Key parameters at a glance

A radius of 2.50 Earth radii
A mass of 6.80 Earth masses
Surface gravity around 1.09 g
An orbital period of 30.942 days
Semi-major axis 0.1898 AU
Equilibrium temperature 615 K (342 °C)
Distance from Earth 1,033.32 light-years
Earth Similarity Index 0.410
Travel time at Voyager 1 speed 18,222,671 years

K2-6 b Planet Profile

Physical Specs

Radius

2.50 R⊕

Radius (Jupiter)

0.223 R♃

Mass

6.80 M⊕

Mass (Jupiter)

0.021 M♃

Density

2.39 g/cm³

Surface Gravity

1.09 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.410

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1168of 1978

top 59.0%

This planet

2.50R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-126 d 2.50 R⊕ Kepler-254 d 2.50 R⊕ GJ 163 c 2.50 R⊕

Metric	Earth	K2-6 b	Jupiter
Radius (R⊕)	1.00	2.50	11.21
Mass (M⊕)	1.00	6.80	317.83
Density (g/cm³)	5.51	2.39	1.33
Surface Gravity (g)	1.00	1.09	2.53
Insolation (S⊕)	1.00	28.60	0.037

Star Catalogue Identifiers

TIC

TIC 446672575

Gaia DR2

Gaia DR2 3794479262419500160

Gaia DR3

Gaia DR3 3794479262419500160

System

K2-6

Percentile among Sub-Neptune cohort

Radius 2.500 R⊕ · percentile 40 / cohort 1978

Mass 6.800 M⊕ · percentile 37 / cohort 1978

Orbital period 30.94 d · percentile 74 / cohort 1946

Distance 316.82 pc · percentile 36 / cohort 1975

ESI 0.410 · percentile 54 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

30.942 days

Semi-major axis

0.1898 AU

Eccentricity

—

Inclination

89.42 °

Year Length

A year here lasts approximately 30.94 Earth days (8.5% of a terrestrial year) at a mean orbital distance of 0.1898 AU.

Transit Fingerprint

Depth

0.068 %

Duration

5.280 h

Impact parameter b

0.110

Rp / R★

0.024562

Transit midpoint (BJD)

2,456,827.5014

Photometric dip

Transit produces a flux drop of 680 ppm lasting ≈ 5.28 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024562

Semi-major axis / stellar radius

50.270

Impact parameter (b)

0.110

Transit mid-time (BJD)

2,456,827.5014

Angular separation (arcsec)

0.59900

Eq. Temperature

615K

(342 °C)

Insolation (S⊕)

28.60

Earth = 1.00

Earth Similarity (ESI)

0.410

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

Montet et al. 2015

Instrument

Kepler CCD Array

Publication

2015-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2015 at K2 (12 shown).

K2-18 b · Sub-Neptune K2-9 b · Sub-Neptune K2-3 d · Super-Earth K2-3 c · Super-Earth K2-21 c · Sub-Neptune K2-5 c · Sub-Neptune K2-13 b · Super-Earth K2-3 b · Sub-Neptune K2-17 b · Sub-Neptune K2-21 b · Super-Earth K2-16 c · Sub-Neptune K2-5 b · Super-Earth

Host System: K2-6

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,850 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.960 R☉

Stellar Mass

0.970 M☉

Metallicity [Fe/H]

-0.14

Extended Stellar Properties

Surface gravity (log g)

4.398 dex

Stellar density

1.847 g/cm³

Systemic radial velocity

7.69 km/s

Metallicity ratio

[Fe/H]

Distance

316.82 parsec

Light-years 1,033.32 ly

V-band magnitude

12.66 mag

Voyager-speed travel 18,222,671 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

3.129 mas

Total Proper Motion

33.027 mas/yr

PM Right Ascension

-32.24 mas/yr

PM Declination

7.15 mas/yr

Galactic Cartesian (pc)

x = -0.999 · y = 0.032 · z = -0.021

Equatorial (J2000)

RA 178.19212° · Dec -1.19844°

Galactic ℓ, b

274.088° · 58.349°

Ecliptic λ, β

178.814° · -1.819°

HTM-20 index

-338783175