PERIODIC OUTBURSTS IN THE OLD NOVA V446 HERCULIS

摘要

We present data showing that over the last 4 yr V446 Her (=Nova Her 1960) has had outbursts or flares at a mean interval of 23 days with an amplitude of ～ 1.5 mag. These events vary in width from 5 to 11 days. During at least some periods of time, the recurrence interval is stable to within the observational error (typically ± 3 days). The spectrum of V446 Her in quiescence is shown to have an excitation level intermediate to that of dwarf novae- and nova-like cataclysmic variables. This fact, along with other evidence, leads us to suggest that these outbursts may be due to mass transfer events rather than dwarf nova-like accretion disk instabilities.