TESS observations of the WASP-121 b phase curve

Understand

We study the red-optical photometry of the ultra-hot Jupiter WASP-121 b as observed by the Transiting Exoplanet Survey Satellite (TESS) and model its atmosphere through a radiative transfer simulation.

• Given its short orbital period of $\sim1.275$ days, inflated state and bright host star, WASP-121 b is exceptionally favorable for detailed atmospheric characterization.
• Towards this purpose, we use \texttt{allesfitter} to characterize its full red-optical phase curve, including the planetary phase modulation and the secondary eclipse.
• We measure the day and nightside brightness temperatures in the TESS passband as $3012\substack{+40 \\ -42}$ K and $2022\substack{+254 \\ -602}$ K, respectively, and do not find a statistically significant phase shift between the brightest and substellar points.