The First Historical Standstill of WW Ceti

TL;DR

This paper presents the first historical observation of a standstill in WW Ceti, confirming its classification as a Z Cam type dwarf nova after 40 years of data suggested otherwise.

Contribution

It provides the first evidence of a standstill in WW Ceti, revising its classification from UG to Z Cam type based on long-term observational data.

Findings

WW Ceti exhibited a standstill starting in 2010.

This is the first recorded standstill in WW Ceti's history.

The classification of WW Ceti is revised to Z Cam type.

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 Ceti is therefore classified as a UG type dwarf nova in the General Catalog 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.