Key parameters at a glance

A radius of 2.73 Earth radii
A mass of 7.90 Earth masses
Surface gravity around 1.06 g
An orbital period of 15.750 days
Semi-major axis 0.1266 AU
Equilibrium temperature 777 K (504 °C)
Distance from Earth 3,600.89 light-years
Earth Similarity Index 0.315
Travel time at Voyager 1 speed 63,501,739 years

Kepler-838 b Planet Profile

Physical Specs

Radius

2.73 R⊕

Radius (Jupiter)

0.244 R♃

Mass

7.90 M⊕

Mass (Jupiter)

0.025 M♃

Density

2.13 g/cm³

Surface Gravity

1.06 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.315

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

#823of 1978

top 41.6%

This planet

2.73R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-436 b 2.73 R⊕ Kepler-506 b 2.73 R⊕ Kepler-221 d 2.73 R⊕

Metric	Earth	Kepler-838 b	Jupiter
Radius (R⊕)	1.00	2.73	11.21
Mass (M⊕)	1.00	7.90	317.83
Density (g/cm³)	5.51	2.13	1.33
Surface Gravity (g)	1.00	1.06	2.53
Insolation (S⊕)	1.00	61.09	0.037

Star Catalogue Identifiers

TIC

TIC 351909828

Gaia DR2

Gaia DR2 2106520040936657536

Gaia DR3

Gaia DR3 2106520040936657536

System

Kepler-838

Percentile among Sub-Neptune cohort

Radius 2.730 R⊕ · percentile 58 / cohort 1978

Mass 7.900 M⊕ · percentile 53 / cohort 1978

Orbital period 15.75 d · percentile 52 / cohort 1946

Distance 1,104.04 pc · percentile 84 / cohort 1975

ESI 0.315 · percentile 32 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

15.750 days

Semi-major axis

0.1266 AU

Eccentricity

0.000

Inclination

88.24 °

Year Length

A year here lasts approximately 15.75 Earth days (4.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1266 AU.

Transit Fingerprint

Depth

0.066 %

Duration

4.694 h

Impact parameter b

0.626

Rp / R★

0.025568

Transit midpoint (BJD)

2,454,983.2454

Photometric dip

Transit produces a flux drop of 660 ppm lasting ≈ 4.69 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025568

Semi-major axis / stellar radius

20.800

Impact parameter (b)

0.626

Transit mid-time (BJD)

2,454,983.2454

Angular separation (arcsec)

0.11500

Eq. Temperature

777K

(504 °C)

Insolation (S⊕)

61.09

Earth = 1.00

Earth Similarity (ESI)

0.315

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-838

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,770 K — cooler than the Sun (5,778 K)

Estimated Age

4.17 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.960 R☉

Stellar Mass

0.980 M☉

Metallicity [Fe/H]

-0.06

Extended Stellar Properties

Surface gravity (log g)

4.460 dex

Stellar density

0.691 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,104.04 parsec

Light-years 3,600.89 ly

V-band magnitude

15.42 mag

Voyager-speed travel 63,501,739 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.877 mas

Total Proper Motion

9.326 mas/yr

PM Right Ascension

-5.88 mas/yr

PM Declination

-7.24 mas/yr

Galactic Cartesian (pc)

x = 0.185 · y = -0.670 · z = 0.719

Equatorial (J2000)

RA 285.43547° · Dec 45.97596°

Galactic ℓ, b

76.230° · 17.462°

Ecliptic λ, β

299.371° · 67.847°

HTM-20 index

-1525233696