Key parameters at a glance

A radius of 4.35 Earth radii
A mass of 17.40 Earth masses
Surface gravity around 0.92 g
An orbital period of 15.434 days
Semi-major axis 0.1240 AU
Equilibrium temperature 721 K (448 °C)
Distance from Earth 4,356.27 light-years
Earth Similarity Index 0.279
Travel time at Voyager 1 speed 76,822,817 years

Kepler-1668 b Planet Profile

Physical Specs

Radius

4.35 R⊕

Radius (Jupiter)

0.388 R♃

Mass

17.40 M⊕

Mass (Jupiter)

0.055 M♃

Density

1.16 g/cm³

Surface Gravity

0.92 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.279

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

#482of 574

top 83.8%

This planet

4.35R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-413 b 4.35 R⊕ HD 106315 c 4.35 R⊕ TOI-470 b 4.34 R⊕

Metric	Earth	Kepler-1668 b	Jupiter
Radius (R⊕)	1.00	4.35	11.21
Mass (M⊕)	1.00	17.40	317.83
Density (g/cm³)	5.51	1.16	1.33
Surface Gravity (g)	1.00	0.92	2.53
Insolation (S⊕)	1.00	63.79	0.037

Star Catalogue Identifiers

TIC

TIC 273132513

Gaia DR2

Gaia DR2 2080249100380387712

Gaia DR3

Gaia DR3 2080249100380387712

System

Kepler-1668

Percentile among Neptune-like cohort

Radius 4.348 R⊕ · percentile 16 / cohort 574

Mass 17.400 M⊕ · percentile 20 / cohort 574

Orbital period 15.43 d · percentile 46 / cohort 524

Distance 1,335.64 pc · percentile 81 / cohort 572

ESI 0.279 · percentile 45 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

15.434 days

Semi-major axis

0.1240 AU

Eccentricity

0.000

Inclination

88.09 °

Year Length

A year here lasts approximately 15.43 Earth days (4.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1240 AU.

Transit Fingerprint

Depth

0.179 %

Duration

4.257 h

Impact parameter b

0.707

Rp / R★

0.042998

Transit midpoint (BJD)

2,455,196.2949

Photometric dip

Transit produces a flux drop of 1,786 ppm lasting ≈ 4.26 h.

Extended Orbital Architecture

Planet / star radius ratio

0.042998

Semi-major axis / stellar radius

24.500

Impact parameter (b)

0.707

Transit mid-time (BJD)

2,455,196.2949

Angular separation (arcsec)

0.09280

Eq. Temperature

721K

(448 °C)

Insolation (S⊕)

63.79

Earth = 1.00

Earth Similarity (ESI)

0.279

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-1668

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,542 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.017 R☉

Stellar Mass

0.980 M☉

Metallicity [Fe/H]

0.07

Extended Stellar Properties

Surface gravity (log g)

4.414 dex

Stellar density

1.312 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,335.64 parsec

Light-years 4,356.27 ly

V-band magnitude

15.79 mag

Voyager-speed travel 76,822,817 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.721 mas

Total Proper Motion

3.567 mas/yr

PM Right Ascension

-1.86 mas/yr

PM Declination

-3.04 mas/yr

Galactic Cartesian (pc)

x = 0.319 · y = -0.616 · z = 0.721

Equatorial (J2000)

RA 297.35231° · Dec 46.09593°

Galactic ℓ, b

79.948° · 10.025°

Ecliptic λ, β

318.840° · 64.965°

HTM-20 index

-2145190106