Key parameters at a glance

A radius of 3.03 Earth radii
A mass of 9.40 Earth masses
Surface gravity around 1.03 g
An orbital period of 23.340 days
Semi-major axis 0.1467 AU
Equilibrium temperature 601 K (328 °C)
Distance from Earth 3,333.35 light-years
Earth Similarity Index 0.389
Travel time at Voyager 1 speed 58,783,570 years

Kepler-1808 b Planet Profile

Physical Specs

Radius

3.03 R⊕

Radius (Jupiter)

0.270 R♃

Mass

9.40 M⊕

Mass (Jupiter)

0.030 M♃

Density

1.87 g/cm³

Surface Gravity

1.03 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.389

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

#499of 1978

top 25.2%

This planet

3.03R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-598 c 3.02 R⊕ Kepler-1937 b 3.02 R⊕ Kepler-498 b 3.03 R⊕

Metric	Earth	Kepler-1808 b	Jupiter
Radius (R⊕)	1.00	3.03	11.21
Mass (M⊕)	1.00	9.40	317.83
Density (g/cm³)	5.51	1.87	1.33
Surface Gravity (g)	1.00	1.03	2.53
Insolation (S⊕)	1.00	30.94	0.037

Star Catalogue Identifiers

TIC

TIC 121215333

Gaia DR2

Gaia DR2 2100414933904708608

Gaia DR3

Gaia DR3 2100414933904708608

System

Kepler-1808

Percentile among Sub-Neptune cohort

Radius 3.025 R⊕ · percentile 75 / cohort 1978

Mass 9.400 M⊕ · percentile 68 / cohort 1978

Orbital period 23.34 d · percentile 67 / cohort 1946

Distance 1,022.01 pc · percentile 79 / cohort 1975

ESI 0.389 · percentile 50 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

23.340 days

Semi-major axis

0.1467 AU

Eccentricity

0.000

Inclination

89.83 °

Year Length

A year here lasts approximately 23.34 Earth days (6.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1467 AU.

Transit Fingerprint

Depth

0.062 %

Duration

2.136 h

Impact parameter b

0.250

Rp / R★

0.022658

Transit midpoint (BJD)

2,454,969.2084

Photometric dip

Transit produces a flux drop of 615 ppm lasting ≈ 2.14 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022658

Semi-major axis / stellar radius

85.500

Impact parameter (b)

0.250

Transit mid-time (BJD)

2,454,969.2084

Angular separation (arcsec)

0.14400

Eq. Temperature

601K

(328 °C)

Insolation (S⊕)

30.94

Earth = 1.00

Earth Similarity (ESI)

0.389

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-1808

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,530 K — cooler than the Sun (5,778 K)

Estimated Age

12.10 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.892 R☉

Stellar Mass

0.773 M☉

Metallicity [Fe/H]

-0.34

Extended Stellar Properties

Surface gravity (log g)

4.425 dex

Stellar density

22.155 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,022.01 parsec

Light-years 3,333.35 ly

V-band magnitude

15.42 mag

Voyager-speed travel 58,783,570 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

0.950 mas

Total Proper Motion

5.905 mas/yr

PM Right Ascension

-0.46 mas/yr

PM Declination

-5.89 mas/yr

Galactic Cartesian (pc)

x = 0.230 · y = -0.738 · z = 0.635

Equatorial (J2000)

RA 287.29247° · Dec 39.38320°

Galactic ℓ, b

70.462° · 13.660°

Ecliptic λ, β

298.408° · 61.128°

HTM-20 index

-551448190