February 6, 2018

Artist's concept of TRAPPIST-1's planets with the Earth (Image ESO/M. Kornmesser)

Two articles, one published in the journal “Astronomy & Astrophysics” and one in the journal “Nature Astronomy”, describe two researches on the TRAPPIST-1 system’s rocky planets. Various telescopes, both space and ground-based, allowed to gather more information on those 7 exoplanets and to improve the measurements of their characteristics. An important result is the estimate of their density, which suggests that some of them are composed up to 5% of water. Spectroscopic detections suggest that at least 3 of them have a compact atmosphere that could allow liquid water to exist on their surface.