Key parameters at a glance

A radius of 2.00 Earth radii
A mass of 13.50 Earth masses
Surface gravity around 3.38 g
An orbital period of 50.447 days
Semi-major axis 0.2864 AU
Equilibrium temperature 568 K (295 °C)
Distance from Earth 5,866.73 light-years
Earth Similarity Index 0.401
Travel time at Voyager 1 speed 103,459,796 years

4 siblings around Kepler-238

Kepler-238 f shares its host star with 4 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-238 b	Super-Earth	1.73	3,305.02	2.091	1,642	2014
Kepler-238 c	Sub-Neptune	2.39	152.52	6.156	1,146	2014
Kepler-238 d	Sub-Neptune	3.07	23.10	13.234	888	2014
Kepler-238 e	Neptune-like	5.60	169.70	23.654	731	2013
Kepler-238 f this	Sub-Neptune	2.00	13.50	50.447	568	2013

Kepler-238 f Planet Profile

Physical Specs

Radius

2.00 R⊕

Radius (Jupiter)

0.178 R♃

Mass

13.50 M⊕

Mass (Jupiter)

0.042 M♃

Density

1.70 g/cm³

Surface Gravity

3.38 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.401

HZ Position Inner

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1955of 1978

top 98.8%

This planet

2.00R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-32 c 2.00 R⊕ Kepler-242 c 2.00 R⊕ Kepler-179 c 2.00 R⊕

Metric	Earth	Kepler-238 f	Jupiter
Radius (R⊕)	1.00	2.00	11.21
Mass (M⊕)	1.00	13.50	317.83
Density (g/cm³)	5.51	1.70	1.33
Surface Gravity (g)	1.00	3.38	2.53
Insolation (S⊕)	1.00	35.87	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	13.500 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 121460918

Gaia DR2

Gaia DR2 2100624562669914240

Gaia DR3

Gaia DR3 2100624562669914240

System

Kepler-238

Percentile among Sub-Neptune cohort

Radius 2.000 R⊕ · percentile 0 / cohort 1978

Mass 13.500 M⊕ · percentile 89 / cohort 1978

Orbital period 50.45 d · percentile 85 / cohort 1946

Distance 1,798.75 pc · percentile 96 / cohort 1975

ESI 0.401 · percentile 53 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

50.447 days

Semi-major axis

0.2864 AU

Eccentricity

0.000

Inclination

89.57 °

Year Length

A year here lasts approximately 50.45 Earth days (13.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2863 AU.

Transit Fingerprint

Depth

0.037 %

Duration

7.159 h

Impact parameter b

0.906

Rp / R★

0.017670

Transit midpoint (BJD)

2,455,011.4920

Photometric dip

Transit produces a flux drop of 370 ppm lasting ≈ 7.16 h.

Extended Orbital Architecture

Planet / star radius ratio

0.017670

Semi-major axis / stellar radius

23.090

Impact parameter (b)

0.906

Transit mid-time (BJD)

2,455,011.4920

Angular separation (arcsec)

0.15900

Eq. Temperature

568K

(295 °C)

Insolation (S⊕)

35.87

Earth = 1.00

Earth Similarity (ESI)

0.401

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Xie 2014

Instrument

Kepler CCD Array

Publication

2014-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: Kepler-238

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,800 K — hotter than the Sun (5,778 K)

Estimated Age

4.79 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.960 R☉

Stellar Mass

1.060 M☉

Metallicity [Fe/H]

0.34

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

0.419 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,798.75 parsec

Light-years 5,866.73 ly

V-band magnitude

15.30 mag

Voyager-speed travel 103,459,796 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.527 mas

Total Proper Motion

0.843 mas/yr

PM Right Ascension

-0.17 mas/yr

PM Declination

-0.83 mas/yr

Galactic Cartesian (pc)

x = 0.233 · y = -0.722 · z = 0.651

Equatorial (J2000)

RA 287.89711° · Dec 40.63781°

Galactic ℓ, b

71.835° · 13.749°

Ecliptic λ, β

300.023° · 62.224°

HTM-20 index

-1303763685