Key parameters at a glance

A radius of 2.33 Earth radii
A mass of 6.04 Earth masses
Surface gravity around 1.11 g
An orbital period of 13.475 days
Semi-major axis 0.1034 AU
Equilibrium temperature 634 K (361 °C)
Distance from Earth 2,642.13 light-years
Earth Similarity Index 0.409
Travel time at Voyager 1 speed 46,593,978 years

Kepler-1021 b Planet Profile

Physical Specs

Radius

2.33 R⊕

Radius (Jupiter)

0.208 R♃

Mass

6.04 M⊕

Mass (Jupiter)

0.019 M♃

Density

2.62 g/cm³

Surface Gravity

1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.409

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1451of 1978

top 73.3%

This planet

2.33R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

GJ 367 d 2.33 R⊕ Kepler-241 b 2.33 R⊕ Kepler-1983 b 2.33 R⊕

Metric	Earth	Kepler-1021 b	Jupiter
Radius (R⊕)	1.00	2.33	11.21
Mass (M⊕)	1.00	6.04	317.83
Density (g/cm³)	5.51	2.62	1.33
Surface Gravity (g)	1.00	1.11	2.53
Insolation (S⊕)	1.00	50.37	0.037

Star Catalogue Identifiers

TIC

TIC 271537790

Gaia DR2

Gaia DR2 2077902914366974464

Gaia DR3

Gaia DR3 2077902914366974464

System

Kepler-1021

Percentile among Sub-Neptune cohort

Radius 2.330 R⊕ · percentile 26 / cohort 1978

Mass 6.040 M⊕ · percentile 25 / cohort 1978

Orbital period 13.47 d · percentile 46 / cohort 1946

Distance 810.08 pc · percentile 66 / cohort 1975

ESI 0.409 · percentile 54 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.475 days

Semi-major axis

0.1034 AU

Eccentricity

0.000

Inclination

89.96 °

Year Length

A year here lasts approximately 13.47 Earth days (3.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1034 AU.

Transit Fingerprint

Depth

0.078 %

Duration

2.617 h

Impact parameter b

0.159

Rp / R★

0.025352

Transit midpoint (BJD)

2,454,966.4924

Photometric dip

Transit produces a flux drop of 782 ppm lasting ≈ 2.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025352

Semi-major axis / stellar radius

40.560

Impact parameter (b)

0.159

Transit mid-time (BJD)

2,454,966.4924

Angular separation (arcsec)

0.12800

Eq. Temperature

634K

(361 °C)

Insolation (S⊕)

50.37

Earth = 1.00

Earth Similarity (ESI)

0.409

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

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1021

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,431 K — cooler than the Sun (5,778 K)

Estimated Age

4.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.860 R☉

Stellar Mass

0.890 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.530 dex

Stellar density

6.589 g/cm³

Metallicity ratio

[Fe/H]

Distance

810.08 parsec

Light-years 2,642.13 ly

V-band magnitude

15.21 mag

Voyager-speed travel 46,593,978 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.206 mas

Total Proper Motion

0.977 mas/yr

PM Right Ascension

-0.96 mas/yr

PM Declination

-0.20 mas/yr

Galactic Cartesian (pc)

x = 0.314 · y = -0.666 · z = 0.676

Equatorial (J2000)

RA 295.20490° · Dec 42.55967°

Galactic ℓ, b

76.050° · 9.686°

Ecliptic λ, β

312.488° · 62.331°

HTM-20 index

-1569779447