Entering into the fifth year of the Z CamPaign, the author has developed a website summarizing our findings which will also act as a living catalog of bona fide Z Cam stars, suspected Z Cams and Z Cam impostors. In this paper we summarize the finding
s of the first four years of research, introduce the website and its contents to the public and discuss the way forward into year five and beyond.
Long term optical monitoring of the dwarf nova OQ Car has been conducted to study the previously unknown behaviour of this star system. The observations have shown OQ Car to have frequent dwarf nova outbursts and revealed the first recorded standstil
l of this star system. Based on this, we conclude that OQ Car is a new member of the Z Cam type dwarf novae.
Z Camelopardalis (Z Cam) stars are a subset of dwarf novae distinguished by the occurrence of standstills, periods of relative constant brightness one to one and a half magnitudes fainter than maximum brightness. As part of an ongoing observing campa
ign, the Z CamPaign, the authors focused attention on several Z Cam suspects in the southern hemisphere. Two stars, BP Coronae Australis and ST Chamaeleontis were found to exhibit standstill behavior in 2013, thus confirming them as Z Cam type systems. This adds two more bona fide members to the 19 confirmed Z Cams, bringing the total to 21.
Z Cam stars are a small subset of dwarf novae that exhibit standstills in their light curves. Most modern literature and catalogs of cataclysmic variables quote the number of known Z Cams to be on the order of 30 or so systems. After a four-year obse
rving campaign and an exhaustive examination of the data in the AAVSO International Database we have trimmed that number by a third. One of the reasons for the misclassification of some systems is the fact that the definition of what a Z Cam is has changed over the last 85 years to what it is today. This has caused many stars formerly assumed to be Z Cams or rumored to be Z Cams to be eliminated from the final list. In this paper we present the results of our investigation into 65 stars listed at one time or another in the literature as Z Cams or possible Z Cams.
Photometry of Leo5 = 1H 1025+220 show that it is a dwarf nova of the Z Cam subtype. Two long standstills have been observed in the last five years.
The Cataclysmic Variable Section of the American Association of Variable Star Observers (AAVSO) has initiated an observing campaign to study a subset of dwarf novae (DNe), known as Z Cam type (UGZ). We call this program the Z CamPaign. Since there is
no strong agreement between the various published catalogues as to which few dozen DNe are actually Z Cam type systems, our primary goal is to accumulate enough data to construct detailed light curves, covering the entire range of variability, to determine unequivocally the 30 Z CamPaign subjects membership in the UGZ class of DNe. We discuss the organization, science goals, and some early results of the Z CamPaign in detail.
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 classificatio
n 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.
