Key parameters at a glance

A radius of 2.00 Earth radii
A mass of 4.66 Earth masses
Surface gravity around 1.17 g
An orbital period of 1.617 days
Semi-major axis 0.0266 AU
Equilibrium temperature 1,774 K (1501 °C)
Distance from Earth 1,765.91 light-years
Earth Similarity Index 0.141
Travel time at Voyager 1 speed 31,141,873 years

Kepler-578 b Planet Profile

Physical Specs

Radius

2.00 R⊕

Radius (Jupiter)

0.178 R♃

Mass

4.66 M⊕

Mass (Jupiter)

0.015 M♃

Density

3.20 g/cm³

Surface Gravity

1.17 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.141

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

#1955of 1978

top 98.8%

This planet

2.00R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-32 c 2.00 R⊕ Kepler-238 f 2.00 R⊕ Kepler-242 c 2.00 R⊕

Metric	Earth	Kepler-578 b	Jupiter
Radius (R⊕)	1.00	2.00	11.21
Mass (M⊕)	1.00	4.66	317.83
Density (g/cm³)	5.51	3.20	1.33
Surface Gravity (g)	1.00	1.17	2.53
Insolation (S⊕)	1.00	496.90	0.037

Star Catalogue Identifiers

TIC

TIC 121734474

Gaia DR2

Gaia DR2 2099714751157275264

Gaia DR3

Gaia DR3 2099714751157275264

System

Kepler-578

Percentile among Sub-Neptune cohort

Radius 2.000 R⊕ · percentile 0 / cohort 1978

Mass 4.660 M⊕ · percentile 2 / cohort 1978

Orbital period 1.62 d · percentile 1 / cohort 1946

Distance 541.43 pc · percentile 49 / cohort 1975

ESI 0.141 · percentile 2 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

1.617 days

Semi-major axis

0.0266 AU

Eccentricity

0.000

Inclination

78.60 °

Year Length

A year here lasts approximately 1.62 Earth days (0.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0266 AU.

Transit Fingerprint

Depth

0.046 %

Duration

1.585 h

Impact parameter b

0.788

Rp / R★

0.021830

Transit midpoint (BJD)

2,455,002.8035

Photometric dip

Transit produces a flux drop of 460 ppm lasting ≈ 1.58 h.

Extended Orbital Architecture

Planet / star radius ratio

0.021830

Semi-major axis / stellar radius

4.330

Impact parameter (b)

0.788

Transit mid-time (BJD)

2,455,002.8035

Angular separation (arcsec)

0.04910

Eq. Temperature

1,774K

(1501 °C)

Insolation (S⊕)

496.90

Earth = 1.00

Earth Similarity (ESI)

0.141

0 = alien, 1 = Earth-identical

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

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-578

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,334 K — cooler than the Sun (5,778 K)

Estimated Age

4.68 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.830 R☉

Stellar Mass

0.870 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.540 dex

Stellar density

0.984 g/cm³

Metallicity ratio

[Fe/H]

Distance

541.43 parsec

Light-years 1,765.91 ly

V-band magnitude

14.58 mag

Voyager-speed travel 31,141,873 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.818 mas

Total Proper Motion

10.432 mas/yr

PM Right Ascension

6.33 mas/yr

PM Declination

8.29 mas/yr

Galactic Cartesian (pc)

x = 0.248 · y = -0.730 · z = 0.637

Equatorial (J2000)

RA 288.75499° · Dec 39.56370°

Galactic ℓ, b

71.110° · 12.707°

Ecliptic λ, β

300.761° · 61.015°

HTM-20 index

-88018104