Outbursts of the recurrent nova T Coronae Borealis

THE recurrent nova T CrB has long been regarded as an anomaly among cataclysmic variables. It is a binary system consisting of an M3III giant and a blue companion¹. From the radial velocity curves, Kraft² found component masses of ≥ 3.7MȮ and ≥ 2.6MȮ, respectively, later revised downwards to 2.6MȮ and 1.9MȮ by Paczyński ³. Nevertheless, the mass of the blue component is clearly greater than the Chandrasekhar limit, even though the blue components of common novae are widely believed to be white dwarfs. The binary period, 227.5 d, is > 300 times longer than that of GK Per³, the longest period known among the remaining cataclysmic variables, and in stark contrast with the 0.0567-d period of WZ Sge, the only other recurrent nova of known binary period. Warner ⁴ has suggested, however, that T CrB is typical of the majority of recurrent novae. In this paper we interpret the behaviour of T CrB in terms of accretion in a binary system.