Discovery Method
Transit
Consistent across records
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ExoplanetDetail
K2-121 b
Host star K2-121 • 7.16 R⊕ • 5.19 d orbit
Records
11
archive rows
Discovery
2017
Transit
Radius
7.16 R⊕
default parameter set
Mass
51 M⊕
default parameter set
K2-121
716 K equilibrium
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: Howard et al. 2025
Host Star
K2-121
Stable across source rows
Discovery Year
2017
Stable across source rows
Orbital Period
5.19 day
5.19 to 5.19
Radius
7.16 Rearth
7.16 to 9.12
Mass
51 Mearth
single adopted value
Density
0.70 g/cm**3
single adopted value
Equilibrium Temperature
716 K
716 to 935
Scale Comparison
Radius against familiar reference worlds
Current adopted radius: 7.16 R⊕ • circles scaled linearly by radius
Earth
1.0 R⊕ baseline
K2-121 b
7.16 R⊕
Jupiter
11.2 R⊕ reference
Provenance
Underlying measurements and references
Evidence Summary
Rows
11
Refs
11
Methods
1
Discoverystable
Facilitystable
Periodstable
Radiusdisputed
Massstable
Eq. Tempdisputed
| Year | Method | Facility | Telescope | Period | Radius | Mass | Eq. Temp | Reference |
|---|---|---|---|---|---|---|---|---|
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.52 Rearth | — | 738 K | Castro-González et al. 2022 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.16 Rearth | 51 Mearth | 716 K | Howard et al. 2025 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 9.12 Rearth | — | — | Dressing et al. 2017 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.50 Rearth | — | 723 K | Livingston et al. 2018 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.44 Rearth | — | — | Kruse et al. 2019 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | — | — | — | Pope et al. 2016 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | — | — | — | Barros et al. 2016 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.70 Rearth | — | — | Petigura et al. 2018 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.64 Rearth | — | — | Mayo et al. 2018 |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | 7.50 Rearth | — | 935 K | ExoFOP |
| 2017 | Transit | K2 | 0.95 m Kepler Telescope | 5.19 day | — | — | — | Kokori et al. 2023 |