Key parameters at a glance

A radius of 2.50 Earth radii
A mass of 54.59 Earth masses
Surface gravity around 8.73 g
An orbital period of 100.283 days
Semi-major axis 0.4480 AU
Equilibrium temperature 475 K (202 °C)
Distance from Earth 774.30 light-years
Earth Similarity Index 0.422
Travel time at Voyager 1 speed 13,654,738 years

2 siblings around Kepler-126

Kepler-126 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-126 b	Super-Earth	1.52	4.12	10.496	1,009	2014
Kepler-126 c	Super-Earth	1.58	1.28	21.870	790	2014
Kepler-126 d this	Sub-Neptune	2.50	54.59	100.283	475	2014

Kepler-126 d Planet Profile

Physical Specs

Radius

2.50 R⊕

Radius (Jupiter)

0.223 R♃

Mass

54.59 M⊕

Mass (Jupiter)

0.172 M♃

Density

18.40 g/cm³

Surface Gravity

8.73 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.422

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

#1168of 1978

top 59.0%

This planet

2.50R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-254 d 2.50 R⊕ Kepler-298 d 2.50 R⊕ GJ 163 c 2.50 R⊕

Metric	Earth	Kepler-126 d	Jupiter
Radius (R⊕)	1.00	2.50	11.21
Mass (M⊕)	1.00	54.59	317.83
Density (g/cm³)	5.51	18.40	1.33
Surface Gravity (g)	1.00	8.73	2.53
Insolation (S⊕)	1.00	14.71	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	54.590 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 159046962

Gaia DR2

Gaia DR2 2126918008858627712

Gaia DR3

Gaia DR3 2126918008858627712

System

Kepler-126

Percentile among Sub-Neptune cohort

Radius 2.500 R⊕ · percentile 40 / cohort 1978

Mass 54.590 M⊕ · percentile 98 / cohort 1978

Orbital period 100.28 d · percentile 94 / cohort 1946

Distance 237.40 pc · percentile 31 / cohort 1975

ESI 0.422 · percentile 57 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

100.283 days

Semi-major axis

0.4480 AU

Eccentricity

0.020

Inclination

89.50 °

Year Length

A year here lasts approximately 100.28 Earth days (27.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4480 AU.

Transit Fingerprint

Depth

0.033 %

Duration

10.841 h

Impact parameter b

0.140

Rp / R★

0.020990

Transit midpoint (BJD)

2,455,078.0443

Photometric dip

Transit produces a flux drop of 329 ppm lasting ≈ 10.84 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020990

Semi-major axis / stellar radius

37.660

Impact parameter (b)

0.140

RV semi-amplitude (K)

7.017 m/s

Transit mid-time (BJD)

2,455,078.0443

Angular separation (arcsec)

1.89000

Eq. Temperature

475K

(202 °C)

Insolation (S⊕)

14.71

Earth = 1.00

Earth Similarity (ESI)

0.422

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.

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-126

Spectral Class

F-type yellow-white

Effective Temperature

6,239 K — hotter than the Sun (5,778 K)

Estimated Age

3.39 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.358 R☉

Stellar Mass

1.108 M☉

Metallicity [Fe/H]

-0.16

Extended Stellar Properties

Surface gravity (log g)

4.247 dex

Stellar density

0.400 g/cm³

Systemic radial velocity

-20.74 km/s

Metallicity ratio

[Fe/H]

Distance

237.40 parsec

Light-years 774.30 ly

V-band magnitude

10.51 mag

Voyager-speed travel 13,654,738 yr

Multi-band Host Photometry — 14 bands

Astrometric Data

Parallax

4.184 mas

Total Proper Motion

23.048 mas/yr

PM Right Ascension

11.48 mas/yr

PM Declination

-19.99 mas/yr

Galactic Cartesian (pc)

x = 0.237 · y = -0.676 · z = 0.697

Equatorial (J2000)

RA 289.34736° · Dec 44.20844°

Galactic ℓ, b

75.644° · 14.233°

Ecliptic λ, β

304.680° · 65.335°

HTM-20 index

141292535