Key parameters at a glance
- A radius of 4.64 Earth radii
- A mass of 19.40 Earth masses
- Surface gravity around 0.90 g
- An orbital period of 10.089 days
- Semi-major axis 0.0910 AU
- Equilibrium temperature 734 K (461 °C)
- Distance from Earth 2,475.05 light-years
- Earth Similarity Index 0.267
- Travel time at Voyager 1 speed 43,647,466 years
2 siblings around Kepler-222
Kepler-222 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-222 b | Sub-Neptune | 3.16 | 10.10 | 3.937 | 1,004 | 2014 |
| Kepler-222 c this | Neptune-like | 4.64 | 19.40 | 10.089 | 734 | 2014 |
| Kepler-222 d | Sub-Neptune | 3.69 | 13.20 | 28.082 | 522 | 2014 |
Kepler-222 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#440of 574
top 76.5%
This planet
4.64R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-222 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.64 | 11.21 |
| Mass (M⊕) | 1.00 | 19.40 | 317.83 |
| Density (g/cm³) | 5.51 | 1.07 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.90 | 2.53 |
| Insolation (S⊕) | 1.00 | 59.08 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 158625100
Gaia DR2
Gaia DR2 2130460394803778816
Gaia DR3
Gaia DR3 2130460394803778816
System
Kepler-222
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 10.09 Earth days (2.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0910 AU.
Transit Fingerprint
Depth
0.218 %
Duration
1.714 h
Impact parameter b
0.900
Rp / R★
0.052900
Transit midpoint (BJD)
2,455,006.0826
Photometric dip
Transit produces a flux drop of 2,176 ppm lasting ≈ 1.71 h.
Extended Orbital Architecture
Planet / star radius ratio
0.052900
Semi-major axis / stellar radius
20.500
Impact parameter (b)
0.900
Transit mid-time (BJD)
2,455,006.0826
Angular separation (arcsec)
0.12000
Eq. Temperature
734K
(461 °C)
Insolation (S⊕)
59.08
Earth = 1.00
Earth Similarity (ESI)
0.267
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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
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-222
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,433 K — cooler than the Sun (5,778 K)
Estimated Age
1.17 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.869 R☉
Stellar Mass
0.933 M☉
Metallicity [Fe/H]
0.33
Extended Stellar Properties
Surface gravity (log g)
4.551 dex
Stellar density
1.570 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.289 mas
Total Proper Motion
1.139 mas/yr
PM Right Ascension
0.60 mas/yr
PM Declination
-0.97 mas/yr
Galactic Cartesian (pc)
x = 0.210 · y = -0.650 · z = 0.731
Equatorial (J2000)
RA 287.90609° · Dec 46.93775°
Galactic ℓ, b
77.826° · 16.242°
Ecliptic λ, β
304.493° · 68.243°
HTM-20 index
-1645614768
Similar Worlds
Kepler-867 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.64 R⊕ · 3,899.3 ly
Kepler-564 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.63 R⊕ · 2,814.8 ly
Kepler-47 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.65 R⊕ · 3,343.2 ly
TOI-1136 d
Neptune-like · G-type yellow (Sun-like)
Radius 4.63 R⊕ · 275.7 ly
Kepler-405 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.66 R⊕ · 3,473.8 ly
K2-390 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.66 R⊕ · 1,487.7 ly