Temperature
3457 K
3440 to 3856.2
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Stellar HostProfile
K2-18
M2.5 V • 38.03 pc
Records
13
literature rows
Planets
2
system count
References
14
distinct source labels
TIC: TIC 388804061
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: Benneke et al. 2017 • System source: TICv8
Mass
0.36 Msun
0.32 to 0.50
Radius
0.41 Rsun
0.25 to 0.47
Distance
38.03 pc
single adopted value
Spectral Type
M2.5 V
Consistent across records
Planets
2
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 0.41 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
K2-18
0.41 R☉
System Layout
Known planets
2 planets linked to this host
K2-18 and Its Planets
K2-18 is an M2.5 V star located 124 light-years away. The star has a mass of 0.359 solar masses, a radius of 0.411 solar radii, and a temperature of 3460 K, all smaller or cooler than the Sun's corresponding values. K2-18 hosts two known planets.
K2-18 b is a Super-Earth discovered by the transit method in 2015. Its radius of 2.37 Earth radii is larger than Earth's, its mass of 8.92 Earth masses is larger than Earth's, and its mean density is 3.69 g/cm³, 0.67 times Earth's. It completes an orbit in 32.9 days.
K2-18 c was discovered by radial velocity in 2017. Its minimum mass is 7.51 Earth masses, larger than Earth's, and its orbital period is 8.96 days. Among the listed planets, K2-18 c has the shortest year and K2-18 b has the longest, with the star's cooler temperature than the Sun rounding out its measured traits.
Provenance
Underlying measurements and references
Evidence Summary
Rows
13
Stellar refs
13
System refs
1
Distancestable
Parallaxstable
Temperaturedisputed
Massdisputed
Radiusdisputed
Luminositydisputed
Surface Gravitydisputed
Metallicitydisputed
Spectral Typestable
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| — | — | 0.25 | — | — | — | 38.03 | Kruse et al. 2019 | TICv8 |
| 3503 | 0.41 | 0.39 | — | — | — | 38.03 | Montet et al. 2015 | TICv8 |
| 3856.2 | — | — | — | — | — | 38.03 | Gaia DR2 | TICv8 |
| 3457 | 0.36 | 0.41 | — | — | — | 38.03 | Cloutier et al. 2017 | TICv8 |
| 3457 | 0.50 | 0.44 | — | -1.60 | — | 38.03 | Benneke et al. 2019 | TICv8 |
| — | — | — | — | — | — | 38.03 | Barros et al. 2016 | TICv8 |
| 3457 | 0.36 | 0.41 | — | — | — | 38.03 | Sarkis et al. 2018 | TICv8 |
| 3449 | 0.32 | 0.47 | — | — | — | 38.03 | Howard et al. 2025 | TICv8 |
| 3464 | — | 0.44 | — | — | — | 38.03 | ExoFOP | TICv8 |
| 3496 | 0.42 | 0.40 | — | — | — | 38.03 | Crossfield et al. 2016 | TICv8 |
| 3457 | 0.36 | 0.41 | — | — | M2.5 V | 38.03 | Benneke et al. 2017 | TICv8 |
| 3440 | — | 0.36 | — | — | — | 38.03 | Vanderburg et al. 2016 | TICv8 |
| 3464 | 0.44 | 0.44 | — | -1.59 | — | 38.03 | TICv8 | TICv8 |