Planetary formation and water delivery in the habitable zone around solar-type stars in different dynamical environments

ZAIN, P. S.; DE ELÍA, G. C.; RONCO, M. P.; GUILERA, O. M.

ASTRONOMY AND ASTROPHYSICS

EDP SCIENCES S A

Lugar: Paris; Año: 2018 vol. 609 p. 1 - 18

0004-6361

Context. Observational and theoretical studies suggest that there aremany and various planetary systems in the Universe. Aims: Westudy the formation and water delivery of planets in the habitable zone(HZ) around solar-type stars. In particular, we study differentdynamical environments that are defined by the most massive body in thesystem. Methods: First of all, a semi-analytical model was usedto define the mass of the protoplanetary disks that produce each of thefive dynamical scenarios of our research. Then, we made use of the samesemi-analytical model to describe the evolution of embryos andplanetesimals during the gaseous phase. Finally, we carried out N-bodysimulations of planetary accretion in order to analyze the formation andwater delivery of planets in the HZ in the different dynamicalenvironments. Results: Water worlds are efficiently formed in theHZ in different dynamical scenarios. In systems with a giant planetanalog to Jupiter or Saturn around the snow line, super-Earths tend tomigrate into the HZ from outside the snow line as a result ofinteractions with other embryos and accrete water only during thegaseous phase. In systems without giant planets, Earths and super-Earthswith high water by mass contents can either be formed in situ in the HZor migrate into it from outer regions, and water can be accreted duringthe gaseous phase and in collisions with water-rich embryos andplanetesimals. Conclusions: The formation of planets in the HZwith very high water by mass contents seems to be a common processaround Sun-like stars. Our research suggests that such planets are stillvery efficiently produced in different dynamical environments. Moreover,our study indicates that the formation of planets in the HZ with massesand water contents similar to those of Earth seems to be a rare processaround solar-type stars in the systems under consideration.