Key parameters at a glance

A radius of 1.54 Earth radii
A mass of 2.98 Earth masses
Surface gravity around 1.26 g
An orbital period of 3.271 days
Semi-major axis 0.0410 AU
Equilibrium temperature 1,187 K (914 °C)
Distance from Earth 689.05 light-years
Earth Similarity Index 0.245
Travel time at Voyager 1 speed 12,151,457 years

K2-226 b Planet Profile

Physical Specs

Radius

1.54 R⊕

Radius (Jupiter)

0.137 R♃

Mass

2.98 M⊕

Mass (Jupiter)

0.009 M♃

Density

4.49 g/cm³

Surface Gravity

1.26 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.245

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

#682of 1176

top 57.9%

This planet

1.54R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-385 b 1.54 R⊕ HIP 29442 d 1.54 R⊕ Kepler-337 b 1.54 R⊕

Metric	Earth	K2-226 b	Jupiter
Radius (R⊕)	1.00	1.54	11.21
Mass (M⊕)	1.00	2.98	317.83
Density (g/cm³)	5.51	4.49	1.33
Surface Gravity (g)	1.00	1.26	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 176938958

Gaia DR2

Gaia DR2 3581264372742210048

Gaia DR3

Gaia DR3 3581264372742210048

System

K2-226

Percentile among Super-Earth cohort

Radius 1.539 R⊕ · percentile 42 / cohort 1176

Mass 2.980 M⊕ · percentile 38 / cohort 1176

Orbital period 3.27 d · percentile 24 / cohort 1164

Distance 211.27 pc · percentile 25 / cohort 1171

ESI 0.245 · percentile 22 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

3.271 days

Semi-major axis

0.0410 AU

Eccentricity

0.220

Inclination

87.60 °

Year Length

A year here lasts approximately 3.27 Earth days (0.9% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0410 AU.

Transit Fingerprint

Depth

0.025 %

Duration

2.323 h

Impact parameter b

0.380

Rp / R★

0.015860

Transit midpoint (BJD)

2,457,620.0082

Photometric dip

Transit produces a flux drop of 252 ppm lasting ≈ 2.32 h.

Extended Orbital Architecture

Planet / star radius ratio

0.015860

Semi-major axis / stellar radius

9.910

Impact parameter (b)

0.380

Transit mid-time (BJD)

2,457,620.0082

Long. of periastron (ω)

-33.00°

Angular separation (arcsec)

0.19400

Eq. Temperature

1,187K

(914 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.245

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: K2-226

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,288 K — cooler than the Sun (5,778 K)

Estimated Age

9.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.889 R☉

Stellar Mass

0.856 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.473 dex

Stellar density

1.720 g/cm³

Systemic radial velocity

16.92 km/s

Metallicity ratio

[Fe/H]

Distance

211.27 parsec

Light-years 689.05 ly

V-band magnitude

12.34 mag

Voyager-speed travel 12,151,457 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

4.706 mas

Total Proper Motion

22.382 mas/yr

PM Right Ascension

-22.29 mas/yr

PM Declination

2.02 mas/yr

Galactic Cartesian (pc)

x = -0.984 · y = -0.063 · z = -0.166

Equatorial (J2000)

RA 183.64566° · Dec -9.56263°

Galactic ℓ, b

287.991° · 52.237°

Ecliptic λ, β

187.155° · -7.324°

HTM-20 index

-16674341