Key parameters at a glance

A radius of 2.53 Earth radii
A mass of 6.94 Earth masses
Surface gravity around 1.08 g
An orbital period of 13.115 days
Distance from Earth 396.70 light-years
Earth Similarity Index 0.699
Travel time at Voyager 1 speed 6,995,867 years
Almost certainly tidally locked to its host star given the close orbit

K2-404 b Planet Profile

Physical Specs

Radius

2.53 R⊕

Radius (Jupiter)

0.226 R♃

Mass

6.94 M⊕

Mass (Jupiter)

0.022 M♃

Density

2.35 g/cm³

Surface Gravity

1.08 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.699

HZ Position Unknown

Controversial No

Discovery

Year 2022

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1133of 1978

top 57.2%

This planet

2.53R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-896 b 2.53 R⊕ Kepler-313 b 2.53 R⊕ TOI-1136 g 2.53 R⊕

Metric	Earth	K2-404 b	Jupiter
Radius (R⊕)	1.00	2.53	11.21
Mass (M⊕)	1.00	6.94	317.83
Density (g/cm³)	5.51	2.35	1.33
Surface Gravity (g)	1.00	1.08	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 61312205

Gaia DR2

Gaia DR2 3884361314332210304

Gaia DR3

Gaia DR3 3884361314332210304

System

K2-404

Percentile among Sub-Neptune cohort

Radius 2.530 R⊕ · percentile 42 / cohort 1978

Mass 6.940 M⊕ · percentile 39 / cohort 1978

Orbital period 13.12 d · percentile 45 / cohort 1946

Distance 121.63 pc · percentile 23 / cohort 1975

ESI 0.699 · percentile 92 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

13.115 days

Semi-major axis

— AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 13.12 Earth days (3.6% of a terrestrial year).

Transit Fingerprint

Duration

2.700 h

Impact parameter b

0.481

Rp / R★

0.042000

Transit midpoint (BJD)

2,457,917.8369

Extended Orbital Architecture

Planet / star radius ratio

0.042000

Semi-major axis / stellar radius

34.740

Impact parameter (b)

0.481

Transit mid-time (BJD)

2,457,917.8369

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.699

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Christiansen et al. 2022

Instrument

Kepler CCD Array

Publication

2022-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2022 at K2 (12 shown).

K2-411 b · Rocky Terrestrial K2-381 b · Rocky Terrestrial K2-384 b · Rocky Terrestrial K2-400 b · Rocky Terrestrial K2-384 c · Rocky Terrestrial K2-369 b · Super-Earth K2-407 b · Super-Earth K2-414 b · Rocky Terrestrial K2-368 b · Super-Earth K2-413 c · Rocky Terrestrial K2-384 e · Super-Earth K2-407 c · Super-Earth

Host System: K2-404

Spectral Class

M-type red dwarf

Effective Temperature

3,748 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.552 R☉

Stellar Mass

0.552 M☉

Metallicity [Fe/H]

0.01

Extended Stellar Properties

Surface gravity (log g)

4.695 dex

Stellar density

4.559 g/cm³

Metallicity ratio

[Fe/H]

Distance

121.63 parsec

Light-years 396.70 ly

V-band magnitude

14.62 mag

Voyager-speed travel 6,995,867 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

8.193 mas

Total Proper Motion

31.799 mas/yr

PM Right Ascension

-11.28 mas/yr

PM Declination

-29.73 mas/yr

Galactic Cartesian (pc)

x = -0.920 · y = 0.329 · z = 0.211

Equatorial (J2000)

RA 160.32495° · Dec 12.19111°

Galactic ℓ, b

232.593° · 56.067°

Ecliptic λ, β

157.247° · 3.603°

HTM-20 index

1958314952