Photometry of some more neglected bright cataclysmic variables and candidates

TL;DR

This study presents new photometric observations of four bright cataclysmic variables, revealing flickering behavior, questioning previous period claims, and suggesting possible orbital variations, thereby enhancing understanding of these less-studied systems.

Contribution

It provides the first time-resolved photometry for some systems and challenges prior period detections, offering new insights into their variability and classification.

Findings

Flickering observed in all but Ret 1, strongest in V504 Cen and CTCV 2056-3014.

Questionable 15.4 min period in CTCV 2056-3014, likely spurious.

Possible orbital period of 0.1952 days in KT Eri, needs confirmation.

Abstract

As part of an effort to better characterize bright cataclysmic variables (CVs) and related systems which have received little attention in the past light curves of four systems (V504 Cen, KT Eri, Ret 1 and CTCV 2056-3014) are analyzed. For some of these stars no time resolved photometry has been published previously. While flickering is observed in all systems except Ret 1, it is particularly strong in V504 Cen and CTCV 2056-3014. In the latter star, a previously observed 15.4 m period, leading to its tentative classification as an intermediate polar, is probably spurious. Variations on time scales of hundredths of days observed in the pre-outburst light curve of the classical nova KT Eri continue after the outburst but appear not to be strictly periodic. Furthermore, the long term post-outburst light curve exhibits modulations with quasi-periods of quite different length. Thus, these variations cannot be due to aspect related variations in a system with a giant component similar to some recurrent novae. Instead, the system possibly exhibits variations with a period of 0.1952 d which may be orbital. However, any such conclusion still requires confirmation.