Key parameters at a glance
- A radius of 2.56 Earth radii
- A mass of 7.08 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 11.463 days
- Semi-major axis 0.0980 AU
- Equilibrium temperature 752 K (479 °C)
- Distance from Earth 2,817.51 light-years
- Earth Similarity Index 0.334
- Travel time at Voyager 1 speed 49,686,873 years
2 siblings around Kepler-171
Kepler-171 c 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-171 b | Sub-Neptune | 2.34 | 6.08 | 4.167 | 1,053 | 2014 |
| Kepler-171 c this | Sub-Neptune | 2.56 | 7.08 | 11.463 | 752 | 2014 |
| Kepler-171 d | Super-Earth | 1.89 | 4.23 | 39.596 | 497 | 2014 |
Kepler-171 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1092of 1978
top 55.2%
This planet
2.56R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-171 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.56 | 11.21 |
| Mass (M⊕) | 1.00 | 7.08 | 317.83 |
| Density (g/cm³) | 5.51 | 2.32 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 78.91 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 239229224
Gaia DR2
Gaia DR2 2076955822541823744
Gaia DR3
Gaia DR3 2076955822541823744
System
Kepler-171
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.46 Earth days (3.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0980 AU.
Transit Fingerprint
Depth
0.102 %
Duration
2.566 h
Impact parameter b
0.040
Rp / R★
0.029045
Transit midpoint (BJD)
2,454,970.3843
Photometric dip
Transit produces a flux drop of 1,025 ppm lasting ≈ 2.57 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029045
Semi-major axis / stellar radius
34.510
Impact parameter (b)
0.040
Transit mid-time (BJD)
2,454,970.3843
Angular separation (arcsec)
0.11300
Eq. Temperature
752K
(479 °C)
Insolation (S⊕)
78.91
Earth = 1.00
Earth Similarity (ESI)
0.334
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-171
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,642 K — cooler than the Sun (5,778 K)
Estimated Age
2.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.839 R☉
Stellar Mass
0.978 M☉
Metallicity [Fe/H]
0.17
Extended Stellar Properties
Surface gravity (log g)
4.566 dex
Stellar density
1.280 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.129 mas
Total Proper Motion
10.425 mas/yr
PM Right Ascension
3.02 mas/yr
PM Declination
9.98 mas/yr
Galactic Cartesian (pc)
x = 0.336 · y = -0.666 · z = 0.666
Equatorial (J2000)
RA 296.77191° · Dec 41.75560°
Galactic ℓ, b
75.900° · 8.281°
Ecliptic λ, β
314.144° · 61.155°
HTM-20 index
-822082316
Similar Worlds
K2-197 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 807.7 ly
Kepler-106 e
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 1,449.2 ly
Kepler-837 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 2,941.6 ly
HD 93385 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 141.4 ly
Kepler-640 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 1,819.3 ly
HD 136352 d
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.56 R⊕ · 47.9 ly