Confirmed Exoplanet Discovered 2014

Kepler-238 c

A sub-neptune orbiting the g-type yellow (sun-like) Kepler-238, located approximately 5,866.7 light-years from Earth.

Key parameters at a glance

  • A radius of 2.39 Earth radii
  • A mass of 152.52 Earth masses
  • Surface gravity around 26.70 g
  • An orbital period of 6.156 days
  • Semi-major axis 0.0690 AU
  • Equilibrium temperature 1,146 K (873 °C)
  • Distance from Earth 5,866.73 light-years
  • Earth Similarity Index 0.184
  • Travel time at Voyager 1 speed 103,459,796 years

4 siblings around Kepler-238

Kepler-238 c 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 this 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 Sub-Neptune 2.00 13.50 50.447 568 2013

Kepler-238 c Planet Profile

Physical Specs

Radius
2.39 R⊕
Radius (Jupiter)
0.213 R♃
Mass
152.52 M⊕
Mass (Jupiter)
0.480 M♃
Density
3.20 g/cm³
Surface Gravity
26.70 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.184
HZ Position Inner
Controversial No

Discovery

Year 2014
Method Transit
Facility Kepler
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1343of 1978

top 67.8%

This planet

2.39R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

TOI-1184 b 2.39 R⊕ Kepler-152 c 2.39 R⊕ Kepler-193 b 2.39 R⊕
Metric Earth Kepler-238 c Jupiter
Radius (R⊕)1.002.3911.21
Mass (M⊕)1.00152.52317.83
Density (g/cm³)5.513.201.33
Surface Gravity (g)1.0026.702.53
Insolation (S⊕)1.00592.300.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 152.522 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 2.390 R⊕ · percentile 31 / cohort 1978
Mass 152.522 M⊕ · percentile 99 / cohort 1978
Orbital period 6.16 d · percentile 18 / cohort 1946
Distance 1,798.75 pc · percentile 96 / cohort 1975
ESI 0.184 · percentile 5 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
6.156 days
Semi-major axis
0.0690 AU
Eccentricity
0.000
Inclination
88.56 °

Year Length

A year here lasts approximately 6.16 Earth days (1.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0690 AU.

Transit Fingerprint

Depth

0.029 %

Duration

4.837 h

Impact parameter b

0.060

Rp / R★

0.015336

Transit midpoint (BJD)

2,454,967.8232

Photometric dip

Transit produces a flux drop of 285 ppm lasting ≈ 4.84 h.

Extended Orbital Architecture

Planet / star radius ratio

0.015336

Semi-major axis / stellar radius

5.680

Impact parameter (b)

0.060

Transit mid-time (BJD)

2,454,967.8232

Angular separation (arcsec)

0.03840

Eq. Temperature

1,146K

(873 °C)

Insolation (S⊕)

592.30

Earth = 1.00

Earth Similarity (ESI)

0.184

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-238

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,751 K — cooler than the Sun (5,778 K)

Estimated Age

4.79 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.430 R☉

Stellar Mass

1.229 M☉

Metallicity [Fe/H]

0.34

Extended Stellar Properties

Surface gravity (log g)

4.194 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

9.316.016.02B15.30V15.02Gaia15.08Kepler14.54TESS15.60Sloan g15.00Sloan r14.86Sloan i14.77Sloan z13.89J13.55H13.51K13.50W113.56W212.86W39.33W4

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

Similar Worlds

Kepler-215 d

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 1,585.1 ly

Kepler-614 b

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 1,722.1 ly

K2-185 c

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 875.3 ly

Kepler-574 b

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 2,227.3 ly

K2-138 d

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 660.7 ly

Kepler-897 b

Sub-Neptune · G-type yellow (Sun-like)

Radius 2.39 R⊕ · 4,955.1 ly

Explore Related Categories

Sub-Neptune Planets Transit Discoveries Kepler Mission G-type yellow (Sun-like) Hosts