Key parameters at a glance

A radius of 3.12 Earth radii
A mass of 9.90 Earth masses
Surface gravity around 1.02 g
An orbital period of 31.032 days
Semi-major axis 0.1964 AU
Equilibrium temperature 561 K (288 °C)
Distance from Earth 4,649.00 light-years
Earth Similarity Index 0.410
Travel time at Voyager 1 speed 81,985,022 years

Kepler-1820 b Planet Profile

Physical Specs

Radius

3.12 R⊕

Radius (Jupiter)

0.278 R♃

Mass

9.90 M⊕

Mass (Jupiter)

0.031 M♃

Density

1.79 g/cm³

Surface Gravity

1.02 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.410

HZ Position Inner

Controversial No

Discovery

Year 2021

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#424of 1978

top 21.4%

This planet

3.12R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1721 b 3.12 R⊕ HD 93963 A c 3.12 R⊕ Kepler-150 e 3.12 R⊕

Metric	Earth	Kepler-1820 b	Jupiter
Radius (R⊕)	1.00	3.12	11.21
Mass (M⊕)	1.00	9.90	317.83
Density (g/cm³)	5.51	1.79	1.33
Surface Gravity (g)	1.00	1.02	2.53
Insolation (S⊕)	1.00	23.41	0.037

Star Catalogue Identifiers

TIC

TIC 351189211

Gaia DR2

Gaia DR2 2086634445439637376

Gaia DR3

Gaia DR3 2086634445439637376

System

Kepler-1820

Percentile among Sub-Neptune cohort

Radius 3.119 R⊕ · percentile 79 / cohort 1978

Mass 9.900 M⊕ · percentile 72 / cohort 1978

Orbital period 31.03 d · percentile 74 / cohort 1946

Distance 1,425.39 pc · percentile 92 / cohort 1975

ESI 0.410 · percentile 54 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

31.032 days

Semi-major axis

0.1964 AU

Eccentricity

0.000

Inclination

89.38 °

Year Length

A year here lasts approximately 31.03 Earth days (8.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1964 AU.

Transit Fingerprint

Depth

0.074 %

Duration

3.403 h

Impact parameter b

0.285

Rp / R★

0.025920

Transit midpoint (BJD)

2,454,985.2694

Photometric dip

Transit produces a flux drop of 737 ppm lasting ≈ 3.40 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025920

Semi-major axis / stellar radius

68.700

Impact parameter (b)

0.285

Transit mid-time (BJD)

2,454,985.2694

Angular separation (arcsec)

0.13800

Eq. Temperature

561K

(288 °C)

Insolation (S⊕)

23.41

Earth = 1.00

Earth Similarity (ESI)

0.410

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

Valizadegan et al. 2022

Instrument

Kepler CCD Array

Publication

2022-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2021 at Kepler (12 shown).

Kepler-1816 b · Super-Earth Kepler-1705 c · Sub-Neptune Kepler-1948 b · Rocky Terrestrial Kepler-196 d · Sub-Neptune Kepler-1853 b · Super-Earth Kepler-1840 b · Sub-Neptune Kepler-1881 b · Sub-Neptune Kepler-1858 b · Sub-Neptune Kepler-1874 b · Sub-Neptune Kepler-1802 c · Sub-Neptune Kepler-1749 b · Super-Earth Kepler-1849 b · Sub-Neptune

Host System: Kepler-1820

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,841 K — hotter than the Sun (5,778 K)

Estimated Age

0.40 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.931 R☉

Stellar Mass

1.047 M☉

Metallicity [Fe/H]

0.07

Extended Stellar Properties

Surface gravity (log g)

4.520 dex

Stellar density

3.493 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,425.39 parsec

Light-years 4,649.00 ly

V-band magnitude

15.76 mag

Voyager-speed travel 81,985,022 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.674 mas

Total Proper Motion

8.684 mas/yr

PM Right Ascension

-3.15 mas/yr

PM Declination

-8.09 mas/yr

Galactic Cartesian (pc)

x = 0.299 · y = -0.595 · z = 0.746

Equatorial (J2000)

RA 296.71274° · Dec 48.27228°

Galactic ℓ, b

81.682° · 11.448°

Ecliptic λ, β

320.270° · 67.107°

HTM-20 index

1988878963