Key parameters at a glance

A radius of 0.82 Earth radii
A mass of 0.48 Earth masses
Surface gravity around 0.71 g
An orbital period of 6.738 days
Semi-major axis 0.0650 AU
Equilibrium temperature 786 K (513 °C)
Distance from Earth 1,419.68 light-years
Earth Similarity Index 0.395
Travel time at Voyager 1 speed 25,036,092 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around Kepler-390

Kepler-390 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-390 b this	Rocky Terrestrial	0.82	0.48	6.738	786	2014
Kepler-390 c	Rocky Terrestrial	0.79	0.42	13.060	630	2014

Kepler-390 b Planet Profile

Physical Specs

Radius

0.82 R⊕

Radius (Jupiter)

0.073 R♃

Mass

0.48 M⊕

Mass (Jupiter)

0.002 M♃

Density

4.75 g/cm³

Surface Gravity

0.71 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.395

HZ Position Inner

Controversial No

Discovery

Year 2014

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#465of 570

top 81.4%

This planet

0.82R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-32 f 0.82 R⊕ Kepler-1446 b 0.82 R⊕ Kepler-106 b 0.82 R⊕

Metric	Earth	Kepler-390 b	Jupiter
Radius (R⊕)	1.00	0.82	11.21
Mass (M⊕)	1.00	0.48	317.83
Density (g/cm³)	5.51	4.75	1.33
Surface Gravity (g)	1.00	0.71	2.53
Insolation (S⊕)	1.00	99.97	0.037

Star Catalogue Identifiers

TIC

TIC 137340986

Gaia DR2

Gaia DR2 2101638759069485568

Gaia DR3

Gaia DR3 2101638759069485568

System

Kepler-390

Percentile among Rocky Terrestrial cohort

Radius 0.820 R⊕ · percentile 17 / cohort 570

Mass 0.477 M⊕ · percentile 15 / cohort 570

Orbital period 6.74 d · percentile 64 / cohort 567

Distance 435.28 pc · percentile 57 / cohort 566

ESI 0.395 · percentile 59 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

6.738 days

Semi-major axis

0.0650 AU

Eccentricity

0.000

Inclination

89.57 °

Year Length

A year here lasts approximately 6.74 Earth days (1.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0650 AU.

Transit Fingerprint

Depth

0.009 %

Duration

2.377 h

Impact parameter b

0.370

Rp / R★

0.009275

Transit midpoint (BJD)

2,454,966.3227

Photometric dip

Transit produces a flux drop of 93 ppm lasting ≈ 2.38 h.

Extended Orbital Architecture

Planet / star radius ratio

0.009275

Semi-major axis / stellar radius

21.280

Impact parameter (b)

0.370

Transit mid-time (BJD)

2,454,966.3227

Angular separation (arcsec)

0.14900

Eq. Temperature

786K

(513 °C)

Insolation (S⊕)

99.97

Earth = 1.00

Earth Similarity (ESI)

0.395

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-390

Spectral Class

K-type orange

Effective Temperature

5,166 K — cooler than the Sun (5,778 K)

Estimated Age

3.24 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.776 R☉

Stellar Mass

0.787 M☉

Metallicity [Fe/H]

-0.04

Extended Stellar Properties

Surface gravity (log g)

4.569 dex

Stellar density

1.500 g/cm³

Metallicity ratio

[M/H]

Distance

435.28 parsec

Light-years 1,419.68 ly

V-band magnitude

14.23 mag

Voyager-speed travel 25,036,092 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.269 mas

Total Proper Motion

52.293 mas/yr

PM Right Ascension

6.66 mas/yr

PM Declination

51.87 mas/yr

Galactic Cartesian (pc)

x = 0.277 · y = -0.699 · z = 0.659

Equatorial (J2000)

RA 291.62881° · Dec 41.20884°

Galactic ℓ, b

73.592° · 11.439°

Ecliptic λ, β

306.146° · 61.961°

HTM-20 index

-503663215