Key parameters at a glance

A radius of 8.37 Earth radii
A mass of 308.30 Earth masses
Surface gravity around 4.40 g
An orbital period of 125.632 days
Semi-major axis 0.4988 AU
Equilibrium temperature 388 K (114 °C)
Distance from Earth 1,002.34 light-years
Earth Similarity Index 0.466
Travel time at Voyager 1 speed 17,676,196 years

1 sibling around Kepler-539

Kepler-539 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-539 b this	Neptune-like	8.37	308.30	125.632	388	2016
Kepler-539 c	Gas Giant	13.30	762.79	1,000.000	253	2016

Kepler-539 b Planet Profile

Physical Specs

Radius

8.37 R⊕

Radius (Jupiter)

0.747 R♃

Mass

308.30 M⊕

Mass (Jupiter)

0.970 M♃

Density

2.90 g/cm³

Surface Gravity

4.40 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.466

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

#132of 574

top 22.8%

This planet

8.37R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

K2-127 b 8.37 R⊕ BD-06 1339 c 8.38 R⊕ OGLE-2012-BLG-0838L b 8.39 R⊕

Metric	Earth	Kepler-539 b	Jupiter
Radius (R⊕)	1.00	8.37	11.21
Mass (M⊕)	1.00	308.30	317.83
Density (g/cm³)	5.51	2.90	1.33
Surface Gravity (g)	1.00	4.40	2.53
Insolation (S⊕)	1.00	3.68	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	308.295 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 171510762

Gaia DR2

Gaia DR2 2075377679763353984

Gaia DR3

Gaia DR3 2075377679763353984

System

Kepler-539

Percentile among Neptune-like cohort

Radius 8.373 R⊕ · percentile 77 / cohort 574

Mass 308.295 M⊕ · percentile 96 / cohort 574

Orbital period 125.63 d · percentile 84 / cohort 524

Distance 307.32 pc · percentile 48 / cohort 572

ESI 0.466 · percentile 84 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

125.632 days

Semi-major axis

0.4988 AU

Eccentricity

0.390

Inclination

89.85 °

Year Length

A year here lasts approximately 125.63 Earth days (34.4% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.4988 AU.

Transit Fingerprint

Depth

0.805 %

Duration

9.299 h

Impact parameter b

0.017

Rp / R★

0.081664

Transit midpoint (BJD)

2,455,588.8710

Photometric dip

Transit produces a flux drop of 8,046 ppm lasting ≈ 9.30 h.

Extended Orbital Architecture

Planet / star radius ratio

0.081664

Semi-major axis / stellar radius

94.607

Impact parameter (b)

0.017

RV semi-amplitude (K)

132.300 m/s

Transit mid-time (BJD)

2,455,588.8710

Angular separation (arcsec)

1.62000

Eq. Temperature

388K

(114 °C)

Insolation (S⊕)

3.68

Earth = 1.00

Earth Similarity (ESI)

0.466

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.

Radial velocity

Stellar wobble has been measured spectroscopically.

Transit timing variations

Gravitational interactions from neighbours have been detected.

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-539

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,820 K — hotter than the Sun (5,778 K)

Estimated Age

0.91 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.952 R☉

Stellar Mass

1.048 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.502 dex

Stellar density

1.713 g/cm³

Systemic radial velocity

9.96 km/s

Rotational v·sin i

4.40 km/s

Rotation period

11.77 days

Metallicity ratio

[Fe/H]

Distance

307.32 parsec

Light-years 1,002.34 ly

V-band magnitude

12.44 mag

Voyager-speed travel 17,676,196 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

3.226 mas

Total Proper Motion

9.816 mas/yr

PM Right Ascension

2.97 mas/yr

PM Declination

9.36 mas/yr

Galactic Cartesian (pc)

x = 0.362 · y = -0.651 · z = 0.667

Equatorial (J2000)

RA 299.12246° · Dec 41.86680°

Galactic ℓ, b

76.878° · 6.818°

Ecliptic λ, β

317.557° · 60.587°

HTM-20 index

-332080675