NASA | GSFC | STScI Webb Telescope | ESA Webb | ESA Space Science | 2023 Mar 27
An international team of researchers has used NASA’s James Webb Space Telescope to measure the temperature of the rocky exoplanet TRAPPIST-1 b. The measurement is based on the planet’s thermal emission: heat energy given off in the form of infrared light detected by Webb’s Mid-Infrared Instrument (MIRI). The result indicates that the planet’s dayside has a temperature of about 500 kelvins (roughly 230°C) and suggests that it has no significant atmosphere.
This is the first detection of any form of light emitted by an exoplanet as small and as cool as the rocky planets in our own solar system. The result marks an important step in determining whether planets orbiting small active stars like TRAPPIST-1 can sustain atmospheres needed to support life. It also bodes well for Webb’s ability to characterize temperate, Earth-sized exoplanets using MIRI.
“These observations really take advantage of Webb’s mid-infrared capability,” said Thomas Greene ... “No previous telescopes have had the sensitivity to measure such dim mid-infrared light.” ...
Thermal emission from the Earth-sized exoplanet TRAPPIST-1 b using JWST ~ Thomas P. Greene et al
- Nature (online 27 Mar 2023) DOI: 10.1038/s41586-023-05951-7
- arXiv > astro-ph > arXiv:2303.14849 > 26 Mar 2023