Key parameters at a glance
- A radius of 1.89 Earth radii
- A mass of 4.23 Earth masses
- Surface gravity around 1.18 g
- An orbital period of 39.596 days
- Semi-major axis 0.2230 AU
- Equilibrium temperature 497 K (224 °C)
- Distance from Earth 2,817.51 light-years
- Earth Similarity Index 0.552
- Travel time at Voyager 1 speed 49,686,873 years
2 siblings around Kepler-171
Kepler-171 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-171 b | Sub-Neptune | 2.34 | 6.08 | 4.167 | 1,053 | 2014 |
| Kepler-171 c | Sub-Neptune | 2.56 | 7.08 | 11.463 | 752 | 2014 |
| Kepler-171 d this | Super-Earth | 1.89 | 4.23 | 39.596 | 497 | 2014 |
Kepler-171 d Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#143of 1176
top 12.1%
This planet
1.89R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-171 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.89 | 11.21 |
| Mass (M⊕) | 1.00 | 4.23 | 317.83 |
| Density (g/cm³) | 5.51 | 3.44 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.18 | 2.53 |
| Insolation (S⊕) | 1.00 | 15.10 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 239229224
Gaia DR2
Gaia DR2 2076955822541823744
Gaia DR3
Gaia DR3 2076955822541823744
System
Kepler-171
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 39.60 Earth days (10.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2230 AU.
Transit Fingerprint
Depth
0.049 %
Duration
6.315 h
Impact parameter b
0.580
Rp / R★
0.020316
Transit midpoint (BJD)
2,455,001.1192
Photometric dip
Transit produces a flux drop of 490 ppm lasting ≈ 6.32 h.
Extended Orbital Architecture
Planet / star radius ratio
0.020316
Semi-major axis / stellar radius
47.010
Impact parameter (b)
0.580
Transit mid-time (BJD)
2,455,001.1192
Angular separation (arcsec)
0.25800
Eq. Temperature
497K
(224 °C)
Insolation (S⊕)
15.10
Earth = 1.00
Earth Similarity (ESI)
0.552
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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-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
Kepler-1986 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 2,974.8 ly
K2-13 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 1,116.7 ly
Kepler-1534 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 3,610.5 ly
Kepler-371 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 2,652.3 ly
Kepler-399 d
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 2,415.3 ly
Kepler-1917 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.89 R⊕ · 2,964.9 ly