ST Chamaeleontis and BP Coronae Australis: Two Southern Dwarf Novae Confirmed as Z Cam Stars

摘要

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 campaign, the Z CamPaign, the authors focused attention on several Z Cam suspects in the southern hemisphere. Two stars, BP CrA and ST Cha, 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 nineteen confirmed Z Cams, bringing the total to twenty-one.