Aurélien Crida et al 2009 ApJ 705 L148 doi:10.1088/0004-637X/705/2/L148
Aurélien Crida1, Frédéric Masset2,3 and Alessandro Morbidelli4
Show affiliationsRecent observations of exoplanets by direct imaging reveal that giant planets orbit at a few dozens to more than a hundred AU from their central star. The question of the origin of these planets challenges the standard theories of planet formation. We propose a new way of obtaining such far planets, by outward migration of a pair of planets formed in the 10 AU region. Two giant planets in mean motion resonance in a common gap in the protoplanetary disk migrate outward, if the inner one is significantly more massive than the outer one. Using hydrodynamical simulations, we show that their semimajor axes can increase by almost 1 order of magnitude. In a flared disk, the pair of planets should reach an asymptotic radius. This mechanism could account for the presence of Fomalhaut b; then, a second, more massive planet, should be orbiting Fomalhaut at about 75 AU.
methods: numerical; planetary systems: formation; planetary systems: protoplanetary disks
97.10.Fy Circumstellar shells, clouds, and expanding envelopes; circumstellar masers
Issue 2 (2009 November 10)
Received 2009 July 1, accepted for publication 2009 October 5
Published 2009 October 21
Aurélien Crida et al 2009 ApJ 705 L148
K. S. Balasubramaniam et al. 2004 ApJ 606 1233
Antonino F. Lanza et al. 2001 ApJ 547 1116
Chyi-Lung Lin et al 2008 EPL 83 30002
Steven Soter 2006 The Astronomical Journal 132 2513
Luca Baiotti et al 2007 Class. Quantum Grav. 24 S187
Izumi Hachisu and Mariko Kato 2003 ApJ 588 1003
M. Núñez-Regueiro 2009 EPL 88 37004
Tomas Tyc et al 2003 J. Phys. A: Math. Gen. 36 7625
M Drakopoulos et al 2003 J. Phys. D: Appl. Phys. 36 A214