THE EVERYTHING MUSEUM

Exhibit Codex

TRAPPIST-1

A small, cool star about 40.5 light-years away in Aquarius. Seven known terrestrial-sized planets form a remarkably compact planetary system. The system age is uncertain; 7.6 billion years is an approximate published estimate.

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About this exhibit

Ultracool red dwarf

Reference and coverage

Time scaling is shared with the interactive atlas. Surface interpretations and reconstructed history have different levels of certainty.

Planetary record

An ultracool dwarf

TRAPPIST-1 has about 9% of the Sun’s mass and 12% of its radius. Its effective temperature is approximately 2,566 K. Low luminosity places temperate orbital distances much closer to the star than in our system.

A long-lived planetary host

The estimated age is 7.6 ± 2.2 billion years. Red dwarfs can remain on the main sequence far longer than Sun-like stars. Activity and radiation are important questions for the surrounding planets.

Time in this exhibit

7.6 billion years ago · An ancient red dwarf

An approximate formation epoch for TRAPPIST-1. Its age is uncertain, and the early disk shown here is illustrative.

Present · Seven compact worlds

The known planets occupy a near-resonant orbital chain. Periods and radii come from the NASA Exoplanet Archive; the scene uses illustrative phases and surfaces.

Read the detailed records

Open the full exhibit Codex for individual structure records and time-specific information. The Credits page lists source creators, licenses and adaptations.

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