CBA Center for Backyard Astrophysics

Superhumps in Cataclysmic Variables. I. T Leonis

Kristi Lemm, Joseph Patterson, Eugene Thomas, and David Skillman

Publications of the Astronomical Society of the Pacific

October 1993, Volume 105, Page 1120

We report photometry of the dwarf nova T Leonis during its 1993 supermaximum. The principle outburst lasted approximately 20 days, during which large-amplitude superhumps were consistently seen in the light curve. The mean period was 86.7 ± 0.1 min, about 2.4% longer than the orbital period determined from radial-velocity measurements. Analysis of data obtained during the 1987 supermaximum implies that the superhump period decreased slowly, with dP/dt = - 6 × 10-5, or dP/dm = -0.6 min/mag. These are typical values for SU Ursae Majoris-type dwarf novae. At the end of the outburst, the star suddenly brightened again to magnitude 13, from which it declined on a time scale of about 1 day and without superhumps. It is possible that this event was a normal outburst. This suggests that superoutbursts can trigger normal outbursts, and may explain the "bump" frequently found in the light curves of SU UMa stars very late in a superoutburst.



Copyright © 1993 Astronomical Society of the Pacific.