Key parameters at a glance

A radius of 1.37 Earth radii
A mass of 2.45 Earth masses
Surface gravity around 1.30 g
An orbital period of 4.623 days
Distance from Earth 1,656.68 light-years
Earth Similarity Index 0.925
Travel time at Voyager 1 speed 29,215,493 years

K2-391 b Planet Profile

Physical Specs

Radius

1.37 R⊕

Radius (Jupiter)

0.122 R♃

Mass

2.45 M⊕

Mass (Jupiter)

0.008 M♃

Density

5.22 g/cm³

Surface Gravity

1.30 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.925

HZ Position Unknown

Controversial No

Discovery

Year 2022

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#965of 1176

top 82.0%

This planet

1.37R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-240 b 1.37 R⊕ Kepler-286 c 1.37 R⊕ Kepler-901 b 1.37 R⊕

Metric	Earth	K2-391 b	Jupiter
Radius (R⊕)	1.00	1.37	11.21
Mass (M⊕)	1.00	2.45	317.83
Density (g/cm³)	5.51	5.22	1.33
Surface Gravity (g)	1.00	1.30	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 9054633

Gaia DR2

Gaia DR2 2439325924144650368

Gaia DR3

Gaia DR3 2439325924144650368

System

K2-391

Percentile among Super-Earth cohort

Radius 1.371 R⊕ · percentile 18 / cohort 1176

Mass 2.450 M⊕ · percentile 17 / cohort 1176

Orbital period 4.62 d · percentile 37 / cohort 1164

Distance 507.94 pc · percentile 48 / cohort 1171

ESI 0.925 · percentile 98 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

4.623 days

Semi-major axis

— AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 4.62 Earth days (1.3% of a terrestrial year).

Transit Fingerprint

Duration

2.700 h

Impact parameter b

0.434

Rp / R★

0.022200

Transit midpoint (BJD)

2,457,741.5165

Extended Orbital Architecture

Planet / star radius ratio

0.022200

Semi-major axis / stellar radius

11.920

Impact parameter (b)

0.434

Transit mid-time (BJD)

2,457,741.5165

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.925

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Christiansen et al. 2022

Instrument

Kepler CCD Array

Publication

2022-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2022 at K2 (12 shown).

K2-411 b · Rocky Terrestrial K2-381 b · Rocky Terrestrial K2-384 b · Rocky Terrestrial K2-400 b · Rocky Terrestrial K2-384 c · Rocky Terrestrial K2-369 b · Super-Earth K2-407 b · Super-Earth K2-414 b · Rocky Terrestrial K2-368 b · Super-Earth K2-413 c · Rocky Terrestrial K2-384 e · Super-Earth K2-407 c · Super-Earth

Host System: K2-391

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,543 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.566 R☉

Stellar Mass

0.757 M☉

Metallicity [Fe/H]

-0.54

Extended Stellar Properties

Surface gravity (log g)

4.973 dex

Stellar density

0.222 g/cm³

Metallicity ratio

[Fe/H]

Distance

507.94 parsec

Light-years 1,656.68 ly

V-band magnitude

12.53 mag

Voyager-speed travel 29,215,493 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.941 mas

Total Proper Motion

9.096 mas/yr

PM Right Ascension

6.58 mas/yr

PM Declination

6.28 mas/yr

Galactic Cartesian (pc)

x = 0.989 · y = -0.065 · z = -0.134

Equatorial (J2000)

RA 356.22602° · Dec -7.70152°

Galactic ℓ, b

80.810° · -64.980°

Ecliptic λ, β

353.468° · -5.567°

HTM-20 index

1725922332