Key parameters at a glance

A radius of 1.12 Earth radii
A mass of 1.46 Earth masses
Surface gravity around 1.16 g
An orbital period of 35.233 days
Semi-major axis 0.1660 AU
Equilibrium temperature 288 K (15 °C)
Distance from Earth 639.08 light-years
Earth Similarity Index 0.975
Travel time at Voyager 1 speed 11,270,165 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

Kepler-438b is a confirmed near-Earth-sized exoplanet. It is likely rocky. It orbits on the inner edge of the habitable zone of a red dwarf, Kepler-438, about 460.2 light-years from Earth in the constellation Lyra. It receives 1.4 times the solar flux of Earth. The planet was discovered by NASA's Kepler spacecraft using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. NASA announced the confirmation of the exoplanet on 6 January 2015.

Excerpted from Wikipedia · full article

Kepler-438 b Planet Profile

Physical Specs

Radius

1.12 R⊕

Radius (Jupiter)

0.100 R♃

Mass

1.46 M⊕

Mass (Jupiter)

0.005 M♃

Density

5.71 g/cm³

Surface Gravity

1.16 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.975

HZ Position Habitable

Controversial No

Discovery

Year 2015

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#193of 570

top 33.7%

This planet

1.12R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-381 c 1.12 R⊕ Kepler-1082 b 1.12 R⊕ Kepler-1288 b 1.12 R⊕

Metric	Earth	Kepler-438 b	Jupiter
Radius (R⊕)	1.00	1.12	11.21
Mass (M⊕)	1.00	1.46	317.83
Density (g/cm³)	5.51	5.71	1.33
Surface Gravity (g)	1.00	1.16	2.53
Insolation (S⊕)	1.00	1.40	0.037

Star Catalogue Identifiers

TIC

TIC 336266673

Gaia DR2

Gaia DR2 2104675781979819776

Gaia DR3

Gaia DR3 2104675781979819776

System

Kepler-438

Percentile among Rocky Terrestrial cohort

Radius 1.120 R⊕ · percentile 64 / cohort 570

Mass 1.460 M⊕ · percentile 59 / cohort 570

Orbital period 35.23 d · percentile 98 / cohort 567

Distance 195.94 pc · percentile 31 / cohort 566

ESI 0.975 · percentile 96 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

35.233 days

Semi-major axis

0.1660 AU

Eccentricity

0.030

Inclination

89.86 °

Year Length

A year here lasts approximately 35.23 Earth days (9.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1660 AU.

Transit Fingerprint

Depth

0.035 %

Duration

3.480 h

Impact parameter b

0.900

Rp / R★

0.020000

Transit midpoint (BJD)

2,455,673.0307

Photometric dip

Transit produces a flux drop of 353 ppm lasting ≈ 3.48 h.

Extended Orbital Architecture

Planet / star radius ratio

0.020000

Semi-major axis / stellar radius

73.000

Impact parameter (b)

0.900

Transit mid-time (BJD)

2,455,673.0307

Angular separation (arcsec)

0.84700

Eq. Temperature

288K

(15 °C)

Insolation (S⊕)

1.40

Earth = 1.00

Earth Similarity (ESI)

0.975

0 = alien, 1 = Earth-identical

Within the conservative habitable zone — liquid water is physically possible with adequate atmospheric pressure. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Torres et al. 2015

Instrument

Kepler CCD Array

Publication

2015-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2015 at Kepler (12 shown).

Kepler-445 d · Super-Earth Kepler-442 b · Super-Earth Kepler-439 b · Sub-Neptune Kepler-437 b · Sub-Neptune Kepler-440 b · Super-Earth KIC 8540376 c · Sub-Neptune Kepler-445 b · Super-Earth Kepler-446 d · Super-Earth Kepler-436 b · Sub-Neptune Kepler-445 c · Sub-Neptune Kepler-443 b · Sub-Neptune Kepler-441 b · Super-Earth

Host System: Kepler-438

Spectral Class

K-type orange

Effective Temperature

3,748 K — cooler than the Sun (5,778 K)

Estimated Age

4.40 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.520 R☉

Stellar Mass

0.544 M☉

Metallicity [Fe/H]

0.16

Extended Stellar Properties

Surface gravity (log g)

4.740 dex

Stellar density

5.520 g/cm³

Metallicity ratio

[Fe/H]

Distance

195.94 parsec

Light-years 639.08 ly

V-band magnitude

15.10 mag

Voyager-speed travel 11,270,165 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

5.104 mas

Total Proper Motion

30.562 mas/yr

PM Right Ascension

-20.34 mas/yr

PM Declination

-22.81 mas/yr

Galactic Cartesian (pc)

x = 0.150 · y = -0.728 · z = 0.668

Equatorial (J2000)

RA 281.64572° · Dec 41.95107°

Galactic ℓ, b

71.258° · 18.593°

Ecliptic λ, β

290.456° · 64.565°

HTM-20 index

-1829473398

Wikipedia → Image: Wikimedia Commons · Aldaron, a.k.a. Aldaron · CC BY-SA 3.0