Superhumps in Cataclysmic Binaries. XX. V751 Cygni

Joseph Patterson, John Thorstensen, Robert Fried, David Skillman, Lewis Cook, and Lasse Jensen

Publications of the Astronomical Society of the Pacific

January 2001, Volume 113, Page 72

We report photometric and spectroscopic observations of the novalike variable V751 Cygni. The radial velocities indicate an underlying binary period of 0.1445(2) d; the long-term cycle count is not firmly decided but the best choice implies a period of 0.144464(1) d. The star shows a moderately low-excitation spectrum with transient P-Cygni absorption suggestive of a wind origin, occasionally seen in cataclysmic variables accreting at a high rate. Curiously, the P-Cygni absorption appears correlated with binary phase in our two most extensive data sets. A photometric wave with P = 0.1394(1) d, slightly shorter than P_orb, rumbles through the light curve, as well as a low-frequency wiggle at 3.94(6) d. We identify the former as a "negative superhump", and the latter as the wobble period of a tilted accretion disk. These characteristics all suggest classification as an ordinary, accretion- powered cataclysmic variable of the VY Scl class. We discuss possible origins for the observed soft X-rays at quiescence.

Article

_____

Copyright © 2001 Astronomical Society of the Pacific.