双星与变星研究组知识库

In a hibernation scenario, systems after a nova outburst will exhibit high mass-transfer rates and change themselves into nova-like variables. The disc winds from the high-state disc bring away extra mass and angular momentum that affect evolution. Assuming the evolution is stable, we calculated the mass-transfer rate. (M) over dot(2) and the effective mass-radius index zeta of the donor stars for nova-likes with respect to the mass-loss proportion alpha based on their secular orbital period variations, and we located their positions on the tau(M) over dot(2)/tau(KH) - zeta diagram, where tau(M) over dot(2) and tau(KH) are the mass-transfer and thermal time-scales, respectively. V1315 Aql, a nova-like star surrounded by a nova shell due to a nova eruption 500-1200 yr earlier, is an exemplar for the hibernation hypothesis. However, in comparison with other nova-likes, we found that the mass transfer in V1315 Aql is unstable, due to irradiation by the white dwarf and accretion, and we estimated its magnitude-decline rate as similar to 10(-4) mag yr(-1), which is consistent with long-term optical observations. Its time-scale of magnitude decline is comparable to the recurrence time-scale of nova eruption, which indicates that V1315 Aql will not enter into hibernation. This conclusion seems to confirm the prediction of Hillman et al. that a post-nova with orbital period >3 h will never hibernate deeply.