Key parameters at a glance

A radius of 1.70 Earth radii
A mass of 2.00 Earth masses
Surface gravity around 0.70 g
An orbital period of 7.306 days
Semi-major axis 0.0756 AU
Equilibrium temperature 972 K (699 °C)
Distance from Earth 1,275.39 light-years
Earth Similarity Index 0.317
Travel time at Voyager 1 speed 22,491,570 years

4 siblings around Kepler-139

Kepler-139 d 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 this	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	Neptune-like	6.67	36.00	355.000	—	2025
Kepler-139 e	Gas Giant	13.70	378.00	2,047.635	—	2023

Kepler-139 d Planet Profile

Physical Specs

Radius

1.70 R⊕

Radius (Jupiter)

0.151 R♃

Mass

2.00 M⊕

Mass (Jupiter)

0.006 M♃

Density

5.27 g/cm³

Surface Gravity

0.70 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.317

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#412of 1176

top 34.9%

This planet

1.70R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-377 b 1.69 R⊕ K2-394 b 1.69 R⊕ Kepler-372 d 1.69 R⊕

Metric	Earth	Kepler-139 d	Jupiter
Radius (R⊕)	1.00	1.70	11.21
Mass (M⊕)	1.00	2.00	317.83
Density (g/cm³)	5.51	5.27	1.33
Surface Gravity (g)	1.00	0.70	2.53
Insolation (S⊕)	1.00	172.30	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2.000 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	4.658 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 Super-Earth cohort

Radius 1.695 R⊕ · percentile 65 / cohort 1176

Mass 2.000 M⊕ · percentile 1 / cohort 1176

Orbital period 7.31 d · percentile 54 / cohort 1164

Distance 391.04 pc · percentile 39 / cohort 1171

ESI 0.317 · percentile 41 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

7.306 days

Semi-major axis

0.0756 AU

Eccentricity

0.000

Inclination

87.97 °

Year Length

A year here lasts approximately 7.31 Earth days (2.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0756 AU.

Transit Fingerprint

Depth

0.026 %

Duration

1.423 h

Impact parameter b

0.932

Rp / R★

0.014849

Transit midpoint (BJD)

2,454,964.7791

Photometric dip

Transit produces a flux drop of 265 ppm lasting ≈ 1.42 h.

Extended Orbital Architecture

Planet / star radius ratio

0.014849

Semi-major axis / stellar radius

14.600

Impact parameter (b)

0.932

RV semi-amplitude (K)

1.460 m/s

Transit mid-time (BJD)

2,454,964.7791

Angular separation (arcsec)

0.19300

Eq. Temperature

972K

(699 °C)

Insolation (S⊕)

172.30

Earth = 1.00

Earth Similarity (ESI)

0.317

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Detection Signatures

Transit photometry

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

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Weiss et al. 2024

Instrument

Kepler CCD Array

Publication

2024-01

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Kepler (12 shown).

Kepler-1126 c · Super-Earth Kepler-2000 c · Super-Earth Kepler-1052 c · Sub-Neptune Kepler-311 d · Sub-Neptune Kepler-1996 c · Sub-Neptune Kepler-1162 c · Super-Earth Kepler-1996 b · Sub-Neptune Kepler-1610 c · Sub-Neptune Kepler-1801 c · Sub-Neptune Kepler-1995 b · Neptune-like Kepler-1992 b · Rocky Terrestrial Kepler-1986 b · Super-Earth

Host System: Kepler-139

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,622 K — cooler than the Sun (5,778 K)

Estimated Age

5.10 Gyr — older 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