Key parameters at a glance

A radius of 2.80 Earth radii
A mass of 8.25 Earth masses
Surface gravity around 1.05 g
An orbital period of 17.816 days
Semi-major axis 0.1352 AU
Equilibrium temperature 699 K (426 °C)
Distance from Earth 3,923.53 light-years
Earth Similarity Index 0.347
Travel time at Voyager 1 speed 69,191,381 years

Kepler-66 b Planet Profile

Physical Specs

Radius

2.80 R⊕

Radius (Jupiter)

0.250 R♃

Mass

8.25 M⊕

Mass (Jupiter)

0.026 M♃

Density

2.07 g/cm³

Surface Gravity

1.05 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.347

HZ Position Inner

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#742of 1978

top 37.5%

This planet

2.80R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-694 b 2.80 R⊕ Kepler-276 d 2.80 R⊕ Kepler-350 d 2.80 R⊕

Metric	Earth	Kepler-66 b	Jupiter
Radius (R⊕)	1.00	2.80	11.21
Mass (M⊕)	1.00	8.25	317.83
Density (g/cm³)	5.51	2.07	1.33
Surface Gravity (g)	1.00	1.05	2.53
Insolation (S⊕)	1.00	62.85	0.037

Star Catalogue Identifiers

TIC

TIC 270790035

Gaia DR2

Gaia DR2 2128198836827103616

Gaia DR3

Gaia DR3 2128198836827103616

System

Kepler-66

Percentile among Sub-Neptune cohort

Radius 2.800 R⊕ · percentile 62 / cohort 1978

Mass 8.250 M⊕ · percentile 57 / cohort 1978

Orbital period 17.82 d · percentile 58 / cohort 1946

Distance 1,202.96 pc · percentile 87 / cohort 1975

ESI 0.347 · percentile 40 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

17.816 days

Semi-major axis

0.1352 AU

Eccentricity

0.000

Inclination

87.08 °

Year Length

A year here lasts approximately 17.82 Earth days (4.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1352 AU.

Transit Fingerprint

Depth

0.091 %

Duration

3.367 h

Impact parameter b

0.560

Rp / R★

0.026460

Transit midpoint (BJD)

2,454,967.4854

Photometric dip

Transit produces a flux drop of 906 ppm lasting ≈ 3.37 h.

Extended Orbital Architecture

Planet / star radius ratio

0.026460

Semi-major axis / stellar radius

30.300

Impact parameter (b)

0.560

Transit mid-time (BJD)

2,454,967.4854

Angular separation (arcsec)

0.11200

Eq. Temperature

699K

(426 °C)

Insolation (S⊕)

62.85

Earth = 1.00

Earth Similarity (ESI)

0.347

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

Meibom et al. 2013

Instrument

Kepler CCD Array

Publication

2013-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: Kepler-66

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,962 K — hotter than the Sun (5,778 K)

Estimated Age

1.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.966 R☉

Stellar Mass

1.038 M☉

Metallicity [Fe/H]

-0.20

Extended Stellar Properties

Surface gravity (log g)

4.484 dex

Stellar density

1.620 g/cm³

Metallicity ratio

[M/H]

Distance

1,202.96 parsec

Light-years 3,923.53 ly

V-band magnitude

15.29 mag

Voyager-speed travel 69,191,381 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.803 mas

Total Proper Motion

9.435 mas/yr

PM Right Ascension

-3.44 mas/yr

PM Declination

-8.78 mas/yr

Galactic Cartesian (pc)

x = 0.279 · y = -0.627 · z = 0.728

Equatorial (J2000)

RA 293.98154° · Dec 46.68773°

Galactic ℓ, b

79.376° · 12.358°

Ecliptic λ, β

314.306° · 66.476°

HTM-20 index

-1312431421