Key parameters at a glance

A radius of 1.67 Earth radii
A mass of 3.43 Earth masses
Surface gravity around 1.23 g
An orbital period of 4.339 days
Semi-major axis 0.0497 AU
Equilibrium temperature 1,061 K (788 °C)
Distance from Earth 2,297.19 light-years
Earth Similarity Index 0.271
Travel time at Voyager 1 speed 40,510,974 years

Kepler-1123 b Planet Profile

Physical Specs

Radius

1.67 R⊕

Radius (Jupiter)

0.149 R♃

Mass

3.43 M⊕

Mass (Jupiter)

0.011 M♃

Density

4.05 g/cm³

Surface Gravity

1.23 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.271

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#452of 1176

top 38.4%

This planet

1.67R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

HD 3167 b 1.67 R⊕ Kepler-24 d 1.67 R⊕ Kepler-288 b 1.67 R⊕

Metric	Earth	Kepler-1123 b	Jupiter
Radius (R⊕)	1.00	1.67	11.21
Mass (M⊕)	1.00	3.43	317.83
Density (g/cm³)	5.51	4.05	1.33
Surface Gravity (g)	1.00	1.23	2.53
Insolation (S⊕)	1.00	190.02	0.037

Star Catalogue Identifiers

TIC

TIC 27188610

Gaia DR2

Gaia DR2 2135239112857020032

Gaia DR3

Gaia DR3 2135239112857020032

System

Kepler-1123

Percentile among Super-Earth cohort

Radius 1.670 R⊕ · percentile 61 / cohort 1176

Mass 3.430 M⊕ · percentile 55 / cohort 1176

Orbital period 4.34 d · percentile 35 / cohort 1164

Distance 704.32 pc · percentile 61 / cohort 1171

ESI 0.271 · percentile 29 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

4.339 days

Semi-major axis

0.0497 AU

Eccentricity

0.000

Inclination

84.46 °

Year Length

A year here lasts approximately 4.34 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0497 AU.

Transit Fingerprint

Depth

0.034 %

Duration

2.297 h

Impact parameter b

0.006

Rp / R★

0.017319

Transit midpoint (BJD)

2,454,965.8025

Photometric dip

Transit produces a flux drop of 337 ppm lasting ≈ 2.30 h.

Extended Orbital Architecture

Planet / star radius ratio

0.017319

Semi-major axis / stellar radius

14.690

Impact parameter (b)

0.006

Transit mid-time (BJD)

2,454,965.8025

Angular separation (arcsec)

0.07060

Eq. Temperature

1,061K

(788 °C)

Insolation (S⊕)

190.02

Earth = 1.00

Earth Similarity (ESI)

0.271

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1123

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,500 K — cooler than the Sun (5,778 K)

Estimated Age

5.13 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.900 R☉

Stellar Mass

0.930 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.500 dex

Stellar density

3.186 g/cm³

Metallicity ratio

[Fe/H]

Distance

704.32 parsec

Light-years 2,297.19 ly

V-band magnitude

14.93 mag

Voyager-speed travel 40,510,974 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.391 mas

Total Proper Motion

9.365 mas/yr

PM Right Ascension

9.36 mas/yr

PM Declination

0.29 mas/yr

Galactic Cartesian (pc)

x = 0.263 · y = -0.577 · z = 0.774

Equatorial (J2000)

RA 294.51773° · Dec 50.67039°

Galactic ℓ, b

83.201° · 13.811°

Ecliptic λ, β

319.909° · 69.894°

HTM-20 index

393017529