Discovery Method
Transit
Consistent across records
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ExoplanetDetail
HAT-P-21 b
Host star HAT-P-21 • 12.44 R⊕ • 4.12 d orbit
Records
8
archive rows
Discovery
2010
Transit
Radius
12.44 R⊕
default parameter set
Mass
1547.8 M⊕
default parameter set
HAT-P-21
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: Stassun et al. 2017
Host Star
HAT-P-21
Stable across source rows
Discovery Year
2010
Stable across source rows
Orbital Period
4.12 day
4.12 to 4.12
Radius
12.44 Rearth
11.48 to 12.67
Mass
1547.8 Mearth
1261.8 to 1547.8
Scale Comparison
Radius against familiar reference worlds
Current adopted radius: 12.44 R⊕ • circles scaled linearly by radius
Earth
1.0 R⊕ baseline
HAT-P-21 b
12.44 R⊕
Jupiter
11.2 R⊕ reference
Provenance
Underlying measurements and references
Evidence Summary
Rows
8
Refs
8
Methods
1
Discoverystable
Facilitystable
Periodstable
Radiusdisputed
Massdisputed
Eq. Tempdisputed
| Year | Method | Facility | Telescope | Period | Radius | Mass | Eq. Temp | Reference |
|---|---|---|---|---|---|---|---|---|
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | — | — | — | Ivshina & Winn 2022 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | 12.67 Rearth | 1344.4 Mearth | 1367 K | Mancini et al. 2022 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | — | — | — | Kokori et al. 2023 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | 12.44 Rearth | 1547.8 Mearth | — | Stassun et al. 2017 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | 11.48 Rearth | 1291.3 Mearth | 1283 K | Bakos et al. 2010 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | — | — | — | Patel & Espinoza 2022 |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | 12.42 Rearth | — | 1289 K | ExoFOP |
| 2010 | Transit | HATNet | Canon 200mm f/1.8L | 4.12 day | 11.48 Rearth | 1261.8 Mearth | — | Bonomo et al. 2017 |