Key parameters at a glance

A radius of 2.89 Earth radii
A mass of 8.70 Earth masses
Surface gravity around 1.04 g
An orbital period of 22.367 days
Semi-major axis 0.1449 AU
Equilibrium temperature 536 K (263 °C)
Distance from Earth 3,691.21 light-years
Earth Similarity Index 0.441
Travel time at Voyager 1 speed 65,094,402 years

Kepler-689 b Planet Profile

Physical Specs

Radius

2.89 R⊕

Radius (Jupiter)

0.258 R♃

Mass

8.70 M⊕

Mass (Jupiter)

0.027 M♃

Density

1.98 g/cm³

Surface Gravity

1.04 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.441

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

#640of 1978

top 32.3%

This planet

2.89R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-781 b 2.89 R⊕ K2-70 b 2.89 R⊕ Kepler-53 b 2.89 R⊕

Metric	Earth	Kepler-689 b	Jupiter
Radius (R⊕)	1.00	2.89	11.21
Mass (M⊕)	1.00	8.70	317.83
Density (g/cm³)	5.51	1.98	1.33
Surface Gravity (g)	1.00	1.04	2.53
Insolation (S⊕)	1.00	35.34	0.037

Star Catalogue Identifiers

TIC

TIC 378086390

Gaia DR2

Gaia DR2 2076253887449048320

Gaia DR3

Gaia DR3 2076253887449048320

System

Kepler-689

Percentile among Sub-Neptune cohort

Radius 2.890 R⊕ · percentile 67 / cohort 1978

Mass 8.700 M⊕ · percentile 61 / cohort 1978

Orbital period 22.37 d · percentile 66 / cohort 1946

Distance 1,131.73 pc · percentile 84 / cohort 1975

ESI 0.441 · percentile 61 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

22.367 days

Semi-major axis

0.1449 AU

Eccentricity

0.000

Inclination

89.26 °

Year Length

A year here lasts approximately 22.37 Earth days (6.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1449 AU.

Transit Fingerprint

Depth

0.099 %

Duration

5.151 h

Impact parameter b

0.815

Rp / R★

0.029896

Transit midpoint (BJD)

2,455,008.4551

Photometric dip

Transit produces a flux drop of 987 ppm lasting ≈ 5.15 h.

Extended Orbital Architecture

Planet / star radius ratio

0.029896

Semi-major axis / stellar radius

34.050

Impact parameter (b)

0.815

Transit mid-time (BJD)

2,455,008.4551

Angular separation (arcsec)

0.12800

Eq. Temperature

536K

(263 °C)

Insolation (S⊕)

35.34

Earth = 1.00

Earth Similarity (ESI)

0.441

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-689

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,518 K — cooler than the Sun (5,778 K)

Estimated Age

4.57 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.880 R☉

Stellar Mass

0.910 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

1.493 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,131.73 parsec

Light-years 3,691.21 ly

V-band magnitude

15.94 mag

Voyager-speed travel 65,094,402 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.857 mas

Total Proper Motion

7.525 mas/yr

PM Right Ascension

3.26 mas/yr

PM Declination

-6.78 mas/yr

Galactic Cartesian (pc)

x = 0.322 · y = -0.701 · z = 0.636

Equatorial (J2000)

RA 294.71063° · Dec 39.52170°

Galactic ℓ, b

73.160° · 8.580°

Ecliptic λ, β

309.596° · 59.610°

HTM-20 index

-2008435155