Research

Giant planets and brown dwarfs remember how they formed — but reading that memory from an atmosphere is hard. Bulk elemental ratios such as C/O have long been discussed as formation tracers (Öberg et al. 2011), while ground-based high-resolution spectroscopy has matured into a workhorse for detecting molecules, winds, and even planetary spin (Snellen 2025; Snellen et al. 2010; Snellen et al. 2014). A newer chapter opened when Zhang et al. (2021) measured $^{13}$CO in a directly imaged super-Jupiter, suggesting that isotope ratios might encode birth location relative to snow lines.

My work sits at that intersection. Within the ESO SupJup Survey and with JWST/NIRSpec and SPIRou, I build atmospheric retrievals that push isotope measurements from first detections toward a comparative sample — across planets, young brown dwarfs, and the cool stars that set the Galactic chemical baseline.