Key parameters at a glance

A radius of 2.42 Earth radii
A mass of 6.44 Earth masses
Surface gravity around 1.10 g
An orbital period of 1.953 days
Semi-major axis 0.0308 AU
Equilibrium temperature 1,403 K (1130 °C)
Distance from Earth 2,787.40 light-years
Earth Similarity Index 0.173
Travel time at Voyager 1 speed 49,155,870 years

Kepler-1871 b Planet Profile

Physical Specs

Radius

2.42 R⊕

Radius (Jupiter)

0.216 R♃

Mass

6.44 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.49 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.173

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

#1297of 1978

top 65.5%

This planet

2.42R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1858 b 2.42 R⊕ HD 1461 b 2.42 R⊕ K2-43 c 2.42 R⊕

Metric	Earth	Kepler-1871 b	Jupiter
Radius (R⊕)	1.00	2.42	11.21
Mass (M⊕)	1.00	6.44	317.83
Density (g/cm³)	5.51	2.49	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	917.15	0.037

Star Catalogue Identifiers

TIC

TIC 137634508

Gaia DR2

Gaia DR2 2051948633156991232

Gaia DR3

Gaia DR3 2051948633156991232

System

Kepler-1871

Percentile among Sub-Neptune cohort

Radius 2.422 R⊕ · percentile 34 / cohort 1978

Mass 6.440 M⊕ · percentile 32 / cohort 1978

Orbital period 1.95 d · percentile 2 / cohort 1946

Distance 854.62 pc · percentile 69 / cohort 1975

ESI 0.173 · percentile 4 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

1.953 days

Semi-major axis

0.0308 AU

Eccentricity

0.000

Inclination

80.96 °

Year Length

A year here lasts approximately 1.95 Earth days (0.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0308 AU.

Transit Fingerprint

Depth

0.040 %

Duration

0.872 h

Impact parameter b

0.160

Rp / R★

0.019064

Transit midpoint (BJD)

2,454,966.1609

Photometric dip

Transit produces a flux drop of 403 ppm lasting ≈ 0.87 h.

Extended Orbital Architecture

Planet / star radius ratio

0.019064

Semi-major axis / stellar radius

6.120

Impact parameter (b)

0.160

Transit mid-time (BJD)

2,454,966.1609

Angular separation (arcsec)

0.03600

Eq. Temperature

1,403K

(1130 °C)

Insolation (S⊕)

917.15

Earth = 1.00

Earth Similarity (ESI)

0.173

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-1871

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,741 K — cooler than the Sun (5,778 K)

Estimated Age

5.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.946 R☉

Stellar Mass

1.020 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.495 dex

Stellar density

1.139 g/cm³

Metallicity ratio

[Fe/H]

Distance

854.62 parsec

Light-years 2,787.40 ly

V-band magnitude

14.82 mag

Voyager-speed travel 49,155,870 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.142 mas

Total Proper Motion

6.011 mas/yr

PM Right Ascension

-1.25 mas/yr

PM Declination

-5.88 mas/yr

Galactic Cartesian (pc)

x = 0.299 · y = -0.724 · z = 0.622

Equatorial (J2000)

RA 292.42750° · Dec 38.47288°

Galactic ℓ, b

71.384° · 9.664°

Ecliptic λ, β

305.642° · 59.168°

HTM-20 index

1164827311