Observations of Faint Eclipsing Cataclysmic Variables

TL;DR

This study provides time-resolved photometry of six faint cataclysmic variables, revealing orbital variability, flickering, and cyclical period changes, with new period measurements and insights into their accretion dynamics.

Contribution

First detailed photometric analysis of these faint CVs, including the first period determination for SDSS J1607+3623 and evidence of magnetic activity-induced cyclical period changes.

Findings

Detection of short-term orbital variability and flickering.

First photometric period measurement for SDSS J1607+3623.

Evidence of cyclical period change due to secondary star magnetic activity.

Abstract

We present time-resolved photometry of six faint (V>17mag) cataclysmic variables (CVs); one of them is V849 Oph and the others are identified from the Sloan Digital Sky Survey (SDSS J0920+0042, SDSS J1327+6528, SDSS J1227+5139, SDSS J1607.02+3623, SDSS J1457+5148). The optical CCD photometric observations of these objects were performed at the T\"UB\.ITAK National Observatory (Turkey) between February 2006 and March 2009. We aimed to detect short time scale orbital variability arisen from hot-spot modulation, flickering structures which occur from rapid fluctuations of material transferring from red star to white dwarf and orbital period changes for selected short-period (P<4h) CVs at quiescence. Results obtained from eclipse timings and light curves morphology related to white dwarf stars, accretion disks and hot-spots are discussed for each system. Analysis of the short time coverage of data, obtained for SDSS J1227+5139 indicates a cyclical period change arisen from magnetic activity on the secondary star. Photometric period of SDSS J1607+3623 is derived firstly in this study, while for the other five systems light elements are corrected using the previous and new photometric observations. The nature of SDSS J1457+5148 is not precisely revealed that its light curve shows any periodicity that could be related to the orbital period.