Key parameters at a glance

A radius of 2.26 Earth radii
A mass of 5.73 Earth masses
Surface gravity around 1.12 g
An orbital period of 12.422 days
Semi-major axis 0.1013 AU
Equilibrium temperature 684 K (411 °C)
Distance from Earth 557.72 light-years
Earth Similarity Index 0.385
Travel time at Voyager 1 speed 9,835,396 years

K2-159 b Planet Profile

Physical Specs

Radius

2.26 R⊕

Radius (Jupiter)

0.202 R♃

Mass

5.73 M⊕

Mass (Jupiter)

0.018 M♃

Density

2.73 g/cm³

Surface Gravity

1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.385

HZ Position Unknown

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1572of 1978

top 79.4%

This planet

2.26R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-163 c 2.26 R⊕ K2-346 b 2.26 R⊕ Kepler-154 b 2.26 R⊕

Metric	Earth	K2-159 b	Jupiter
Radius (R⊕)	1.00	2.26	11.21
Mass (M⊕)	1.00	5.73	317.83
Density (g/cm³)	5.51	2.73	1.33
Surface Gravity (g)	1.00	1.12	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 35064295

Gaia DR2

Gaia DR2 3600851450836925312

Gaia DR3

Gaia DR3 3600851450836925312

System

K2-159

Percentile among Sub-Neptune cohort

Radius 2.260 R⊕ · percentile 20 / cohort 1978

Mass 5.730 M⊕ · percentile 20 / cohort 1978

Orbital period 12.42 d · percentile 43 / cohort 1946

Distance 171.00 pc · percentile 27 / cohort 1975

ESI 0.385 · percentile 49 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

12.422 days

Semi-major axis

0.1013 AU

Eccentricity

—

Inclination

89.06 °

Year Length

A year here lasts approximately 12.42 Earth days (3.4% of a terrestrial year) at a mean orbital distance of 0.1013 AU.

Transit Fingerprint

Depth

0.065 %

Duration

3.300 h

Impact parameter b

0.440

Rp / R★

0.025000

Transit midpoint (BJD)

2,457,586.5082

Photometric dip

Transit produces a flux drop of 650 ppm lasting ≈ 3.30 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025000

Semi-major axis / stellar radius

27.900

Impact parameter (b)

0.440

Transit mid-time (BJD)

2,457,586.5082

Angular separation (arcsec)

0.59200

Eq. Temperature

684K

(411 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.385

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Mayo et al. 2018

Instrument

Kepler CCD Array

Publication

2018-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2018 at K2 (12 shown).

K2-190 c · Rocky Terrestrial K2-183 b · Rocky Terrestrial K2-209 b · Rocky Terrestrial K2-210 b · Rocky Terrestrial K2-165 b · Super-Earth K2-169 b · Super-Earth K2-148 b · Super-Earth K2-219 b · Super-Earth K2-190 b · Super-Earth K2-200 b · Super-Earth K2-201 b · Super-Earth K2-170 b · Super-Earth

Host System: K2-159

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,425 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.830 R☉

Stellar Mass

0.900 M☉

Metallicity [Fe/H]

-0.07

Extended Stellar Properties

Surface gravity (log g)

4.560 dex

Stellar density

2.784 g/cm³

Systemic radial velocity

16.42 km/s

Metallicity ratio

[Fe/H]

Distance

171.00 parsec

Light-years 557.72 ly

V-band magnitude

12.00 mag

Voyager-speed travel 9,835,396 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

5.820 mas

Total Proper Motion

26.543 mas/yr

PM Right Ascension

-1.36 mas/yr

PM Declination

-26.51 mas/yr

Galactic Cartesian (pc)

x = -0.998 · y = -0.009 · z = -0.062

Equatorial (J2000)

RA 180.54089° · Dec -3.58091°

Galactic ℓ, b

279.873° · 57.068°

Ecliptic λ, β

181.918° · -3.070°

HTM-20 index

1696056293