Key parameters at a glance

A radius of 2.24 Earth radii
A mass of 5.65 Earth masses
Surface gravity around 1.13 g
An orbital period of 11.723 days
Semi-major axis 0.0983 AU
Equilibrium temperature 766 K (493 °C)
Distance from Earth 2,200.24 light-years
Earth Similarity Index 0.345
Travel time at Voyager 1 speed 38,801,263 years

Kepler-556 b Planet Profile

Physical Specs

Radius

2.24 R⊕

Radius (Jupiter)

0.200 R♃

Mass

5.65 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.76 g/cm³

Surface Gravity

1.13 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.345

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

#1607of 1978

top 81.2%

This planet

2.24R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-69 b 2.24 R⊕ Kepler-284 b 2.24 R⊕ Kepler-196 c 2.24 R⊕

Metric	Earth	Kepler-556 b	Jupiter
Radius (R⊕)	1.00	2.24	11.21
Mass (M⊕)	1.00	5.65	317.83
Density (g/cm³)	5.51	2.76	1.33
Surface Gravity (g)	1.00	1.13	2.53
Insolation (S⊕)	1.00	81.64	0.037

Star Catalogue Identifiers

TIC

TIC 122449752

Gaia DR2

Gaia DR2 2052912492534229504

Gaia DR3

Gaia DR3 2052912492534229504

System

Kepler-556

Percentile among Sub-Neptune cohort

Radius 2.240 R⊕ · percentile 18 / cohort 1978

Mass 5.650 M⊕ · percentile 18 / cohort 1978

Orbital period 11.72 d · percentile 40 / cohort 1946

Distance 674.60 pc · percentile 58 / cohort 1975

ESI 0.345 · percentile 39 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

11.723 days

Semi-major axis

0.0983 AU

Eccentricity

0.000

Inclination

89.97 °

Year Length

A year here lasts approximately 11.72 Earth days (3.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0983 AU.

Transit Fingerprint

Depth

0.049 %

Duration

4.175 h

Impact parameter b

0.710

Rp / R★

0.020827

Transit midpoint (BJD)

2,455,010.3185

Photometric dip

Transit produces a flux drop of 492 ppm lasting ≈ 4.18 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020827

Semi-major axis / stellar radius

21.723

Impact parameter (b)

0.710

Transit mid-time (BJD)

2,455,010.3185

Angular separation (arcsec)

0.14600

Eq. Temperature

766K

(493 °C)

Insolation (S⊕)

81.64

Earth = 1.00

Earth Similarity (ESI)

0.345

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

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-556

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,740 K — cooler than the Sun (5,778 K)

Estimated Age

4.17 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.980 R☉

Stellar Mass

1.000 M☉

Metallicity [Fe/H]

0.03

Extended Stellar Properties

Surface gravity (log g)

4.460 dex

Stellar density

1.270 g/cm³

Metallicity ratio

[Fe/H]

Distance

674.60 parsec

Light-years 2,200.24 ly

V-band magnitude

14.32 mag

Voyager-speed travel 38,801,263 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.454 mas

Total Proper Motion

18.915 mas/yr

PM Right Ascension

9.19 mas/yr

PM Declination

16.54 mas/yr

Galactic Cartesian (pc)

x = 0.273 · y = -0.728 · z = 0.629

Equatorial (J2000)

RA 290.52948° · Dec 38.94273°

Galactic ℓ, b

71.139° · 11.199°

Ecliptic λ, β

303.106° · 60.044°

HTM-20 index

1417465303