Key parameters at a glance

A radius of 2.38 Earth radii
A mass of 6.26 Earth masses
Surface gravity around 1.10 g
An orbital period of 4.888 days
Semi-major axis 0.0574 AU
Equilibrium temperature 1,003 K (730 °C)
Distance from Earth 3,139.68 light-years
Earth Similarity Index 0.254
Travel time at Voyager 1 speed 55,368,174 years

Kepler-1781 b Planet Profile

Physical Specs

Radius

2.38 R⊕

Radius (Jupiter)

0.212 R♃

Mass

6.26 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.55 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.254

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

#1364of 1978

top 68.9%

This planet

2.38R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1824 b 2.38 R⊕ Kepler-166 c 2.38 R⊕ Kepler-1249 b 2.38 R⊕

Metric	Earth	Kepler-1781 b	Jupiter
Radius (R⊕)	1.00	2.38	11.21
Mass (M⊕)	1.00	6.26	317.83
Density (g/cm³)	5.51	2.55	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	239.11	0.037

Star Catalogue Identifiers

TIC

TIC 63005080

Gaia DR2

Gaia DR2 2101755788338161920

Gaia DR3

Gaia DR3 2101755788338161920

System

Kepler-1781

Percentile among Sub-Neptune cohort

Radius 2.381 R⊕ · percentile 31 / cohort 1978

Mass 6.260 M⊕ · percentile 29 / cohort 1978

Orbital period 4.89 d · percentile 12 / cohort 1946

Distance 962.63 pc · percentile 76 / cohort 1975

ESI 0.254 · percentile 17 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

4.888 days

Semi-major axis

0.0574 AU

Eccentricity

0.000

Inclination

89.55 °

Year Length

A year here lasts approximately 4.89 Earth days (1.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0574 AU.

Transit Fingerprint

Depth

0.073 %

Duration

1.991 h

Impact parameter b

0.900

Rp / R★

0.024304

Transit midpoint (BJD)

2,454,965.7071

Photometric dip

Transit produces a flux drop of 729 ppm lasting ≈ 1.99 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024304

Semi-major axis / stellar radius

19.190

Impact parameter (b)

0.900

Transit mid-time (BJD)

2,454,965.7071

Angular separation (arcsec)

0.05960

Eq. Temperature

1,003K

(730 °C)

Insolation (S⊕)

239.11

Earth = 1.00

Earth Similarity (ESI)

0.254

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

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-1781

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,568 K — cooler than the Sun (5,778 K)

Estimated Age

0.90 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.957 R☉

Stellar Mass

1.053 M☉

Metallicity [Fe/H]

0.44

Extended Stellar Properties

Surface gravity (log g)

4.499 dex

Stellar density

5.097 g/cm³

Metallicity ratio

[Fe/H]

Distance

962.63 parsec

Light-years 3,139.68 ly

V-band magnitude

15.71 mag

Voyager-speed travel 55,368,174 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.011 mas

Total Proper Motion

1.954 mas/yr

PM Right Ascension

0.11 mas/yr

PM Declination

1.95 mas/yr

Galactic Cartesian (pc)

x = 0.273 · y = -0.687 · z = 0.674

Equatorial (J2000)

RA 291.71149° · Dec 42.34151°

Galactic ℓ, b

74.658° · 11.882°

Ecliptic λ, β

307.052° · 63.015°

HTM-20 index

-335650653