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 3.950 days
- Semi-major axis 0.0463 AU
- Equilibrium temperature 966 K (693 °C)
- Distance from Earth 2,773.39 light-years
- Earth Similarity Index 0.269
- Travel time at Voyager 1 speed 48,908,775 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-861 b 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-861 b | 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 | 197.29 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 63206411
Gaia DR2
Gaia DR2 2128256286308183552
Gaia DR3
Gaia DR3 2128256286308183552
System
Kepler-861
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.95 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0463 AU.
Transit Fingerprint
Depth
0.081 %
Duration
1.579 h
Impact parameter b
0.020
Rp / R★
0.026662
Transit midpoint (BJD)
2,454,967.6094
Photometric dip
Transit produces a flux drop of 807 ppm lasting ≈ 1.58 h.
Extended Orbital Architecture
Planet / star radius ratio
0.026662
Semi-major axis / stellar radius
19.966
Impact parameter (b)
0.020
Transit mid-time (BJD)
2,454,967.6094
Angular separation (arcsec)
0.05440
Eq. Temperature
966K
(693 °C)
Insolation (S⊕)
197.29
Earth = 1.00
Earth Similarity (ESI)
0.269
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
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-861
Spectral Class
K-type orange
Effective Temperature
5,047 K — cooler than the Sun (5,778 K)
Estimated Age
4.47 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.780 R☉
Stellar Mass
0.820 M☉
Metallicity [Fe/H]
0.01
Extended Stellar Properties
Surface gravity (log g)
4.580 dex
Stellar density
7.449 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.148 mas
Total Proper Motion
8.776 mas/yr
PM Right Ascension
5.65 mas/yr
PM Declination
-6.72 mas/yr
Galactic Cartesian (pc)
x = 0.263 · y = -0.640 · z = 0.722
Equatorial (J2000)
RA 292.35396° · Dec 46.22625°
Galactic ℓ, b
78.445° · 13.161°
Ecliptic λ, β
311.267° · 66.491°
HTM-20 index
-832010834
Similar Worlds
K2-326 b
Sub-Neptune · K-type orange
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Kepler-250 c
Sub-Neptune · K-type orange
Radius 2.28 R⊕ · 2,480.7 ly
Kepler-1712 b
Sub-Neptune · K-type orange
Radius 2.28 R⊕ · 509.7 ly
Kepler-1503 b
Sub-Neptune · K-type orange
Radius 2.27 R⊕ · 3,997.3 ly
Kepler-306 e
Sub-Neptune · K-type orange
Radius 2.27 R⊕ · 2,529.9 ly
EPIC 212297394 c
Sub-Neptune · K-type orange
Radius 2.27 R⊕ · 1,364.6 ly