Stephanie Merritt

Current research project

Characterising exoplanet atmospheres using high-resolution spectroscopy

The exoplanets known as hot Jupiters (gas giants orbiting close to their parent stars) represent a unique opportunity to explore extreme atmospheric chemistry. The hottest of these planets have temperatures > 2500K and are predicted to host thermal inversions (the rise of temperature with altitude) due to the presence of gaseous titanium oxide and vanadium oxide causing local heating. However, evidence to confirm these models has proven elusive. My work used Doppler spectroscopy in an attempt to unambiguously detect the presence of TiO or VO in the hot Jupiter WASP-121b, which has previously been shown to host a thermal inversion. I have found neither, suggesting that TiO and VO are not always the main drivers of thermal inversions and that our models need to be refined. Future work will focus on detecting other potential drivers of the thermal inversion in WASP-121b and on exploring the atmospheres of other ultra-hot Jupiters to clarify our understanding of these extreme worlds.

• Exoplanet atmospheres

• Transmission spectroscopy

• High-resolution spectroscopy

• Statistical methods

• Atmospheric modelling