Key parameters at a glance

A radius of 3.19 Earth radii
A mass of 10.30 Earth masses
Surface gravity around 1.01 g
An orbital period of 5.997 days
Semi-major axis 0.0660 AU
Equilibrium temperature 1,025 K (752 °C)
Distance from Earth 3,158.96 light-years
Earth Similarity Index 0.221
Travel time at Voyager 1 speed 55,708,334 years

1 sibling around Kepler-188

Kepler-188 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-188 b	Super-Earth	1.68	3.46	2.062	1,463	2014
Kepler-188 c this	Sub-Neptune	3.19	10.30	5.997	1,025	2014

Kepler-188 c Planet Profile

Physical Specs

Radius

3.19 R⊕

Radius (Jupiter)

0.285 R♃

Mass

10.30 M⊕

Mass (Jupiter)

0.032 M♃

Density

1.74 g/cm³

Surface Gravity

1.01 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.221

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

#358of 1978

top 18.0%

This planet

3.19R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1294 b 3.19 R⊕ Kepler-1634 b 3.19 R⊕ Kepler-351 c 3.19 R⊕

Metric	Earth	Kepler-188 c	Jupiter
Radius (R⊕)	1.00	3.19	11.21
Mass (M⊕)	1.00	10.30	317.83
Density (g/cm³)	5.51	1.74	1.33
Surface Gravity (g)	1.00	1.01	2.53
Insolation (S⊕)	1.00	257.35	0.037

Star Catalogue Identifiers

TIC

TIC 123235018

Gaia DR2

Gaia DR2 2117317829237452160

Gaia DR3

Gaia DR3 2117317829237452160

System

Kepler-188

Percentile among Sub-Neptune cohort

Radius 3.190 R⊕ · percentile 82 / cohort 1978

Mass 10.300 M⊕ · percentile 75 / cohort 1978

Orbital period 6.00 d · percentile 17 / cohort 1946

Distance 968.54 pc · percentile 76 / cohort 1975

ESI 0.221 · percentile 10 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.997 days

Semi-major axis

0.0660 AU

Eccentricity

0.000

Inclination

87.63 °

Year Length

A year here lasts approximately 6.00 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0660 AU.

Transit Fingerprint

Depth

0.071 %

Duration

3.231 h

Impact parameter b

0.660

Rp / R★

0.026000

Transit midpoint (BJD)

2,455,005.5031

Photometric dip

Transit produces a flux drop of 711 ppm lasting ≈ 3.23 h.

Extended Orbital Architecture

Planet / star radius ratio

0.026000

Semi-major axis / stellar radius

10.600

Impact parameter (b)

0.660

Transit mid-time (BJD)

2,455,005.5031

Angular separation (arcsec)

0.06810

Eq. Temperature

1,025K

(752 °C)

Insolation (S⊕)

257.35

Earth = 1.00

Earth Similarity (ESI)

0.221

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-188

Spectral Class

F-type yellow-white

Effective Temperature

6,021 K — hotter than the Sun (5,778 K)

Estimated Age

5.80 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.141 R☉

Stellar Mass

1.021 M☉

Metallicity [Fe/H]

0.15

Extended Stellar Properties

Surface gravity (log g)

4.346 dex

Stellar density

0.960 g/cm³

Systemic radial velocity

-8.36 km/s

Rotational v·sin i

6.30 km/s

Metallicity ratio

[Fe/H]

Distance

968.54 parsec

Light-years 3,158.96 ly

V-band magnitude

14.72 mag

Voyager-speed travel 55,708,334 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.004 mas

Total Proper Motion

14.936 mas/yr

PM Right Ascension

2.20 mas/yr

PM Declination

-14.77 mas/yr

Galactic Cartesian (pc)

x = 0.140 · y = -0.702 · z = 0.699

Equatorial (J2000)

RA 281.27972° · Dec 44.31547°

Galactic ℓ, b

73.519° · 19.640°

Ecliptic λ, β

290.928° · 66.937°

HTM-20 index

-59008110