FU Orionis are young stellar objects undergoing episodes of enhanced luminosity , which are generally ascribed to a sudden increase of mass accretion rate in the surrounding protostellar disc .
Models invoking a thermal instability in the disc are able to reproduce many features of the outburst , but can not explain the rapid rise time-scale observed in many cases .
Here we explore the possibility ( originally suggested by ) that the thermal instability is triggered away from the disc inner edge ( at a distance of \approx 10 R _ { \odot } from the central protostar ) due to the presence of a massive planet embedded in the disc .
We have constructed simple , one-dimensional , time-dependent models of the disc evolution , taking into account both the interaction between the disc and the planet , and the thermal evolution of the disc .
We are indeed able to reproduce rapid rise outbursts ( with rise time-scale \approx 1 yr ) , with a planet mass M _ { \mathrm { s } } = 10 - 15 M _ { \mathrm { Jupiter } } .
We show that the luminosity and the duration of the outbursts are increasing functions of planet mass .
We also show that the inward migration of the planet is significantly slowed once it reaches the radius where it is able to trigger FU Orionis outbursts , thus suggesting that a single planet may be involved in triggering several outbursts .