Key parameters at a glance
- A radius of 4.57 Earth radii
- A mass of 18.90 Earth masses
- Surface gravity around 0.91 g
- An orbital period of 3.435 days
- Equilibrium temperature 969 K (696 °C)
- Distance from Earth 643.29 light-years
- Earth Similarity Index 0.201
- Travel time at Voyager 1 speed 11,344,428 years
- Almost certainly tidally locked to its host star given the close orbit
K2-405 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#455of 574
top 79.1%
This planet
4.57R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | K2-405 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.57 | 11.21 |
| Mass (M⊕) | 1.00 | 18.90 | 317.83 |
| Density (g/cm³) | 5.51 | 1.09 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.91 | 2.53 |
| Insolation (S⊕) | 1.00 | 146.58 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 149496868
Gaia DR2
Gaia DR2 3871908447498807296
Gaia DR3
Gaia DR3 3871908447498807296
System
K2-405
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.44 Earth days (0.9% of a terrestrial year).
Transit Fingerprint
Depth
0.258 %
Duration
2.110 h
Impact parameter b
0.871
Rp / R★
0.054800
Transit midpoint (BJD)
2,457,908.9959
Photometric dip
Transit produces a flux drop of 2,580 ppm lasting ≈ 2.11 h.
Extended Orbital Architecture
Planet / star radius ratio
0.054800
Semi-major axis / stellar radius
6.330
Impact parameter (b)
0.871
Transit mid-time (BJD)
2,457,908.9959
Eq. Temperature
969K
(696 °C)
Insolation (S⊕)
146.58
Earth = 1.00
Earth Similarity (ESI)
0.201
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
Christiansen et al. 2022Instrument
Kepler CCD Array
Publication
2022-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2022 at K2 (12 shown).
Host System: K2-405
Spectral Class
K-type orange
Effective Temperature
4,927 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.765 R☉
Stellar Mass
1.034 M☉
Metallicity [Fe/H]
0.13
Extended Stellar Properties
Surface gravity (log g)
4.685 dex
Stellar density
2.168 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
5.042 mas
Total Proper Motion
43.028 mas/yr
PM Right Ascension
-42.78 mas/yr
PM Declination
-4.60 mas/yr
Galactic Cartesian (pc)
x = -0.940 · y = 0.263 · z = 0.217
Equatorial (J2000)
RA 164.37600° · Dec 12.53561°
Galactic ℓ, b
235.980° · 59.608°
Ecliptic λ, β
160.787° · 5.426°
HTM-20 index
-1793777438
Similar Worlds
K2-43 b
Neptune-like · K-type orange
Radius 4.51 R⊕ · 595.4 ly
TOI-942 c
Neptune-like · K-type orange
Radius 4.67 R⊕ · 497.7 ly
HD 69830 d
Neptune-like · K-type orange
Radius 4.45 R⊕ · 41.0 ly
K2-55 b
Neptune-like · K-type orange
Radius 4.43 R⊕ · 520.3 ly
Kepler-411 c
Neptune-like · K-type orange
Radius 4.42 R⊕ · 501.2 ly
HD 99492 c
Neptune-like · K-type orange
Radius 4.42 R⊕ · 59.4 ly