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Paper: Evolution and Atmospheric Circulation of "Pegasi Planets"
Volume: 294, Scientific Frontiers in Research on Extrasolar Planets
Page: 503
Authors: Guillot, T.; Showman, A.
Abstract: About one-quarter of the extrasolar giant planets discovered so far have orbital distances smaller than 0.1 AU. Among those are the first genuine giant planet detected outside our solar system, 51 Peg b, and the first characterized extrasolar planet, HD 209458b (also in the Pegasus constellation). These ``Pegasi planets'' form a class of objects whose evolution and structure is strongly affected by stellar irradiation and tides. We show in particular that the radius of HD 209458b cannot be reproduced by conventional evolution models unless its atmosphere is assumed to be unrealistically hot. We argue that the combination of the synchronization by stellar tides and the strong irradiation yield an atmosphere that has significant temperature variations and strong winds. The kinetic energy thus generated can be transported in the deep interior and slow the planet's contraction. We also discuss the consequences of the atmospheric circulation on the chemistry.
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