Photometry of some neglected bright cataclysmic variables and candidates

• Published in: New astronomy 2017-04, Vol.52, p.112-121
• Main Author: Bruch, Albert
• Format: Article
• Language: English
• Subjects: Cataclysmic variables – Stars: individual: CZ Aql - BO Cet - V380 Oph - EF Tuc - Lib 3; Stars: novae
• ISSN: 1384-1076; 1384-1092
• DOI: 10.1016/j.newast.2016.10.013

•The light curves of CZ Aql, BO Cet, V380 Oph and EF Tuc are dominated by strong flickering.•The absence of flickering in Lib 3 permits to exclude the star from the list of CV candidates.•Orbital variations are observed in BO Cet and V380 Oph but not in CZ Aql and EF Tuc.•CZ Aql may exhibit superhump-like variations.•Circumstantial evidence points at a possible magnetic nature of CZ Aql. As part of an effort to better characterize bright cataclysmic variables (CVs) which have received little attention in the past light curves of four confirmed systems (CZ Aql, BO Cet, V380 Oph and EF Tuc) and one candidate (Lib 3) are analyzed. For none of these stars time resolved photometry has been published previously. While no variability was found in the case of Lib 3, which thus cannot be confirmed as a CV, the light curves of all other targets are dominated by strong flickering. Modulations on hourly time scales superimposed on the flickering can probably be related to orbital variations in BO Cet and V380 Oph, but not in CZ Aql and EF Tuc. Variations on the time scale of 10  min in CZ Aql, while not yet constituting convincing evidence, together with previous suspicions of a magnetically channeled accretion flow may point at an intermediate polar nature of this star. Some properties of the flickering are quantified in an effort to enlarge the data base for future comparative flickering studies in CVs and to refine the classification of the target stars.