Key parameters at a glance

A radius of 2.40 Earth radii
A mass of 6.35 Earth masses
Surface gravity around 1.10 g
An orbital period of 52.815 days
Semi-major axis 0.2750 AU
Equilibrium temperature 562 K (289 °C)
Distance from Earth 3,581.10 light-years
Earth Similarity Index 0.454
Travel time at Voyager 1 speed 63,152,607 years

2 siblings around Kepler-194

Kepler-194 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-194 b	Super-Earth	1.51	2.89	2.092	1,648	2014
Kepler-194 c	Sub-Neptune	2.59	7.22	17.308	815	2014
Kepler-194 d this	Sub-Neptune	2.40	6.35	52.815	562	2014

Kepler-194 d Planet Profile

Physical Specs

Radius

2.40 R⊕

Radius (Jupiter)

0.214 R♃

Mass

6.35 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.52 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.454

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

#1333of 1978

top 67.3%

This planet

2.40R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

KIC 8540376 c 2.40 R⊕ Kepler-129 b 2.40 R⊕ Kepler-112 c 2.40 R⊕

Metric	Earth	Kepler-194 d	Jupiter
Radius (R⊕)	1.00	2.40	11.21
Mass (M⊕)	1.00	6.35	317.83
Density (g/cm³)	5.51	2.52	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	12.86	0.037

Star Catalogue Identifiers

TIC

TIC 63070427

Gaia DR2

Gaia DR2 2129234336259850240

Gaia DR3

Gaia DR3 2129234336259850240

System

Kepler-194

Percentile among Sub-Neptune cohort

Radius 2.400 R⊕ · percentile 32 / cohort 1978

Mass 6.350 M⊕ · percentile 31 / cohort 1978

Orbital period 52.81 d · percentile 86 / cohort 1946

Distance 1,097.97 pc · percentile 84 / cohort 1975

ESI 0.454 · percentile 63 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

52.815 days

Semi-major axis

0.2750 AU

Eccentricity

0.000

Inclination

90.00 °

Year Length

A year here lasts approximately 52.81 Earth days (14.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2750 AU.

Transit Fingerprint

Depth

0.055 %

Duration

7.300 h

Impact parameter b

0.180

Rp / R★

0.021932

Transit midpoint (BJD)

2,454,997.9032

Photometric dip

Transit produces a flux drop of 554 ppm lasting ≈ 7.30 h.

Extended Orbital Architecture

Planet / star radius ratio

0.021932

Semi-major axis / stellar radius

56.380

Impact parameter (b)

0.180

Transit mid-time (BJD)

2,454,997.9032

Angular separation (arcsec)

0.25000

Eq. Temperature

562K

(289 °C)

Insolation (S⊕)

12.86

Earth = 1.00

Earth Similarity (ESI)

0.454

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

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-194

Spectral Class

F-type yellow-white

Effective Temperature

6,089 K — hotter than the Sun (5,778 K)

Estimated Age

2.50 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.025 R☉

Stellar Mass

0.940 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.415 dex

Stellar density

1.020 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,097.97 parsec

Light-years 3,581.10 ly

V-band magnitude

14.97 mag

Voyager-speed travel 63,152,607 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.882 mas

Total Proper Motion

25.300 mas/yr

PM Right Ascension

-7.30 mas/yr

PM Declination

-24.22 mas/yr

Galactic Cartesian (pc)

x = 0.251 · y = -0.622 · z = 0.742

Equatorial (J2000)

RA 291.97143° · Dec 47.86405°

Galactic ℓ, b

79.854° · 14.098°

Ecliptic λ, β

312.297° · 68.102°

HTM-20 index

-231707313