Key parameters at a glance

A radius of 2.31 Earth radii
A mass of 5.95 Earth masses
Surface gravity around 1.12 g
An orbital period of 4.470 days
Semi-major axis 0.0535 AU
Equilibrium temperature 1,103 K (830 °C)
Distance from Earth 2,863.92 light-years
Earth Similarity Index 0.231
Travel time at Voyager 1 speed 50,505,176 years

Kepler-981 b Planet Profile

Physical Specs

Radius

2.31 R⊕

Radius (Jupiter)

0.206 R♃

Mass

5.95 M⊕

Mass (Jupiter)

0.019 M♃

Density

2.65 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.231

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

#1486of 1978

top 75.1%

This planet

2.31R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-624 b 2.31 R⊕ Kepler-244 d 2.31 R⊕ Kepler-926 b 2.31 R⊕

Metric	Earth	Kepler-981 b	Jupiter
Radius (R⊕)	1.00	2.31	11.21
Mass (M⊕)	1.00	5.95	317.83
Density (g/cm³)	5.51	2.65	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	337.47	0.037

Star Catalogue Identifiers

TIC

TIC 158984916

Gaia DR2

Gaia DR2 2127914132032810112

Gaia DR3

Gaia DR3 2127914132032810112

System

Kepler-981

Percentile among Sub-Neptune cohort

Radius 2.310 R⊕ · percentile 25 / cohort 1978

Mass 5.950 M⊕ · percentile 24 / cohort 1978

Orbital period 4.47 d · percentile 10 / cohort 1946

Distance 878.08 pc · percentile 71 / cohort 1975

ESI 0.231 · percentile 12 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

4.470 days

Semi-major axis

0.0535 AU

Eccentricity

0.000

Inclination

88.32 °

Year Length

A year here lasts approximately 4.47 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0535 AU.

Transit Fingerprint

Depth

0.059 %

Duration

1.806 h

Impact parameter b

0.006

Rp / R★

0.022303

Transit midpoint (BJD)

2,454,964.8437

Photometric dip

Transit produces a flux drop of 593 ppm lasting ≈ 1.81 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022303

Semi-major axis / stellar radius

19.330

Impact parameter (b)

0.006

Transit mid-time (BJD)

2,454,964.8437

Angular separation (arcsec)

0.06090

Eq. Temperature

1,103K

(830 °C)

Insolation (S⊕)

337.47

Earth = 1.00

Earth Similarity (ESI)

0.231

0 = alien, 1 = Earth-identical

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

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-981

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,718 K — cooler than the Sun (5,778 K)

Estimated Age

4.07 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.960 R☉

Stellar Mass

0.980 M☉

Metallicity [Fe/H]

0.01

Extended Stellar Properties

Surface gravity (log g)

4.470 dex

Stellar density

6.844 g/cm³

Metallicity ratio

[Fe/H]

Distance

878.08 parsec

Light-years 2,863.92 ly

V-band magnitude

14.88 mag

Voyager-speed travel 50,505,176 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.110 mas

Total Proper Motion

3.674 mas/yr

PM Right Ascension

0.37 mas/yr

PM Declination

3.66 mas/yr

Galactic Cartesian (pc)

x = 0.222 · y = -0.636 · z = 0.739

Equatorial (J2000)

RA 289.24891° · Dec 47.65011°

Galactic ℓ, b

78.877° · 15.680°

Ecliptic λ, β

307.485° · 68.598°

HTM-20 index

-476276715