Key parameters at a glance
- A radius of 2.27 Earth radii
- A mass of 45.20 Earth masses
- Surface gravity around 8.77 g
- An orbital period of 5.350 days
- Semi-major axis 0.0580 AU
- Equilibrium temperature 919 K (646 °C)
- Distance from Earth 3,196.78 light-years
- Earth Similarity Index 0.220
- Travel time at Voyager 1 speed 56,375,193 years
2 siblings around Kepler-226
Kepler-226 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-226 b | Super-Earth | 1.55 | 24.00 | 3.941 | 1,018 | 2014 |
| Kepler-226 c this | Sub-Neptune | 2.27 | 45.20 | 5.350 | 919 | 2014 |
| Kepler-226 d | Rocky Terrestrial | 1.22 | 1.98 | 8.109 | 800 | 2014 |
Kepler-226 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1554of 1978
top 78.5%
This planet
2.27R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-226 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.27 | 11.21 |
| Mass (M⊕) | 1.00 | 45.20 | 317.83 |
| Density (g/cm³) | 5.51 | 21.20 | 1.33 |
| Surface Gravity (g) | 1.00 | 8.77 | 2.53 |
| Insolation (S⊕) | 1.00 | 180.51 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 45.200 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 63204017
Gaia DR2
Gaia DR2 2128504397979254528
Gaia DR3
Gaia DR3 2128504397979254528
System
Kepler-226
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.35 Earth days (1.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0580 AU.
Transit Fingerprint
Depth
0.083 %
Duration
3.051 h
Impact parameter b
0.250
Rp / R★
0.025706
Transit midpoint (BJD)
2,455,004.8060
Photometric dip
Transit produces a flux drop of 831 ppm lasting ≈ 3.05 h.
Extended Orbital Architecture
Planet / star radius ratio
0.025706
Semi-major axis / stellar radius
13.802
Impact parameter (b)
0.250
Transit mid-time (BJD)
2,455,004.8060
Angular separation (arcsec)
0.05920
Eq. Temperature
919K
(646 °C)
Insolation (S⊕)
180.51
Earth = 1.00
Earth Similarity (ESI)
0.220
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
Discovery Paper
Primary reference
Rowe et al. 2014Instrument
Kepler CCD Array
Publication
2014-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2014 at Kepler (12 shown).
Host System: Kepler-226
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,571 K — cooler than the Sun (5,778 K)
Estimated Age
4.17 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.802 R☉
Stellar Mass
0.904 M☉
Metallicity [Fe/H]
0.09
Extended Stellar Properties
Surface gravity (log g)
4.586 dex
Stellar density
1.430 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.992 mas
Total Proper Motion
10.217 mas/yr
PM Right Ascension
-6.26 mas/yr
PM Declination
-8.07 mas/yr
Galactic Cartesian (pc)
x = 0.255 · y = -0.620 · z = 0.742
Equatorial (J2000)
RA 292.37609° · Dec 47.88096°
Galactic ℓ, b
79.988° · 13.859°
Ecliptic λ, β
312.980° · 68.008°
HTM-20 index
-603487203
Similar Worlds
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Radius 2.27 R⊕ · —
Kepler-166 b
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Kepler-589 b
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Kepler-121 c
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Kepler-183 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · 3,426.7 ly