Key parameters at a glance

A radius of 7.55 Earth radii
A mass of 44.40 Earth masses
Surface gravity around 0.78 g
An orbital period of 39.938 days
Semi-major axis 0.2257 AU
Equilibrium temperature 734 K (461 °C)
Distance from Earth 1,074.06 light-years
Earth Similarity Index 0.212
Travel time at Voyager 1 speed 18,941,066 years

K2-11 b Planet Profile

Physical Specs

Radius

7.55 R⊕

Radius (Jupiter)

0.674 R♃

Mass

44.40 M⊕

Mass (Jupiter)

0.140 M♃

Density

0.57 g/cm³

Surface Gravity

0.78 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.212

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#176of 574

top 30.5%

This planet

7.55R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

TOI-1823 b 7.54 R⊕ OGLE-2018-BLG-0298L b 7.56 R⊕ HD 134606 d 7.59 R⊕

Metric	Earth	K2-11 b	Jupiter
Radius (R⊕)	1.00	7.55	11.21
Mass (M⊕)	1.00	44.40	317.83
Density (g/cm³)	5.51	0.57	1.33
Surface Gravity (g)	1.00	0.78	2.53
Insolation (S⊕)	1.00	9.84	0.037

Star Catalogue Identifiers

TIC

TIC 301609547

Gaia DR2

Gaia DR2 3810535361999701376

Gaia DR3

Gaia DR3 3810535361999701376

System

K2-11

Percentile among Neptune-like cohort

Radius 7.550 R⊕ · percentile 69 / cohort 574

Mass 44.400 M⊕ · percentile 67 / cohort 574

Orbital period 39.94 d · percentile 66 / cohort 524

Distance 329.31 pc · percentile 49 / cohort 572

ESI 0.212 · percentile 30 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

39.938 days

Semi-major axis

0.2257 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 39.94 Earth days (10.9% of a terrestrial year) at a mean orbital distance of 0.2257 AU.

Transit Fingerprint

Depth

0.070 %

Duration

5.808 h

Impact parameter b

0.390

Rp / R★

0.026600

Transit midpoint (BJD)

2,456,829.8290

Photometric dip

Transit produces a flux drop of 700 ppm lasting ≈ 5.81 h.

Extended Orbital Architecture

Planet / star radius ratio

0.026600

Semi-major axis / stellar radius

45.080

Impact parameter (b)

0.390

Transit mid-time (BJD)

2,456,829.8290

Angular separation (arcsec)

0.68500

Eq. Temperature

734K

(461 °C)

Insolation (S⊕)

9.84

Earth = 1.00

Earth Similarity (ESI)

0.212

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Discovery Paper

Primary reference

Montet et al. 2015

Instrument

Kepler CCD Array

Publication

2015-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2015 at K2 (12 shown).

K2-18 b · Sub-Neptune K2-9 b · Sub-Neptune K2-3 d · Super-Earth K2-3 c · Super-Earth K2-21 c · Sub-Neptune K2-5 c · Sub-Neptune K2-13 b · Super-Earth K2-3 b · Sub-Neptune K2-17 b · Sub-Neptune K2-21 b · Super-Earth K2-16 c · Sub-Neptune K2-5 b · Super-Earth

Host System: K2-11

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,433 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

5.150 R☉

Stellar Mass

1.350 M☉

Metallicity [Fe/H]

-0.12

Extended Stellar Properties

Surface gravity (log g)

4.560 dex

Stellar density

2.114 g/cm³

Metallicity ratio

[Fe/H]

Distance

329.31 parsec

Light-years 1,074.06 ly

V-band magnitude

13.41 mag

Voyager-speed travel 18,941,066 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

3.008 mas

Total Proper Motion

54.125 mas/yr

PM Right Ascension

-39.54 mas/yr

PM Declination

-36.96 mas/yr

Galactic Cartesian (pc)

x = -0.981 · y = 0.190 · z = 0.035

Equatorial (J2000)

RA 169.04183° · Dec 1.98668°

Galactic ℓ, b

256.660° · 56.049°

Ecliptic λ, β

169.144° · -2.508°

HTM-20 index

626044280