Abstract

In this talk, I will present observations and first results of six hot Jupiters with JWST NIR Spec/G395H, which are part of two JWST programmes set out to test planet formation and migration predictions. With these programmes we will measure the atmospheric metallicities and carbon-to-oxygen (C/O) ratios of a sample of misaligned and aligned hot Jupiters. All hot Jupiters must have undergone migration as they are too close to their host star to have formed in their current orbit. We further selected our sample such that the exoplanet host stars do not allow tidal orbital realignment, which means that our sample of misaligned planets have undergone high-eccentricity migration (after the disk dissipated) while our aligned targets migrated within the disk. These two different migration mechanism are predicted to result in different atmospheric composition. Hence these hot Jupiters allow us to test model predictions and shed light on the question whether we can infer migration scenarios from atmospheric measurements. Here I will present our transmission spectra of our aligned and misaligned hot Jupiters, show preliminary results and discuss current limitations when it comes to comparing C/O ratio and metallicity with predictions from planet formation and migration models.