文章基本信息

标题：An Optical Study of Two VY Sculptoris-type Cataclysmic Binary Stars: V704 And and RX J2338+431
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作者：Kathryn E. Weil ; John R. Thorstensen ; Frank Haberl 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2018
卷号：156
期号：5
页码：1-9
DOI：10.3847/1538-3881/aae203
语种：English
出版社：American Institute of Physics
摘要：We report observations of the known cataclysmic variable star (CV) V704And, and also confirm that the optical counterpart of the ROSAT Galactic Plane Survey source RXJ2338+431 is a heretofore-neglected CV. Photometric and spectroscopic observations from MDM Observatory show both systems to be nova-like variables that exhibit dips of 4–5 mag from their mean brightnesses, establishing them as members of the VYScl subclass. From high-state emission-line radial velocities, we determine orbital periods of 0.151424(3) days (3.63 hr) for V704And and 0.130400 (1) days (3.13hr) for RXJ2338+431. In V704 And, we find that the Hα emission-line measures cluster into distinct regions on a plot of equivalent width versus full width at half-maximum, which evidently correspond to high, intermediate, and low photometric states. This allows us to assign spectra to photometric states when contemporaneous photometry is not available, an apparently novel method that may be useful in studies of other novalikes. Our low-state spectra of RXJ2338+431 show features of an M-type secondary star, from which we estimate a distance of 890±200 pc, in good agreement with the Gaia DR2 parallax.
关键词：novae;cataclysmic variables