Key parameters at a glance

A radius of 1.23 Earth radii
A mass of 2.04 Earth masses
Surface gravity around 1.35 g
An orbital period of 4.486 days
Semi-major axis 0.0295 AU
Equilibrium temperature 365 K (92 °C)
Distance from Earth 416.15 light-years
Earth Similarity Index 0.798
Travel time at Voyager 1 speed 7,338,729 years
Almost certainly tidally locked to its host star given the close orbit

Kepler-1646 b Planet Profile

Physical Specs

Radius

1.23 R⊕

Radius (Jupiter)

0.110 R♃

Mass

2.04 M⊕

Mass (Jupiter)

0.006 M♃

Density

6.02 g/cm³

Surface Gravity

1.35 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.798

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

#17of 570

top 2.8%

This planet

1.23R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-252 b 1.23 R⊕ Kepler-271 b 1.23 R⊕ Kepler-197 c 1.23 R⊕

Metric	Earth	Kepler-1646 b	Jupiter
Radius (R⊕)	1.00	1.23	11.21
Mass (M⊕)	1.00	2.04	317.83
Density (g/cm³)	5.51	6.02	1.33
Surface Gravity (g)	1.00	1.35	2.53
Insolation (S⊕)	1.00	4.20	0.037

Star Catalogue Identifiers

TIC

TIC 158552258

Gaia DR2

Gaia DR2 2102601381497162240

Gaia DR3

Gaia DR3 2102601381497162240

System

Kepler-1646

Percentile among Rocky Terrestrial cohort

Radius 1.230 R⊕ · percentile 94 / cohort 570

Mass 2.040 M⊕ · percentile 86 / cohort 570

Orbital period 4.49 d · percentile 50 / cohort 567

Distance 127.59 pc · percentile 26 / cohort 566

ESI 0.798 · percentile 87 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

4.486 days

Semi-major axis

0.0295 AU

Eccentricity

0.000

Inclination

89.36 °

Year Length

A year here lasts approximately 4.49 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0295 AU.

Transit Fingerprint

Depth

0.227 %

Duration

0.821 h

Impact parameter b

0.376

Rp / R★

0.044393

Transit midpoint (BJD)

2,454,968.4322

Photometric dip

Transit produces a flux drop of 2,265 ppm lasting ≈ 0.82 h.

Extended Orbital Architecture

Planet / star radius ratio

0.044393

Semi-major axis / stellar radius

39.800

Impact parameter (b)

0.376

Transit mid-time (BJD)

2,454,968.4322

Angular separation (arcsec)

0.23100

Eq. Temperature

365K

(92 °C)

Insolation (S⊕)

4.20

Earth = 1.00

Earth Similarity (ESI)

0.798

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure. Close-orbiting tidally-locked around a cool host.

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-1646

Spectral Class

M-type red dwarf

Effective Temperature

3,299 K — cooler than the Sun (5,778 K)

Estimated Age

4.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.260 R☉

Stellar Mass

0.240 M☉

Metallicity [Fe/H]

0.04

Extended Stellar Properties

Surface gravity (log g)

5.010 dex

Stellar density

9.785 g/cm³

Metallicity ratio

[Fe/H]

Distance

127.59 parsec

Light-years 416.15 ly

V-band magnitude

16.84 mag

Voyager-speed travel 7,338,729 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

7.809 mas

Total Proper Motion

17.815 mas/yr

PM Right Ascension

14.54 mas/yr

PM Declination

10.30 mas/yr

Galactic Cartesian (pc)

x = 0.221 · y = -0.698 · z = 0.681

Equatorial (J2000)

RA 287.52649° · Dec 42.91294°

Galactic ℓ, b

73.870° · 14.918°

Ecliptic λ, β

300.801° · 64.489°

HTM-20 index

-2096742090