We show that outside-in disc instabilities, which can produce rapid-rise FU Orionis outbursts in T Tauri systems, are a natural consequence of the existence of proto-planetary/protostellar companions. The protoplanetary/protostellar companion would be formed through gravitational instability on a dynamical time-scale ( ∼ 105 yr), and, provided that it was formed at less than a few au, it would be swept in to ∼ 15 R⊙ in less than 105 yr. A companion of mass 10−2 M⊙ at this radius would act as a flood gate which stores material upstream and periodically releases it following the ignition of the thermal ionization instability.
No takes yet. Share an insight, caveat, or question.
Clarke et al. (1996) studied this question.