Key parameters at a glance

A radius of 6.91 Earth radii
A mass of 38.20 Earth masses
Surface gravity around 0.80 g
An orbital period of 38.584 days
Semi-major axis 0.2503 AU
Equilibrium temperature 761 K (488 °C)
Distance from Earth 2,084.92 light-years
Earth Similarity Index 0.214
Travel time at Voyager 1 speed 36,767,498 years

Kepler-522 b Planet Profile

Physical Specs

Radius

6.91 R⊕

Radius (Jupiter)

0.616 R♃

Mass

38.20 M⊕

Mass (Jupiter)

0.120 M♃

Density

0.64 g/cm³

Surface Gravity

0.80 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.214

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

#209of 574

top 36.2%

This planet

6.91R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

KMT-2021-BLG-0712L b 6.91 R⊕ KMT-2021-BLG-1554L b 6.90 R⊕ KIC 3558849 b 6.90 R⊕

Metric	Earth	Kepler-522 b	Jupiter
Radius (R⊕)	1.00	6.91	11.21
Mass (M⊕)	1.00	38.20	317.83
Density (g/cm³)	5.51	0.64	1.33
Surface Gravity (g)	1.00	0.80	2.53
Insolation (S⊕)	1.00	63.86	0.037

Star Catalogue Identifiers

TIC

TIC 158657354

Gaia DR2

Gaia DR2 2103117666624517888

Gaia DR3

Gaia DR3 2103117666624517888

System

Kepler-522

Percentile among Neptune-like cohort

Radius 6.910 R⊕ · percentile 63 / cohort 574

Mass 38.200 M⊕ · percentile 61 / cohort 574

Orbital period 38.58 d · percentile 65 / cohort 524

Distance 639.24 pc · percentile 62 / cohort 572

ESI 0.214 · percentile 30 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

38.584 days

Semi-major axis

0.2503 AU

Eccentricity

0.000

Inclination

85.76 °

Year Length

A year here lasts approximately 38.58 Earth days (10.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2503 AU.

Transit Fingerprint

Depth

0.124 %

Duration

10.368 h

Impact parameter b

0.905

Rp / R★

0.032303

Transit midpoint (BJD)

2,455,007.8334

Photometric dip

Transit produces a flux drop of 1,244 ppm lasting ≈ 10.37 h.

Extended Orbital Architecture

Planet / star radius ratio

0.032303

Semi-major axis / stellar radius

29.352

Impact parameter (b)

0.905

Transit mid-time (BJD)

2,455,007.8334

Angular separation (arcsec)

0.39200

Eq. Temperature

761K

(488 °C)

Insolation (S⊕)

63.86

Earth = 1.00

Earth Similarity (ESI)

0.214

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-522

Spectral Class

F-type yellow-white

Effective Temperature

6,392 K — hotter than the Sun (5,778 K)

Estimated Age

1.70 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.980 R☉

Stellar Mass

1.540 M☉

Metallicity [Fe/H]

0.41

Extended Stellar Properties

Surface gravity (log g)

4.040 dex

Stellar density

0.321 g/cm³

Systemic radial velocity

-3.40 km/s

Metallicity ratio

[Fe/H]

Distance

639.24 parsec

Light-years 2,084.92 ly

V-band magnitude

12.22 mag

Voyager-speed travel 36,767,498 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.536 mas

Total Proper Motion

4.837 mas/yr

PM Right Ascension

-4.09 mas/yr

PM Declination

-2.59 mas/yr

Galactic Cartesian (pc)

x = 0.224 · y = -0.683 · z = 0.696

Equatorial (J2000)

RA 288.15397° · Dec 44.06882°

Galactic ℓ, b

75.155° · 14.960°

Ecliptic λ, β

302.619° · 65.465°

HTM-20 index

1104462201