V803 Centauri: A Helium-rich Dwarf Nova
Abstract
We report 1992-1999 photometry of the helium-rich cataclysmic variable V803 Centauri. In its high brightness state at V=13, the star shows a strong periodic signal with P=1618 s; this resembles the superhumps associated with many dwarf novae. However, it is unusual because the superhump appears to endure through all brightness states, including the very faint state at V=17. The star also becomes occasionally stuck in a ``cycling state,'' in which the brightness varies in the range 13.4-14.5, with a period of 22+/-1 hr. This appears to be the recurrence pattern of ``normal'' dwarf nova outbursts. Thus the underlying physics is probably that of a dwarf nova, but with an accretion disk dominated by helium. Reckoned as a dwarf nova, V803 Cen presents an interesting test for accretion disk theory, because it appears to display two timescales for eruption recurrence: 0.94 day at V=14.5 and ~5 days at V=17.2. This is roughly consistent with the general idea that recurrence time scales inversely with accretion rate.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- May 2000
- DOI:
- 10.1086/316561
- Bibcode:
- 2000PASP..112..625P
- Keywords:
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- Stars: Binaries: Close;
- Stars: Novae;
- Cataclysmic Variables;
- Stars: Individual: Constellation Name: V803 Centauri