Cam stars. The system was included as a Z Cam star in the General Catalogue of Variable Stars (GCVS, Kukarkin et al. 1969) Read more
Date of outburst: 22nd September 2008 Magnitude: 9.3 - 16.8 V Period between the flashes: 31.2 days Satellite orbital period: 24 hours ? Type: UG, Hot White Dwarf binary