Spectroscopy of Four Cataclysmic Variables with Periods above 7 Hours
arXiv:astro-ph/0511461 · doi:10.1086/497384
Abstract
We present spectroscopy of four cataclysmic variables. Using radial velocity measurements, we find orbital periods for the first time. The stars and their periods are GY Hya, 0.347230(9) d; SDSS J204448-045929, 1.68(1) d; V392 Hya, 0.324952(5) d; and RX J1951.7+3716, 0.492(1) d. We also detect the spectra of the secondary stars, estimate their spectral types, and derive distances based on surface brightness and Roche lobe constraints.
22 pages, 3 figures, 5 tables, to be published in December 2006 PASP