Key parameters at a glance
- A radius of 2.57 Earth radii
- A mass of 7.13 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 22.790 days
- Semi-major axis 0.1528 AU
- Equilibrium temperature 634 K (361 °C)
- Distance from Earth 2,791.31 light-years
- Earth Similarity Index 0.395
- Travel time at Voyager 1 speed 49,224,719 years
1 sibling around Kepler-1991
Kepler-1991 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-1991 b | Super-Earth | 1.47 | 2.76 | 13.261 | 760 | 2023 |
| Kepler-1991 c this | Sub-Neptune | 2.57 | 7.13 | 22.790 | 634 | 2023 |
Kepler-1991 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1074of 1978
top 54.2%
This planet
2.57R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1991 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.57 | 11.21 |
| Mass (M⊕) | 1.00 | 7.13 | 317.83 |
| Density (g/cm³) | 5.51 | 2.31 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 38.27 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 164831457
Gaia DR2
Gaia DR2 2106371744306291328
Gaia DR3
Gaia DR3 2106371744306291328
System
Kepler-1991
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 22.79 Earth days (6.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1528 AU.
Transit Fingerprint
Depth
0.062 %
Duration
5.039 h
Impact parameter b
0.036
Rp / R★
0.022330
Transit midpoint (BJD)
2,454,971.6852
Photometric dip
Transit produces a flux drop of 618 ppm lasting ≈ 5.04 h.
Extended Orbital Architecture
Planet / star radius ratio
0.022330
Semi-major axis / stellar radius
35.303
Impact parameter (b)
0.036
Transit mid-time (BJD)
2,454,971.6852
Angular separation (arcsec)
0.17900
Eq. Temperature
634K
(361 °C)
Insolation (S⊕)
38.27
Earth = 1.00
Earth Similarity (ESI)
0.395
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
Valizadegan et al. 2023Instrument
Kepler CCD Array
Publication
2023-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2023 at Kepler (12 shown).
Host System: Kepler-1991
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,478 K — cooler than the Sun (5,778 K)
Estimated Age
6.76 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.053 R☉
Stellar Mass
0.914 M☉
Metallicity [Fe/H]
0.16
Extended Stellar Properties
Surface gravity (log g)
4.354 dex
Stellar density
1.603 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 15 bands
Astrometric Data
Parallax
1.140 mas
Total Proper Motion
15.107 mas/yr
PM Right Ascension
-7.94 mas/yr
PM Declination
-12.85 mas/yr
Galactic Cartesian (pc)
x = 0.183 · y = -0.682 · z = 0.708
Equatorial (J2000)
RA 285.03605° · Dec 45.07099°
Galactic ℓ, b
75.239° · 17.395°
Ecliptic λ, β
298.026° · 67.053°
HTM-20 index
416626189
Similar Worlds
Kepler-1549 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 2,619.2 ly
Kepler-549 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 2,071.6 ly
Kepler-313 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 3,520.5 ly
Kepler-879 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 2,618.0 ly
K2-248 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 1,325.0 ly
Kepler-203 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.57 R⊕ · 2,293.9 ly