Key parameters at a glance

A radius of 3.72 Earth radii
A mass of 13.40 Earth masses
Surface gravity around 0.97 g
An orbital period of 16.349 days
Semi-major axis 0.1450 AU
Equilibrium temperature 735 K (462 °C)
Distance from Earth 1,688.47 light-years
Earth Similarity Index 0.294
Travel time at Voyager 1 speed 29,776,118 years

K2-357 b Planet Profile

Physical Specs

Radius

3.72 R⊕

Radius (Jupiter)

0.332 R♃

Mass

13.40 M⊕

Mass (Jupiter)

0.042 M♃

Density

1.43 g/cm³

Surface Gravity

0.97 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.294

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

#81of 1978

top 4.0%

This planet

3.72R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-79 c 3.72 R⊕ Kepler-937 b 3.72 R⊕ pi Men d 3.72 R⊕

Metric	Earth	K2-357 b	Jupiter
Radius (R⊕)	1.00	3.72	11.21
Mass (M⊕)	1.00	13.40	317.83
Density (g/cm³)	5.51	1.43	1.33
Surface Gravity (g)	1.00	0.97	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 293459761

Gaia DR2

Gaia DR2 610181468257262464

Gaia DR3

Gaia DR3 610181468257262464

System

K2-357

Percentile among Sub-Neptune cohort

Radius 3.720 R⊕ · percentile 96 / cohort 1978

Mass 13.400 M⊕ · percentile 89 / cohort 1978

Orbital period 16.35 d · percentile 55 / cohort 1946

Distance 517.69 pc · percentile 48 / cohort 1975

ESI 0.294 · percentile 26 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

16.349 days

Semi-major axis

0.1450 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 16.35 Earth days (4.5% of a terrestrial year) at a mean orbital distance of 0.1450 AU.

Transit Fingerprint

Impact parameter b

0.350

Rp / R★

0.034000

Transit midpoint (BJD)

2,458,255.1162

Extended Orbital Architecture

Planet / star radius ratio

0.034000

Semi-major axis / stellar radius

31.620

Impact parameter (b)

0.350

Transit mid-time (BJD)

2,458,255.1162

Angular separation (arcsec)

0.28000

Eq. Temperature

735K

(462 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.294

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: K2-357

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,794 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.000 R☉

Stellar Mass

0.980 M☉

Metallicity [Fe/H]

-0.02

Extended Stellar Properties

Surface gravity (log g)

4.430 dex

Stellar density

1.595 g/cm³

Metallicity ratio

[Fe/H]

Distance

517.69 parsec

Light-years 1,688.47 ly

V-band magnitude

13.75 mag

Voyager-speed travel 29,776,118 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.903 mas

Total Proper Motion

9.272 mas/yr

PM Right Ascension

-8.58 mas/yr

PM Declination

-3.51 mas/yr

Galactic Cartesian (pc)

x = -0.641 · y = 0.714 · z = 0.281

Equatorial (J2000)

RA 131.93866° · Dec 16.32891°

Galactic ℓ, b

210.369° · 32.909°

Ecliptic λ, β

129.907° · -1.490°

HTM-20 index

-1374609543