V2051 Oph's disc evolution on decline from superoutburst

Abstract

We present an Eclipse Mapping analysis of ten eclipses taken during decline from superoutburst of the dwarf nova V2051 Oph. On decline from superoutburst the disc cools down considerably from nearly 50,000 K in the intermediate disc (approx. 0.2 R_L1) near maximum to about 25,000 K at the end of our observing run, i.e. within 4 days. The average mass accretion rate through the disc drops in the same time from 10^18 g/s to below 10^17 g/s. While in some maps the brightness temperature follows the steady state model, in others the temperature profile shows flattenings and/or indication of an inward travelling cooling front with a speed of approximately -0.12 km/s, possibly a reflected heating front with a speed of +1.8 km/s and a newly reflected cooling front with the same speed as the first one. Such scenario has been predicted (Menou et al. 2000) but not been observed before. Furthermore, we see a prograde precession of the enlarged disc with a precession period of about 52.5 hours in very good agreement with the independently determined superhump period observed by Kiyota & Kato (1998). At the same time, the uneclipsed component -- presumeably a disc wind -- decreases significantly in strength during decline from superoutburst.

12 pages, 9 figures, accepted for publication in MNRAS

References in corpus (3)

• The 2001 Superoutburst of WZ Sagittae
• Changes in the structure of the accretion disc of EX Draconis through the outburst cycle
• Physical Parameter Eclipse Mapping of the quiescent disc in V2051 Ophiuchi

Cited by in corpus (8)

• Variable Star Network: World Center for Transient Object Astronomy and Variable Stars
• Superhumps in Cataclysmic Binaries. XXIV. Twenty More Dwarf Novae
• Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. VIII: The Eighth Year (2015-2016)
• Global MHD Simulations of Accretion Disks in Cataclysmic Variables (CVs): II The Relative Importance of MRI and Spiral Shocks
• A study of the evolution of the accretion disk of V2051 Oph through two outburst cycles
• Infrared photometry of the dwarf nova V2051 Ophiuchi: II -- The quiescent accretion disc and its spiral arms
• Long-term Periodicities of Cataclysmic Variables with Synoptic Surveys
• Infrared photometry of the dwarf nova V2051 Ophiuchi: I - The mass donor star and the distance