Key parameters at a glance
- A radius of 2.19 Earth radii
- A mass of 5.43 Earth masses
- Surface gravity around 1.13 g
- An orbital period of 6.494 days
- Semi-major axis 0.0615 AU
- Equilibrium temperature 688 K (415 °C)
- Distance from Earth 841.85 light-years
- Earth Similarity Index 0.387
- Travel time at Voyager 1 speed 14,846,042 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around K2-247
K2-247 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 |
|---|---|---|---|---|---|---|
| K2-247 b | Sub-Neptune | 2.12 | 5.14 | 2.250 | 979 | 2018 |
| K2-247 c this | Sub-Neptune | 2.19 | 5.43 | 6.494 | 688 | 2018 |
K2-247 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1691of 1978
top 85.4%
This planet
2.19R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-247 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.19 | 11.21 |
| Mass (M⊕) | 1.00 | 5.43 | 317.83 |
| Density (g/cm³) | 5.51 | 2.84 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.13 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Star Catalogue Identifiers
TIC
TIC 110999033
Gaia DR2
Gaia DR2 3578596339057980160
Gaia DR3
Gaia DR3 3578596339057980160
System
K2-247
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.49 Earth days (1.8% of a terrestrial year) at a mean orbital distance of 0.0615 AU.
Transit Fingerprint
Depth
0.110 %
Duration
1.700 h
Impact parameter b
0.410
Rp / R★
0.029200
Transit midpoint (BJD)
2,457,588.1369
Photometric dip
Transit produces a flux drop of 1,100 ppm lasting ≈ 1.70 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029200
Semi-major axis / stellar radius
18.200
Impact parameter (b)
0.410
Transit mid-time (BJD)
2,457,588.1369
Angular separation (arcsec)
0.23800
Eq. Temperature
688K
(415 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.387
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Livingston et al. 2018Instrument
Kepler CCD Array
Publication
2018-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-247
Spectral Class
K-type orange
Effective Temperature
4,667 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.690 R☉
Stellar Mass
0.740 M☉
Metallicity [Fe/H]
-0.08
Extended Stellar Properties
Surface gravity (log g)
4.630 dex
Stellar density
2.038 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
3.846 mas
Total Proper Motion
38.464 mas/yr
PM Right Ascension
-36.64 mas/yr
PM Declination
-11.69 mas/yr
Galactic Cartesian (pc)
x = -0.973 · y = -0.152 · z = -0.175
Equatorial (J2000)
RA 188.89352° · Dec -10.06928°
Galactic ℓ, b
296.494° · 52.604°
Ecliptic λ, β
192.133° · -5.731°
HTM-20 index
-656576183
Similar Worlds
TOI-880.02
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Radius 2.19 R⊕ · 197.9 ly
Kepler-1630 b
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Kepler-1042 b
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Kepler-174 d
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K2-254 c
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Kepler-57 c
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Radius 2.20 R⊕ · 2,100.9 ly