Astronomy and Astrophysics – Astrophysics – Earth and Planetary Astrophysics
Scientific paper
2010-04-06
Astronomy and Astrophysics
Astrophysics
Earth and Planetary Astrophysics
10 pages, submitted to ApJ
Scientific paper
We present a comparative study of the thermal emission of the transiting exoplanets WASP-1b and WASP-2b using the Spitzer Space Telescope. The two planets have very similar masses but suffer different levels of irradiation and are predicted to fall either side of a sharp transition between planets with and without hot stratospheres. WASP-1b is one of the most highly irradiated planets studied to date. We measure planet/star contrast ratios in all four of the IRAC bands for both planets (3.6-8.0um), and our results indicate the presence of a strong temperature inversion in the atmosphere of WASP-1b, particularly apparent at 8um, and no inversion in WASP-2b. In both cases the measured eclipse depths favor models in which incident energy is not redistributed efficiently from the day side to the night side of the planet. We fit the Spitzer light curves simultaneously with the best available radial velocity curves and transit photometry in order to provide updated measurements of system parameters. We do not find significant eccentricity in the orbit of either planet, suggesting that the inflated radius of WASP-1b is unlikely to be the result of tidal heating. Finally, by plotting ratios of secondary eclipse depths at 8um and 4.5um against irradiation for all available planets, we find evidence for a sharp transition in the emission spectra of hot Jupiters at an irradiation level of 2 x 10^9 erg/s/cm^2. We suggest this transition may be due to the presence of TiO in the upper atmospheres of the most strongly irradiated hot Jupiters.
Aigrain Suzanne
Anderson David R.
Clarkson William I.
Collier Cameron Andrew
Fortney Jonathan J.
No associations
LandOfFree
The thermal emission of the exoplanets WASP-1b and WASP-2b 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 The thermal emission of the exoplanets WASP-1b and WASP-2b, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The thermal emission of the exoplanets WASP-1b and WASP-2b will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-57296