Discovery Method
Transit
Consistent across records
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ExoplanetDetail
TRAPPIST-1 d
Host star TRAPPIST-1 • 0.79 R⊕ • 4.05 d orbit
Records
5
archive rows
Discovery
2016
Transit
Radius
0.79 R⊕
default parameter set
Mass
0.39 M⊕
default parameter set
TRAPPIST-1
temperature unconstrained
Canonical Summary
Adopted planet values from the default parameter set
Values come from the archive's default parameter set. Missing values stay missing. Ranges and counts describe all source rows.
Selected source: Agol et al. 2021
Host Star
TRAPPIST-1
Stable across source rows
Discovery Year
2016
Stable across source rows
Orbital Period
4.05 day
4.05 to 4.05
Semi-Major Axis
0.02 au
0.02 to 0.02
Radius
0.79 Rearth
0.77 to 0.80
Mass
0.39 Mearth
0.30 to 0.41
Density
4.37 g/cm**3
3.40 to 4.90
Scale Comparison
Radius against familiar reference worlds
Current adopted radius: 0.79 R⊕ • circles scaled linearly by radius
Earth
1.0 R⊕ baseline
TRAPPIST-1 d
0.79 R⊕
Jupiter
11.2 R⊕ reference
Provenance
Underlying measurements and references
Evidence Summary
Rows
5
Refs
5
Methods
1
Discoverystable
Facilitystable
Periodstable
Radiusdisputed
Massdisputed
Eq. Tempdisputed
| Year | Method | Facility | Telescope | Period | Radius | Mass | Eq. Temp | Reference |
|---|---|---|---|---|---|---|---|---|
| 2016 | Transit | La Silla Observatory | 0.60 m Transiting Planets and Planetesimals Small Telescope | — | 0.78 Rearth | 0.30 Mearth | — | Grimm et al. 2018 |
| 2016 | Transit | La Silla Observatory | 0.60 m Transiting Planets and Planetesimals Small Telescope | 4.05 day | — | — | 286.2 K | Ducrot et al. 2020 |
| 2016 | Transit | La Silla Observatory | 0.60 m Transiting Planets and Planetesimals Small Telescope | 4.05 day | 0.80 Rearth | 0.39 Mearth | 286 K | Piaulet-Ghorayeb et al. 2025 |
| 2016 | Transit | La Silla Observatory | 0.60 m Transiting Planets and Planetesimals Small Telescope | 4.05 day | 0.77 Rearth | 0.41 Mearth | 288 K | Gillon et al. 2017 |
| 2016 | Transit | La Silla Observatory | 0.60 m Transiting Planets and Planetesimals Small Telescope | 4.05 day | 0.79 Rearth | 0.39 Mearth | — | Agol et al. 2021 |