The Buildup of a Tightly Bound Comet Cloud around an Early Sun Immersed in a Dense Galactic Environment: Numerical Experiments

FERNANDEZ, J. A.; BRUNINI, A.

ICARUS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: New York; Año: 2000 vol. 145 p. 580 - 590

0019-1035

We simulate numerically the buildup of a comet reservoir aroundthe early Sun assumed to be still immersed in the placental moleculargas that gave birth to it, and to be gravitationally bound to otheryoung stars formed out of the same gas.We show that under certainreasonable assumptions about the early galactic environment of theSun, an inner core of the Oort cloud of radius from a few 102 AU toa few 103 AUforms on a time scale of a few million year. Jupiter andSaturn are the main scatterers of matter to this inner core, thougha significant fraction of the matter scattered by these two planets(perhaps more than 50%) might originally come from the accretionzones of Uranus and Neptune. If the formation process of the jovianplanets left unaccreted an amount of solid material of the sameorder of their own planet masses (the rock-icy cores for the cases ofJupiter and Saturn), then a few M© of the scattered solid materialmight have been trapped in the Oort reservoir, most of it in the inner