Forming the Trappist-1 system in two steps during the recession of the disc inner edge

Gabriele Pichierri, Alessandro Morbidelli, Konstantin Batygin +1

Trappist-1 hosts 7 planets where period ratios of neighbouring pairs are close to the 8:5, 5:3, 3:2, 3:2, 4:3, and 3:2 ratios in increasing distance from the star. The Laplace angl…