Key parameters at a glance

A radius of 2.32 Earth radii
A mass of 5.99 Earth masses
Surface gravity around 1.11 g
An orbital period of 39.314 days
Semi-major axis 0.2270 AU
Equilibrium temperature 540 K (267 °C)
Distance from Earth 2,539.46 light-years
Earth Similarity Index 0.477
Travel time at Voyager 1 speed 44,783,324 years

Kepler-1787 b Planet Profile

Physical Specs

Radius

2.32 R⊕

Radius (Jupiter)

0.207 R♃

Mass

5.99 M⊕

Mass (Jupiter)

0.019 M♃

Density

2.64 g/cm³

Surface Gravity

1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.477

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

#1484of 1978

top 75.0%

This planet

2.32R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1208 b 2.32 R⊕ K2-28 b 2.32 R⊕ Kepler-321 c 2.32 R⊕

Metric	Earth	Kepler-1787 b	Jupiter
Radius (R⊕)	1.00	2.32	11.21
Mass (M⊕)	1.00	5.99	317.83
Density (g/cm³)	5.51	2.64	1.33
Surface Gravity (g)	1.00	1.11	2.53
Insolation (S⊕)	1.00	20.04	0.037

Star Catalogue Identifiers

TIC

TIC 158983401

Gaia DR2

Gaia DR2 2127803321876716928

Gaia DR3

Gaia DR3 2127803321876716928

System

Kepler-1787

Percentile among Sub-Neptune cohort

Radius 2.319 R⊕ · percentile 25 / cohort 1978

Mass 5.990 M⊕ · percentile 24 / cohort 1978

Orbital period 39.31 d · percentile 80 / cohort 1946

Distance 778.60 pc · percentile 64 / cohort 1975

ESI 0.477 · percentile 67 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

39.314 days

Semi-major axis

0.2270 AU

Eccentricity

0.000

Inclination

89.99 °

Year Length

A year here lasts approximately 39.31 Earth days (10.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2270 AU.

Transit Fingerprint

Depth

0.050 %

Duration

4.890 h

Impact parameter b

0.936

Rp / R★

0.020516

Transit midpoint (BJD)

2,454,987.9392

Photometric dip

Transit produces a flux drop of 500 ppm lasting ≈ 4.89 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020516

Semi-major axis / stellar radius

21.300

Impact parameter (b)

0.936

Transit mid-time (BJD)

2,454,987.9392

Angular separation (arcsec)

0.29200

Eq. Temperature

540K

(267 °C)

Insolation (S⊕)

20.04

Earth = 1.00

Earth Similarity (ESI)

0.477

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-1787

Spectral Class

F-type yellow-white

Effective Temperature

6,060 K — hotter than the Sun (5,778 K)

Estimated Age

0.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.925 R☉

Stellar Mass

1.008 M☉

Metallicity [Fe/H]

-0.22

Extended Stellar Properties

Surface gravity (log g)

4.509 dex

Stellar density

2.796 g/cm³

Metallicity ratio

[Fe/H]

Distance

778.60 parsec

Light-years 2,539.46 ly

V-band magnitude

14.56 mag

Voyager-speed travel 44,783,324 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.256 mas

Total Proper Motion

8.303 mas/yr

PM Right Ascension

-1.23 mas/yr

PM Declination

-8.21 mas/yr

Galactic Cartesian (pc)

x = 0.222 · y = -0.643 · z = 0.733

Equatorial (J2000)

RA 289.06430° · Dec 47.11740°

Galactic ℓ, b

78.317° · 15.585°

Ecliptic λ, β

306.656° · 68.144°

HTM-20 index

1654441710