Key parameters at a glance

A radius of 2.25 Earth radii
A mass of 5.69 Earth masses
Surface gravity around 1.12 g
An orbital period of 25.384 days
Semi-major axis 0.1728 AU
Equilibrium temperature 649 K (376 °C)
Distance from Earth 3,904.22 light-years
Earth Similarity Index 0.405
Travel time at Voyager 1 speed 68,850,877 years

Kepler-1381 b Planet Profile

Physical Specs

Radius

2.25 R⊕

Radius (Jupiter)

0.201 R♃

Mass

5.69 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.74 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.405

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

#1589of 1978

top 80.3%

This planet

2.25R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-300 c 2.25 R⊕ GJ 667 C b 2.25 R⊕ Kepler-342 b 2.25 R⊕

Metric	Earth	Kepler-1381 b	Jupiter
Radius (R⊕)	1.00	2.25	11.21
Mass (M⊕)	1.00	5.69	317.83
Density (g/cm³)	5.51	2.74	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	29.70	0.037

Star Catalogue Identifiers

TIC

TIC 399953616

Gaia DR2

Gaia DR2 2131228815991876736

Gaia DR3

Gaia DR3 2131228815991876736

System

Kepler-1381

Percentile among Sub-Neptune cohort

Radius 2.250 R⊕ · percentile 19 / cohort 1978

Mass 5.690 M⊕ · percentile 19 / cohort 1978

Orbital period 25.38 d · percentile 69 / cohort 1946

Distance 1,197.04 pc · percentile 86 / cohort 1975

ESI 0.405 · percentile 53 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

25.384 days

Semi-major axis

0.1728 AU

Eccentricity

0.000

Inclination

89.74 °

Year Length

A year here lasts approximately 25.38 Earth days (6.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1728 AU.

Transit Fingerprint

Depth

0.059 %

Duration

3.638 h

Impact parameter b

0.123

Rp / R★

0.022195

Transit midpoint (BJD)

2,454,970.7734

Photometric dip

Transit produces a flux drop of 585 ppm lasting ≈ 3.64 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022195

Semi-major axis / stellar radius

53.840

Impact parameter (b)

0.123

Transit mid-time (BJD)

2,454,970.7734

Angular separation (arcsec)

0.14400

Eq. Temperature

649K

(376 °C)

Insolation (S⊕)

29.70

Earth = 1.00

Earth Similarity (ESI)

0.405

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

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-1381

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,747 K — cooler than the Sun (5,778 K)

Estimated Age

4.07 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.940 R☉

Stellar Mass

0.960 M☉

Metallicity [Fe/H]

-0.10

Extended Stellar Properties

Surface gravity (log g)

4.480 dex

Stellar density

4.582 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,197.04 parsec

Light-years 3,904.22 ly

V-band magnitude

15.58 mag

Voyager-speed travel 68,850,877 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.807 mas

Total Proper Motion

1.221 mas/yr

PM Right Ascension

0.35 mas/yr

PM Declination

-1.17 mas/yr

Galactic Cartesian (pc)

x = 0.199 · y = -0.629 · z = 0.752

Equatorial (J2000)

RA 287.53579° · Dec 48.72778°

Galactic ℓ, b

79.458° · 17.148°

Ecliptic λ, β

305.547° · 70.011°

HTM-20 index

692041576