Key parameters at a glance

A radius of 0.89 Earth radii
A mass of 0.64 Earth masses
Surface gravity around 0.81 g
An orbital period of 0.506 days
Semi-major axis 0.0127 AU
Equilibrium temperature 2,271 K (1998 °C)
Distance from Earth 647.76 light-years
Earth Similarity Index 0.120
Travel time at Voyager 1 speed 11,423,227 years

1 sibling around K2-223

K2-223 b 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
K2-223 b this	Rocky Terrestrial	0.89	0.64	0.506	2,271	2018
K2-223 c	Super-Earth	1.50	2.86	4.563	1,091	2018

K2-223 b Planet Profile

Physical Specs

Radius

0.89 R⊕

Radius (Jupiter)

0.079 R♃

Mass

0.64 M⊕

Mass (Jupiter)

0.002 M♃

Density

4.99 g/cm³

Surface Gravity

0.81 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.120

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

#418of 570

top 73.2%

This planet

0.89R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-353 b 0.89 R⊕ Kepler-387 c 0.89 R⊕ Kepler-303 b 0.89 R⊕

Metric	Earth	K2-223 b	Jupiter
Radius (R⊕)	1.00	0.89	11.21
Mass (M⊕)	1.00	0.64	317.83
Density (g/cm³)	5.51	4.99	1.33
Surface Gravity (g)	1.00	0.81	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 98594138

Gaia DR2

Gaia DR2 3578046995560843520

Gaia DR3

Gaia DR3 3578046995560843520

System

K2-223

Percentile among Rocky Terrestrial cohort

Radius 0.890 R⊕ · percentile 25 / cohort 570

Mass 0.640 M⊕ · percentile 21 / cohort 570

Orbital period 0.51 d · percentile 3 / cohort 567

Distance 198.60 pc · percentile 32 / cohort 566

ESI 0.120 · percentile 2 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

0.506 days

Semi-major axis

0.0127 AU

Eccentricity

—

Inclination

89.70 °

Year Length

A year here lasts roughly 12.1 hours long at a mean orbital distance of 0.0127 AU.

Transit Fingerprint

Depth

0.010 %

Duration

0.900 h

Impact parameter b

0.410

Rp / R★

0.008010

Transit midpoint (BJD)

2,457,637.6640

Photometric dip

Transit produces a flux drop of 100 ppm lasting ≈ 0.90 h.

Extended Orbital Architecture

Planet / star radius ratio

0.008010

Semi-major axis / stellar radius

3.300

Impact parameter (b)

0.410

Transit mid-time (BJD)

2,457,637.6640

Angular separation (arcsec)

0.06390

Eq. Temperature

2,271K

(1998 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.120

0 = alien, 1 = Earth-identical

Insufficient insolation data — the dayside is scorched.

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: K2-223

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,859 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.000 R☉

Stellar Mass

1.060 M☉

Metallicity [Fe/H]

0.19

Extended Stellar Properties

Surface gravity (log g)

4.500 dex

Stellar density

1.551 g/cm³

Systemic radial velocity

9.40 km/s

Metallicity ratio

[Fe/H]

Distance

198.60 parsec

Light-years 647.76 ly

V-band magnitude

11.44 mag

Voyager-speed travel 11,423,227 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

5.007 mas

Total Proper Motion

16.752 mas/yr

PM Right Ascension

7.38 mas/yr

PM Declination

-15.04 mas/yr

Galactic Cartesian (pc)

x = -0.980 · y = -0.091 · z = -0.178

Equatorial (J2000)

RA 185.30618° · Dec -10.28209°

Galactic ℓ, b

290.838° · 51.879°

Ecliptic λ, β

188.957° · -7.329°

HTM-20 index

2078357997