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 32.648 days
Semi-major axis 0.1716 AU
Equilibrium temperature 337 K (64 °C)
Distance from Earth 353.71 light-years
Earth Similarity Index 0.709
Travel time at Voyager 1 speed 6,237,727 years
Almost certainly tidally locked to its host star given the close orbit

K2-152 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 0.709

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

#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	K2-152 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	2.90	0.037

Star Catalogue Identifiers

TIC

TIC 56754291

Gaia DR2

Gaia DR2 3596508242468505216

Gaia DR3

Gaia DR3 3596508242468505216

System

K2-152

Percentile among Sub-Neptune cohort

Radius 2.290 R⊕ · percentile 23 / cohort 1978

Mass 5.860 M⊕ · percentile 22 / cohort 1978

Orbital period 32.65 d · percentile 75 / cohort 1946

Distance 108.45 pc · percentile 21 / cohort 1975

ESI 0.709 · percentile 93 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

32.648 days

Semi-major axis

0.1716 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 32.65 Earth days (8.9% of a terrestrial year) at a mean orbital distance of 0.1716 AU.

Transit Fingerprint

Depth

0.159 %

Duration

4.000 h

Impact parameter b

0.250

Rp / R★

0.034400

Transit midpoint (BJD)

2,457,608.6222

Photometric dip

Transit produces a flux drop of 1,590 ppm lasting ≈ 4.00 h.

Extended Orbital Architecture

Planet / star radius ratio

0.034400

Semi-major axis / stellar radius

58.800

Impact parameter (b)

0.250

Transit mid-time (BJD)

2,457,608.6222

Angular separation (arcsec)

1.58000

Eq. Temperature

337K

(64 °C)

Insolation (S⊕)

2.90

Earth = 1.00

Earth Similarity (ESI)

0.709

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure. 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: K2-152

Spectral Class

M-type red dwarf

Effective Temperature

4,044 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.610 R☉

Stellar Mass

0.630 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.670 dex

Stellar density

3.494 g/cm³

Systemic radial velocity

-6.70 km/s

Metallicity ratio

[Fe/H]

Distance

108.45 parsec

Light-years 353.71 ly

V-band magnitude

13.73 mag

Voyager-speed travel 6,237,727 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

9.192 mas

Total Proper Motion

92.964 mas/yr

PM Right Ascension

-92.85 mas/yr

PM Declination

-4.52 mas/yr

Galactic Cartesian (pc)

x = -0.994 · y = -0.028 · z = -0.102

Equatorial (J2000)

RA 181.63241° · Dec -5.82743°

Galactic ℓ, b

283.040° · 55.300°

Ecliptic λ, β

183.816° · -4.697°

HTM-20 index

-1479676212