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 Title: 

            Planet-disc interaction in FU Orionis objects: analytic and numerical models

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 Authors:

          Giuseppe Lodato, Institute of Astronomy, Cambridge, UK 

          Cathie Clarke, Institute of Astronomy, Cambridge, UK

          Gennaro D'Angelo, University of Exeter, UK

          Stanislav Melnikov, Ulugh Beg Astronomical Inst., Uzbekistan 

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 Abstract:

            FU Orionis outbursts are generally considered to be episodes of high mass accretion in a protostellar disc. We have recently constructed disc thermal instability models (Lodato & Clarke 2004), showing that the fast rise in the light curve observed in some of these systems (FU Ori and V1057 Cyg) can be explained in terms of the interaction between the disc and an embedded massive planet. Here we present detailed comparison of our models with observations, and show that the colour evolution of V1057 Cyg is better reproduced by our time-dependent calculations than by a series of steady-state accretion disc models, as sometimes done in the past. We also present the results of high-resultion 3D simulations of planet-disc interaction in FU Orionis type discs, describing in particular the issues of planetary migration and accretion. Accretion on the planet during the outburst could explain the periodic variability of the line profiles recently observed both in infrared CO absorption lines, and in Halpha emission.

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