Key parameters at a glance
- A radius of 4.87 Earth radii
- A mass of 21.10 Earth masses
- Surface gravity around 0.89 g
- An orbital period of 76.136 days
- Semi-major axis 0.3394 AU
- Equilibrium temperature 399 K (126 °C)
- Distance from Earth 973.68 light-years
- Earth Similarity Index 0.454
- Travel time at Voyager 1 speed 17,170,846 years
Kepler-858 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#403of 574
top 70.0%
This planet
4.87R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-858 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.87 | 11.21 |
| Mass (M⊕) | 1.00 | 21.10 | 317.83 |
| Density (g/cm³) | 5.51 | 1.00 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.89 | 2.53 |
| Insolation (S⊕) | 1.00 | 6.34 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 299089652
Gaia DR2
Gaia DR2 2133344791759137152
Gaia DR3
Gaia DR3 2133344791759137152
System
Kepler-858
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 76.14 Earth days (20.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.3394 AU.
Transit Fingerprint
Depth
0.295 %
Duration
7.960 h
Impact parameter b
0.011
Rp / R★
0.049278
Transit midpoint (BJD)
2,455,032.4790
Photometric dip
Transit produces a flux drop of 2,950 ppm lasting ≈ 7.96 h.
Extended Orbital Architecture
Planet / star radius ratio
0.049278
Semi-major axis / stellar radius
76.789
Impact parameter (b)
0.011
Transit mid-time (BJD)
2,455,032.4790
Angular separation (arcsec)
1.14000
Eq. Temperature
399K
(126 °C)
Insolation (S⊕)
6.34
Earth = 1.00
Earth Similarity (ESI)
0.454
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-858
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,653 K — cooler than the Sun (5,778 K)
Estimated Age
3.39 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.910 R☉
Stellar Mass
0.960 M☉
Metallicity [Fe/H]
-0.04
Extended Stellar Properties
Surface gravity (log g)
4.500 dex
Stellar density
1.110 g/cm³
Systemic radial velocity
-24.76 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
3.321 mas
Total Proper Motion
32.033 mas/yr
PM Right Ascension
31.93 mas/yr
PM Declination
-2.51 mas/yr
Galactic Cartesian (pc)
x = 0.202 · y = -0.593 · z = 0.779
Equatorial (J2000)
RA 288.84886° · Dec 51.20904°
Galactic ℓ, b
82.198° · 17.291°
Ecliptic λ, β
310.864° · 71.981°
HTM-20 index
267341651
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HD 219666 b
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Kepler-82 f
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Kepler-27 c
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TOI-6109 c
Neptune-like · G-type yellow (Sun-like)
Radius 4.83 R⊕ · 494.9 ly