Temperature
3390 K
3390 to 4052
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Stellar HostProfile
K2-9
M2.5 V • 82.96 pc
Records
7
literature rows
Planets
1
system count
References
8
distinct source labels
TIC: TIC 82050863
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: Schlieder et al. 2016 • System source: TICv8
Mass
0.30 Msun
0.24 to 0.52
Radius
0.31 Rsun
0.25 to 0.52
Age
1 Gyr
single adopted value
Luminosity
-1.92 log(Lsun)
-1.92 to -1.84
Distance
82.96 pc
single adopted value
Spectral Type
M2.5 V
Consistent across records
Planets
1
Stable across source rows
Scale Comparison
Radius against the Sun
Current adopted radius: 0.31 R☉ (circles scaled linearly by radius)
Sun
1.0 R☉ baseline
K2-9
0.31 R☉
System Layout
Known planets
1 planets linked to this host
K2-9 b
Transit
◌
Discovery
2015
Period
18.45 days
Radius
2.25 R⊕
Mass
—
Eq. Temp
314 K
K2-9 and Its Super-Earth
K2-9 is an M2.5 V star, a small, cool red dwarf, located 271 light-years away. Its reported mass is 0.3 solar masses and its reported radius is 0.31 solar radii, both smaller than the Sun's. The star's temperature is 3390 K, cooler than the Sun's, and its age is given as a reported lower limit of 1 billion years. One planet is known to orbit this star.
That planet is K2-9 b, a Super-Earth discovered by transit in 2015. Its radius of 2.25 Earth radii is larger than Earth's, placing it within the Super-Earth size class, which reaches 2.5 times Earth's radius. The planet completes an orbit every 18.4 days.
Provenance
Underlying measurements and references
Evidence Summary
Rows
7
Stellar refs
7
System refs
1
Distancestable
Parallaxstable
Temperaturedisputed
Massdisputed
Radiusdisputed
Agestable
Luminositydisputed
Surface Gravitydisputed
Metallicitydisputed
Spectral Typestable
| ST TEFF | ST MASS | ST RAD | ST AGE | ST LUM | ST SPECTYPE | SY DIST | Stellar Ref | System Ref |
|---|---|---|---|---|---|---|---|---|
| 3390 | 0.30 | 0.31 | 1 | -1.92 | M2.5 V | 82.96 | Schlieder et al. 2016 | TICv8 |
| — | — | 0.47 | — | — | — | 82.96 | Kruse et al. 2019 | TICv8 |
| 4052 | 0.52 | 0.47 | — | — | — | 82.96 | Crossfield et al. 2016 | TICv8 |
| 3765 | — | 0.52 | — | — | — | 82.96 | Vanderburg et al. 2016 | TICv8 |
| 3468 | 0.24 | 0.25 | — | — | — | 82.96 | Montet et al. 2015 | TICv8 |
| 3528 | 0.30 | 0.32 | — | -1.84 | — | 82.96 | TICv8 | TICv8 |
| 3972.7 | — | — | — | — | — | 82.96 | Gaia DR2 | TICv8 |