Key parameters at a glance

A radius of 0.43 Earth radii
A mass of 0.05 Earth masses
Surface gravity around 0.26 g
An orbital period of 0.645 days
Distance from Earth 1,027.97 light-years
Earth Similarity Index 0.694
Travel time at Voyager 1 speed 18,128,227 years
Almost certainly tidally locked to its host star given the close orbit

2 siblings around Kepler-158

Kepler-158 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-158 d this	Rocky Terrestrial	0.43	0.05	0.645	—	2024
Kepler-158 b	Sub-Neptune	2.12	5.14	16.709	500	2014
Kepler-158 c	Super-Earth	1.90	4.27	28.551	418	2014

Kepler-158 d Planet Profile

Physical Specs

Radius

0.43 R⊕

Radius (Jupiter)

0.038 R♃

Mass

0.05 M⊕

Mass (Jupiter)

0.000 M♃

Density

3.26 g/cm³

Surface Gravity

0.26 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.694

HZ Position Unknown

Controversial No

Discovery

Year 2024

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#565of 570

top 98.9%

This planet

0.43R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-444 b 0.40 R⊕ Kepler-102 b 0.46 R⊕ Kepler-879 c 0.40 R⊕

Metric	Earth	Kepler-158 d	Jupiter
Radius (R⊕)	1.00	0.43	11.21
Mass (M⊕)	1.00	0.05	317.83
Density (g/cm³)	5.51	3.26	1.33
Surface Gravity (g)	1.00	0.26	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 120103325

Gaia DR2

Gaia DR2 2103295173333142784

Gaia DR3

Gaia DR3 2103295173333142784

System

Kepler-158

Percentile among Rocky Terrestrial cohort

Radius 0.430 R⊕ · percentile 1 / cohort 570

Mass 0.047 M⊕ · percentile 1 / cohort 570

Orbital period 0.65 d · percentile 4 / cohort 567

Distance 315.18 pc · percentile 42 / cohort 566

ESI 0.694 · percentile 82 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

0.645 days

Semi-major axis

— AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts roughly 15.5 hours long.

Transit Fingerprint

Duration

1.200 h

Transit midpoint (BJD)

2,454,833.0520

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.694

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Wang et al. 2024

Instrument

Kepler CCD Array

Publication

2024-11

Observation locale

Space

Discovery cohort

Planets confirmed in 2024 at Kepler (4 shown).

KOI-4978 b · Rocky Terrestrial Kepler-963 c · Rocky Terrestrial Kepler-1489 c · Rocky Terrestrial Kepler-879 c · Rocky Terrestrial

Host System: Kepler-158

Spectral Class

K-type orange

Effective Temperature

4,896 K — cooler than the Sun (5,778 K)

Estimated Age

13.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.668 R☉

Stellar Mass

0.656 M☉

Metallicity [Fe/H]

-0.30

Extended Stellar Properties

Surface gravity (log g)

4.620 dex

Stellar density

3.100 g/cm³

Metallicity ratio

[Fe/H]

Distance

315.18 parsec

Light-years 1,027.97 ly

V-band magnitude

14.74 mag

Voyager-speed travel 18,128,227 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

3.144 mas

Total Proper Motion

49.513 mas/yr

PM Right Ascension

24.34 mas/yr

PM Declination

43.12 mas/yr

Galactic Cartesian (pc)

x = 0.186 · y = -0.746 · z = 0.640

Equatorial (J2000)

RA 284.03237° · Dec 39.78154°

Galactic ℓ, b

69.821° · 16.127°

Ecliptic λ, β

293.449° · 62.083°

HTM-20 index

-167544801