On the long-term tidal evolution of GJ 436b in the presence of a resonant companion

dc.creatorMardling, Rosemary A.
dc.date2008-05-13
dc.date.accessioned2026-07-07T09:38:45Z
dc.date.available2026-07-07T09:38:45Z
dc.descriptionIn order to explain the significant orbital eccentricity of the short-period transiting Neptune-mass planet GJ 436b and at the same time satisfy various observational constraints and anomalies, Ribas, Font-Ribera and Beaulieu have proposed the existence of an eccentric low-mass companion planet at the position of the outer 2:1 resonance. The authors demonstrate the viability of their proposal using point-mass three-body integrations, arguing that as long as the system appears to be dynamically stable, the short-term secular variations ought to dominate the long-term dissipative evolution. Here we demonstrate that if one includes tidal dissipation, both orbits circularize after a few times the circularization timescale of the inner planet. We conclude that with or without a nearby companion planet, in or out of the 2:1 resonance, the Q-value of GJ 436b must be near the upper bound estimate for Neptune if the system is as young as 1 Gyr, and an order of magnitude higher if the system is as old as 10 Gyr. We show detail of passage through resonance and conclude that even out of resonance, a companion planet should still be detectable through transit timing variations.
dc.description5 pages, 5 figures. Submitted to MNRAS Letters
dc.identifierhttps://arxiv.org/abs/0805.1928
dc.identifierhttp://arxiv.org/abs/0805.1928
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/160920
dc.subjectAstrophysics
dc.titleOn the long-term tidal evolution of GJ 436b in the presence of a resonant companion
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