Key parameters at a glance

A radius of 4.00 Earth radii
A mass of 24.47 Earth masses
Surface gravity around 1.53 g
An orbital period of 3.213 days
Semi-major axis 0.0456 AU
Equilibrium temperature 1,650 K (1377 °C)
Distance from Earth 1,591.37 light-years
Earth Similarity Index 0.123
Travel time at Voyager 1 speed 28,063,761 years

Kepler-4 b Planet Profile

Physical Specs

Radius

4.00 R⊕

Radius (Jupiter)

0.357 R♃

Mass

24.47 M⊕

Mass (Jupiter)

0.077 M♃

Density

1.91 g/cm³

Surface Gravity

1.53 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.123

HZ Position Inner

Controversial No

Discovery

Year 2009

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#569of 574

top 99.0%

This planet

4.00R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-647 c 4.00 R⊕ HD 177565 b 4.00 R⊕ Kepler-462 c 4.00 R⊕

Metric	Earth	Kepler-4 b	Jupiter
Radius (R⊕)	1.00	4.00	11.21
Mass (M⊕)	1.00	24.47	317.83
Density (g/cm³)	5.51	1.91	1.33
Surface Gravity (g)	1.00	1.53	2.53
Insolation (S⊕)	1.00	1,245.43	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	24.472 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 350814622

Gaia DR2

Gaia DR2 2132152916856093952

Gaia DR3

Gaia DR3 2132152916856093952

System

Kepler-4

Percentile among Neptune-like cohort

Radius 4.002 R⊕ · percentile 1 / cohort 574

Mass 24.472 M⊕ · percentile 41 / cohort 574

Orbital period 3.21 d · percentile 5 / cohort 524

Distance 487.92 pc · percentile 56 / cohort 572

ESI 0.123 · percentile 6 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

3.213 days

Semi-major axis

0.0456 AU

Eccentricity

0.000

Inclination

89.76 °

Year Length

A year here lasts approximately 3.21 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0456 AU.

Transit Fingerprint

Depth

0.087 %

Duration

3.982 h

Impact parameter b

0.022

Rp / R★

0.024700

Transit midpoint (BJD)

2,454,956.6127

Photometric dip

Transit produces a flux drop of 870 ppm lasting ≈ 3.98 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024700

Semi-major axis / stellar radius

6.470

Impact parameter (b)

0.022

RV semi-amplitude (K)

9.300 m/s

Transit mid-time (BJD)

2,454,956.6127

Angular separation (arcsec)

0.09350

Eq. Temperature

1,650K

(1377 °C)

Insolation (S⊕)

1,245.43

Earth = 1.00

Earth Similarity (ESI)

0.123

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.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Borucki et al. 2010

Instrument

Kepler CCD Array

Publication

2010-04

Observation locale

Space

Discovery cohort

Planets confirmed in 2009 at Kepler (3 shown).

Kepler-6 b · Gas Giant Kepler-5 b · Gas Giant Kepler-7 b · Gas Giant

Host System: Kepler-4

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,857 K — hotter than the Sun (5,778 K)

Estimated Age

4.50 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.487 R☉

Stellar Mass

1.223 M☉

Metallicity [Fe/H]

0.17

Extended Stellar Properties

Surface gravity (log g)

4.170 dex

Stellar density

0.467 g/cm³

Systemic radial velocity

-61.00 km/s

Rotational v·sin i

2.20 km/s

Metallicity ratio

[Fe/H]

Distance

487.92 parsec

Light-years 1,591.37 ly

V-band magnitude

12.29 mag

Voyager-speed travel 28,063,761 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.021 mas

Total Proper Motion

7.606 mas/yr

PM Right Ascension

6.00 mas/yr

PM Declination

4.67 mas/yr

Galactic Cartesian (pc)

x = 0.173 · y = -0.617 · z = 0.768

Equatorial (J2000)

RA 285.61545° · Dec 50.13577°

Galactic ℓ, b

80.370° · 18.818°

Ecliptic λ, β

303.458° · 71.765°

HTM-20 index

287035939