Key parameters at a glance
- A radius of 2.66 Earth radii
- A mass of 7.56 Earth masses
- Surface gravity around 1.07 g
- An orbital period of 124.524 days
- Semi-major axis 0.4988 AU
- Equilibrium temperature 356 K (83 °C)
- Distance from Earth 2,140.82 light-years
- Earth Similarity Index 0.642
- Travel time at Voyager 1 speed 37,753,407 years
2 siblings around Kepler-218
Kepler-218 d 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-218 b | Super-Earth | 1.48 | 2.79 | 3.619 | 1,156 | 2014 |
| Kepler-218 c | Sub-Neptune | 3.14 | 10.00 | 44.700 | 500 | 2014 |
| Kepler-218 d this | Sub-Neptune | 2.66 | 7.56 | 124.524 | 356 | 2016 |
Kepler-218 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#928of 1978
top 46.9%
This planet
2.66R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-218 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.66 | 11.21 |
| Mass (M⊕) | 1.00 | 7.56 | 317.83 |
| Density (g/cm³) | 5.51 | 2.21 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.07 | 2.53 |
| Insolation (S⊕) | 1.00 | 4.12 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 271662623
Gaia DR2
Gaia DR2 2080452613110460928
Gaia DR3
Gaia DR3 2080452613110460928
System
Kepler-218
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 124.52 Earth days (34.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4988 AU.
Transit Fingerprint
Depth
0.069 %
Duration
9.598 h
Impact parameter b
0.500
Rp / R★
0.024212
Transit midpoint (BJD)
2,455,087.1801
Photometric dip
Transit produces a flux drop of 690 ppm lasting ≈ 9.60 h.
Extended Orbital Architecture
Planet / star radius ratio
0.024212
Semi-major axis / stellar radius
100.861
Impact parameter (b)
0.500
Transit mid-time (BJD)
2,455,087.1801
Angular separation (arcsec)
0.76000
Eq. Temperature
356K
(83 °C)
Insolation (S⊕)
4.12
Earth = 1.00
Earth Similarity (ESI)
0.642
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.
Discovery Paper
Primary reference
Morton et al. 2016Instrument
Kepler CCD Array
Publication
2016-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at Kepler (12 shown).
Host System: Kepler-218
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,542 K — cooler than the Sun (5,778 K)
Estimated Age
5.62 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.020 R☉
Stellar Mass
1.010 M☉
Metallicity [Fe/H]
0.31
Extended Stellar Properties
Surface gravity (log g)
4.420 dex
Stellar density
0.980 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.495 mas
Total Proper Motion
22.395 mas/yr
PM Right Ascension
8.12 mas/yr
PM Declination
20.87 mas/yr
Galactic Cartesian (pc)
x = 0.297 · y = -0.624 · z = 0.723
Equatorial (J2000)
RA 295.41288° · Dec 46.26658°
Galactic ℓ, b
79.453° · 11.289°
Ecliptic λ, β
316.098° · 65.688°
HTM-20 index
-1972364724
Similar Worlds
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Kepler-963 b
Sub-Neptune · G-type yellow (Sun-like)
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Kepler-1642 c
Sub-Neptune · G-type yellow (Sun-like)
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TOI-1279 b
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Kepler-1924 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.65 R⊕ · 6,232.1 ly