Key parameters at a glance

A radius of 2.37 Earth radii
A mass of 6.21 Earth masses
Surface gravity around 1.11 g
An orbital period of 28.843 days
Semi-major axis 0.1679 AU
Equilibrium temperature 491 K (218 °C)
Distance from Earth 2,756.02 light-years
Earth Similarity Index 0.515
Travel time at Voyager 1 speed 48,602,378 years

Kepler-1309 b Planet Profile

Physical Specs

Radius

2.37 R⊕

Radius (Jupiter)

0.211 R♃

Mass

6.21 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.56 g/cm³

Surface Gravity

1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.515

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

#1375of 1978

top 69.5%

This planet

2.37R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-81 c 2.37 R⊕ K2-18 b 2.37 R⊕ Kepler-125 b 2.37 R⊕

Metric	Earth	Kepler-1309 b	Jupiter
Radius (R⊕)	1.00	2.37	11.21
Mass (M⊕)	1.00	6.21	317.83
Density (g/cm³)	5.51	2.56	1.33
Surface Gravity (g)	1.00	1.11	2.53
Insolation (S⊕)	1.00	13.77	0.037

Star Catalogue Identifiers

TIC

TIC 171098231

Gaia DR2

Gaia DR2 2073622068939722368

Gaia DR3

Gaia DR3 2073622068939722368

System

Kepler-1309

Percentile among Sub-Neptune cohort

Radius 2.370 R⊕ · percentile 30 / cohort 1978

Mass 6.210 M⊕ · percentile 29 / cohort 1978

Orbital period 28.84 d · percentile 72 / cohort 1946

Distance 845.00 pc · percentile 68 / cohort 1975

ESI 0.515 · percentile 72 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

28.843 days

Semi-major axis

0.1679 AU

Eccentricity

0.000

Inclination

88.43 °

Year Length

A year here lasts approximately 28.84 Earth days (7.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1679 AU.

Transit Fingerprint

Depth

0.076 %

Duration

3.100 h

Impact parameter b

0.013

Rp / R★

0.026533

Transit midpoint (BJD)

2,454,976.8221

Photometric dip

Transit produces a flux drop of 757 ppm lasting ≈ 3.10 h.

Extended Orbital Architecture

Planet / star radius ratio

0.026533

Semi-major axis / stellar radius

33.300

Impact parameter (b)

0.013

Transit mid-time (BJD)

2,454,976.8221

Angular separation (arcsec)

0.19900

Eq. Temperature

491K

(218 °C)

Insolation (S⊕)

13.77

Earth = 1.00

Earth Similarity (ESI)

0.515

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-1309

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,235 K — cooler than the Sun (5,778 K)

Estimated Age

4.27 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.800 R☉

Stellar Mass

0.850 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.560 dex

Stellar density

7.957 g/cm³

Metallicity ratio

[Fe/H]

Distance

845.00 parsec

Light-years 2,756.02 ly

V-band magnitude

16.51 mag

Voyager-speed travel 48,602,378 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.040 mas

Total Proper Motion

14.432 mas/yr

PM Right Ascension

-12.94 mas/yr

PM Declination

-6.39 mas/yr

Galactic Cartesian (pc)

x = 0.364 · y = -0.664 · z = 0.653

Equatorial (J2000)

RA 298.73511° · Dec 40.76413°

Galactic ℓ, b

75.773° · 6.508°

Ecliptic λ, β

316.162° · 59.683°

HTM-20 index

-233076498