Paper: astro-ph/0507422
Date: Mon, 18 Jul 2005 21:49:23 GMT (134kb)

Title: Atmosphere, Interior, and Evolution of the Metal-Rich Transiting Planet
HD 149026b

Authors: J. J. Fortney, D. Saumon, M. S. Marley, K. Lodders, R. S. Freedman
Comments: Submitted to the Astrophysical Journal. 13 pages, including 7 figures
\\
We investigate the atmosphere and interior of the new transiting planet HD
149026b, which appears to be very rich in heavy elements. We first compute
model atmospheres at metallicities ranging from solar to ten times solar, and
show how for cases with high metallicity or inefficient redistribution of
energy from the day side, the planet can develop a hot stratosphere due to
absorption of stellar flux by TiO and VO. The resulting spectra of these models
are very different than cooler atmosphere models without stratospheres. The
spectral effects are potentially detectable with the Spitzer Space Telescope.
In addition the models with hot stratospheres lead to a large limb brightening,
rather than darkening. Using a grid of self-consistent model atmospheres and
high-pressure equations of state for all components, we compute thermal
evolution models of the planet, and estimate that the mass of heavy elements
within the planet is in the range of 66 to 79 Earth masses. Finally, we discuss
trends in the radii of transiting planets with metallicity in light of this new
member of the class.

\\ ( http://arXiv.org/abs/astro-ph/0507422 , 134kb)