Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO

Understand

WASP-121b is one of the most studied Ultra-hot Jupiters: many recent analyses of its atmosphere report interesting features at different wavelength ranges.

• In this paper we analyze one transit of WASP-121b acquired with the high-resolution spectrograph ESPRESSO at VLT in 1-telescope mode, and one partial transit taken during the commissioning of the instrument in 4-telescope mode.
• We investigate the anomalous in-transit radial velocity curve and study the transmission spectrum of the planet.
• By analysing the in-transit radial velocities we were able to infer the presence of the atmospheric Rossiter-McLaughlin effect.