Tidal Heating Models for the Radii of the Inflated Transiting Giant Planets WASP-4b, WASP-6b, WASP-12b, WASP-15b, and TrES-4

In order to explain the inflated radii of some transiting extrasolar giant planets, we investigate a tidal heating scenario for the inflated planets WASP-4b, WASP-6b, WASP-12b, WASP-15b, and TrES-4. To do so, we assume that they retain a nonzero eccentricity, possibly by dint of continuing interacti...

Full description

Saved in:
Bibliographic Details
Published in:The Astrophysical journal 2010-04, Vol.713 (2), p.751-763
Main Authors: Ibgui, Laurent, Burrows, Adam, Spiegel, David S
Format: Article
Language:English
Subjects:
Astronomy
Astrophysics
Earth, ocean, space
Exact sciences and technology
Physics
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In order to explain the inflated radii of some transiting extrasolar giant planets, we investigate a tidal heating scenario for the inflated planets WASP-4b, WASP-6b, WASP-12b, WASP-15b, and TrES-4. To do so, we assume that they retain a nonzero eccentricity, possibly by dint of continuing interaction with a third body. We calculate the amount of extra heating in the envelope that is then required to fit the radius of each planet, and we explore how this additional power depends on the planetary atmospheric opacity and on the mass of a heavy-element central core. There is a degeneracy between the core mass M core and the heating \dot{E}_heating. Therefore, in the case of tidal heating, there is for each planet a range of {M core , e 2 /Q' p } that can lead to the same radius, where Q' p is the tidal dissipation factor and e is the eccentricity. With this in mind, we also investigate the case of the non-inflated planet HAT-P-12b, which can admit solutions combining a heavy-element core and tidal heating. A substantial improvement of the measured eccentricities of such planetary systems could simplify this degeneracy by linking the two unknown parameters {M core , Q' p }. Further independent constraints on either of these parameters would, through our calculations, constrain the other.
ISSN:0004-637X
1538-4357
DOI:10.1088/0004-637X/713/2/751