CBA Center for Backyard Astrophysics

Superhumps in Cataclysmic Binaries. X. V1974 Cygni (Nova Cygni 1992)

David Skillman, David Harvey, Joseph Patterson, and Tonny Vanmunster

Publications of the Astronomical Society of the Pacific

February 1997, Volume 109, Page 114

We report photometry of V1974 Cygni, the remnant of Nova Cygni 1992. A very nearly stable photometric signal with a period of 117.012 (± 0.002) min was present throughout 1993-6, with declining amplitude. This appears to be the underlying orbital period of the binary; at least during 1993, it probably manifested itself through the external heating of the secondary star's atsmophere. We interpret the declining signal amplitude as the result of white dwarf cooling after the nova outburst. This suggests an e-folding timescale of ~80 d for luminosity decline, consistent with teh UV flux which probably arises from the heated accretion disk.

During 1994-1996 there appeared another photometric signal, far less stable. The period varied in the range 122.4-122.7 min, with an average |P-dot| of about 10-6. We interpret this as a "superhump," a common phenomenon in cataclysmic binaries of short Porb and high accretion rate.



Copyright © 1997 Astronomical Society of the Pacific.