Key parameters at a glance

A radius of 1.99 Earth radii
A mass of 4.62 Earth masses
Surface gravity around 1.17 g
An orbital period of 15.874 days
Semi-major axis 0.1125 AU
Equilibrium temperature 632 K (359 °C)
Distance from Earth 1,473.55 light-years
Earth Similarity Index 0.435
Travel time at Voyager 1 speed 25,986,110 years

Kepler-646 b Planet Profile

Physical Specs

Radius

1.99 R⊕

Radius (Jupiter)

0.178 R♃

Mass

4.62 M⊕

Mass (Jupiter)

0.015 M♃

Density

3.22 g/cm³

Surface Gravity

1.17 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.435

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

#4of 1176

top 0.3%

This planet

1.99R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-62 c 1.99 R⊕ Kepler-136 c 1.99 R⊕ Kepler-243 c 1.99 R⊕

Metric	Earth	Kepler-646 b	Jupiter
Radius (R⊕)	1.00	1.99	11.21
Mass (M⊕)	1.00	4.62	317.83
Density (g/cm³)	5.51	3.22	1.33
Surface Gravity (g)	1.00	1.17	2.53
Insolation (S⊕)	1.00	38.23	0.037

Star Catalogue Identifiers

TIC

TIC 159441621

Gaia DR2

Gaia DR2 2126970579257130112

Gaia DR3

Gaia DR3 2126970579257130112

System

Kepler-646

Percentile among Super-Earth cohort

Radius 1.990 R⊕ · percentile 98 / cohort 1176

Mass 4.620 M⊕ · percentile 90 / cohort 1176

Orbital period 15.87 d · percentile 79 / cohort 1164

Distance 451.79 pc · percentile 44 / cohort 1171

ESI 0.435 · percentile 66 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

15.874 days

Semi-major axis

0.1125 AU

Eccentricity

0.000

Inclination

89.30 °

Year Length

A year here lasts approximately 15.87 Earth days (4.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1125 AU.

Transit Fingerprint

Depth

0.042 %

Duration

3.612 h

Impact parameter b

0.395

Rp / R★

0.019945

Transit midpoint (BJD)

2,455,015.4013

Photometric dip

Transit produces a flux drop of 416 ppm lasting ≈ 3.61 h.

Extended Orbital Architecture

Planet / star radius ratio

0.019945

Semi-major axis / stellar radius

32.300

Impact parameter (b)

0.395

Transit mid-time (BJD)

2,455,015.4013

Angular separation (arcsec)

0.24900

Eq. Temperature

632K

(359 °C)

Insolation (S⊕)

38.23

Earth = 1.00

Earth Similarity (ESI)

0.435

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-646

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,634 K — cooler than the Sun (5,778 K)

Estimated Age

4.57 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.910 R☉

Stellar Mass

0.930 M☉

Metallicity [Fe/H]

-0.07

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

1.420 g/cm³

Metallicity ratio

[Fe/H]

Distance

451.79 parsec

Light-years 1,473.55 ly

V-band magnitude

14.03 mag

Voyager-speed travel 25,986,110 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.185 mas

Total Proper Motion

21.311 mas/yr

PM Right Ascension

20.91 mas/yr

PM Declination

-4.10 mas/yr

Galactic Cartesian (pc)

x = 0.250 · y = -0.669 · z = 0.700

Equatorial (J2000)

RA 290.47146° · Dec 44.38704°

Galactic ℓ, b

76.155° · 13.575°

Ecliptic λ, β

306.639° · 65.243°

HTM-20 index

661395116