Key parameters at a glance
- A radius of 3.30 Earth radii
- A mass of 11.27 Earth masses
- Surface gravity around 1.03 g
- An orbital period of 0.659 days
- Semi-major axis 0.0131 AU
- Equilibrium temperature 1,515 K (1242 °C)
- Distance from Earth 252.96 light-years
- Earth Similarity Index 0.141
- 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 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.
K2-266 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#280of 1978
top 14.1%
This planet
3.30R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-266 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.30 | 11.21 |
| Mass (M⊕) | 1.00 | 11.27 | 317.83 |
| Density (g/cm³) | 5.51 | 1.72 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.03 | 2.53 |
| Insolation (S⊕) | 1.00 | 879.50 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Computed mass | 11.268 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 roughly 15.8 hours long at a mean orbital distance of 0.0131 AU.
Transit Fingerprint
Depth
0.180 %
Duration
0.333 h
Impact parameter b
1.011
Rp / R★
0.043000
Transit midpoint (BJD)
2,457,949.6747
Photometric dip
Transit produces a flux drop of 1,800 ppm lasting ≈ 0.33 h.
Extended Orbital Architecture
Planet / star radius ratio
0.043000
Semi-major axis / stellar radius
4.000
Impact parameter (b)
1.011
Transit mid-time (BJD)
2,457,949.6747
Angular separation (arcsec)
0.16800
Eq. Temperature
1,515K
(1242 °C)
Insolation (S⊕)
879.50
Earth = 1.00
Earth Similarity (ESI)
0.141
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. Close-orbiting tidally-locked around a cool host.
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-305 c
Sub-Neptune · K-type orange
Radius 3.30 R⊕ · 2,832.6 ly
Kepler-1663 b
Sub-Neptune · K-type orange
Radius 3.30 R⊕ · 1,102.2 ly
TOI-431 d
Sub-Neptune · K-type orange
Radius 3.29 R⊕ · 106.2 ly
Kepler-1999 b
Sub-Neptune · K-type orange
Radius 3.29 R⊕ · 2,287.2 ly
Kepler-411 d
Sub-Neptune · K-type orange
Radius 3.32 R⊕ · 501.2 ly
Kepler-411 e
Sub-Neptune · K-type orange
Radius 3.28 R⊕ · 501.2 ly