LHS 1140

LHS 1140 is an exoplanetary system in Cetus 12-13 parsecs away which I hadn't deemed worth blogging. It bears two planets, c and b; remember, we enumerate these things in order-of-discovery. Today we learn outer planet b is not a Neptune. It is too dense for that thick atmosphere assumed of heavy, temperate-zone, set-in-place planets.

LHS 1140 as a system is indeed nonresonant. If we avoid NASA's catalog, which we should because they never update it just insert to it, the EU has a c which orbits 3.78 days, against b's 24.7. So a superEarth, perhaps, should have been expected even of outer b.

It seems that Webb offers director's discretionary time for targeted observations over short periods, if the researcher knows when and where precisely to look.

1.7 Earth radius and 5.6 mass mean less density than Earth but, still, nonNeptunian. It could be a waterworld or Hycean; but more likely the former, with nitrogen atmosphere. The researchers think they can detect CO₂ with more Webb time.