Molecular signatures in a diverse set of transiting exoplanets

Star system: HD 189733 A | Distance from the Sun: 64.5 light years

High-resolution spectroscopy is a powerful tool for studying the atmospheres of exoplanets. This research analyzed 50 transits of 14 different exoplanets, ranging from super-Earths to ultra-hot Jupiters, using data from the SPIRou instrument. The team used automated data reduction and advanced atmospheric retrieval techniques to search for molecular signatures in these planets’ atmospheres.

The study confirmed previous detections of water (H2O) and carbon monoxide (CO) in the atmospheres of HD 189733 b, WASP-76 b, and WASP-127 b. It also found tentative evidence for hydrogen sulfide (H2S) in HD 189733 b and TOI-1807 b, and a possible detection of an atmosphere around GJ 3470 b. For planets where no molecules were detected, the team provided upper limits on their abundances. This work demonstrates a scalable approach for analyzing large archives of ground-based exoplanet data and supports future space-based atmospheric studies by providing a statistical overview of atmospheric diversity across many exoplanets.

Key findings
- 50 SPIRou transits of 14 exoplanets were analyzed for molecular signatures
- Water and carbon monoxide were confirmed in HD 189733 b, WASP-76 b, and WASP-127 b
- Tentative hydrogen sulfide detections in HD 189733 b and TOI-1807 b
- Possible atmospheric detection for GJ 3470 b
- The method provides a scalable way to analyze large ground-based exoplanet datasets

Scientific study

Searching for Molecular Signatures in 14 Transiting Exoplanets with SPIRou (external link)