Key parameters at a glance

A radius of 2.37 Earth radii
A mass of 6.21 Earth masses
Surface gravity around 1.11 g
An orbital period of 13.682 days
Semi-major axis 0.1104 AU
Equilibrium temperature 761 K (488 °C)
Distance from Earth 761.62 light-years
Earth Similarity Index 0.340
Travel time at Voyager 1 speed 13,431,167 years

K2-220 b Planet Profile

Physical Specs

Radius

2.37 R⊕

Radius (Jupiter)

0.211 R♃

Mass

6.21 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.56 g/cm³

Surface Gravity

1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.340

HZ Position Inner

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1375of 1978

top 69.5%

This planet

2.37R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-81 c 2.37 R⊕ K2-18 b 2.37 R⊕ Kepler-125 b 2.37 R⊕

Metric	Earth	K2-220 b	Jupiter
Radius (R⊕)	1.00	2.37	11.21
Mass (M⊕)	1.00	6.21	317.83
Density (g/cm³)	5.51	2.56	1.33
Surface Gravity (g)	1.00	1.11	2.53
Insolation (S⊕)	1.00	79.70	0.037

Star Catalogue Identifiers

TIC

TIC 266012991

Gaia DR2

Gaia DR2 2581918597853527424

Gaia DR3

Gaia DR3 2581918597853527424

System

K2-220

Percentile among Sub-Neptune cohort

Radius 2.370 R⊕ · percentile 30 / cohort 1978

Mass 6.210 M⊕ · percentile 29 / cohort 1978

Orbital period 13.68 d · percentile 46 / cohort 1946

Distance 233.51 pc · percentile 31 / cohort 1975

ESI 0.340 · percentile 38 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.682 days

Semi-major axis

0.1104 AU

Eccentricity

—

Inclination

88.88 °

Year Length

A year here lasts approximately 13.68 Earth days (3.7% of a terrestrial year) at a mean orbital distance of 0.1104 AU.

Transit Fingerprint

Depth

0.054 %

Duration

3.120 h

Impact parameter b

0.380

Rp / R★

0.021600

Transit midpoint (BJD)

2,457,401.2729

Photometric dip

Transit produces a flux drop of 537 ppm lasting ≈ 3.12 h.

Extended Orbital Architecture

Planet / star radius ratio

0.021600

Semi-major axis / stellar radius

31.180

Impact parameter (b)

0.380

Transit mid-time (BJD)

2,457,401.2729

Angular separation (arcsec)

0.47300

Eq. Temperature

761K

(488 °C)

Insolation (S⊕)

79.70

Earth = 1.00

Earth Similarity (ESI)

0.340

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

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: K2-220

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,612 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.026 R☉

Stellar Mass

0.910 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.450 dex

Stellar density

3.061 g/cm³

Systemic radial velocity

13.88 km/s

Rotational v·sin i

1.10 km/s

Activity index (log R'HK)

-5.155

Metallicity ratio

[Fe/H]

Distance

233.51 parsec

Light-years 761.62 ly

V-band magnitude

11.87 mag

Voyager-speed travel 13,431,167 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

4.254 mas

Total Proper Motion

31.514 mas/yr

PM Right Ascension

30.63 mas/yr

PM Declination

-7.40 mas/yr

Galactic Cartesian (pc)

x = 0.962 · y = 0.218 · z = 0.165

Equatorial (J2000)

RA 12.77001° · Dec 9.51677°

Galactic ℓ, b

122.784° · -53.355°

Ecliptic λ, β

15.443° · 3.726°

HTM-20 index

1045714755