Before the Molecule Has a Name

Webb on IC 348 in Perseus, about a thousand light-years out — Luhman and Alves de Oliveira.

Same team that in twenty twenty-two found brown dwarfs down to three or four Jupiter masses. NIRCam in twenty twenty-four, then NIRSpec in twenty twenty-five: thirty-nine candidates, fifteen spectra, nine new confirmed members.

The faintest sit at about two Jupiter masses — nought one nine percent of the Sun — below what formation models liked to allow for cloud collapse.

Two of them show disks: raw material for planets around something already planet-mass.

Eight of the nine carry an unidentified aliphatic hydrocarbon at three point four micrometres, stronger at fainter magnitudes; they propose a spectral class H for that band. Outside the solar system, only Saturn and Titan had held that feature before.

Failed star is a late mouth. Free-floating planet is a late mouth. Mystery solved is a late mouth. Looking is the mass that still sits where theory said collapse should stop, and the unnamed hydrocarbon only the coolest newborns keep.

The leftover is both: the about two Jupiter-mass objects that shouldn’t have formed by the old cut, and the H band that names a class before the molecule has a name.