Key parameters at a glance

A radius of 2.90 Earth radii
A mass of 8.75 Earth masses
Surface gravity around 1.04 g
An orbital period of 17.980 days
Semi-major axis 0.1402 AU
Equilibrium temperature 828 K (555 °C)
Distance from Earth 2,485.20 light-years
Earth Similarity Index 0.288
Travel time at Voyager 1 speed 43,826,461 years

Kepler-631 b Planet Profile

Physical Specs

Radius

2.90 R⊕

Radius (Jupiter)

0.259 R♃

Mass

8.75 M⊕

Mass (Jupiter)

0.028 M♃

Density

1.97 g/cm³

Surface Gravity

1.04 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.288

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

#621of 1978

top 31.3%

This planet

2.90R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-130 c 2.90 R⊕ Kepler-276 c 2.90 R⊕ Kepler-314 c 2.90 R⊕

Metric	Earth	Kepler-631 b	Jupiter
Radius (R⊕)	1.00	2.90	11.21
Mass (M⊕)	1.00	8.75	317.83
Density (g/cm³)	5.51	1.97	1.33
Surface Gravity (g)	1.00	1.04	2.53
Insolation (S⊕)	1.00	94.14	0.037

Star Catalogue Identifiers

TIC

TIC 168816237

Gaia DR2

Gaia DR2 2073719238270085504

Gaia DR3

Gaia DR3 2073719238270085504

System

Kepler-631

Percentile among Sub-Neptune cohort

Radius 2.900 R⊕ · percentile 68 / cohort 1978

Mass 8.750 M⊕ · percentile 62 / cohort 1978

Orbital period 17.98 d · percentile 58 / cohort 1946

Distance 761.97 pc · percentile 63 / cohort 1975

ESI 0.288 · percentile 25 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

17.980 days

Semi-major axis

0.1402 AU

Eccentricity

0.000

Inclination

89.84 °

Year Length

A year here lasts approximately 17.98 Earth days (4.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1402 AU.

Transit Fingerprint

Depth

0.048 %

Duration

5.602 h

Impact parameter b

0.758

Rp / R★

0.020145

Transit midpoint (BJD)

2,455,015.2435

Photometric dip

Transit produces a flux drop of 476 ppm lasting ≈ 5.60 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020145

Semi-major axis / stellar radius

24.926

Impact parameter (b)

0.758

Transit mid-time (BJD)

2,455,015.2435

Angular separation (arcsec)

0.18400

Eq. Temperature

828K

(555 °C)

Insolation (S⊕)

94.14

Earth = 1.00

Earth Similarity (ESI)

0.288

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-631

Spectral Class

F-type yellow-white

Effective Temperature

6,185 K — hotter than the Sun (5,778 K)

Estimated Age

2.51 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.330 R☉

Stellar Mass

1.240 M☉

Metallicity [Fe/H]

0.23

Extended Stellar Properties

Surface gravity (log g)

4.280 dex

Stellar density

0.670 g/cm³

Metallicity ratio

[Fe/H]

Distance

761.97 parsec

Light-years 2,485.20 ly

V-band magnitude

13.56 mag

Voyager-speed travel 43,826,461 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.284 mas

Total Proper Motion

12.100 mas/yr

PM Right Ascension

-4.80 mas/yr

PM Declination

-11.11 mas/yr

Galactic Cartesian (pc)

x = 0.345 · y = -0.681 · z = 0.646

Equatorial (J2000)

RA 296.88572° · Dec 40.22817°

Galactic ℓ, b

74.598° · 7.458°

Ecliptic λ, β

313.180° · 59.701°

HTM-20 index

-1335946773