Key parameters at a glance

A radius of 1.84 Earth radii
A mass of 5.35 Earth masses
Surface gravity around 1.59 g
An orbital period of 5.352 days
Semi-major axis 0.0565 AU
Equilibrium temperature 1,293 K (1020 °C)
Distance from Earth 653.60 light-years
Earth Similarity Index 0.218
Travel time at Voyager 1 speed 11,526,183 years

1 sibling around K2-111

K2-111 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
K2-111 b this	Super-Earth	1.84	5.35	5.352	1,293	2017
K2-111 c	Sub-Neptune	3.34	11.10	15.675	923	2020

K2-111 b Planet Profile

Physical Specs

Radius

1.84 R⊕

Radius (Jupiter)

0.164 R♃

Mass

5.35 M⊕

Mass (Jupiter)

0.017 M♃

Density

5.07 g/cm³

Surface Gravity

1.59 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.218

HZ Position Inner

Controversial No

Discovery

Year 2017

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#219of 1176

top 18.5%

This planet

1.84R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1892 b 1.84 R⊕ TOI-1782.02 1.84 R⊕ Kepler-1691 b 1.83 R⊕

Metric	Earth	K2-111 b	Jupiter
Radius (R⊕)	1.00	1.84	11.21
Mass (M⊕)	1.00	5.35	317.83
Density (g/cm³)	5.51	5.07	1.33
Surface Gravity (g)	1.00	1.59	2.53
Insolation (S⊕)	1.00	490.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	5.350 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 14227229

Gaia DR2

Gaia DR2 53006669599267328

Gaia DR3

Gaia DR3 53006669599267328

System

K2-111

Percentile among Super-Earth cohort

Radius 1.837 R⊕ · percentile 81 / cohort 1176

Mass 5.350 M⊕ · percentile 93 / cohort 1176

Orbital period 5.35 d · percentile 42 / cohort 1164

Distance 200.39 pc · percentile 24 / cohort 1171

ESI 0.218 · percentile 16 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

5.352 days

Semi-major axis

0.0565 AU

Eccentricity

0.134

Inclination

86.34 °

Year Length

A year here lasts approximately 5.35 Earth days (1.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0565 AU.

Transit Fingerprint

Depth

0.012 %

Duration

3.236 h

Impact parameter b

0.602

Rp / R★

0.013500

Transit midpoint (BJD)

2,459,519.1348

Photometric dip

Transit produces a flux drop of 118 ppm lasting ≈ 3.24 h.

Extended Orbital Architecture

Planet / star radius ratio

0.013500

Semi-major axis / stellar radius

9.730

Impact parameter (b)

0.602

RV semi-amplitude (K)

2.230 m/s

Transit mid-time (BJD)

2,459,519.1348

Long. of periastron (ω)

-69.30°

Angular separation (arcsec)

0.28200

Eq. Temperature

1,293K

(1020 °C)

Insolation (S⊕)

490.00

Earth = 1.00

Earth Similarity (ESI)

0.218

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Fridlund et al. 2017

Instrument

Kepler CCD Array

Publication

2017-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2017 at K2 (12 shown).

K2-129 b · Rocky Terrestrial K2-130 b · Super-Earth K2-133 b · Super-Earth K2-128 b · Super-Earth K2-133 c · Super-Earth K2-116 b · Rocky Terrestrial K2-125 b · Sub-Neptune K2-118 b · Sub-Neptune K2-136 d · Super-Earth K2-123 b · Sub-Neptune K2-136 c · Sub-Neptune K2-124 b · Sub-Neptune

Host System: K2-111

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,775 K — cooler than the Sun (5,778 K)

Estimated Age

12.30 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.250 R☉

Stellar Mass

0.840 M☉

Metallicity [Fe/H]

-0.46

Extended Stellar Properties

Surface gravity (log g)

4.250 dex

Stellar density

0.600 g/cm³

Systemic radial velocity

-16.28 km/s

Rotational v·sin i

1.10 km/s

Rotation period

29.20 days

Activity index (log R'HK)

-5.133

Metallicity ratio

[Fe/H]

Distance

200.39 parsec

Light-years 653.60 ly

V-band magnitude

11.13 mag

Voyager-speed travel 11,526,183 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

4.963 mas

Total Proper Motion

127.366 mas/yr

PM Right Ascension

122.34 mas/yr

PM Declination

-35.44 mas/yr

Galactic Cartesian (pc)

x = 0.467 · y = 0.806 · z = 0.363

Equatorial (J2000)

RA 59.89031° · Dec 21.29853°

Galactic ℓ, b

170.979° · -23.551°

Ecliptic λ, β

62.128° · 0.725°

HTM-20 index

-771258425