Key parameters at a glance

A radius of 6.67 Earth radii
A mass of 36.00 Earth masses
Surface gravity around 0.81 g
An orbital period of 355.000 days
Distance from Earth 1,275.39 light-years
Earth Similarity Index 0.398
Travel time at Voyager 1 speed 22,491,570 years

4 siblings around Kepler-139

Kepler-139 f shares its host star with 4 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-139 d	Super-Earth	1.70	2.00	7.306	972	2023
Kepler-139 b	Sub-Neptune	2.94	7.00	15.771	752	2014
Kepler-139 c	Sub-Neptune	3.38	13.00	157.073	350	2014
Kepler-139 f this	Neptune-like	6.67	36.00	355.000	—	2025
Kepler-139 e	Gas Giant	13.70	378.00	2,047.635	—	2023

Kepler-139 f Planet Profile

Physical Specs

Radius

6.67 R⊕

Radius (Jupiter)

0.595 R♃

Mass

36.00 M⊕

Mass (Jupiter)

0.113 M♃

Density

0.67 g/cm³

Surface Gravity

0.81 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.398

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Transit Timing Variations

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#226of 574

top 39.2%

This planet

6.67R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

GJ 15 A c 6.67 R⊕ Kepler-767 b 6.64 R⊕ K2-45 b 6.71 R⊕

Metric	Earth	Kepler-139 f	Jupiter
Radius (R⊕)	1.00	6.67	11.21
Mass (M⊕)	1.00	36.00	317.83
Density (g/cm³)	5.51	0.67	1.33
Surface Gravity (g)	1.00	0.81	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	36.000 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 123450224

Gaia DR2

Gaia DR2 2105362903731391744

Gaia DR3

Gaia DR3 2105362903731391744

System

Kepler-139

Percentile among Neptune-like cohort

Radius 6.670 R⊕ · percentile 60 / cohort 574

Mass 36.000 M⊕ · percentile 58 / cohort 574

Orbital period 355.00 d · percentile 94 / cohort 524

Distance 391.04 pc · percentile 53 / cohort 572

ESI 0.398 · percentile 73 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

355.000 days

Semi-major axis

— AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 355.00 Earth days (97.2% of a terrestrial year).

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.398

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Lammers & Winn 2025

Instrument

Multiple Instruments

Publication

2025-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2025 at Multiple Observatories (12 shown).

Gl 725 A b · Super-Earth HD 20794 f · Sub-Neptune GJ 3998 d · Sub-Neptune GJ 251 c · Super-Earth HD 86728 b · Sub-Neptune TOI-2015 c · Sub-Neptune HD 73344 d · Gas Giant TOI-1472 c · Sub-Neptune TOI-6695 c · Gas Giant AT2021ueyL b · Gas Giant HIP 111909 b · Gas Giant TOI-6041 c · Gas Giant

Host System: Kepler-139

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,630 K — cooler than the Sun (5,778 K)

Estimated Age

2.82 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.045 R☉

Stellar Mass

1.078 M☉

Metallicity [Fe/H]

0.35

Extended Stellar Properties

Surface gravity (log g)

4.345 dex

Stellar density

0.960 g/cm³

Metallicity ratio

[Fe/H]

Distance

391.04 parsec

Light-years 1,275.39 ly

V-band magnitude

12.78 mag

Voyager-speed travel 22,491,570 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.529 mas

Total Proper Motion

17.161 mas/yr

PM Right Ascension

5.40 mas/yr

PM Declination

16.29 mas/yr

Galactic Cartesian (pc)

x = 0.155 · y = -0.704 · z = 0.693

Equatorial (J2000)

RA 282.39195° · Dec 43.88942°

Galactic ℓ, b

73.378° · 18.745°

Ecliptic λ, β

292.678° · 66.356°

HTM-20 index

-675728923