Sniffing the skies of new worlds: characterising the atmospheres of extrasolar planets using ground-based secondary eclipse observations

Observations of exoplanets during their secondary eclipses — when they are occulted by their host stars — are important tools to classify the atmospheres of their daysides.<br><br>In the first study, I present a secondary eclipse observation of KELT-9b — the hottest known exoplanet — in the {/-band, a window particularly sensitive to reflected light from Rayleigh scattering.

I did not detect a secondary eclipse signal, but my 3cr upper limit of 181 ppm on the eclipse depth allowed me to constrain the dayside temperature of KELT-9b at pressures of ~ 30mbar to < 4,995 K at 3o\ Although I could place an observational constraint on the geometric albedo of Ag < 0.14, models suggest that the actual value is considerably lower due to H~ opacity.<br><br>In the second study, I present two secondary eclipse observations of WASP-12b in the /'-band, a window expected to be dominated by TiO and VO features if present in appreciable quantities in the upper atmosphere.