Key parameters at a glance
- A radius of 2.28 Earth radii
- A mass of 5.82 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 5.945 days
- Semi-major axis 0.0610 AU
- Equilibrium temperature 857 K (584 °C)
- Distance from Earth 1,938.88 light-years
- Earth Similarity Index 0.305
- Travel time at Voyager 1 speed 34,192,147 years
2 siblings around Kepler-191
Kepler-191 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-191 d this | Sub-Neptune | 2.28 | 5.82 | 5.945 | 857 | 2016 |
| Kepler-191 b | Super-Earth | 1.34 | 2.36 | 9.940 | 722 | 2014 |
| Kepler-191 c | Super-Earth | 1.86 | 4.12 | 17.739 | 596 | 2014 |
Kepler-191 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1536of 1978
top 77.6%
This planet
2.28R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-191 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.28 | 11.21 |
| Mass (M⊕) | 1.00 | 5.82 | 317.83 |
| Density (g/cm³) | 5.51 | 2.70 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 99.60 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 159647213
Gaia DR2
Gaia DR2 2126648731589350272
Gaia DR3
Gaia DR3 2126648731589350272
System
Kepler-191
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.95 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0610 AU.
Transit Fingerprint
Depth
0.080 %
Duration
2.571 h
Impact parameter b
0.050
Rp / R★
0.026289
Transit midpoint (BJD)
2,455,003.4730
Photometric dip
Transit produces a flux drop of 800 ppm lasting ≈ 2.57 h.
Extended Orbital Architecture
Planet / star radius ratio
0.026289
Semi-major axis / stellar radius
18.117
Impact parameter (b)
0.050
Transit mid-time (BJD)
2,455,003.4730
Angular separation (arcsec)
0.10300
Eq. Temperature
857K
(584 °C)
Insolation (S⊕)
99.60
Earth = 1.00
Earth Similarity (ESI)
0.305
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
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-191
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,215 K — cooler than the Sun (5,778 K)
Estimated Age
4.90 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.800 R☉
Stellar Mass
0.840 M☉
Metallicity [Fe/H]
-0.05
Extended Stellar Properties
Surface gravity (log g)
4.560 dex
Stellar density
1.820 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.654 mas
Total Proper Motion
17.649 mas/yr
PM Right Ascension
-5.50 mas/yr
PM Declination
-16.77 mas/yr
Galactic Cartesian (pc)
x = 0.254 · y = -0.656 · z = 0.711
Equatorial (J2000)
RA 291.18332° · Dec 45.32309°
Galactic ℓ, b
77.247° · 13.512°
Ecliptic λ, β
308.563° · 65.950°
HTM-20 index
1586289339
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