V803 Centauri: A helium-rich dwarf nova

Citation
J. Patterson et al., V803 Centauri: A helium-rich dwarf nova, PUB AST S P, 112(771), 2000, pp. 625-631
Citations number
20
Categorie Soggetti
Space Sciences
Journal title
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
ISSN journal
00046280 → ACNP
Volume
112
Issue
771
Year of publication
2000
Pages
625 - 631
Database
ISI
SICI code
0004-6280(200005)112:771<625:VCAHDN>2.0.ZU;2-T
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 w ith 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 "cyclingstate," in wh ich 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 out bursts. Thus the underlying physics is probably that of a dwarf nova, but w ith an accretion disk dominated by helium. Reckoned as a dwarf nova, V803 C en presents an interesting test for accretion disk, theory, because it appe ars to display two timescales for eruption recurrence: 0.94 day at V = 14.5 and similar to 5 days at V = 17.2. This is roughly consistent with the gen eral idea that recurrence time scales inversely with accretion rate.