Key parameters at a glance

A radius of 3.38 Earth radii
A mass of 13.00 Earth masses
Surface gravity around 1.14 g
An orbital period of 157.073 days
Semi-major axis 0.5860 AU
Equilibrium temperature 350 K (77 °C)
Distance from Earth 1,275.39 light-years
Earth Similarity Index 0.676
Travel time at Voyager 1 speed 22,491,570 years

4 siblings around Kepler-139

Kepler-139 c 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 this	Sub-Neptune	3.38	13.00	157.073	350	2014
Kepler-139 f	Neptune-like	6.67	36.00	355.000	—	2025
Kepler-139 e	Gas Giant	13.70	378.00	2,047.635	—	2023

Kepler-139 c Planet Profile

Physical Specs

Radius

3.38 R⊕

Radius (Jupiter)

0.302 R♃

Mass

13.00 M⊕

Mass (Jupiter)

0.041 M♃

Density

8.70 g/cm³

Surface Gravity

1.14 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.676

HZ Position Inner

Controversial No

Discovery

Year 2014

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#230of 1978

top 11.6%

This planet

3.38R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-965 b 3.38 R⊕ Kepler-268 c 3.38 R⊕ Kepler-533 b 3.38 R⊕

Metric	Earth	Kepler-139 c	Jupiter
Radius (R⊕)	1.00	3.38	11.21
Mass (M⊕)	1.00	13.00	317.83
Density (g/cm³)	5.51	8.70	1.33
Surface Gravity (g)	1.00	1.14	2.53
Insolation (S⊕)	1.00	3.02	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	13.000 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	23.256 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 123450224

Gaia DR2

Gaia DR2 2105362903731391744

Gaia DR3

Gaia DR3 2105362903731391744

System

Kepler-139

Percentile among Sub-Neptune cohort

Radius 3.380 R⊕ · percentile 88 / cohort 1978

Mass 13.000 M⊕ · percentile 87 / cohort 1978

Orbital period 157.07 d · percentile 97 / cohort 1946

Distance 391.04 pc · percentile 41 / cohort 1975

ESI 0.676 · percentile 90 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

157.073 days

Semi-major axis

0.5860 AU

Eccentricity

0.000

Inclination

90.00 °

Year Length

A year here lasts approximately 157.07 Earth days (43.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.5860 AU.

Transit Fingerprint

Depth

0.055 %

Duration

8.517 h

Impact parameter b

0.830

Rp / R★

0.021105

Transit midpoint (BJD)

2,455,314.2627

Photometric dip

Transit produces a flux drop of 551 ppm lasting ≈ 8.52 h.

Extended Orbital Architecture

Planet / star radius ratio

0.021105

Semi-major axis / stellar radius

150.720

Impact parameter (b)

0.830

RV semi-amplitude (K)

2.622 m/s

Transit mid-time (BJD)

2,455,314.2627

Angular separation (arcsec)

1.50000

Eq. Temperature

350K

(77 °C)

Insolation (S⊕)

3.02

Earth = 1.00

Earth Similarity (ESI)

0.676

0 = alien, 1 = Earth-identical

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

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-139

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,594 K — cooler than the Sun (5,778 K)

Estimated Age

5.10 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.300 R☉

Stellar Mass

1.078 M☉

Metallicity [Fe/H]

0.35

Extended Stellar Properties

Surface gravity (log g)

4.247 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