Key parameters at a glance

A radius of 2.90 Earth radii
A mass of 8.75 Earth masses
Surface gravity around 1.04 g
An orbital period of 5.191 days
Semi-major axis 0.0625 AU
Equilibrium temperature 1,183 K (910 °C)
Distance from Earth 6,981.70 light-years
Earth Similarity Index 0.196
Travel time at Voyager 1 speed 123,122,190 years

Kepler-1239 b Planet Profile

Physical Specs

Radius

2.90 R⊕

Radius (Jupiter)

0.259 R♃

Mass

8.75 M⊕

Mass (Jupiter)

0.028 M♃

Density

1.97 g/cm³

Surface Gravity

1.04 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.196

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

#621of 1978

top 31.3%

This planet

2.90R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-130 c 2.90 R⊕ Kepler-276 c 2.90 R⊕ Kepler-314 c 2.90 R⊕

Metric	Earth	Kepler-1239 b	Jupiter
Radius (R⊕)	1.00	2.90	11.21
Mass (M⊕)	1.00	8.75	317.83
Density (g/cm³)	5.51	1.97	1.33
Surface Gravity (g)	1.00	1.04	2.53
Insolation (S⊕)	1.00	462.91	0.037

Star Catalogue Identifiers

TIC

TIC 275496016

Gaia DR2

Gaia DR2 2077689059355373440

Gaia DR3

Gaia DR3 2077689059355373440

System

Kepler-1239

Percentile among Sub-Neptune cohort

Radius 2.900 R⊕ · percentile 68 / cohort 1978

Mass 8.750 M⊕ · percentile 62 / cohort 1978

Orbital period 5.19 d · percentile 13 / cohort 1946

Distance 2,140.60 pc · percentile 98 / cohort 1975

ESI 0.196 · percentile 6 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.191 days

Semi-major axis

0.0625 AU

Eccentricity

0.000

Inclination

89.30 °

Year Length

A year here lasts approximately 5.19 Earth days (1.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0625 AU.

Transit Fingerprint

Depth

0.029 %

Duration

4.268 h

Impact parameter b

0.809

Rp / R★

0.016685

Transit midpoint (BJD)

2,454,968.2147

Photometric dip

Transit produces a flux drop of 290 ppm lasting ≈ 4.27 h.

Extended Orbital Architecture

Planet / star radius ratio

0.016685

Semi-major axis / stellar radius

9.496

Impact parameter (b)

0.809

Transit mid-time (BJD)

2,454,968.2147

Angular separation (arcsec)

0.02920

Eq. Temperature

1,183K

(910 °C)

Insolation (S⊕)

462.91

Earth = 1.00

Earth Similarity (ESI)

0.196

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-1239

Spectral Class

F-type yellow-white

Effective Temperature

6,564 K — hotter than the Sun (5,778 K)

Estimated Age

1.62 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.570 R☉

Stellar Mass

1.400 M☉

Metallicity [Fe/H]

0.22

Extended Stellar Properties

Surface gravity (log g)

4.200 dex

Stellar density

0.485 g/cm³

Metallicity ratio

[Fe/H]

Distance

2,140.60 parsec

Light-years 6,981.70 ly

V-band magnitude

15.39 mag

Voyager-speed travel 123,122,190 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

0.439 mas

Total Proper Motion

7.945 mas/yr

PM Right Ascension

-2.06 mas/yr

PM Declination

-7.67 mas/yr

Galactic Cartesian (pc)

x = 0.290 · y = -0.680 · z = 0.673

Equatorial (J2000)

RA 293.12734° · Dec 42.32006°

Galactic ℓ, b

75.114° · 10.935°

Ecliptic λ, β

309.199° · 62.647°

HTM-20 index

-179506532