Name/Affiliation: Laetitia Delrez (University of Liège (Belgium))
Ground-based transmission spectrum of WASP-80 b, a gas giant transiting an M-dwarf
At the current point in time, transiting exoplanets are the only extrasolar planets whose atmospheric properties can be studied in detail. During a transit, a small portion of the star light passes through the upper atmosphere of the planet, at the day-night terminator region. Some wavelengths are absorbed or scattered more effectively by the atmospheric constituents, causing wavelength-dependent transit depth variations. Via simultaneous multi-wavelength observations of transits, these variations can be measured and used to study the chemical composition, thermal structure and cloud coverage of the atmospheric limb. We will present here some results from our ground-based multi-object spectroscopy program aiming to measure the transmission spectrum of the hot Jupiter WASP-80 b using the VLT/FORS2 and Magellan/MMIRS instruments. WASP-80 b is a unique object as it is the only known specimen of gas giant orbiting an M-dwarf that is bright enough for high SNR follow-up measurements. Due to the nature of its host star, this hot Jupiter is actually more ‘warm’ than ‘hot’, with an estimated equilibrium temperature of only 800K. It is thus a prime target to improve our understanding of giant exoplanet atmospheres in this temperature range.