Co-orbital satellites of Saturn: congenital formation

• Published in: Monthly notices of the Royal Astronomical Society 2010-07, Vol.405 (4), p.2132-2140
• Main Authors: Izidoro, A., Winter, O. C., Tsuchida, M.
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology; planets and satellites: formation; planets and satellites: individual: Saturn; Satellites; Saturn
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1111/j.1365-2966.2010.16655.x

Saturn is the only known planet to have co-orbital satellite systems. In the present work we studied the process of mass accretion as a possible mechanism for co-orbital satellites formation. The system considered is composed of Saturn, a protosatellite and a cloud of planetesimals distributed in the co-orbital region around a triangular Lagrangian point. The adopted relative mass for the protosatellite was 10−6 of Saturn’s mass and for each planetesimal of the cloud three cases of relative mass were considered, 10−14, 10−13 and 10−12 masses of Saturn. In the simulations each cloud of planetesimal was composed of 103, 5 × 103 or 104 planetesimals. The results of the simulations show the formation of co-orbital satellites with relative masses of the same order of those found in the Saturnian system (10−13–10−9). Most of them present horseshoe-type orbits, but a significant part is in tadpole orbit around L4 or L5. Therefore, the results indicate that this is a plausible mechanism for the formation of co-orbital satellites.