Key parameters at a glance

A radius of 2.71 Earth radii
A mass of 7.80 Earth masses
Surface gravity around 1.06 g
An orbital period of 13.222 days
Semi-major axis 0.1032 AU
Equilibrium temperature 640 K (367 °C)
Distance from Earth 1,369.86 light-years
Earth Similarity Index 0.383
Travel time at Voyager 1 speed 24,157,395 years

Kepler-478 b Planet Profile

Physical Specs

Radius

2.71 R⊕

Radius (Jupiter)

0.242 R♃

Mass

7.80 M⊕

Mass (Jupiter)

0.025 M♃

Density

2.15 g/cm³

Surface Gravity

1.06 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.383

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

#849of 1978

top 42.9%

This planet

2.71R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-48 c 2.71 R⊕ Kepler-355 c 2.71 R⊕ Kepler-233 c 2.71 R⊕

Metric	Earth	Kepler-478 b	Jupiter
Radius (R⊕)	1.00	2.71	11.21
Mass (M⊕)	1.00	7.80	317.83
Density (g/cm³)	5.51	2.15	1.33
Surface Gravity (g)	1.00	1.06	2.53
Insolation (S⊕)	1.00	39.56	0.037

Star Catalogue Identifiers

TIC

TIC 63289259

Gaia DR2

Gaia DR2 2128256492466658176

Gaia DR3

Gaia DR3 2128256492468364160

System

Kepler-478

Percentile among Sub-Neptune cohort

Radius 2.710 R⊕ · percentile 57 / cohort 1978

Mass 7.800 M⊕ · percentile 52 / cohort 1978

Orbital period 13.22 d · percentile 45 / cohort 1946

Distance 420.00 pc · percentile 42 / cohort 1975

ESI 0.383 · percentile 49 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.222 days

Semi-major axis

0.1032 AU

Eccentricity

0.000

Inclination

89.23 °

Year Length

A year here lasts approximately 13.22 Earth days (3.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1032 AU.

Transit Fingerprint

Depth

0.088 %

Duration

2.907 h

Impact parameter b

0.451

Rp / R★

0.031317

Transit midpoint (BJD)

2,454,972.5702

Photometric dip

Transit produces a flux drop of 877 ppm lasting ≈ 2.91 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031317

Semi-major axis / stellar radius

21.700

Impact parameter (b)

0.451

Transit mid-time (BJD)

2,454,972.5702

Angular separation (arcsec)

0.24600

Eq. Temperature

640K

(367 °C)

Insolation (S⊕)

39.56

Earth = 1.00

Earth Similarity (ESI)

0.383

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

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-478

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,210 K — cooler than the Sun (5,778 K)

Estimated Age

4.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.800 R☉

Stellar Mass

0.850 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.560 dex

Stellar density

4.047 g/cm³

Metallicity ratio

[Fe/H]

Distance

420.00 parsec

Light-years 1,369.86 ly

V-band magnitude

14.16 mag

Voyager-speed travel 24,157,395 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.494 mas

Total Proper Motion

12.279 mas/yr

PM Right Ascension

11.64 mas/yr

PM Declination

-3.92 mas/yr

Galactic Cartesian (pc)

x = 0.265 · y = -0.640 · z = 0.722

Equatorial (J2000)

RA 292.48701° · Dec 46.19619°

Galactic ℓ, b

78.459° · 13.065°

Ecliptic λ, β

311.452° · 66.429°

HTM-20 index

-824021967