3 research outputs found
The Emission Spectrum of the Hot Jupiter WASP-79b from HST/WFC3
Here we present a thermal emission spectrum of WASP-79b, obtained via Hubble Space Telescope Wide Field Camera 3 G141 observations as part of the PanCET program. As we did not observe the ingress or egress of WASP-79b\u27s secondary eclipse, we consider two scenarios: a fixed mid-eclipse time based on the expected occurrence time, and a mid-eclipse time as a free parameter. In both scenarios, we can measure thermal emission from WASP-79b from 1.1 to 1.7 μm at 2.4σ confidence consistent with a 1900 K brightness temperature for the planet. We combine our observations with Spitzer dayside photometry (3.6 and 4.5 μm) and compare these observations to a grid of atmospheric forward models that span a range of metallicities, carbon-to-oxygen ratios, and recirculation factors. Given the strength of the planetary emission and the precision of our measurements, we found a wide range of forward models to be consistent with our data. The best-match equilibrium model suggests that WASP-79b\u27s dayside has a solar metallicity and carbon-to-oxygen ratio, alongside a recirculation factor of 0.75. Models including significant H− opacity provide the best match to WASP-79b\u27s emission spectrum near 1.58 μm. However, models featuring high-temperature cloud species—formed via vigorous vertical mixing and low sedimentation efficiencies—with little day-to-night energy transport also match WASP-79b\u27s emission spectrum. Given the broad range of equilibrium chemistry, disequilibrium chemistry, and cloudy atmospheric models consistent with our observations of WASP-79b\u27s dayside emission, further observations will be necessary to constrain WASP-79b\u27s dayside atmospheric properties
The Emission Spectrum of the Hot Jupiter WASP-79b from HST/WFC3
Here we present a thermal emission spectrum of WASP-79b, obtained via Hubble
Space Telescope Wide Field Camera 3 G141 observations as part of the PanCET
program. As we did not observe the ingress or egress of WASP-79b's secondary
eclipse, we consider two scenarios: a fixed mid-eclipse time based on the
expected occurrence time, and a mid-eclipse time as a free parameter. In both
scenarios, we can measure thermal emission from WASP-79b from 1.1 to 1.7 m
at 2.4 confidence consistent with a 1900 K brightness temperature for
the planet. We combine our observations with Spitzer dayside photometry (3.6
and 4.5 m) and compare these observations to a grid of atmospheric forward
models that span a range of metallicities, carbon-to-oxygen ratios, and
recirculation factors. Given the strength of the planetary emission and the
precision of our measurements, we found a wide range of forward models to be
consistent with our data. The best-match equilibrium model suggests that
WASP-79b's dayside has a solar metallicity and carbon-to-oxygen ratio,
alongside a recirculation factor of 0.75. Models including significant H-
opacity provide the best match to WASP-79b's emission spectrum near 1.58
m. However, models featuring high-temperature cloud species-formed via
vigorous vertical mixing and low sedimentation efficiencies-with little
day-to-night energy transport also match WASP-79b's emission spectrum. Given
the broad range of equilibrium chemistry, disequilibrium chemistry, and cloudy
atmospheric models consistent with our observations of WASP-79b's dayside
emission, further observations will be necessary to constrain WASP-79b's
dayside atmospheric properties.Comment: 13 pages, 8 figures. Accepted for publication in A