Key parameters at a glance
- A radius of 1.80 Earth radii
- A mass of 3.89 Earth masses
- Surface gravity around 1.20 g
- An orbital period of 6.342 days
- Semi-major axis 0.0562 AU
- Equilibrium temperature 708 K (435 °C)
- Distance from Earth 237.44 light-years
- Earth Similarity Index 0.403
- Travel time at Voyager 1 speed 4,187,270 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around K2-155
K2-155 b shares its host star with 2 other confirmed planets. Side-by-side measurements below.
K2-155 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#253of 1176
top 21.4%
This planet
1.80R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | K2-155 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.80 | 11.21 |
| Mass (M⊕) | 1.00 | 3.89 | 317.83 |
| Density (g/cm³) | 5.51 | 3.67 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.20 | 2.53 |
| Insolation (S⊕) | 1.00 | 19.90 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 17307715
Gaia DR2
Gaia DR2 145333927996558976
Gaia DR3
Gaia DR3 145333927996558976
System
K2-155
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.34 Earth days (1.7% of a terrestrial year) at a mean orbital distance of 0.0562 AU.
Transit Fingerprint
Depth
0.068 %
Duration
2.410 h
Impact parameter b
0.340
Rp / R★
0.026100
Transit midpoint (BJD)
2,457,818.7153
Photometric dip
Transit produces a flux drop of 680 ppm lasting ≈ 2.41 h.
Extended Orbital Architecture
Planet / star radius ratio
0.026100
Semi-major axis / stellar radius
18.500
Impact parameter (b)
0.340
Transit mid-time (BJD)
2,457,818.7153
Angular separation (arcsec)
0.77200
Eq. Temperature
708K
(435 °C)
Insolation (S⊕)
19.90
Earth = 1.00
Earth Similarity (ESI)
0.403
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Hirano et al. 2018Instrument
Kepler CCD Array
Publication
2018-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-155
Spectral Class
K-type orange
Effective Temperature
4,258 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.580 R☉
Stellar Mass
0.650 M☉
Metallicity [Fe/H]
-0.30
Extended Stellar Properties
Surface gravity (log g)
4.600 dex
Stellar density
5.410 g/cm³
Systemic radial velocity
19.10 km/s
Rotation period
34.80 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 18 bands
Astrometric Data
Parallax
13.708 mas
Total Proper Motion
214.791 mas/yr
PM Right Ascension
200.61 mas/yr
PM Declination
-76.76 mas/yr
Galactic Cartesian (pc)
x = 0.387 · y = 0.847 · z = 0.364
Equatorial (J2000)
RA 65.46961° · Dec 21.35326°
Galactic ℓ, b
174.749° · -19.713°
Ecliptic λ, β
67.248° · -0.170°
HTM-20 index
-463828751
Similar Worlds
TOI-2427 b
Super-Earth · K-type orange
Radius 1.80 R⊕ · 93.0 ly
Kepler-1353 b
Super-Earth · K-type orange
Radius 1.80 R⊕ · 1,935.4 ly
Kepler-1794 b
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Radius 1.79 R⊕ · 1,830.5 ly
Kepler-305 e
Super-Earth · K-type orange
Radius 1.79 R⊕ · 2,832.6 ly
TOI-1075 b
Super-Earth · K-type orange
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Kepler-768 b
Super-Earth · K-type orange
Radius 1.79 R⊕ · 2,558.9 ly