Key parameters at a glance
- A radius of 3.39 Earth radii
- A mass of 11.40 Earth masses
- Surface gravity around 0.99 g
- An orbital period of 81.169 days
- Semi-major axis 0.3554 AU
- Equilibrium temperature 436 K (163 °C)
- Distance from Earth 2,560.77 light-years
- Earth Similarity Index 0.494
- Travel time at Voyager 1 speed 45,159,202 years
Kepler-591 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#226of 1978
top 11.4%
This planet
3.39R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-591 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.39 | 11.21 |
| Mass (M⊕) | 1.00 | 11.40 | 317.83 |
| Density (g/cm³) | 5.51 | 1.61 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.99 | 2.53 |
| Insolation (S⊕) | 1.00 | 5.62 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 405686888
Gaia DR2
Gaia DR2 2131901682747346432
Gaia DR3
Gaia DR3 2131901682747346432
System
Kepler-591
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 81.17 Earth days (22.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.3554 AU.
Transit Fingerprint
Depth
0.118 %
Duration
7.709 h
Impact parameter b
0.548
Rp / R★
0.033112
Transit midpoint (BJD)
2,455,011.5932
Photometric dip
Transit produces a flux drop of 1,183 ppm lasting ≈ 7.71 h.
Extended Orbital Architecture
Planet / star radius ratio
0.033112
Semi-major axis / stellar radius
41.300
Impact parameter (b)
0.548
Transit mid-time (BJD)
2,455,011.5932
Angular separation (arcsec)
0.45300
Eq. Temperature
436K
(163 °C)
Insolation (S⊕)
5.62
Earth = 1.00
Earth Similarity (ESI)
0.494
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
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-591
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,677 K — cooler than the Sun (5,778 K)
Estimated Age
4.17 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.940 R☉
Stellar Mass
0.970 M☉
Metallicity [Fe/H]
0.01
Extended Stellar Properties
Surface gravity (log g)
4.480 dex
Stellar density
1.003 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.245 mas
Total Proper Motion
10.471 mas/yr
PM Right Ascension
1.27 mas/yr
PM Declination
-10.39 mas/yr
Galactic Cartesian (pc)
x = 0.183 · y = -0.638 · z = 0.748
Equatorial (J2000)
RA 286.02405° · Dec 48.43173°
Galactic ℓ, b
78.786° · 17.972°
Ecliptic λ, β
302.496° · 70.069°
HTM-20 index
-225199421
Similar Worlds
Kepler-335 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.39 R⊕ · 4,171.4 ly
Kepler-766 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.39 R⊕ · 7,493.8 ly
K2-138 e
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.39 R⊕ · 660.7 ly
Kepler-310 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.38 R⊕ · 1,964.3 ly
Kepler-965 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.38 R⊕ · 1,900.9 ly
Kepler-139 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.38 R⊕ · 1,275.4 ly