Key parameters at a glance

A radius of 2.22 Earth radii
A mass of 5.56 Earth masses
Surface gravity around 1.13 g
An orbital period of 52.630 days
Semi-major axis 0.2689 AU
Equilibrium temperature 544 K (271 °C)
Distance from Earth 3,855.33 light-years
Earth Similarity Index 0.481
Travel time at Voyager 1 speed 67,988,688 years

Kepler-938 b Planet Profile

Physical Specs

Radius

2.22 R⊕

Radius (Jupiter)

0.198 R♃

Mass

5.56 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.79 g/cm³

Surface Gravity

1.13 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.481

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

#1642of 1978

top 83.0%

This planet

2.22R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1151 b 2.22 R⊕ KMT-2018-BLG-1988L b 2.22 R⊕ Kepler-1432 b 2.22 R⊕

Metric	Earth	Kepler-938 b	Jupiter
Radius (R⊕)	1.00	2.22	11.21
Mass (M⊕)	1.00	5.56	317.83
Density (g/cm³)	5.51	2.79	1.33
Surface Gravity (g)	1.00	1.13	2.53
Insolation (S⊕)	1.00	8.57	0.037

Star Catalogue Identifiers

TIC

TIC 271253308

System

Kepler-938

Percentile among Sub-Neptune cohort

Radius 2.220 R⊕ · percentile 17 / cohort 1978

Mass 5.560 M⊕ · percentile 17 / cohort 1978

Orbital period 52.63 d · percentile 86 / cohort 1946

Distance 1,182.05 pc · percentile 86 / cohort 1975

ESI 0.481 · percentile 68 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

52.630 days

Semi-major axis

0.2689 AU

Eccentricity

0.000

Inclination

89.72 °

Year Length

A year here lasts approximately 52.63 Earth days (14.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2689 AU.

Transit Fingerprint

Depth

0.064 %

Duration

5.964 h

Impact parameter b

0.828

Rp / R★

0.023073

Transit midpoint (BJD)

2,454,988.6115

Photometric dip

Transit produces a flux drop of 637 ppm lasting ≈ 5.96 h.

Extended Orbital Architecture

Planet / star radius ratio

0.023073

Semi-major axis / stellar radius

64.100

Impact parameter (b)

0.828

Transit mid-time (BJD)

2,454,988.6115

Angular separation (arcsec)

0.22700

Eq. Temperature

544K

(271 °C)

Insolation (S⊕)

8.57

Earth = 1.00

Earth Similarity (ESI)

0.481

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-938

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,533 K — cooler than the Sun (5,778 K)

Estimated Age

4.27 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.890 R☉

Stellar Mass

0.920 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.510 dex

Stellar density

1.952 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,182.05 parsec

Light-years 3,855.33 ly

V-band magnitude

15.15 mag

Voyager-speed travel 67,988,688 yr

Multi-band Host Photometry — 15 bands

Astrometric Data

Total Proper Motion

19.538 mas/yr

PM Right Ascension

-12.42 mas/yr

PM Declination

-15.08 mas/yr

Galactic Cartesian (pc)

x = 0.286 · y = -0.619 · z = 0.731

Equatorial (J2000)

RA 294.78906° · Dec 46.98394°

Galactic ℓ, b

79.902° · 11.999°

Ecliptic λ, β

315.874° · 66.519°

HTM-20 index

-1113094811