Temperature
5354 K
5057.0 to 5354
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Stellar HostProfile
Kepler-121
Unclassified star • 510.5 pc
Records
21
literature rows
Planets
2
system count
References
15
distinct source labels
TIC: TIC 120765800
Approximate color
from effective temperature
Canonical Summary
Adopted host values from one source row
Values come from the row with the most populated summary measurements. Missing values stay missing. Ranges and counts describe all source rows.
Stellar source: Morton et al. 2016 • System source: TICv8
Mass
0.86 Msun
0.77 to 0.92
Radius
0.82 Rsun
0.67 to 0.82
Age
4.47 Gyr
0.50 to 4.47
Distance
510.5 pc
single adopted value
Planets
2
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 0.82 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
Kepler-121
0.82 R☉
System Layout
Known planets
2 planets linked to this host
Kepler-121 b
Transit
◌
Discovery
2014
Period
3.18 days
Radius
2.34 R⊕
Mass
—
Eq. Temp
—
Kepler-121 c
Transit
◌
Discovery
2014
Period
41.01 days
Radius
2.27 R⊕
Mass
—
Eq. Temp
—
Kepler-121: A Cooler, Smaller Sun With Two Super-Earths
Kepler-121 is a star located 1670 light-years away. It hosts two planets, both discovered by transit in 2014, when each passed in front of the star from our viewpoint and caused a small dip in observed brightness. The star is 4.47 billion years old, has a mass of 0.86 solar masses and a radius of 0.82 solar radii, and a temperature of 5350 K. Its reported mass and radius estimates are smaller than the Sun's, and its reported temperature is cooler than the Sun's.
The two planets are Kepler-121 b and Kepler-121 c, both classified as Super-Earths, meaning their radii reach up to 2.5 times Earth's. Kepler-121 b has a radius of 2.34 Earth radii and an orbital period of 3.18 days, the shortest year among the listed planets. Kepler-121 c has a radius of 2.27 Earth radii and an orbital period of 41 days, the longest year among the listed planets and the smallest radius of the pair. Both planets' reported radius estimates are larger than Earth's.
Provenance
Underlying measurements and references
Evidence Summary
Rows
21
Stellar refs
14
System refs
1
Distancestable
Parallaxstable
Temperaturedisputed
Massdisputed
Radiusdisputed
Agedisputed
Luminositydisputed
Surface Gravitydisputed
Metallicitydisputed
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| 5311 | — | 0.69 | — | — | — | 510.5 | Berger et al. 2018 | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q12 KOI Table | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q12 KOI Table | TICv8 |
| 5311 | — | 0.70 | — | — | — | 510.5 | Rowe et al. 2014 | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q16 KOI Table | TICv8 |
| 5350 | 0.86 | 0.75 | 0.50 | — | — | 510.5 | Q1-Q8 KOI Table | TICv8 |
| 5128 | — | 0.74 | — | — | — | 510.5 | Latham et al. 2005 | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q17 DR24 KOI Table | TICv8 |
| 5318 | 0.92 | 0.68 | — | -0.47 | — | 510.5 | TICv8 | TICv8 |
| — | — | — | — | — | — | 510.5 | Q1-Q17 DR25 Supplemental KOI Table | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q17 DR24 KOI Table | TICv8 |
| — | — | — | — | — | — | 510.5 | Q1-Q17 DR25 Supplemental KOI Table | TICv8 |
| 5128 | — | 0.67 | — | — | — | 510.5 | Batalha et al. 2013 | TICv8 |
| 5057.0 | — | 0.71 | — | -0.53 | — | 510.5 | Gaia DR2 | TICv8 |
| 5354 | 0.86 | 0.82 | 4.47 | — | — | 510.5 | Morton et al. 2016 | TICv8 |
| 5128 | — | 0.67 | — | — | — | 510.5 | Q1-Q6 KOI Table | TICv8 |
| 5303 | 0.79 | 0.71 | — | — | — | 510.5 | Q1-Q17 DR25 KOI Table | TICv8 |
| 5350 | 0.86 | 0.75 | 0.50 | — | — | 510.5 | Q1-Q8 KOI Table | TICv8 |
| 5128 | — | 0.67 | — | — | — | 510.5 | Q1-Q6 KOI Table | TICv8 |
| 5303 | 0.79 | 0.71 | — | — | — | 510.5 | Q1-Q17 DR25 KOI Table | TICv8 |
| 5316 | 0.77 | 0.72 | — | — | — | 510.5 | Q1-Q16 KOI Table | TICv8 |