Orbits and Radii of Transiting EGPs

Details Orbits and Radii of Transiting EGPs Orbits and Radii of Transiting EGPs

Dec 2009

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009dps....41.6807i&link_type=abstract

American Astronomical Society, DPS meeting #41, #68.07

Astronomy and Astrophysics

Astronomy

Scientific paper

In order to explain the inflated radii of some transiting extrasolar giant planets (EGP), we explore the
possibilities of two distinct scenarios.
The first scenario assumes a quasi-steady state evolution of the system. This can be made possible by
the gravitational influence of a second planet. The semi-major axis and the eccentricities may then remain
quasi-constant on Gyr timescales. The radius may also quickly reach an equilibrium value. Further, if we
assume that the main source of heating the inside of the planet comes from the tidal interaction with its
parent star, we relate the core mass of the planet Mcore, its tidal dissipation factor Q'p, and the eccentricity e.
Using the current best-estimate values of e, we determine a range of plausible pairs (Mcore , Q'p), that may
be refined by improvements of the measurements of e.
The second scenario assumes a two-body tidal interaction that consistently couples the evolution of
the radius and the orbit of the planet. It includes the tides raised on the planet and the tides raised on the
star, along with stellar irradiation and detailed model atmospheres. Controlled by four free parameters (Q'p,
Q'*, ei, ai), it has been tested on recently discovered inflated transiting EGPs. It enables the simultaneous
fit of the observed radius, semi-major axis and eccentricity of HD209458b, WASP-4b, WASP-6b, WASP-
12b, WASP-15b, but not TrES-4. However, the fits are sometimes obtained for a very narrow age range
and require high eccentricities after migration due to disk-planet interactions.
We also address the plunging timescale uncertainties of the planet into its parent star. The timescale
depends linearly on Q'*, a poorly known parameter. Thus, the uncertainties can span 2 to 3 orders of
magnitude.

Affiliated with

Also associated with

No associations

Rating

Orbits and Radii of Transiting EGPs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Orbits and Radii of Transiting EGPs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Orbits and Radii of Transiting EGPs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1887036