Protostars and Planets VI, Heidelberg, July 15-20, 2013
Pre-Main Sequence evolution including intense mass accretion
Kunitomo, Masanobu (Tokyo Institute of Technology)
Guillot, Tristan (Observatoire de la Côte dfAzur)
Ida, Shigeru (Tokyo Institute of Technology)
We have studied the evolution of the convective envelope in Pre-Main-Sequence (PMS) stars with the intense disk mass accretion and efficient radiation under a variety of conditions. Recent fluid dynamical numerical simulations suggest that protostars are formed with initial mass as small as Jovian mass and the solar-mass stars are formed through the intense disk accretion afterward. If the energy loss of the accreting materials by radiation is efficient, the PMS evolution can be different from that in the traditional theory. If a star evolves from the state with the smaller radius and higher center temperature, a radiative core develops and convective envelope shrinks at the earlier stage. The evolution of the convective envelope is important for the surface composition, the magnetic field, and the tidal dissipation of the star. Through the calculations with a stellar evolution code MESA modified by us, we have found that the treatment of the entropy of the accreting material is the most important factor for the convective envelope evolution. We also study the effects of the efficiency of the radiation and the mass accretion rate on the convective envelope evolution. With these results, we will discuss PMS evolution and connection to planet formation.
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