Key parameters at a glance

A radius of 5.30 Earth radii
A mass of 17.90 Earth masses
Surface gravity around 0.64 g
An orbital period of 88.505 days
Semi-major axis 0.3895 AU
Equilibrium temperature 390 K (117 °C)
Distance from Earth 729.80 light-years
Earth Similarity Index 0.421
Travel time at Voyager 1 speed 12,869,967 years

1 sibling around Kepler-396

Kepler-396 c 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-396 b	Sub-Neptune	3.50	75.50	42.994	496	2013
Kepler-396 c this	Neptune-like	5.30	17.90	88.505	390	2013

Kepler-396 c Planet Profile

Physical Specs

Radius

5.30 R⊕

Radius (Jupiter)

0.473 R♃

Mass

17.90 M⊕

Mass (Jupiter)

0.056 M♃

Density

0.66 g/cm³

Surface Gravity

0.64 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.421

HZ Position Inner

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#342of 574

top 59.4%

This planet

5.30R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

TOI-3568 b 5.30 R⊕ Kepler-31 c 5.30 R⊕ K2-32 b 5.30 R⊕

Metric	Earth	Kepler-396 c	Jupiter
Radius (R⊕)	1.00	5.30	11.21
Mass (M⊕)	1.00	17.90	317.83
Density (g/cm³)	5.51	0.66	1.33
Surface Gravity (g)	1.00	0.64	2.53
Insolation (S⊕)	1.00	5.24	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	17.900 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 27769688

Gaia DR2

Gaia DR2 2134847343119885440

Gaia DR3

Gaia DR3 2134847343121798528

System

Kepler-396

Percentile among Neptune-like cohort

Radius 5.300 R⊕ · percentile 40 / cohort 574

Mass 17.900 M⊕ · percentile 21 / cohort 574

Orbital period 88.51 d · percentile 80 / cohort 524

Distance 223.76 pc · percentile 41 / cohort 572

ESI 0.421 · percentile 77 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

88.505 days

Semi-major axis

0.3895 AU

Eccentricity

0.000

Inclination

90.00 °

Year Length

A year here lasts approximately 88.51 Earth days (24.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.3895 AU.

Transit Fingerprint

Depth

0.264 %

Duration

7.407 h

Impact parameter b

0.806

Rp / R★

0.052424

Transit midpoint (BJD)

2,455,015.6526

Photometric dip

Transit produces a flux drop of 2,636 ppm lasting ≈ 7.41 h.

Extended Orbital Architecture

Planet / star radius ratio

0.052424

Semi-major axis / stellar radius

96.100

Impact parameter (b)

0.806

Transit mid-time (BJD)

2,455,015.6526

Angular separation (arcsec)

1.74000

Eq. Temperature

390K

(117 °C)

Insolation (S⊕)

5.24

Earth = 1.00

Earth Similarity (ESI)

0.421

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.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Xie 2014

Instrument

Kepler CCD Array

Publication

2014-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: Kepler-396

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,656 K — cooler than the Sun (5,778 K)

Estimated Age

0.62 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.060 R☉

Stellar Mass

0.850 M☉

Metallicity [Fe/H]

0.16

Extended Stellar Properties

Surface gravity (log g)

4.320 dex

Stellar density

1.340 g/cm³

Metallicity ratio

[M/H]

Distance

223.76 parsec

Light-years 729.80 ly

V-band magnitude

12.26 mag

Voyager-speed travel 12,869,967 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

4.441 mas

Total Proper Motion

16.115 mas/yr

PM Right Ascension

2.46 mas/yr

PM Declination

-15.93 mas/yr

Galactic Cartesian (pc)

x = 0.289 · y = -0.589 · z = 0.754

Equatorial (J2000)

RA 296.13281° · Dec 48.97731°

Galactic ℓ, b

82.135° · 12.116°

Ecliptic λ, β

320.235° · 67.909°

HTM-20 index

1790813612