Key parameters at a glance
- A radius of 3.94 Earth radii
- A mass of 14.70 Earth masses
- Surface gravity around 0.95 g
- An orbital period of 20.478 days
- Semi-major axis 0.1400 AU
- Equilibrium temperature 530 K (257 °C)
- Distance from Earth 2,164.73 light-years
- Earth Similarity Index 0.391
- Travel time at Voyager 1 speed 38,175,069 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around Kepler-247
Kepler-247 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-247 b | Super-Earth | 1.64 | 3.33 | 3.336 | 970 | 2014 |
| Kepler-247 c | Neptune-like | 4.09 | 15.70 | 9.439 | 686 | 2014 |
| Kepler-247 d this | Sub-Neptune | 3.94 | 14.70 | 20.478 | 530 | 2014 |
Kepler-247 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#12of 1978
top 0.6%
This planet
3.94R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-247 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.94 | 11.21 |
| Mass (M⊕) | 1.00 | 14.70 | 317.83 |
| Density (g/cm³) | 5.51 | 1.32 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.95 | 2.53 |
| Insolation (S⊕) | 1.00 | 19.21 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 158792051
Gaia DR2
Gaia DR2 2102911576914748032
Gaia DR3
Gaia DR3 2102911581215700096
System
Kepler-247
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 20.48 Earth days (5.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1400 AU.
Transit Fingerprint
Depth
0.138 %
Duration
3.068 h
Impact parameter b
0.130
Rp / R★
0.034376
Transit midpoint (BJD)
2,455,011.6680
Photometric dip
Transit produces a flux drop of 1,382 ppm lasting ≈ 3.07 h.
Extended Orbital Architecture
Planet / star radius ratio
0.034376
Semi-major axis / stellar radius
50.000
Impact parameter (b)
0.130
Transit mid-time (BJD)
2,455,011.6680
Angular separation (arcsec)
0.21100
Eq. Temperature
530K
(257 °C)
Insolation (S⊕)
19.21
Earth = 1.00
Earth Similarity (ESI)
0.391
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Transit timing variations
Gravitational interactions from neighbours have been detected.
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-247
Spectral Class
K-type orange
Effective Temperature
5,100 K — cooler than the Sun (5,778 K)
Estimated Age
2.14 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.768 R☉
Stellar Mass
0.887 M☉
Metallicity [Fe/H]
0.30
Extended Stellar Properties
Surface gravity (log g)
4.608 dex
Stellar density
1.680 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.478 mas
Total Proper Motion
17.702 mas/yr
PM Right Ascension
5.53 mas/yr
PM Declination
16.82 mas/yr
Galactic Cartesian (pc)
x = 0.234 · y = -0.693 · z = 0.683
Equatorial (J2000)
RA 288.64256° · Dec 43.03938°
Galactic ℓ, b
74.328° · 14.221°
Ecliptic λ, β
302.698° · 64.377°
HTM-20 index
112671829
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TOI-500 e
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