Key parameters at a glance

A radius of 2.39 Earth radii
A mass of 6.30 Earth masses
Surface gravity around 1.10 g
An orbital period of 52.713 days
Equilibrium temperature 477 K (204 °C)
Distance from Earth 875.26 light-years
Earth Similarity Index 0.526
Travel time at Voyager 1 speed 15,435,253 years

1 sibling around K2-185

K2-185 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
K2-185 b	Rocky Terrestrial	1.15	1.60	10.616	809	2018
K2-185 c this	Sub-Neptune	2.39	6.30	52.713	477	2018

K2-185 c Planet Profile

Physical Specs

Radius

2.39 R⊕

Radius (Jupiter)

0.213 R♃

Mass

6.30 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.54 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.526

HZ Position Unknown

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1343of 1978

top 67.8%

This planet

2.39R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-193 b 2.39 R⊕ Kepler-152 c 2.39 R⊕ Kepler-238 c 2.39 R⊕

Metric	Earth	K2-185 c	Jupiter
Radius (R⊕)	1.00	2.39	11.21
Mass (M⊕)	1.00	6.30	317.83
Density (g/cm³)	5.51	2.54	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 337607207

Gaia DR2

Gaia DR2 609508120464763264

Gaia DR3

Gaia DR3 609508120464763264

System

K2-185

Percentile among Sub-Neptune cohort

Radius 2.390 R⊕ · percentile 31 / cohort 1978

Mass 6.300 M⊕ · percentile 30 / cohort 1978

Orbital period 52.71 d · percentile 86 / cohort 1946

Distance 268.36 pc · percentile 33 / cohort 1975

ESI 0.526 · percentile 74 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

52.713 days

Semi-major axis

— AU

Eccentricity

—

Inclination

89.00 °

Year Length

A year here lasts approximately 52.71 Earth days (14.4% of a terrestrial year).

Transit Fingerprint

Depth

0.076 %

Duration

4.640 h

Impact parameter b

0.730

Rp / R★

0.023200

Transit midpoint (BJD)

2,457,159.1574

Photometric dip

Transit produces a flux drop of 757 ppm lasting ≈ 4.64 h.

Extended Orbital Architecture

Planet / star radius ratio

0.023200

Semi-major axis / stellar radius

62.620

Impact parameter (b)

0.730

Transit mid-time (BJD)

2,457,159.1574

Eq. Temperature

477K

(204 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.526

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Mayo et al. 2018

Instrument

Kepler CCD Array

Publication

2018-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2018 at K2 (12 shown).

K2-190 c · Rocky Terrestrial K2-183 b · Rocky Terrestrial K2-209 b · Rocky Terrestrial K2-210 b · Rocky Terrestrial K2-165 b · Super-Earth K2-169 b · Super-Earth K2-148 b · Super-Earth K2-219 b · Super-Earth K2-190 b · Super-Earth K2-200 b · Super-Earth K2-201 b · Super-Earth K2-170 b · Super-Earth

Host System: K2-185

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,788 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.940 R☉

Stellar Mass

0.960 M☉

Metallicity [Fe/H]

-0.10

Extended Stellar Properties

Surface gravity (log g)

4.480 dex

Stellar density

2.107 g/cm³

Systemic radial velocity

-7.04 km/s

Rotation period

17.35 days

Metallicity ratio

[Fe/H]

Distance

268.36 parsec

Light-years 875.26 ly

V-band magnitude

12.24 mag

Voyager-speed travel 15,435,253 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

3.698 mas

Total Proper Motion

24.199 mas/yr

PM Right Ascension

2.17 mas/yr

PM Declination

-24.10 mas/yr

Galactic Cartesian (pc)

x = -0.625 · y = 0.738 · z = 0.254

Equatorial (J2000)

RA 130.25966° · Dec 14.69022°

Galactic ℓ, b

211.417° · 30.785°

Ecliptic λ, β

128.773° · -3.495°

HTM-20 index

-36492891