Key parameters at a glance

A radius of 12.60 Earth radii
A mass of 2,637.98 Earth masses
Surface gravity around 16.62 g
An orbital period of 2,646.000 days
Semi-major axis 4.0000 AU
Distance from Earth 1,333.47 light-years
Earth Similarity Index 0.409
Travel time at Voyager 1 speed 23,515,786 years

2 siblings around Kepler-129

Kepler-129 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-129 b	Sub-Neptune	2.40	20.00	15.790	910	2014
Kepler-129 c	Sub-Neptune	2.52	43.00	82.200	525	2014
Kepler-129 d this	Gas Giant	12.60	2,637.98	2,646.000	—	2021

Kepler-129 d Planet Profile

Physical Specs

Radius

12.60 R⊕

Radius (Jupiter)

1.120 R♃

Mass

2,637.98 M⊕

Mass (Jupiter)

8.300 M♃

Density

7.25 g/cm³

Surface Gravity

16.62 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.409

HZ Position Unknown

Controversial No

Discovery

Year 2021

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#1179of 1771

top 66.5%

This planet

12.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Kepler-419 c 12.60 R⊕ 2MASS J04414489+2301513 b 12.60 R⊕ HD 47536 b 12.60 R⊕

Metric	Earth	Kepler-129 d	Jupiter
Radius (R⊕)	1.00	12.60	11.21
Mass (M⊕)	1.00	2,637.98	317.83
Density (g/cm³)	5.51	7.25	1.33
Surface Gravity (g)	1.00	16.62	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	2,637.976 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 164999822

Gaia DR2

Gaia DR2 2131494313689868416

Gaia DR3

Gaia DR3 2131494313689868416

System

Kepler-129

Percentile among Gas Giant cohort

Radius 12.600 R⊕ · percentile 31 / cohort 1771

Mass 2,637.976 M⊕ · percentile 84 / cohort 1747

Orbital period 2,646.00 d · percentile 88 / cohort 1533

Distance 408.85 pc · percentile 70 / cohort 1759

ESI 0.409 · percentile 88 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

2,646.000 days

Semi-major axis

4.0000 AU

Eccentricity

0.150

Inclination

— °

Year Length

A year here lasts about 7.24 Earth years on a mildly elliptical path at a mean orbital distance of 4.0000 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.409

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Zhang et al. 2021

Instrument

HIRES Spectrometer

Publication

2021-09

Observation locale

Ground

Discovery cohort

Planets confirmed in 2021 at W. M. Keck Observatory (2 shown).

GJ 414 A b · Sub-Neptune GJ 414 A c · Neptune-like

Host System: Kepler-129

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,770 K — cooler than the Sun (5,778 K)

Estimated Age

6.43 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.653 R☉

Stellar Mass

1.178 M☉

Metallicity [Fe/H]

0.29

Extended Stellar Properties

Surface gravity (log g)

4.080 dex

Stellar density

0.280 g/cm³

Systemic radial velocity

-20.21 km/s

Rotational v·sin i

2.13 km/s

Metallicity ratio

[Fe/H]

Distance

408.85 parsec

Light-years 1,333.47 ly

V-band magnitude

11.81 mag

Voyager-speed travel 23,515,786 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

2.417 mas

Total Proper Motion

27.975 mas/yr

PM Right Ascension

-13.26 mas/yr

PM Declination

-24.63 mas/yr

Galactic Cartesian (pc)

x = 0.177 · y = -0.647 · z = 0.741

Equatorial (J2000)

RA 285.31118° · Dec 47.84848°

Galactic ℓ, b

78.035° · 18.210°

Ecliptic λ, β

300.654° · 69.663°

HTM-20 index

-86559688