Key parameters at a glance
- A radius of 2.38 Earth radii
- A mass of 22.70 Earth masses
- Surface gravity around 4.01 g
- An orbital period of 20.135 days
- Semi-major axis 0.1370 AU
- Equilibrium temperature 544 K (271 °C)
- Distance from Earth 1,929.32 light-years
- Earth Similarity Index 0.453
- Travel time at Voyager 1 speed 34,023,620 years
1 sibling around Kepler-189
Kepler-189 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-189 b | Rocky Terrestrial | 1.21 | 1.92 | 10.400 | 678 | 2014 |
| Kepler-189 c this | Sub-Neptune | 2.38 | 22.70 | 20.135 | 544 | 2014 |
Kepler-189 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1365of 1978
top 69.0%
This planet
2.38R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-189 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.38 | 11.21 |
| Mass (M⊕) | 1.00 | 22.70 | 317.83 |
| Density (g/cm³) | 5.51 | 9.25 | 1.33 |
| Surface Gravity (g) | 1.00 | 4.01 | 2.53 |
| Insolation (S⊕) | 1.00 | 18.81 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 22.700 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 158494327
Gaia DR2
Gaia DR2 2106137960646125312
Gaia DR3
Gaia DR3 2106137960646125312
System
Kepler-189
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 20.13 Earth days (5.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1370 AU.
Transit Fingerprint
Depth
0.104 %
Duration
3.565 h
Impact parameter b
0.130
Rp / R★
0.032994
Transit midpoint (BJD)
2,455,004.3655
Photometric dip
Transit produces a flux drop of 1,035 ppm lasting ≈ 3.57 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032994
Semi-major axis / stellar radius
26.600
Impact parameter (b)
0.130
Transit mid-time (BJD)
2,455,004.3655
Angular separation (arcsec)
0.23200
Eq. Temperature
544K
(271 °C)
Insolation (S⊕)
18.81
Earth = 1.00
Earth Similarity (ESI)
0.453
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-189
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,235 K — cooler than the Sun (5,778 K)
Estimated Age
3.98 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.750 R☉
Stellar Mass
0.803 M☉
Metallicity [Fe/H]
-0.04
Extended Stellar Properties
Surface gravity (log g)
4.619 dex
Stellar density
1.860 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.662 mas
Total Proper Motion
19.140 mas/yr
PM Right Ascension
-11.98 mas/yr
PM Declination
14.93 mas/yr
Galactic Cartesian (pc)
x = 0.216 · y = -0.682 · z = 0.698
Equatorial (J2000)
RA 287.56463° · Dec 44.30507°
Galactic ℓ, b
75.207° · 15.441°
Ecliptic λ, β
301.810° · 65.816°
HTM-20 index
1113426526
Similar Worlds
Kepler-166 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 1,968.4 ly
Kepler-1060 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 3,087.3 ly
Kepler-1071 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 3,399.4 ly
Kepler-639 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 2,773.1 ly
Kepler-1781 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 3,139.7 ly
Kepler-1872 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.38 R⊕ · 2,740.3 ly