Key parameters at a glance

A radius of 3.52 Earth radii
A mass of 12.20 Earth masses
Surface gravity around 0.98 g
An orbital period of 24.544 days
Semi-major axis 0.1734 AU
Equilibrium temperature 616 K (343 °C)
Distance from Earth 5,518.17 light-years
Earth Similarity Index 0.357
Travel time at Voyager 1 speed 97,312,890 years

Kepler-657 b Planet Profile

Physical Specs

Radius

3.52 R⊕

Radius (Jupiter)

0.314 R♃

Mass

12.20 M⊕

Mass (Jupiter)

0.038 M♃

Density

1.54 g/cm³

Surface Gravity

0.98 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.357

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

#169of 1978

top 8.5%

This planet

3.52R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

K2-283 b 3.52 R⊕ HD 45184 b 3.52 R⊕ Kepler-687 b 3.52 R⊕

Metric	Earth	Kepler-657 b	Jupiter
Radius (R⊕)	1.00	3.52	11.21
Mass (M⊕)	1.00	12.20	317.83
Density (g/cm³)	5.51	1.54	1.33
Surface Gravity (g)	1.00	0.98	2.53
Insolation (S⊕)	1.00	62.20	0.037

Star Catalogue Identifiers

TIC

TIC 159643991

Gaia DR2

Gaia DR2 2129158435598210816

Gaia DR3

Gaia DR3 2129158435598210816

System

Kepler-657

Percentile among Sub-Neptune cohort

Radius 3.520 R⊕ · percentile 91 / cohort 1978

Mass 12.200 M⊕ · percentile 84 / cohort 1978

Orbital period 24.54 d · percentile 69 / cohort 1946

Distance 1,691.88 pc · percentile 95 / cohort 1975

ESI 0.357 · percentile 42 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

24.544 days

Semi-major axis

0.1734 AU

Eccentricity

0.000

Inclination

89.91 °

Year Length

A year here lasts approximately 24.54 Earth days (6.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1734 AU.

Transit Fingerprint

Depth

0.115 %

Duration

7.310 h

Impact parameter b

0.788

Rp / R★

0.031854

Transit midpoint (BJD)

2,455,020.9195

Photometric dip

Transit produces a flux drop of 1,151 ppm lasting ≈ 7.31 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031854

Semi-major axis / stellar radius

26.641

Impact parameter (b)

0.788

Transit mid-time (BJD)

2,455,020.9195

Angular separation (arcsec)

0.10200

Eq. Temperature

616K

(343 °C)

Insolation (S⊕)

62.20

Earth = 1.00

Earth Similarity (ESI)

0.357

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-657

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,808 K — hotter than the Sun (5,778 K)

Estimated Age

4.17 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.010 R☉

Stellar Mass

1.010 M☉

Metallicity [Fe/H]

0.03

Extended Stellar Properties

Surface gravity (log g)

4.440 dex

Stellar density

0.594 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,691.88 parsec

Light-years 5,518.17 ly

V-band magnitude

15.40 mag

Voyager-speed travel 97,312,890 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.562 mas

Total Proper Motion

5.709 mas/yr

PM Right Ascension

0.97 mas/yr

PM Declination

-5.63 mas/yr

Galactic Cartesian (pc)

x = 0.245 · y = -0.632 · z = 0.735

Equatorial (J2000)

RA 291.19730° · Dec 47.30775°

Galactic ℓ, b

79.107° · 14.338°

Ecliptic λ, β

310.438° · 67.793°

HTM-20 index

-26221734