Presentation #102.388 in the session Poster Session.
The CHEWIE survey (Clouds, Hazes and Elements vieWed on giant Exoplanets) aims to study the impact of the stellar environment on planet atmospheres and their aerosols at the day-night terminator through transmission spectra of planets in the Jupiter to Neptune mass range. It does this with ground-based, medium resolution observations with the FORS2 instrument on the VLT. In this talk we present the first transmission spectrum of the survey, WASP-69b. This Saturn-mass planet has a puffed up atmosphere, making it an excellent target for atmospheric characterisation.