Key parameters at a glance

A radius of 1.64 Earth radii
A mass of 2.56 Earth masses
Surface gravity around 0.95 g
An orbital period of 7.100 days
Semi-major axis 0.0721 AU
Equilibrium temperature 1,157 K (884 °C)
Distance from Earth 2,725.87 light-years
Earth Similarity Index 0.240
Travel time at Voyager 1 speed 48,070,685 years

2 siblings around Kepler-23

Kepler-23 b 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-23 b this	Super-Earth	1.64	2.56	7.100	1,157	2011
Kepler-23 c	Sub-Neptune	3.01	7.81	10.740	1,008	2011
Kepler-23 d	Sub-Neptune	2.21	4.44	15.270	896	2014

Kepler-23 b Planet Profile

Physical Specs

Radius

1.64 R⊕

Radius (Jupiter)

0.146 R♃

Mass

2.56 M⊕

Mass (Jupiter)

0.008 M♃

Density

3.19 g/cm³

Surface Gravity

0.95 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.240

HZ Position Inner

Controversial No

Discovery

Year 2011

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#516of 1176

top 43.8%

This planet

1.64R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-21 b 1.64 R⊕ Kepler-179 b 1.64 R⊕ Kepler-247 b 1.64 R⊕

Metric	Earth	Kepler-23 b	Jupiter
Radius (R⊕)	1.00	1.64	11.21
Mass (M⊕)	1.00	2.56	317.83
Density (g/cm³)	5.51	3.19	1.33
Surface Gravity (g)	1.00	0.95	2.53
Insolation (S⊕)	1.00	446.11	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2.560 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 27083727

Gaia DR2

Gaia DR2 2135019107451751168

Gaia DR3

Gaia DR3 2135019107451751168

System

Kepler-23

Percentile among Super-Earth cohort

Radius 1.638 R⊕ · percentile 56 / cohort 1176

Mass 2.560 M⊕ · percentile 21 / cohort 1176

Orbital period 7.10 d · percentile 53 / cohort 1164

Distance 835.76 pc · percentile 70 / cohort 1171

ESI 0.240 · percentile 21 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

7.100 days

Semi-major axis

0.0721 AU

Eccentricity

0.017

Inclination

89.57 °

Year Length

A year here lasts approximately 7.10 Earth days (1.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0721 AU.

Transit Fingerprint

Depth

0.013 %

Duration

5.146 h

Impact parameter b

0.072

Rp / R★

0.010390

Transit midpoint (BJD)

2,454,971.3227

Photometric dip

Transit produces a flux drop of 131 ppm lasting ≈ 5.15 h.

Extended Orbital Architecture

Planet / star radius ratio

0.010390

Semi-major axis / stellar radius

10.643

Impact parameter (b)

0.072

Transit mid-time (BJD)

2,454,971.3227

Angular separation (arcsec)

0.08630

Eq. Temperature

1,157K

(884 °C)

Insolation (S⊕)

446.11

Earth = 1.00

Earth Similarity (ESI)

0.240

0 = alien, 1 = Earth-identical

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

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

Ford et al. 2012

Instrument

Kepler CCD Array

Publication

2012-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2011 at Kepler (12 shown).

Kepler-22 b · Sub-Neptune Kepler-20 d · Sub-Neptune Kepler-26 c · Sub-Neptune Kepler-19 c · Sub-Neptune Kepler-26 b · Sub-Neptune Kepler-28 c · Super-Earth Kepler-10 c · Sub-Neptune Kepler-20 f · Rocky Terrestrial Kepler-42 d · Rocky Terrestrial Kepler-16 b · Neptune-like Kepler-28 b · Super-Earth Kepler-34 b · Neptune-like

Host System: Kepler-23

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,828 K — hotter than the Sun (5,778 K)

Estimated Age

9.12 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.548 R☉

Stellar Mass

1.078 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

4.090 dex

Stellar density

0.410 g/cm³

Metallicity ratio

[M/H]

Distance

835.76 parsec

Light-years 2,725.87 ly

V-band magnitude

13.57 mag

Voyager-speed travel 48,070,685 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.168 mas

Total Proper Motion

4.466 mas/yr

PM Right Ascension

2.26 mas/yr

PM Declination

3.85 mas/yr

Galactic Cartesian (pc)

x = 0.267 · y = -0.593 · z = 0.760

Equatorial (J2000)

RA 294.21891° · Dec 49.47925°

Galactic ℓ, b

82.014° · 13.458°

Ecliptic λ, β

317.845° · 68.930°

HTM-20 index

275671563