Terrestrial planet formation at the sub-stellar mass limit

DOWNES WALLACE, J. J.; DE ELÍA, G. C.; SÁNCHEZ, M. B.

Antofagasta

Conferencia; LARIM 2019: XVI Latin American Regional IAU Meeting; 2019

International Astronomical Union

During the last decades several observational and theoretical works suggest that the formation of rocky planets seems to be a common process in the Universe and that planets could also form around very low mass stars and  brown dwarfs. However, planetary systems detections in the sub-stellar regime are still challenging due to very demanding instrumental accuracies and sensitivities as well as the relative small number of targets available so far in the solar neighborhood. Moreover, it is necessary to develop more realistic numerical simulations which include contraction and spin up of those objects as well as tidal-locked close-in bodies, in order to obtain a better understanding of planetary systems formation from the early stages. In this work, we present the results from N-body simulations intended to analyze the formation of terrestrial planets around stars close to the sub-stellar mass limit (~0.08 M_{Sun}) after the gas from their primordial disk has been dissipated. In our simulations, we included external tidal forces as well as general relativistic effects which are expected to be relevant in such compact planetary systems. We also incorporated the contraction of the radius and the spin up of the central object with time to recreate a more realistic scenario. We compare our results with those simulations disregarding both effects. We found an internal population of terrestrial-planets, close-in to the central object, that do not appear if an evolving object and tidal forces are neglected. We also analyzed which planets can remain into the habitable zone of the system during the integration time. Finally we present our results about the masses, sizes and amount of water in mass of the resulting planets, with the aim of contributing in a selection criteria for future searches of potentially habitable planets around stars and brown dwarfs close to the sub-stellar mass limit.