Vol. 613
In section 10. Planets and planetary systems

The nature of the TRAPPIST-1 exoplanets

by S. Grimm, B.-O. Demory, M. Gillon, et al. A&A 613, A68


Using time-transit variations and a genetic algorithm, Grimm et al. improve the uncertainties on the internal densities of the TRAPPIST planets by a factor of between five and eight. These results will help shed light on the compositions of these planets and eventually on the formation of this system.