IA/U.Porto Seminar - The effects of planet formation and planet engulfment on stellar surface composition - 1 setembro 2016

Recent observations have revealed that more than half of stars harbor a planet. Planet formation and evolution may be imprinted in stellar surface composition. In this talk I will present how the existence of planets affects stellar surface composition. The first is accretion from planet-forming disks onto young stellar objects. Since refractory elements are deposited in rocky planetesimals, the composition of planet-forming disks can be different from the primordial one. This effect is important not only for the stellar surface composition but also the luminosity spread problem of young stars. The second is planet engulfment by red giants. The orbit of planets around red giants is dramatically changed by stellar tide and stellar mass loss.

Eventually close-in planets can be engulfed by their host star, which yield the pollution of stellar surface. I will discuss the implication for the origin of Li-rich giants.

Centro de Astrofísica da Universidade do Porto (Auditorium)

Rua das Estrelas, 4150-762 Porto