TRAPPIST-1

System and reported orbital measurement

The supplied arXiv record describes TRAPPIST-1 as the first transiting planet system found orbiting an ultracool dwarf and reports that at least seven planets similar to Earth in radius and mass had been found to transit the host. Using K2 observations together with dynamical relationships, the study reports an 18.77 d orbital period for TRAPPIST-1h, described there as the outermost planet and previously unconstrained.

Resonant-chain interpretation

The abstract states that the 18.77 d value matches theoretical expectations based on Laplace relations and places TRAPPIST-1h as the seventh member of a complex chain, with three-body resonances linking every member. These are interpretations reported by the cited study; the supplied material does not include an independent or later check.

Reported parameters and evidentiary limits

The same record reports a radius of 0.727 Earth radii and an equilibrium temperature of 173 K for TRAPPIST-1h, plus a 3.3 d stellar rotation period. It says detected flares were consistent with a low-activity, middle-aged, late M dwarf; those descriptors are not presented here as definitive classifications. The supplied material provides no life detection or later atmospheric analysis, so the orbital result should not be presented as evidence that any planet is inhabited or habitable.

Publication context and source scope

The supplied arXiv record lists an initial submission on 12 March 2017, a last revision on 22 May 2017 as version 2, and a journal reference to Nature Astronomy 1, 0129 (2017). The provided material is a landing-page and abstract record rather than the full paper, and no later or independent literature is supplied.

Source chronology

Dates below describe source publication, which may differ from the date of an observation or event.

Connected knowledge

Source trail

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