Optical Studies of Seven Bright Southern Cataclysmic Variable Stars

Abstract

We report spectroscopic observations of seven bright southern cataclysmic variable stars, collected on a single two-week observing run using the 1.9 m Radcliffe telescope at the South African Astronomical Observatory. We used a radial-velocity time series, in some cases in combination with other data, to determine or clarify orbital periods for five of them, namely ATO J061.1478−31.0634, BMAM-V547, MGAB-V202, NSV 4202, and V1147 Cen. For BMAM-V547, we use data from the Transiting Exoplanet Survey Satellite (TESS) to corroborate and sharpen the orbital period; the TESS data also show a photometric period near 3.93 days, likely indicating precession of the accretion disk. Also, we find a periodic modulation in the radial velocities of the SU UMa-type dwarf nova Var Ret2005, but are unable to specify a unique cycle count. Finally, we show a spectrum of ASASSN-V J061528.41−412007.3 that appears typical of a luminous novalike variable.

Keywords

• Cataclysmic variable stars
• Nova-like variable stars
• SU Ursae Majoris stars
• U Geminorum stars