TY - JOUR
T1 - A global map of the atmospheric circulation and thermal structure for an ultrahot exoplanet
AU - Evans, Tom
AU - Sing, David
AU - Tiffany, Kataria
AU - Nikolov, Nikolay
AU - Deming, Drake
AU - Lewis, Nikole
AU - Wakeford, Hannah
AU - Marley, Mark
AU - Gibson, Neale
AU - Spake, Jessica
AU - Drummond, Benjamin
AU - Barstow, Joanna
AU - Henry, Gregory
AU - Mayne, Nathan
PY - 2017/10/1
Y1 - 2017/10/1
N2 - WASP-121b is one of the standout exoplanets available for atmospheric
characterization, both in transmission and emission, due to its large
radius (1.8 Jupiter radii), high temperature ( 2700K), and bright host
star (H=9.4mag). Recent HST/WFC3 eclipse observations made by our group
have revealed the 1.4 micron water band in emission on the dayside
hemisphere of WASP-121b, implying that the atmosphere has a thermal
inversion. This new development, combined with the favorable system
properties, makes it clear that WASP-121b is an ideal target to
empirically probe the variation of thermal inversions with longitude. To
do this, we propose phase curve measurements of WASP-121b over a full
orbital period in each of the Spitzer/IRAC channels. Given the
measurement precision demonstrated by our previous IRAC observations of
WASP-121b, we anticipate this dataset will be one of the highest
signal-to-noise phase curve measurements for an exoplanet to date. It
will provide a powerful complement to full-orbit phase curves that have
recently been confirmed for shorter wavelengths, to be made by HST/WFC3
and JWST/NIRISS. Combined, this Spitzer+HST+JWST phase curve dataset
will produce an unprecedented map of the longitudinally-resolved thermal
structure, chemical composition and global circulation of an exoplanet
atmosphere, and, in particular, give crucial new insight into the
long-standing mystery of thermal inversions in strongly-irradiated gas
giants.
AB - WASP-121b is one of the standout exoplanets available for atmospheric
characterization, both in transmission and emission, due to its large
radius (1.8 Jupiter radii), high temperature ( 2700K), and bright host
star (H=9.4mag). Recent HST/WFC3 eclipse observations made by our group
have revealed the 1.4 micron water band in emission on the dayside
hemisphere of WASP-121b, implying that the atmosphere has a thermal
inversion. This new development, combined with the favorable system
properties, makes it clear that WASP-121b is an ideal target to
empirically probe the variation of thermal inversions with longitude. To
do this, we propose phase curve measurements of WASP-121b over a full
orbital period in each of the Spitzer/IRAC channels. Given the
measurement precision demonstrated by our previous IRAC observations of
WASP-121b, we anticipate this dataset will be one of the highest
signal-to-noise phase curve measurements for an exoplanet to date. It
will provide a powerful complement to full-orbit phase curves that have
recently been confirmed for shorter wavelengths, to be made by HST/WFC3
and JWST/NIRISS. Combined, this Spitzer+HST+JWST phase curve dataset
will produce an unprecedented map of the longitudinally-resolved thermal
structure, chemical composition and global circulation of an exoplanet
atmosphere, and, in particular, give crucial new insight into the
long-standing mystery of thermal inversions in strongly-irradiated gas
giants.
M3 - Meeting abstract
JO - Spitzer Proposal ID 13242
JF - Spitzer Proposal ID 13242
ER -