Key parameters at a glance
- A radius of 3.16 Earth radii
- A mass of 10.10 Earth masses
- Surface gravity around 1.01 g
- An orbital period of 3.937 days
- Semi-major axis 0.0480 AU
- Equilibrium temperature 1,004 K (731 °C)
- Distance from Earth 2,475.05 light-years
- Earth Similarity Index 0.227
- Travel time at Voyager 1 speed 43,647,466 years
2 siblings around Kepler-222
Kepler-222 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-222 b this | Sub-Neptune | 3.16 | 10.10 | 3.937 | 1,004 | 2014 |
| Kepler-222 c | 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 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#387of 1978
top 19.5%
This planet
3.16R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-222 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.16 | 11.21 |
| Mass (M⊕) | 1.00 | 10.10 | 317.83 |
| Density (g/cm³) | 5.51 | 1.76 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.01 | 2.53 |
| Insolation (S⊕) | 1.00 | 206.77 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 158625100
Gaia DR2
Gaia DR2 2130460394803778816
Gaia DR3
Gaia DR3 2130460394803778816
System
Kepler-222
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.94 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0480 AU.
Transit Fingerprint
Depth
0.140 %
Duration
1.828 h
Impact parameter b
0.570
Rp / R★
0.036300
Transit midpoint (BJD)
2,455,002.6508
Photometric dip
Transit produces a flux drop of 1,398 ppm lasting ≈ 1.83 h.
Extended Orbital Architecture
Planet / star radius ratio
0.036300
Semi-major axis / stellar radius
10.900
Impact parameter (b)
0.570
Transit mid-time (BJD)
2,455,002.6508
Angular separation (arcsec)
0.06330
Eq. Temperature
1,004K
(731 °C)
Insolation (S⊕)
206.77
Earth = 1.00
Earth Similarity (ESI)
0.227
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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
HD 134060 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.16 R⊕ · 78.3 ly
Kepler-619 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.16 R⊕ · 2,937.6 ly
Kepler-569 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.16 R⊕ · 2,081.9 ly
Kepler-1786 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.16 R⊕ · 2,817.7 ly
Kepler-1001 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.15 R⊕ · 3,029.9 ly
Kepler-896 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.15 R⊕ · 7,615.5 ly