Key parameters at a glance

A radius of 1.79 Earth radii
A mass of 3.86 Earth masses
Surface gravity around 1.20 g
An orbital period of 9.399 days
Equilibrium temperature 909 K (636 °C)
Distance from Earth 689.59 light-years
Earth Similarity Index 0.312
Travel time at Voyager 1 speed 12,160,948 years

1 sibling around K2-331

K2-331 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
K2-331 b this	Super-Earth	1.79	3.86	9.399	909	2021
K2-331 c	Sub-Neptune	2.72	7.85	22.997	673	2021

K2-331 b Planet Profile

Physical Specs

Radius

1.79 R⊕

Radius (Jupiter)

0.160 R♃

Mass

3.86 M⊕

Mass (Jupiter)

0.012 M♃

Density

3.70 g/cm³

Surface Gravity

1.20 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.312

HZ Position Unknown

Controversial No

Discovery

Year 2021

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#271of 1176

top 23.0%

This planet

1.79R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-376 c 1.79 R⊕ Kepler-272 c 1.79 R⊕ Kepler-204 c 1.79 R⊕

Metric	Earth	K2-331 b	Jupiter
Radius (R⊕)	1.00	1.79	11.21
Mass (M⊕)	1.00	3.86	317.83
Density (g/cm³)	5.51	3.70	1.33
Surface Gravity (g)	1.00	1.20	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 46296576

Gaia DR2

Gaia DR2 608206676654888064

Gaia DR3

Gaia DR3 608206676654888064

System

K2-331

Percentile among Super-Earth cohort

Radius 1.790 R⊕ · percentile 76 / cohort 1176

Mass 3.860 M⊕ · percentile 70 / cohort 1176

Orbital period 9.40 d · percentile 63 / cohort 1164

Distance 211.43 pc · percentile 25 / cohort 1171

ESI 0.312 · percentile 39 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

9.399 days

Semi-major axis

— AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 9.40 Earth days (2.6% of a terrestrial year).

Transit Fingerprint

Duration

3.920 h

Impact parameter b

0.430

Rp / R★

0.015500

Transit midpoint (BJD)

2,458,100.9202

Extended Orbital Architecture

Planet / star radius ratio

0.015500

Semi-major axis / stellar radius

16.760

Impact parameter (b)

0.430

Transit mid-time (BJD)

2,458,100.9202

Eq. Temperature

909K

(636 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.312

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

De Leon et al. 2021

Instrument

Kepler CCD Array

Publication

2021-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2021 at K2 (12 shown).

EPIC 220492298 b · Rocky Terrestrial EPIC 206042996 c · Rocky Terrestrial EPIC 212624936 b · Rocky Terrestrial EPIC 206024342 c · Super-Earth EPIC 201427007 b · Super-Earth K2-332 b · Sub-Neptune EPIC 212624936 c · Sub-Neptune EPIC 206024342 d · Sub-Neptune K2-345 b · Sub-Neptune K2-349 b · Super-Earth K2-343 c · Sub-Neptune K2-346 b · Sub-Neptune

Host System: K2-331

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,994 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.060 R☉

Stellar Mass

1.100 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.430 dex

Stellar density

1.227 g/cm³

Rotation period

9.98 days

Metallicity ratio

[Fe/H]

Distance

211.43 parsec

Light-years 689.59 ly

V-band magnitude

11.31 mag

Voyager-speed travel 12,160,948 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

4.701 mas

Total Proper Motion

20.905 mas/yr

PM Right Ascension

-5.89 mas/yr

PM Declination

-20.06 mas/yr

Galactic Cartesian (pc)

x = -0.661 · y = 0.715 · z = 0.228

Equatorial (J2000)

RA 132.73764° · Dec 13.17027°

Galactic ℓ, b

214.180° · 32.384°

Ecliptic λ, β

131.501° · -4.326°

HTM-20 index

2119077450