CBA Center for Backyard Astrophysics

Superhumps in Cataclysmic Binaries. II. PG 0917+342

David Skillman and Joseph Patterson

Astrophysical Journal

1 November 1993, Volume 417, Page 298

We have found a 113.1 minute period in the light curve of the nova-like variable PG 0917+342. The signal is of 0.027 mag semiamplitude and appears to change its period slightly (dP/P ~ 3 × 10-4) over the 1 yr baseline of observations. As this period is ~5% longer than the spectroscopically determined orbital period, it seems to be another example of the "superhump" phenomenon which afflicts cataclysmic variables of short orbital period and high accretion rate. The rate of period change is ~500 times smaller than that seen in the familiar superhumps of dwarf novae, presumably because changes of the accretion disk in this binary are much milder than those occurring in a dwarf novae. This interpretation implies that the hydrogen absorption lines should display a skewness variation with a period of 1.7 days.



Copyright © 1993 American Astronomical Society.