Key parameters at a glance
- A radius of 2.73 Earth radii
- A mass of 14.30 Earth masses
- Surface gravity around 1.92 g
- An orbital period of 19.482 days
- Semi-major axis 0.1249 AU
- Equilibrium temperature 490 K (217 °C)
- Distance from Earth 252.96 light-years
- Earth Similarity Index 0.475
- Travel time at Voyager 1 speed 4,460,985 years
- Almost certainly tidally locked to its host star given the close orbit
3 siblings around K2-266
K2-266 e shares its host star with 3 other confirmed planets. Side-by-side measurements below.
K2-266 e Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#823of 1978
top 41.6%
This planet
2.73R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-266 e | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.73 | 11.21 |
| Mass (M⊕) | 1.00 | 14.30 | 317.83 |
| Density (g/cm³) | 5.51 | 2.21 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.92 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.58 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 14.300 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 8.300 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 8.300 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 374180079
Gaia DR2
Gaia DR2 3855246074629979264
Gaia DR3
Gaia DR3 3855246074629979264
System
K2-266
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 19.48 Earth days (5.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1249 AU.
Transit Fingerprint
Depth
0.127 %
Duration
3.665 h
Impact parameter b
0.360
Rp / R★
0.035640
Transit midpoint (BJD)
2,457,938.5410
Photometric dip
Transit produces a flux drop of 1,270 ppm lasting ≈ 3.66 h.
Extended Orbital Architecture
Planet / star radius ratio
0.035640
Semi-major axis / stellar radius
38.200
Impact parameter (b)
0.360
Transit mid-time (BJD)
2,457,938.5410
Long. of periastron (ω)
89.00°
Angular separation (arcsec)
1.61000
Eq. Temperature
490K
(217 °C)
Insolation (S⊕)
9.58
Earth = 1.00
Earth Similarity (ESI)
0.475
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.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Rodriguez et al. 2018Instrument
Kepler CCD Array
Publication
2018-11
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-266
Spectral Class
K-type orange
Effective Temperature
4,285 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.703 R☉
Stellar Mass
0.686 M☉
Metallicity [Fe/H]
-0.12
Extended Stellar Properties
Surface gravity (log g)
4.581 dex
Stellar density
2.790 g/cm³
Systemic radial velocity
10.85 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
12.865 mas
Total Proper Motion
89.284 mas/yr
PM Right Ascension
56.87 mas/yr
PM Declination
-68.83 mas/yr
Galactic Cartesian (pc)
x = -0.927 · y = 0.376 · z = 0.016
Equatorial (J2000)
RA 157.93569° · Dec 0.93728°
Galactic ℓ, b
245.045° · 47.483°
Ecliptic λ, β
159.244° · -7.724°
HTM-20 index
266358226
Similar Worlds
Kepler-436 b
Sub-Neptune · K-type orange
Radius 2.73 R⊕ · 1,920.6 ly
Kepler-551 b
Sub-Neptune · K-type orange
Radius 2.73 R⊕ · 1,014.9 ly
Kepler-2000 b
Sub-Neptune · K-type orange
Radius 2.73 R⊕ · 1,045.6 ly
TOI-125 b
Sub-Neptune · K-type orange
Radius 2.73 R⊕ · 362.2 ly
Kepler-1058 b
Sub-Neptune · K-type orange
Radius 2.72 R⊕ · 1,604.7 ly
Kepler-80 c
Sub-Neptune · K-type orange
Radius 2.74 R⊕ · 1,205.0 ly