Superhumps in Cataclysmic Binaries. XXII. 1RXS J232953.9+062814

David Skillman, Thomas Krajci, Edward Beshore, Joseph Patterson, Jonathan Kemp, Donn Starkey, Arto Oksanen, Tonny Vanmunster, Brian Martin, and Robert Rea

Publications of the Astronomical Society of the Pacific

June 2002, Volume 113, Page 630

We report photometry of a recently discovered dwarf nova with a remarkably short 64.2-minute orbital period. In quiescence, the star's light curve is that of a double sinusoid, arising from the "ellipsoidal" distortion of the Roche-lobe-filling secondary. During superoutburst, common superhumps develop with a period 3-4% longer than P_orb. This indicates a mass ratio M₂/M₁=0.19±0.02, a surprisingly large value in so compact a binary. This implies that the secondary star has a density 2-3 times higher than that of other short-period dwarf novae, suggesting a secondary enriched by H-burning prior to the common-envelope phase of evolution. We estimate i=50±5°, M_a=0.63^+0.12_-0.09 M_solar, M₂=0.12^+0.03_-0.02 M_solar, R₂=0.121^+0.010_-0.007 R_solar, and a distance to the binary of 180±40 pc.

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Copyright © 2002 Astronomical Society of the Pacific.