Abstract
We revisit the atmospheric properties of the extremely hot Jupiter WASP-12b in light of several new developments. First, we present new narrowband (2.315 μm) secondary eclipse photometry, which exhibits a planet/star flux ratio of 0.45% ± 0.06%, corresponding to a brightness temperature of 3640 ± 230 K; second, recent Spitzer/Infrared Array Camera and Hubble Space Telescope/Wide Field Camera 3 observations; and third, a recently observed star only 1″ from WASP-12, which has diluted previous observations and which we further characterize here. We correct past WASP-12b eclipse measurements for the presence of this object, and we revisit the interpretation of WASP-12b's dilution-corrected emission spectrum. The resulting planetary emission spectrum is well approximated by a blackbody, and consequently our primary conclusion is that the planet's infrared photosphere is nearly isothermal. Thus, secondary eclipse spectroscopy is relatively ill suited to constrain WASP-12b's atmospheric abundances, and transmission spectroscopy may be necessary to achieve this goal.
Original language | English (US) |
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Article number | 140 |
Journal | Astrophysical Journal |
Volume | 760 |
Issue number | 2 |
DOIs | |
State | Published - Dec 1 2012 |
Externally published | Yes |
Keywords
- eclipses
- infrared: planetary systems
- stars: individual (WASP-12, Bergfors-6)
- techniques: photometric
- techniques: spectroscopic
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science