Key parameters at a glance

A radius of 1.49 Earth radii
A mass of 2.83 Earth masses
Surface gravity around 1.27 g
An orbital period of 3.835 days
Semi-major axis 0.0373 AU
Equilibrium temperature 566 K (293 °C)
Distance from Earth 226.61 light-years
Earth Similarity Index 0.531
Travel time at Voyager 1 speed 3,996,312 years
Almost certainly tidally locked to its host star given the close orbit

K2-151 b Planet Profile

Physical Specs

Radius

1.49 R⊕

Radius (Jupiter)

0.133 R♃

Mass

2.83 M⊕

Mass (Jupiter)

0.009 M♃

Density

4.70 g/cm³

Surface Gravity

1.27 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.531

HZ Position Inner

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#766of 1176

top 65.1%

This planet

1.49R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-174 c 1.49 R⊕ TOI-431 c 1.49 R⊕ Kepler-400 c 1.49 R⊕

Metric	Earth	K2-151 b	Jupiter
Radius (R⊕)	1.00	1.49	11.21
Mass (M⊕)	1.00	2.83	317.83
Density (g/cm³)	5.51	4.70	1.33
Surface Gravity (g)	1.00	1.27	2.53
Insolation (S⊕)	1.00	20.80	0.037

Star Catalogue Identifiers

TIC

TIC 376936928

Gaia DR2

Gaia DR2 2579620343673729408

Gaia DR3

Gaia DR3 2579620343673729408

System

K2-151

Percentile among Super-Earth cohort

Radius 1.490 R⊕ · percentile 34 / cohort 1176

Mass 2.830 M⊕ · percentile 32 / cohort 1176

Orbital period 3.84 d · percentile 30 / cohort 1164

Distance 69.48 pc · percentile 14 / cohort 1171

ESI 0.531 · percentile 76 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

3.835 days

Semi-major axis

0.0373 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 3.84 Earth days (1.1% of a terrestrial year) at a mean orbital distance of 0.0373 AU.

Transit Fingerprint

Depth

0.098 %

Duration

1.541 h

Impact parameter b

0.440

Rp / R★

0.030300

Transit midpoint (BJD)

2,457,395.2374

Photometric dip

Transit produces a flux drop of 983 ppm lasting ≈ 1.54 h.

Extended Orbital Architecture

Planet / star radius ratio

0.030300

Semi-major axis / stellar radius

17.360

Impact parameter (b)

0.440

Transit mid-time (BJD)

2,457,395.2374

Angular separation (arcsec)

0.53700

Eq. Temperature

566K

(293 °C)

Insolation (S⊕)

20.80

Earth = 1.00

Earth Similarity (ESI)

0.531

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Hirano et al. 2018

Instrument

Kepler CCD Array

Publication

2018-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2018 at K2 (12 shown).

K2-190 c · Rocky Terrestrial K2-183 b · Rocky Terrestrial K2-209 b · Rocky Terrestrial K2-210 b · Rocky Terrestrial K2-165 b · Super-Earth K2-169 b · Super-Earth K2-148 b · Super-Earth K2-219 b · Super-Earth K2-190 b · Super-Earth K2-200 b · Super-Earth K2-201 b · Super-Earth K2-170 b · Super-Earth

Host System: K2-151

Spectral Class

M-type red dwarf

Effective Temperature

3,695 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.450 R☉

Stellar Mass

0.470 M☉

Metallicity [Fe/H]

-0.19

Extended Stellar Properties

Surface gravity (log g)

4.800 dex

Stellar density

6.736 g/cm³

Systemic radial velocity

-49.63 km/s

Metallicity ratio

[Fe/H]

Distance

69.48 parsec

Light-years 226.61 ly

V-band magnitude

14.18 mag

Voyager-speed travel 3,996,312 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

14.364 mas

Total Proper Motion

62.523 mas/yr

PM Right Ascension

55.39 mas/yr

PM Declination

-29.01 mas/yr

Galactic Cartesian (pc)

x = 0.931 · y = 0.326 · z = 0.165

Equatorial (J2000)

RA 19.30477° · Dec 9.50127°

Galactic ℓ, b

133.494° · -52.841°

Ecliptic λ, β

21.398° · 1.246°

HTM-20 index

706469216