Key parameters at a glance
- A radius of 1.40 Earth radii
- A mass of 3.20 Earth masses
- Surface gravity around 1.63 g
- An orbital period of 0.685 days
- Semi-major axis 0.0130 AU
- Equilibrium temperature 1,355 K (1082 °C)
- Distance from Earth 317.08 light-years
- Earth Similarity Index 0.215
- Travel time at Voyager 1 speed 5,591,741 years
- Almost certainly tidally locked to its host star given the close orbit
K2-85 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#923of 1176
top 78.4%
This planet
1.40R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | K2-85 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.40 | 11.21 |
| Mass (M⊕) | 1.00 | 3.20 | 317.83 |
| Density (g/cm³) | 5.51 | 5.90 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.63 | 2.53 |
| Insolation (S⊕) | 1.00 | 800.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 3.200 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 14160842
Gaia DR2
Gaia DR2 49784688211974144
Gaia DR3
Gaia DR3 49784688211974144
System
K2-85
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts roughly 16.4 hours long on a mildly elliptical path at a mean orbital distance of 0.0130 AU.
Transit Fingerprint
Depth
0.040 %
Duration
0.818 h
Rp / R★
0.015500
Transit midpoint (BJD)
2,457,065.3678
Photometric dip
Transit produces a flux drop of 400 ppm lasting ≈ 0.82 h.
Extended Orbital Architecture
Planet / star radius ratio
0.015500
Semi-major axis / stellar radius
4.300
Transit mid-time (BJD)
2,457,065.3678
Long. of periastron (ω)
67.59°
Angular separation (arcsec)
0.13400
Eq. Temperature
1,355K
(1082 °C)
Insolation (S⊕)
800.00
Earth = 1.00
Earth Similarity (ESI)
0.215
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. Close-orbiting tidally-locked around a cool host.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Discovery Paper
Primary reference
Crossfield et al. 2016Instrument
Kepler CCD Array
Publication
2016-09
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-85
Spectral Class
K-type orange
Effective Temperature
4,232 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.710 R☉
Stellar Mass
0.700 M☉
Metallicity [Fe/H]
0.14
Extended Stellar Properties
Surface gravity (log g)
4.440 dex
Stellar density
2.352 g/cm³
Systemic radial velocity
-3.94 km/s
Rotational v·sin i
3.00 km/s
Activity index (log R'HK)
-4.402
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
10.257 mas
Total Proper Motion
116.428 mas/yr
PM Right Ascension
94.03 mas/yr
PM Declination
-68.66 mas/yr
Galactic Cartesian (pc)
x = 0.482 · y = 0.817 · z = 0.317
Equatorial (J2000)
RA 59.46483° · Dec 18.46495°
Galactic ℓ, b
172.898° · -25.820°
Ecliptic λ, β
61.167° · -1.970°
HTM-20 index
1186637469
Similar Worlds
Kepler-1301 b
Super-Earth · K-type orange
Radius 1.40 R⊕ · 2,786.3 ly
Kepler-329 b
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Kepler-326 c
Super-Earth · K-type orange
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Kepler-1145 b
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Kepler-716 c
Super-Earth · K-type orange
Radius 1.39 R⊕ · 2,071.1 ly