Key parameters at a glance
- A radius of 2.20 Earth radii
- A mass of 5.48 Earth masses
- Surface gravity around 1.13 g
- An orbital period of 6.253 days
- Semi-major axis 0.0620 AU
- Equilibrium temperature 823 K (550 °C)
- Distance from Earth 2,694.91 light-years
- Earth Similarity Index 0.323
- Travel time at Voyager 1 speed 47,524,786 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around Kepler-229
Kepler-229 b 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-229 b this | Sub-Neptune | 2.20 | 5.48 | 6.253 | 823 | 2014 |
| Kepler-229 c | Neptune-like | 4.92 | 21.50 | 16.069 | 600 | 2014 |
| Kepler-229 d | Sub-Neptune | 3.85 | 14.20 | 41.195 | 439 | 2014 |
Kepler-229 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1673of 1978
top 84.5%
This planet
2.20R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-229 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.20 | 11.21 |
| Mass (M⊕) | 1.00 | 5.48 | 317.83 |
| Density (g/cm³) | 5.51 | 2.83 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.13 | 2.53 |
| Insolation (S⊕) | 1.00 | 76.22 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 399912169
Gaia DR2
Gaia DR2 2131114947819394816
Gaia DR3
Gaia DR3 2131114947819394816
System
Kepler-229
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.25 Earth days (1.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0620 AU.
Transit Fingerprint
Depth
0.104 %
Duration
2.640 h
Impact parameter b
0.110
Rp / R★
0.029697
Transit midpoint (BJD)
2,455,004.2988
Photometric dip
Transit produces a flux drop of 1,037 ppm lasting ≈ 2.64 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029697
Semi-major axis / stellar radius
18.940
Impact parameter (b)
0.110
Transit mid-time (BJD)
2,455,004.2988
Angular separation (arcsec)
0.07500
Eq. Temperature
823K
(550 °C)
Insolation (S⊕)
76.22
Earth = 1.00
Earth Similarity (ESI)
0.323
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
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-229
Spectral Class
K-type orange
Effective Temperature
5,120 K — cooler than the Sun (5,778 K)
Estimated Age
2.04 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.728 R☉
Stellar Mass
0.808 M☉
Metallicity [Fe/H]
0.06
Extended Stellar Properties
Surface gravity (log g)
4.633 dex
Stellar density
1.940 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.182 mas
Total Proper Motion
5.627 mas/yr
PM Right Ascension
-1.33 mas/yr
PM Declination
-5.47 mas/yr
Galactic Cartesian (pc)
x = 0.194 · y = -0.635 · z = 0.748
Equatorial (J2000)
RA 286.99948° · Dec 48.37579°
Galactic ℓ, b
78.978° · 17.348°
Ecliptic λ, β
304.224° · 69.803°
HTM-20 index
-565252898
Similar Worlds
Kepler-169 e
Sub-Neptune · K-type orange
Radius 2.20 R⊕ · 1,325.9 ly
Kepler-240 c
Sub-Neptune · K-type orange
Radius 2.20 R⊕ · 2,436.1 ly
Kepler-1378 b
Sub-Neptune · K-type orange
Radius 2.20 R⊕ · 1,651.8 ly
HD 110067 b
Sub-Neptune · K-type orange
Radius 2.20 R⊕ · 104.9 ly
Kepler-57 c
Sub-Neptune · K-type orange
Radius 2.20 R⊕ · 2,100.9 ly
Kepler-55 c
Sub-Neptune · K-type orange
Radius 2.21 R⊕ · 1,887.8 ly