Key parameters at a glance

A radius of 2.82 Earth radii
A mass of 8.35 Earth masses
Surface gravity around 1.05 g
An orbital period of 175.139 days
Semi-major axis 0.6095 AU
Equilibrium temperature 346 K (73 °C)
Distance from Earth 3,670.23 light-years
Earth Similarity Index 0.642
Travel time at Voyager 1 speed 64,724,564 years

Kepler-1538 b Planet Profile

Physical Specs

Radius

2.82 R⊕

Radius (Jupiter)

0.252 R♃

Mass

8.35 M⊕

Mass (Jupiter)

0.026 M♃

Density

2.05 g/cm³

Surface Gravity

1.05 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.642

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

#720of 1978

top 36.3%

This planet

2.82R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-281 b 2.82 R⊕ Kepler-198 b 2.82 R⊕ Kepler-722 c 2.82 R⊕

Metric	Earth	Kepler-1538 b	Jupiter
Radius (R⊕)	1.00	2.82	11.21
Mass (M⊕)	1.00	8.35	317.83
Density (g/cm³)	5.51	2.05	1.33
Surface Gravity (g)	1.00	1.05	2.53
Insolation (S⊕)	1.00	1.99	0.037

Star Catalogue Identifiers

TIC

TIC 164522561

Gaia DR2

Gaia DR2 2106988158011587072

Gaia DR3

Gaia DR3 2106988158011587072

System

Kepler-1538

Percentile among Sub-Neptune cohort

Radius 2.820 R⊕ · percentile 63 / cohort 1978

Mass 8.350 M⊕ · percentile 58 / cohort 1978

Orbital period 175.14 d · percentile 98 / cohort 1946

Distance 1,125.30 pc · percentile 84 / cohort 1975

ESI 0.642 · percentile 87 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

175.139 days

Semi-major axis

0.6095 AU

Eccentricity

0.000

Inclination

89.97 °

Year Length

A year here lasts approximately 175.14 Earth days (48.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.6095 AU.

Transit Fingerprint

Depth

0.063 %

Duration

10.666 h

Impact parameter b

0.070

Rp / R★

0.024503

Transit midpoint (BJD)

2,455,129.0399

Photometric dip

Transit produces a flux drop of 635 ppm lasting ≈ 10.67 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024503

Semi-major axis / stellar radius

126.800

Impact parameter (b)

0.070

Transit mid-time (BJD)

2,455,129.0399

Angular separation (arcsec)

0.54200

Eq. Temperature

346K

(73 °C)

Insolation (S⊕)

1.99

Earth = 1.00

Earth Similarity (ESI)

0.642

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.

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-1538

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,837 K — hotter than the Sun (5,778 K)

Estimated Age

4.37 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.030 R☉

Stellar Mass

1.030 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.420 dex

Stellar density

1.256 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,125.30 parsec

Light-years 3,670.23 ly

V-band magnitude

15.55 mag

Voyager-speed travel 64,724,564 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.860 mas

Total Proper Motion

17.704 mas/yr

PM Right Ascension

-13.48 mas/yr

PM Declination

-11.48 mas/yr

Galactic Cartesian (pc)

x = 0.162 · y = -0.685 · z = 0.710

Equatorial (J2000)

RA 283.34561° · Dec 45.27436°

Galactic ℓ, b

74.997° · 18.582°

Ecliptic λ, β

295.170° · 67.551°

HTM-20 index

507207535