Key parameters at a glance

A radius of 2.29 Earth radii
A mass of 5.86 Earth masses
Surface gravity around 1.12 g
An orbital period of 16.129 days
Semi-major axis 0.1202 AU
Equilibrium temperature 715 K (442 °C)
Distance from Earth 7,097.42 light-years
Earth Similarity Index 0.366
Travel time at Voyager 1 speed 125,162,915 years

Kepler-1304 b Planet Profile

Physical Specs

Radius

2.29 R⊕

Radius (Jupiter)

0.204 R♃

Mass

5.86 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.68 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.366

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

#1519of 1978

top 76.7%

This planet

2.29R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-379 c 2.29 R⊕ Kepler-319 d 2.29 R⊕ Kepler-626 b 2.29 R⊕

Metric	Earth	Kepler-1304 b	Jupiter
Radius (R⊕)	1.00	2.29	11.21
Mass (M⊕)	1.00	5.86	317.83
Density (g/cm³)	5.51	2.68	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	61.87	0.037

Star Catalogue Identifiers

TIC

TIC 399819857

Gaia DR2

Gaia DR2 2100309827464993536

Gaia DR3

Gaia DR3 2100309827464993536

System

Kepler-1304

Percentile among Sub-Neptune cohort

Radius 2.290 R⊕ · percentile 23 / cohort 1978

Mass 5.860 M⊕ · percentile 22 / cohort 1978

Orbital period 16.13 d · percentile 54 / cohort 1946

Distance 2,176.08 pc · percentile 98 / cohort 1975

ESI 0.366 · percentile 45 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

16.129 days

Semi-major axis

0.1202 AU

Eccentricity

0.000

Inclination

81.65 °

Year Length

A year here lasts approximately 16.13 Earth days (4.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1202 AU.

Transit Fingerprint

Depth

0.039 %

Duration

5.938 h

Impact parameter b

0.884

Rp / R★

0.025756

Transit midpoint (BJD)

2,454,976.7543

Photometric dip

Transit produces a flux drop of 389 ppm lasting ≈ 5.94 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025756

Semi-major axis / stellar radius

11.300

Impact parameter (b)

0.884

Transit mid-time (BJD)

2,454,976.7543

Angular separation (arcsec)

0.05520

Eq. Temperature

715K

(442 °C)

Insolation (S⊕)

61.87

Earth = 1.00

Earth Similarity (ESI)

0.366

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-1304

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,259 K — cooler than the Sun (5,778 K)

Estimated Age

4.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.810 R☉

Stellar Mass

0.850 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.560 dex

Stellar density

0.022 g/cm³

Metallicity ratio

[Fe/H]

Distance

2,176.08 parsec

Light-years 7,097.42 ly

V-band magnitude

15.41 mag

Voyager-speed travel 125,162,915 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

0.430 mas

Total Proper Motion

10.875 mas/yr

PM Right Ascension

-4.35 mas/yr

PM Declination

-9.97 mas/yr

Galactic Cartesian (pc)

x = 0.203 · y = -0.745 · z = 0.635

Equatorial (J2000)

RA 285.27637° · Dec 39.44683°

Galactic ℓ, b

69.881° · 15.114°

Ecliptic λ, β

295.280° · 61.552°

HTM-20 index

-480220086