Resumption of mass accretion in RS Oph

• Published in: Monthly notices of the Royal Astronomical Society Vol. 379; no. 4; pp. 1557 - 1561
• Main Authors: Worters, H. L., Eyres, S. P. S., Bromage, G. E., Osborne, J. P.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 21.08.2007; Blackwell Science; Oxford University Press
• Subjects: Accretion disks; Astronomy; Astrophysics; binaries: symbiotic; cataclysmic variables; Earth, ocean, space; Exact sciences and technology; novae; novae, cataclysmic variables; outflows; Spectrum analysis; Stars & galaxies; stars: individual: RS Oph; stars: mass-loss; stars: winds; stars: winds, outflows; Supernovae; stars: mass-loss; stars: winds, outflows; stars: individual: RS Oph; binaries: symbiotic; novae, cataclysmic variables; Stellar winds; Accretion; Accretion rate; Mass loss; Stellar mass; Cataclysmic variable stars; Models; Roche lobe; Recurrent novae
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2007.12066.x

The latest outburst of the recurrent nova RS Oph occurred in 2006 February. Photometric data presented here show evidence of the resumption of optical flickering, indicating re-establishment of accretion by day 241 of the outburst. Magnitude variations of up to 0.32 mag in V band and 0.14 mag in B band on time-scales of 600–7000 s are detected. Over the two-week observational period, we also detect a 0.5 mag decline in the mean brightness, from V≈ 11.4 to 11.9, and record B≈ 12.9 mag. Limits on the mass accretion rate of are calculated, which span the range of accretion rates modelled for direct wind accretion and Roche lobe overflow mechanisms. The current accretion rates make it difficult for thermonuclear runaway models to explain the observed recurrence interval, and this implies average accretion rates are typically higher than seen immediately post-outburst.