The dwarf nova PQ andromedae
Abstract
We report a photometric study of the WZ Sagittae-type dwarf nova PQ Andromedae. The light curve shows strong (0.05 mag full amplitude) signals with periods of 1263(1) and 634(1) s, and a likely double-humped signal with P = 80.6(2) minutes. We interpret the first two as nonradial pulsation periods of the underlying white dwarf, and the last as the orbital period of the underlying binary. We estimate a distance of 150(50) pc from proper motions and the two standard candles available: the white dwarf and the dwarf-nova outburst. At this distance, the K magnitude implies that the secondary is probably fainter than any star on the main sequence-indicating a mass below the Kumar limit at 0.075 M⊙. PQ And may be another "period bouncer," where evolution now drives the binary out to a longer period. © 2005. The Astronomical Society of the Pacific. All rights reserved.