Key parameters at a glance

A radius of 2.29 Earth radii
A mass of 5.86 Earth masses
Surface gravity around 1.12 g
An orbital period of 21.027 days
Semi-major axis 0.1599 AU
Equilibrium temperature 624 K (351 °C)
Distance from Earth 1,159.62 light-years
Earth Similarity Index 0.418
Travel time at Voyager 1 speed 20,449,810 years

K2-356 b Planet Profile

Physical Specs

Radius

2.29 R⊕

Radius (Jupiter)

0.204 R♃

Mass

5.86 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.68 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.418

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

#1519of 1978

top 76.7%

This planet

2.29R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-379 c 2.29 R⊕ Kepler-319 d 2.29 R⊕ Kepler-626 b 2.29 R⊕

Metric	Earth	K2-356 b	Jupiter
Radius (R⊕)	1.00	2.29	11.21
Mass (M⊕)	1.00	5.86	317.83
Density (g/cm³)	5.51	2.68	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 20536788

Gaia DR2

Gaia DR2 651370037123678080

Gaia DR3

Gaia DR3 651370037123678080

System

K2-356

Percentile among Sub-Neptune cohort

Radius 2.290 R⊕ · percentile 23 / cohort 1978

Mass 5.860 M⊕ · percentile 22 / cohort 1978

Orbital period 21.03 d · percentile 64 / cohort 1946

Distance 355.54 pc · percentile 39 / cohort 1975

ESI 0.418 · percentile 56 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

21.027 days

Semi-major axis

0.1599 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 21.03 Earth days (5.8% of a terrestrial year) at a mean orbital distance of 0.1599 AU.

Transit Fingerprint

Impact parameter b

0.360

Rp / R★

0.024400

Transit midpoint (BJD)

2,458,256.0408

Extended Orbital Architecture

Planet / star radius ratio

0.024400

Semi-major axis / stellar radius

40.150

Impact parameter (b)

0.360

Transit mid-time (BJD)

2,458,256.0408

Angular separation (arcsec)

0.45000

Eq. Temperature

624K

(351 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.418

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Castro Gonz Aacute Lez et al. 2022

Instrument

Kepler CCD Array

Publication

2022-01

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: K2-356

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,568 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.860 R☉

Stellar Mass

0.900 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

4.520 dex

Stellar density

2.351 g/cm³

Metallicity ratio

[Fe/H]

Distance

355.54 parsec

Light-years 1,159.62 ly

V-band magnitude

13.27 mag

Voyager-speed travel 20,449,810 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

2.784 mas

Total Proper Motion

24.820 mas/yr

PM Right Ascension

11.53 mas/yr

PM Declination

-21.98 mas/yr

Galactic Cartesian (pc)

x = -0.603 · y = 0.762 · z = 0.236

Equatorial (J2000)

RA 128.32191° · Dec 13.66138°

Galactic ℓ, b

211.645° · 28.652°

Ecliptic λ, β

127.211° · -4.965°

HTM-20 index

1055641433