Modeling of a transient, high accretion state of the recurrent nova T CrB as a enhanced mass transfer event

Abstract

T Coronae Borealis is the nearest symbiotic recurrent nova. Twice in the last two centuries, in 1866 and 1946, the accreted material ignited on the surface of the white dwarf via runaway thermonuclear fusion reactions and produced a nova eruption. The most recent nova eruption occurred during a transient high-accretion state. A natural origin of such state is a dwarf nova like outburst, where a possible explanation is an instability in the mass transfer rate of the donor star (MTIM) during the transient. We simulate the response of an accretion disc to pulses of enhanced mass transfer, in the context of the MTIM, to model the optical light curve of T CrB. The observed brightening can be satisfactorily reproduced by models with a viscosity parameter α > 1 and a pulse of width ∆t ∼ 1.0 × 108 s (∼ 3.2 yr)