Key parameters at a glance

A radius of 2.58 Earth radii
A mass of 7.16 Earth masses
Surface gravity around 1.08 g
An orbital period of 20.491 days
Semi-major axis 0.1485 AU
Equilibrium temperature 625 K (352 °C)
Distance from Earth 3,724.34 light-years
Earth Similarity Index 0.400
Travel time at Voyager 1 speed 65,678,781 years

Kepler-1685 b Planet Profile

Physical Specs

Radius

2.58 R⊕

Radius (Jupiter)

0.230 R♃

Mass

7.16 M⊕

Mass (Jupiter)

0.023 M♃

Density

2.30 g/cm³

Surface Gravity

1.08 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.400

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1070of 1978

top 54.0%

This planet

2.58R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-219 d 2.58 R⊕ K2-195 c 2.58 R⊕ BD+20 594 b 2.58 R⊕

Metric	Earth	Kepler-1685 b	Jupiter
Radius (R⊕)	1.00	2.58	11.21
Mass (M⊕)	1.00	7.16	317.83
Density (g/cm³)	5.51	2.30	1.33
Surface Gravity (g)	1.00	1.08	2.53
Insolation (S⊕)	1.00	36.01	0.037

Star Catalogue Identifiers

TIC

TIC 272270869

Gaia DR2

Gaia DR2 2079576783379820928

Gaia DR3

Gaia DR3 2079576783379820928

System

Kepler-1685

Percentile among Sub-Neptune cohort

Radius 2.577 R⊕ · percentile 46 / cohort 1978

Mass 7.160 M⊕ · percentile 43 / cohort 1978

Orbital period 20.49 d · percentile 63 / cohort 1946

Distance 1,141.89 pc · percentile 85 / cohort 1975

ESI 0.400 · percentile 52 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

20.491 days

Semi-major axis

0.1485 AU

Eccentricity

0.000

Inclination

89.98 °

Year Length

A year here lasts approximately 20.49 Earth days (5.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1485 AU.

Transit Fingerprint

Depth

0.066 %

Duration

4.961 h

Impact parameter b

0.011

Rp / R★

0.023227

Transit midpoint (BJD)

2,454,977.4206

Photometric dip

Transit produces a flux drop of 662 ppm lasting ≈ 4.96 h.

Extended Orbital Architecture

Planet / star radius ratio

0.023227

Semi-major axis / stellar radius

36.660

Impact parameter (b)

0.011

Transit mid-time (BJD)

2,454,977.4206

Angular separation (arcsec)

0.13000

Eq. Temperature

625K

(352 °C)

Insolation (S⊕)

36.01

Earth = 1.00

Earth Similarity (ESI)

0.400

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

Armstrong et al. 2021

Instrument

Kepler CCD Array

Publication

2021-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at Kepler (12 shown).

Kepler-1649 c · Rocky Terrestrial Kepler-1701 b · Sub-Neptune Kepler-1690 b · Sub-Neptune Kepler-1700 b · Sub-Neptune Kepler-1684 b · Sub-Neptune Kepler-1678 b · Sub-Neptune Kepler-598 c · Sub-Neptune Kepler-1661 b · Sub-Neptune Kepler-1663 b · Sub-Neptune Kepler-1681 b · Sub-Neptune Kepler-1672 b · Sub-Neptune Kepler-1702 b · Super-Earth

Host System: Kepler-1685

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,484 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.835 R☉

Stellar Mass

0.960 M☉

Metallicity [Fe/H]

0.21

Extended Stellar Properties

Surface gravity (log g)

4.577 dex

Stellar density

2.321 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,141.89 parsec

Light-years 3,724.34 ly

V-band magnitude

16.10 mag

Voyager-speed travel 65,678,781 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.848 mas

Total Proper Motion

9.234 mas/yr

PM Right Ascension

-4.79 mas/yr

PM Declination

-7.90 mas/yr

Galactic Cartesian (pc)

x = 0.318 · y = -0.646 · z = 0.694

Equatorial (J2000)

RA 296.18826° · Dec 43.93681°

Galactic ℓ, b

77.625° · 9.709°

Ecliptic λ, β

315.081° · 63.335°

HTM-20 index

-1535683493