High-resolution spectroscopy reveals signs of CO2 in the cloudy atmosphere of GJ 1214 b

Star system: Gliese 1214 | Distance from the Sun: 47.8 light years

GJ 1214 b is a sub-Neptune exoplanet known for its cloudy atmosphere, which has made it difficult to detect specific molecules. Using high-resolution K-band spectroscopy, scientists observed eight transits of the planet and searched for atmospheric signatures. While water vapor, methane, hydrogen sulfide, ammonia, and carbon monoxide were not detected, the data show a possible signal from carbon dioxide (CO2) at a confidence level of 3.4 sigma.

The analysis suggests that CO2 is likely a significant component of GJ 1214 b's atmosphere, with a metallicity higher than the Sun and a temperature between the planet's day and night sides. The results are consistent with previous JWST observations, though more data and modeling are needed to confirm the findings and fully understand the planet's atmosphere. The study highlights the challenges of probing cloudy exoplanet atmospheres and the importance of combining different observational techniques.

These findings support the idea that CO2 plays a key role in the atmospheres of sub-Neptune planets like GJ 1214 b and demonstrate the power of high-resolution spectroscopy in exoplanet research.

Key findings
- Possible detection of CO2 in GJ 1214 b's atmosphere
- No detection of H2O, CH4, H2S, NH3, or CO
- Atmospheric metallicity is higher than solar
- Temperature is intermediate between day and night sides
- Results are consistent with JWST data but need further confirmation

Scientific study

Cloudy with a chance of metals: Indications of CO_2 in the atmosphere of GJ 1214 b from high-resolution K-band spectroscopy (external link)