Key parameters at a glance
- A radius of 1.33 Earth radii
- A mass of 2.33 Earth masses
- Surface gravity around 1.32 g
- An orbital period of 4.791 days
- Semi-major axis 0.0530 AU
- Equilibrium temperature 990 K (717 °C)
- Distance from Earth 3,015.72 light-years
- Earth Similarity Index 0.313
- Travel time at Voyager 1 speed 53,182,218 years
3 siblings around Kepler-251
Kepler-251 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-251 b this | Super-Earth | 1.33 | 2.33 | 4.791 | 990 | 2014 |
| Kepler-251 c | Sub-Neptune | 2.77 | 8.10 | 16.514 | 655 | 2014 |
| Kepler-251 d | Sub-Neptune | 2.77 | 8.10 | 30.133 | 536 | 2014 |
| Kepler-251 e | Sub-Neptune | 2.77 | 8.10 | 99.640 | 360 | 2014 |
Kepler-251 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#1022of 1176
top 86.8%
This planet
1.33R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-251 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.33 | 11.21 |
| Mass (M⊕) | 1.00 | 2.33 | 317.83 |
| Density (g/cm³) | 5.51 | 5.44 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.32 | 2.53 |
| Insolation (S⊕) | 1.00 | 203.17 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 272489533
Gaia DR2
Gaia DR2 2078832551450444032
Gaia DR3
Gaia DR3 2078832551450444032
System
Kepler-251
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.79 Earth days (1.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0530 AU.
Transit Fingerprint
Depth
0.025 %
Duration
2.705 h
Impact parameter b
0.250
Rp / R★
0.015386
Transit midpoint (BJD)
2,454,969.3115
Photometric dip
Transit produces a flux drop of 251 ppm lasting ≈ 2.71 h.
Extended Orbital Architecture
Planet / star radius ratio
0.015386
Semi-major axis / stellar radius
13.700
Impact parameter (b)
0.250
Transit mid-time (BJD)
2,454,969.3115
Angular separation (arcsec)
0.05730
Eq. Temperature
990K
(717 °C)
Insolation (S⊕)
203.17
Earth = 1.00
Earth Similarity (ESI)
0.313
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-251
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,526 K — cooler than the Sun (5,778 K)
Estimated Age
2.00 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.890 R☉
Stellar Mass
0.891 M☉
Metallicity [Fe/H]
-0.06
Extended Stellar Properties
Surface gravity (log g)
4.486 dex
Stellar density
1.610 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
1.054 mas
Total Proper Motion
13.968 mas/yr
PM Right Ascension
-3.18 mas/yr
PM Declination
-13.60 mas/yr
Galactic Cartesian (pc)
x = 0.321 · y = -0.642 · z = 0.696
Equatorial (J2000)
RA 296.56622° · Dec 44.10581°
Galactic ℓ, b
77.907° · 9.551°
Ecliptic λ, β
315.786° · 63.383°
HTM-20 index
-1274721983
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Kepler-1185 b
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