WASP-12b and 4b: closing in on compositions of highly-irradiated exoplanet atmospheres
Abstract
We present an analysis of the atmospheres of the exoplanets WASP-12b [2] and WASP-4b [4], using new data obtained from the WFC-3 instrument on the Hubble Space Telescope, in a previously sparselysampled wavelength range of 1.3 - 1.7 μm. The highly-irradiated atmospheres, located in the starplanet crossover regime for temperature, along with a possible high C/O ratio, make these intriguing candidates for studies of atmospheric composition and dynamics; we use a line-by-line radiative transfer model to fit the transmission spectrum in this wavelength range, and retrieve the atmospheric compositions and molecular abundances. We find that both planets exhibit some features more characteristic of atmospheres of late M-and L-dwarfs rather than of other exoplanets, and compare our results with theoretical predictions for such highlyirradiated hot-Jupiter atmospheres.
- Publication:
-
European Planetary Science Congress 2012
- Pub Date:
- September 2012
- Bibcode:
- 2012epsc.conf..523H