Key parameters at a glance

A radius of 1.64 Earth radii
A mass of 3.33 Earth masses
Surface gravity around 1.24 g
An orbital period of 3.116 days
Semi-major axis 0.0415 AU
Equilibrium temperature 1,123 K (850 °C)
Distance from Earth 3,555.10 light-years
Earth Similarity Index 0.256
Travel time at Voyager 1 speed 62,694,192 years

Kepler-1281 b Planet Profile

Physical Specs

Radius

1.64 R⊕

Radius (Jupiter)

0.146 R♃

Mass

3.33 M⊕

Mass (Jupiter)

0.011 M♃

Density

4.15 g/cm³

Surface Gravity

1.24 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.256

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

#495of 1176

top 42.0%

This planet

1.64R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-46 d 1.64 R⊕ Kepler-179 b 1.64 R⊕ Kepler-247 b 1.64 R⊕

Metric	Earth	Kepler-1281 b	Jupiter
Radius (R⊕)	1.00	1.64	11.21
Mass (M⊕)	1.00	3.33	317.83
Density (g/cm³)	5.51	4.15	1.33
Surface Gravity (g)	1.00	1.24	2.53
Insolation (S⊕)	1.00	375.55	0.037

Star Catalogue Identifiers

TIC

TIC 27458799

Gaia DR2

Gaia DR2 2134725911507401984

Gaia DR3

Gaia DR3 2134725915805229952

System

Kepler-1281

Percentile among Super-Earth cohort

Radius 1.640 R⊕ · percentile 56 / cohort 1176

Mass 3.330 M⊕ · percentile 51 / cohort 1176

Orbital period 3.12 d · percentile 23 / cohort 1164

Distance 1,090.00 pc · percentile 85 / cohort 1171

ESI 0.256 · percentile 25 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

3.116 days

Semi-major axis

0.0415 AU

Eccentricity

0.000

Inclination

89.17 °

Year Length

A year here lasts approximately 3.12 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0415 AU.

Transit Fingerprint

Depth

0.035 %

Duration

1.909 h

Impact parameter b

0.195

Rp / R★

0.018007

Transit midpoint (BJD)

2,454,966.8545

Photometric dip

Transit produces a flux drop of 345 ppm lasting ≈ 1.91 h.

Extended Orbital Architecture

Planet / star radius ratio

0.018007

Semi-major axis / stellar radius

13.389

Impact parameter (b)

0.195

Transit mid-time (BJD)

2,454,966.8545

Angular separation (arcsec)

0.03810

Eq. Temperature

1,123K

(850 °C)

Insolation (S⊕)

375.55

Earth = 1.00

Earth Similarity (ESI)

0.256

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-1281

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,353 K — cooler than the Sun (5,778 K)

Estimated Age

4.37 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.830 R☉

Stellar Mass

0.870 M☉

Metallicity [Fe/H]

-0.04

Extended Stellar Properties

Surface gravity (log g)

4.550 dex

Stellar density

2.442 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,090.00 parsec

Light-years 3,555.10 ly

V-band magnitude

15.96 mag

Voyager-speed travel 62,694,192 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.819 mas

Total Proper Motion

10.475 mas/yr

PM Right Ascension

-6.73 mas/yr

PM Declination

-8.02 mas/yr

Galactic Cartesian (pc)

x = 0.284 · y = -0.599 · z = 0.749

Equatorial (J2000)

RA 295.35436° · Dec 48.51539°

Galactic ℓ, b

81.474° · 12.359°

Ecliptic λ, β

318.466° · 67.733°

HTM-20 index

1860341666