Abstract
We calculate the meteorology of the close-in transiting extrasolar planet HD 209458h using a global, three-dimensional atmospheric circulation model. Dynamics are driven by perpetual irradiation of one hemisphere of this tidally locked planet. The simulation predicts global temperature contrasts of ∼500 K at the photosphere and the development of a steady superrotating jet. The jet extends from the equator to midlatitudes and from the top model layer at 1 mbar down to 10 bar at the base of the heated region. Wind velocities near the equator exceed 4 km s-1 at 300 mbar. The hottest regions of the atmosphere are blown downstream from the substellar point by ∼60° of longitude. We predict from these results a factor of ∼2 ratio between the maximum and minimum observed radiation from the planet over a full orbital period, with peak infrared emission preceding the time of the secondary eclipse by ∼14 hr.
Original language | English (US) |
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Pages (from-to) | L45-L48 |
Journal | Astrophysical Journal |
Volume | 629 |
Issue number | 1 II |
DOIs | |
State | Published - Aug 10 2005 |
Externally published | Yes |
Keywords
- Atmospheric effects
- Methods: numerical
- Planets and satellites: general
- Planets and satellites: individual (HD 209458b)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science