Recurrent Novae

Abstract

AbstractAn examination of the existing observational material on all the objects classified as recurrent novae, reveals that only T Pyx, U Sco, T CrB and RS Oph deserve such a classification. We review the properties of outbursts powered by thermonuclear runaways and accretion events and determine their observational consequences. We conclude that the outbursts of T CrB and RS Oph are very probably caused by accretion events from a giant companion onto a main sequence star. The outbursts of T Pyx and U Sco may be powered by thermonuclear runaways on the surface of white dwarfs with masses close to the Chandrasekhar limit. However, some questions, in particular regarding the composition of the accreted material in U Sco remain to be answered.