Studying primordial spins of extrasolar planets

MIGUEL YAMILA, ADRIAN BRUNINI

South Hadley, MA, Estados Unidos

Conferencia; Gordon Resarch Conference, Origin of Solar Systems; 2009

SOuth West Reasearch Institute

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} p.MsoPlainText, li.MsoPlainText, div.MsoPlainText {margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Courier New"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> We develop a simple model for computing planetary formation, focusing our attention on planets with masses less than 10 Earth masses and studying particularly the effects produced by the collisions between the embryos. As initial conditions, we adopt the oligarchic growth regime of protoplanets in a disc where several embryos are allowed to form. The orbital evolution of the embryos and the migration of the planetesimals due to the interaction with the disc of gas are also taken into account. With this model we consider different initial conditions to generate a variety of planetary systems and analyze them statistically. We have taken special attention to the planetary obliquities and rotation periods, such as the information obtained from the mass and semi major diagram, who reflects the process of planetary formation. We found that the primordial rotation periods of terrestrial planets are dependent on the semi major axis, which means on the region where the embryo was formed and evolve. We also found that most of the terrestrial planets have primordial rotation periods greater than those observed today in the terrestrial planets of our solar system.