Key parameters at a glance

A radius of 2.67 Earth radii
A mass of 7.61 Earth masses
Surface gravity around 1.07 g
An orbital period of 14.567 days
Semi-major axis 0.0962 AU
Equilibrium temperature 430 K (157 °C)
Distance from Earth 323.06 light-years
Earth Similarity Index 0.551
Travel time at Voyager 1 speed 5,697,142 years
Almost certainly tidally locked to its host star given the close orbit

K2-26 b Planet Profile

Physical Specs

Radius

2.67 R⊕

Radius (Jupiter)

0.238 R♃

Mass

7.61 M⊕

Mass (Jupiter)

0.024 M♃

Density

2.20 g/cm³

Surface Gravity

1.07 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.551

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#904of 1978

top 45.7%

This planet

2.67R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 155918 b 2.67 R⊕ Kepler-96 b 2.67 R⊕ Kepler-357 c 2.67 R⊕

Metric	Earth	K2-26 b	Jupiter
Radius (R⊕)	1.00	2.67	11.21
Mass (M⊕)	1.00	7.61	317.83
Density (g/cm³)	5.51	2.20	1.33
Surface Gravity (g)	1.00	1.07	2.53
Insolation (S⊕)	1.00	5.80	0.037

Star Catalogue Identifiers

TIC

TIC 83181153

Gaia DR2

Gaia DR2 3425691139632545152

Gaia DR3

Gaia DR3 3425691139632545152

System

K2-26

Percentile among Sub-Neptune cohort

Radius 2.670 R⊕ · percentile 53 / cohort 1978

Mass 7.610 M⊕ · percentile 49 / cohort 1978

Orbital period 14.57 d · percentile 50 / cohort 1946

Distance 99.05 pc · percentile 19 / cohort 1975

ESI 0.551 · percentile 77 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

14.567 days

Semi-major axis

0.0962 AU

Eccentricity

—

Inclination

88.40 °

Year Length

A year here lasts approximately 14.57 Earth days (4.0% of a terrestrial year) at a mean orbital distance of 0.0962 AU.

Transit Fingerprint

Depth

0.259 %

Duration

4.730 h

Impact parameter b

0.570

Rp / R★

0.047100

Transit midpoint (BJD)

2,456,775.1659

Photometric dip

Transit produces a flux drop of 2,589 ppm lasting ≈ 4.73 h.

Extended Orbital Architecture

Planet / star radius ratio

0.047100

Semi-major axis / stellar radius

20.700

Impact parameter (b)

0.570

Transit mid-time (BJD)

2,456,775.1659

Angular separation (arcsec)

0.97100

Eq. Temperature

430K

(157 °C)

Insolation (S⊕)

5.80

Earth = 1.00

Earth Similarity (ESI)

0.551

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Schlieder et al. 2016

Instrument

Kepler CCD Array

Publication

2016-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at K2 (12 shown).

K2-72 d · Rocky Terrestrial K2-72 b · Rocky Terrestrial K2-91 b · Rocky Terrestrial K2-72 c · Rocky Terrestrial K2-102 b · Super-Earth K2-90 c · Super-Earth K2-72 e · Super-Earth K2-83 b · Rocky Terrestrial K2-88 b · Rocky Terrestrial K2-80 c · Super-Earth K2-83 c · Super-Earth K2-65 b · Super-Earth

Host System: K2-26

Spectral Class

M-type red dwarf

Effective Temperature

3,785 K — cooler than the Sun (5,778 K)

Estimated Age

1.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.520 R☉

Stellar Mass

0.560 M☉

Metallicity [Fe/H]

-0.13

Extended Stellar Properties

Surface gravity (log g)

4.724 dex

Stellar density

3.920 g/cm³

Systemic radial velocity

95.34 km/s

Metallicity ratio

[Fe/H]

Distance

99.05 parsec

Light-years 323.06 ly

V-band magnitude

14.53 mag

Voyager-speed travel 5,697,142 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

10.067 mas

Total Proper Motion

118.991 mas/yr

PM Right Ascension

-28.04 mas/yr

PM Declination

-115.64 mas/yr

Galactic Cartesian (pc)

x = -0.067 · y = 0.907 · z = 0.416

Equatorial (J2000)

RA 94.20643° · Dec 24.59583°

Galactic ℓ, b

187.222° · 3.901°

Ecliptic λ, β

93.821° · 1.212°

HTM-20 index

1524504559