Key parameters at a glance

A radius of 4.13 Earth radii
A mass of 56.00 Earth masses
Surface gravity around 3.28 g
An orbital period of 98.353 days
Semi-major axis 0.4390 AU
Equilibrium temperature 552 K (279 °C)
Distance from Earth 3,383.54 light-years
Earth Similarity Index 0.428
Travel time at Voyager 1 speed 59,668,766 years

Context from the literature

Kepler-279 e is a gas giant exoplanet that orbits Kepler-279, an F-type star located at 3,383 light years from Earth, it takes 98.4 days to orbit its star. This planet is the farthest from its star in its planetary system, located at distance of 0.439 AU. It has mass of 0.1761957 Jupiter masses and radius approximately 0.36845456 of Jupiter; this planet was discovered in 2025.

Excerpted from Wikipedia · full article

3 siblings around Kepler-279

Kepler-279 e shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-279 b	Sub-Neptune	3.62	4,180.93	12.310	1,104	2014
Kepler-279 c	Neptune-like	4.30	49.40	35.736	774	2013
Kepler-279 d	Sub-Neptune	3.10	37.50	54.414	574	2013
Kepler-279 e this	Neptune-like	4.13	56.00	98.353	552	2025

Kepler-279 e Planet Profile

Physical Specs

Radius

4.13 R⊕

Radius (Jupiter)

0.368 R♃

Mass

56.00 M⊕

Mass (Jupiter)

0.176 M♃

Density

7.30 g/cm³

Surface Gravity

3.28 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.428

HZ Position Inner

Controversial No

Discovery

Year 2025

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#537of 574

top 93.4%

This planet

4.13R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-966 b 4.13 R⊕ HD 28109 c 4.13 R⊕ Kepler-697 b 4.13 R⊕

Metric	Earth	Kepler-279 e	Jupiter
Radius (R⊕)	1.00	4.13	11.21
Mass (M⊕)	1.00	56.00	317.83
Density (g/cm³)	5.51	7.30	1.33
Surface Gravity (g)	1.00	3.28	2.53
Insolation (S⊕)	1.00	21.96	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	56.000 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 158428960

Gaia DR2

Gaia DR2 2102456726998624640

Gaia DR3

Gaia DR3 2102456726998624640

System

Kepler-279

Percentile among Neptune-like cohort

Radius 4.130 R⊕ · percentile 6 / cohort 574

Mass 56.000 M⊕ · percentile 76 / cohort 574

Orbital period 98.35 d · percentile 81 / cohort 524

Distance 1,037.40 pc · percentile 76 / cohort 572

ESI 0.428 · percentile 78 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

98.353 days

Semi-major axis

0.4390 AU

Eccentricity

0.000

Inclination

86.40 °

Year Length

A year here lasts approximately 98.35 Earth days (26.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4390 AU.

Transit Fingerprint

Depth

0.042 %

Duration

24.708 h

Impact parameter b

0.910

Rp / R★

0.022300

Transit midpoint (BJD)

2,455,050.8830

Photometric dip

Transit produces a flux drop of 423 ppm lasting ≈ 24.71 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022300

Semi-major axis / stellar radius

14.400

Impact parameter (b)

0.910

Transit mid-time (BJD)

2,455,050.8830

Angular separation (arcsec)

0.42300

Eq. Temperature

552K

(279 °C)

Insolation (S⊕)

21.96

Earth = 1.00

Earth Similarity (ESI)

0.428

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Ofir et al. 2025

Instrument

Kepler CCD Array

Publication

2025-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2025 at Kepler (4 shown).

Kepler-289 e · Sub-Neptune Kepler-725 c · Sub-Neptune KOI-134 c · Neptune-like KOI-134 b · Gas Giant

Host System: Kepler-279

Spectral Class

F-type yellow-white

Effective Temperature

6,689 K — hotter than the Sun (5,778 K)

Estimated Age

0.22 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.430 R☉

Stellar Mass

1.164 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

4.120 dex

Stellar density

0.044 g/cm³

Metallicity ratio

[M/H]

Distance

1,037.40 parsec

Light-years 3,383.54 ly

V-band magnitude

13.65 mag

Voyager-speed travel 59,668,766 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.935 mas

Total Proper Motion

3.988 mas/yr

PM Right Ascension

3.99 mas/yr

PM Declination

0.14 mas/yr

Galactic Cartesian (pc)

x = 0.221 · y = -0.707 · z = 0.672

Equatorial (J2000)

RA 287.39130° · Dec 42.19482°

Galactic ℓ, b

73.147° · 14.724°

Ecliptic λ, β

300.130° · 63.826°

HTM-20 index

-2058739019

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