Key parameters at a glance

A radius of 2.25 Earth radii
A mass of 5.69 Earth masses
Surface gravity around 1.12 g
An orbital period of 5.739 days
Semi-major axis 0.0632 AU
Equilibrium temperature 1,066 K (793 °C)
Distance from Earth 1,632.40 light-years
Earth Similarity Index 0.243
Travel time at Voyager 1 speed 28,787,390 years

K2-355 b Planet Profile

Physical Specs

Radius

2.25 R⊕

Radius (Jupiter)

0.201 R♃

Mass

5.69 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.74 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.243

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

#1589of 1978

top 80.3%

This planet

2.25R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-300 c 2.25 R⊕ GJ 667 C b 2.25 R⊕ Kepler-342 b 2.25 R⊕

Metric	Earth	K2-355 b	Jupiter
Radius (R⊕)	1.00	2.25	11.21
Mass (M⊕)	1.00	5.69	317.83
Density (g/cm³)	5.51	2.74	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 186853124

Gaia DR2

Gaia DR2 650463970824290816

Gaia DR3

Gaia DR3 650463970824290816

System

K2-355

Percentile among Sub-Neptune cohort

Radius 2.250 R⊕ · percentile 19 / cohort 1978

Mass 5.690 M⊕ · percentile 19 / cohort 1978

Orbital period 5.74 d · percentile 16 / cohort 1946

Distance 500.50 pc · percentile 47 / cohort 1975

ESI 0.243 · percentile 15 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.739 days

Semi-major axis

0.0632 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 5.74 Earth days (1.6% of a terrestrial year) at a mean orbital distance of 0.0632 AU.

Transit Fingerprint

Impact parameter b

0.430

Rp / R★

0.022300

Transit midpoint (BJD)

2,458,252.1918

Extended Orbital Architecture

Planet / star radius ratio

0.022300

Semi-major axis / stellar radius

14.850

Impact parameter (b)

0.430

Transit mid-time (BJD)

2,458,252.1918

Angular separation (arcsec)

0.12600

Eq. Temperature

1,066K

(793 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.243

0 = alien, 1 = Earth-identical

Insufficient insolation data — the dayside is scorched.

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: K2-355

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,790 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.920 R☉

Stellar Mass

0.960 M☉

Metallicity [Fe/H]

-0.12

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

1.660 g/cm³

Metallicity ratio

[Fe/H]

Distance

500.50 parsec

Light-years 1,632.40 ly

V-band magnitude

13.71 mag

Voyager-speed travel 28,787,390 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.969 mas

Total Proper Motion

10.642 mas/yr

PM Right Ascension

-4.76 mas/yr

PM Declination

-9.52 mas/yr

Galactic Cartesian (pc)

x = -0.553 · y = 0.800 · z = 0.233

Equatorial (J2000)

RA 124.64262° · Dec 13.50278°

Galactic ℓ, b

210.188° · 25.316°

Ecliptic λ, β

123.759° · -5.969°

HTM-20 index

961771096