Temperature
5183.8 K
5114 to 5262
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Stellar HostProfile
K2-198
Unclassified star • 110.6 pc
Records
7
literature rows
Planets
3
system count
References
7
distinct source labels
TIC: TIC 135043332
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: TICv8 • System source: TICv8
Mass
0.88 Msun
0.80 to 0.88
Radius
0.78 Rsun
0.76 to 0.80
Luminosity
-0.40 log(Lsun)
-0.40 to -0.40
Distance
110.6 pc
single adopted value
Planets
3
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 0.78 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
K2-198
0.78 R☉
System Layout
Known planets
3 planets linked to this host
K2-198: A Cool Star with Three Transiting Planets
K2-198 is a star located 361 light-years away, and three planets have been found in orbit around it. The star has a reported mass of 0.879 solar masses and a radius of 0.782 solar radii, both smaller than the Sun's corresponding values. Its temperature of 5180 K is cooler than the Sun's. All three planets were found using the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness; repeated dips help establish orbital periods.
K2-198 c is an Earth-like planet with a radius of 1.42 Earth radii and an orbital period of 3.36 days. K2-198 d is a Super-Earth with a radius of 2.44 Earth radii and a period of 7.45 days. K2-198 b is a Jupiter-like planet with a radius of 4.19 Earth radii and a period of 17 days. Among the listed planets, K2-198 c has the shortest year and the smallest radius, K2-198 d has the second-shortest year and the second-smallest radius, and K2-198 b has the longest year and the largest radius. Each planet's radius is larger than Earth's.
K2-198 b was discovered in 2018. K2-198 c and K2-198 d were both discovered in 2019. The three planets span a range of sizes and orbital periods around a star smaller in mass and radius, and cooler, than the Sun.
Provenance
Underlying measurements and references
Evidence Summary
Rows
7
Stellar refs
6
System refs
1
Distancestable
Parallaxstable
Temperaturedisputed
Massdisputed
Radiusdisputed
Luminositydisputed
Surface Gravitydisputed
Metallicitydisputed
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| — | — | 0.80 | — | — | — | 110.6 | Kruse et al. 2019 | TICv8 |
| — | — | 0.80 | — | — | — | 110.6 | Kruse et al. 2019 | TICv8 |
| 5212.9 | 0.80 | 0.76 | — | — | — | 110.6 | Hedges et al. 2019 | TICv8 |
| 5114 | — | 0.80 | — | -0.40 | — | 110.6 | Gaia DR2 | TICv8 |
| 5183.8 | 0.88 | 0.78 | — | -0.40 | — | 110.6 | TICv8 | TICv8 |
| 5262 | 0.84 | 0.78 | — | — | — | 110.6 | Mayo et al. 2018 | TICv8 |
| — | — | — | — | — | — | 110.6 | Pope et al. 2016 | TICv8 |