TY - JOUR
T1 - Mass loss from the exoplanetWASP-12b inferred from Spitzer phase curves
AU - Bell, Taylor J.
AU - Zhang, Michael
AU - Cubillos, Patricio E.
AU - Dang, Lisa
AU - Fossati, Luca
AU - Todorov, Kamen O.
AU - Cowan, Nicolas B.
AU - Deming, Drake
AU - Zellem, Robert T.
AU - Stevenson, Kevin B.
AU - Crossfield, Ian J.M.
AU - Dobbs-Dixon, Ian
AU - Fortney, Jonathan J.
AU - Knutson, Heather A.
AU - Line, Michael R.
N1 - Publisher Copyright:
© 2019 The Author(s).
PY - 2019/10/21
Y1 - 2019/10/21
N2 - The exoplanet WASP-12b is the prototype for the emerging class of ultrahot, Jupiter-mass exoplanets. Past models have predicted - and near-ultraviolet observations have shown - that this planet is losing mass. We present an analysis of two sets of 3.6 and 4.5 μm Spitzer phase curve observations of the system which show clear evidence of infrared radiation from gas stripped from the planet, and the gas appears to be flowing directly toward or away from the host star. This accretion signature is only seen at 4.5 μm, not at 3.6 μm, which is indicative either of CO emission at the longer wavelength or blackbody emission from cool, ≲600 K gas. It is unclear why WASP-12b is the only ultrahot Jupiter to exhibit this mass-loss signature, but perhaps WASP-12b's orbit is decaying as some have claimed, while the orbits of other exoplanets may be more stable; alternatively, the high-energy irradiation from WASP-12A may be stronger than the other host stars. We also find evidence for phase offset variability at the level of 6.4σ (46.2°) at 3.6 μm.
AB - The exoplanet WASP-12b is the prototype for the emerging class of ultrahot, Jupiter-mass exoplanets. Past models have predicted - and near-ultraviolet observations have shown - that this planet is losing mass. We present an analysis of two sets of 3.6 and 4.5 μm Spitzer phase curve observations of the system which show clear evidence of infrared radiation from gas stripped from the planet, and the gas appears to be flowing directly toward or away from the host star. This accretion signature is only seen at 4.5 μm, not at 3.6 μm, which is indicative either of CO emission at the longer wavelength or blackbody emission from cool, ≲600 K gas. It is unclear why WASP-12b is the only ultrahot Jupiter to exhibit this mass-loss signature, but perhaps WASP-12b's orbit is decaying as some have claimed, while the orbits of other exoplanets may be more stable; alternatively, the high-energy irradiation from WASP-12A may be stronger than the other host stars. We also find evidence for phase offset variability at the level of 6.4σ (46.2°) at 3.6 μm.
KW - Accretion
KW - Accretion discs
KW - Planet-star interactions
KW - Planets and satellites: Individual (WASP-12b)
KW - Techniques: Photometric
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U2 - 10.1093/mnras/stz2018
DO - 10.1093/mnras/stz2018
M3 - Article
AN - SCOPUS:85075181940
SN - 0035-8711
VL - 489
SP - 1995
EP - 2013
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -