TRAPPIST-1
TRAPPIST-1 is a low-mass star in the constellation Aquarius, about 40.5 light-years from Earth.
Facts
| Type | Low-mass star (spectral type M7.5e) |
|---|---|
| Constellation | Aquarius |
| Position (J2000) | 23h 06m 30s, −5° 02′ |
| Distance | 40.5 light-years (its light set off about 40.5 years ago) |
| Brightness | magnitude 18.8 (smaller is brighter; the faintest stars the eye sees are about 6) |
| Studied in | 1,373 scientific papers (SIMBAD) |
Planets
7 known| Planet | Size (Earth = 1) | Year (days) | Habitable zone |
|---|---|---|---|
| TRAPPIST-1 b | 1.12 | 1.51 | no |
| TRAPPIST-1 c | 1.1 | 2.42 | no |
| TRAPPIST-1 d | 0.79 | 4.05 | yes (optimistic) |
| TRAPPIST-1 e | 0.92 | 6.1 | yes (conservative) |
| TRAPPIST-1 f | 1.05 | 9.21 | yes (conservative) |
| TRAPPIST-1 g | 1.13 | 12.35 | yes (conservative) |
| TRAPPIST-1 h | 0.76 | 18.77 | no |
When and how to see it
TRAPPIST-1 is highest in the sky at midnight in September. From India (about 20° N) it climbs to about 65° above the horizon; from 50° N, to about 35°. To see it you need a large telescope or long-exposure photos.
Heights are worked out for India and for 50° N. Set your location in Settings to see them for where you are.
For tonight's best time from your own town, the darkness and the Moon, open it on the map and see its "Tonight from your location" card.
More in Aquarius
Everything in Aquarius · All 88 constellations · All sky objects
Data: SIMBAD (CDS, Strasbourg; the site's weekly copy) · NASA Exoplanet Archive · Data sources & credits