Formation of TRAPPIST-1 and other compact systems

  title={Formation of TRAPPIST-1 and other compact systems},
  author={Chris W. Ormel and Beibei Liu and Djoeke Schoonenberg},
  journal={Astronomy and Astrophysics},
TRAPPIST-1 is a nearby 0.08  M ⊙ M-star that was recently found to harbor a planetary system of at least seven Earth-sized planets, all within 0.1 au. The configuration confounds theorists as the planets are not easily explained by either in situ or migration models. In this paper we present a scenario for the formation and orbital architecture of the TRAPPIST-1 system. In our model, planet formation starts at the H 2 O iceline, where pebble-sized particles whose origin is the outer disk… 

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