Key parameters at a glance
- A radius of 4.71 Earth radii
- A mass of 19.96 Earth masses
- Surface gravity around 0.90 g
- An orbital period of 34.940 days
- Semi-major axis 0.2055 AU
- Equilibrium temperature 524 K (251 °C)
- Distance from Earth 921.60 light-years
- Earth Similarity Index 0.365
- Travel time at Voyager 1 speed 16,252,348 years
5 siblings around Kepler-20
Kepler-20 g shares its host star with 5 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-20 b | Super-Earth | 1.77 | 9.70 | 3.696 | 1,187 | 2011 |
| Kepler-20 e | Rocky Terrestrial | 0.82 | 0.76 | 6.098 | 1,004 | 2011 |
| Kepler-20 c | Sub-Neptune | 2.89 | 11.10 | 10.854 | 828 | 2011 |
| Kepler-20 f | Rocky Terrestrial | 0.95 | 1.40 | 19.578 | 681 | 2011 |
| Kepler-20 g this | Neptune-like | 4.71 | 19.96 | 34.940 | 524 | 2016 |
| Kepler-20 d | Sub-Neptune | 2.61 | 13.40 | 77.611 | 430 | 2011 |
Kepler-20 g Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#429of 574
top 74.6%
This planet
4.71R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-20 g | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.71 | 11.21 |
| Mass (M⊕) | 1.00 | 19.96 | 317.83 |
| Density (g/cm³) | 5.51 | 1.05 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.90 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 19.960 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
TIC
TIC 158554588
Gaia DR2
Gaia DR2 2102548708017562112
Gaia DR3
Gaia DR3 2102548708017562112
System
Kepler-20
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 34.94 Earth days (9.6% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.2055 AU.
Eq. Temperature
524K
(251 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.365
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water.
Discovery Paper
Primary reference
Buchhave et al. 2016Instrument
Multiple Instruments
Publication
2016-12
Observation locale
Ground
Discovery cohort
Planets confirmed in 2016 at Multiple Observatories (12 shown).
Host System: Kepler-20
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,495 K — cooler than the Sun (5,778 K)
Estimated Age
7.60 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.964 R☉
Stellar Mass
0.948 M☉
Metallicity [Fe/H]
0.07
Extended Stellar Properties
Surface gravity (log g)
4.446 dex
Stellar density
1.360 g/cm³
Systemic radial velocity
-20.93 km/s
Rotational v·sin i
2.00 km/s
Metallicity ratio
[M/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
3.510 mas
Total Proper Motion
27.251 mas/yr
PM Right Ascension
-3.98 mas/yr
PM Declination
-26.96 mas/yr
Galactic Cartesian (pc)
x = 0.225 · y = -0.704 · z = 0.674
Equatorial (J2000)
RA 287.69799° · Dec 42.33858°
Galactic ℓ, b
73.377° · 14.573°
Ecliptic λ, β
300.714° · 63.902°
HTM-20 index
-1933436408
Similar Worlds
Kepler-318 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.71 R⊕ · 1,595.4 ly
HD 213885 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.71 R⊕ · 156.8 ly
HD 107148 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.70 R⊕ · 161.2 ly
LTT 9779 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.72 R⊕ · 262.4 ly
TCP J05074264+2447555 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.72 R⊕ · 1,647.1 ly
Kepler-667 b
Neptune-like · G-type yellow (Sun-like)
Radius 4.73 R⊕ · 7,509.6 ly