Key parameters at a glance
- A radius of 2.71 Earth radii
- A mass of 20.98 Earth masses
- Surface gravity around 2.85 g
- An orbital period of 4.737 days
- Semi-major axis 0.0517 AU
- Equilibrium temperature 966 K (693 °C)
- Distance from Earth 504.99 light-years
- Earth Similarity Index 0.275
- Travel time at Voyager 1 speed 8,905,451 years
- Almost certainly tidally locked to its host star given the close orbit
K2-182 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#846of 1978
top 42.7%
This planet
2.71R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-182 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.71 | 11.21 |
| Mass (M⊕) | 1.00 | 20.98 | 317.83 |
| Density (g/cm³) | 5.51 | 5.70 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.85 | 2.53 |
| Insolation (S⊕) | 1.00 | 146.90 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 20.977 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 366631954
Gaia DR2
Gaia DR2 601480723509077632
Gaia DR3
Gaia DR3 601480723509077632
System
K2-182
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.74 Earth days (1.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0517 AU.
Transit Fingerprint
Depth
0.099 %
Duration
2.566 h
Impact parameter b
0.270
Rp / R★
0.031430
Transit midpoint (BJD)
2,457,652.7976
Photometric dip
Transit produces a flux drop of 988 ppm lasting ≈ 2.57 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031430
Semi-major axis / stellar radius
14.110
Impact parameter (b)
0.270
RV semi-amplitude (K)
9.100 m/s
Transit mid-time (BJD)
2,457,652.7976
Long. of periastron (ω)
-160.00°
Angular separation (arcsec)
0.33400
Eq. Temperature
966K
(693 °C)
Insolation (S⊕)
146.90
Earth = 1.00
Earth Similarity (ESI)
0.275
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.
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
Mayo et al. 2018Instrument
Kepler CCD Array
Publication
2018-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-182
Spectral Class
K-type orange
Effective Temperature
5,128 K — cooler than the Sun (5,778 K)
Estimated Age
6.20 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.789 R☉
Stellar Mass
0.823 M☉
Metallicity [Fe/H]
0.02
Extended Stellar Properties
Surface gravity (log g)
4.560 dex
Stellar density
2.370 g/cm³
Systemic radial velocity
22.98 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
6.430 mas
Total Proper Motion
65.177 mas/yr
PM Right Ascension
-65.16 mas/yr
PM Declination
1.42 mas/yr
Galactic Cartesian (pc)
x = -0.633 · y = 0.750 · z = 0.191
Equatorial (J2000)
RA 130.18005° · Dec 10.98295°
Galactic ℓ, b
215.288° · 29.201°
Ecliptic λ, β
129.659° · -7.097°
HTM-20 index
-685577863
Similar Worlds
K2-250 b
Sub-Neptune · K-type orange
Radius 2.71 R⊕ · 1,352.6 ly
Kepler-48 c
Sub-Neptune · K-type orange
Radius 2.71 R⊕ · 1,000.4 ly
Kepler-1058 b
Sub-Neptune · K-type orange
Radius 2.72 R⊕ · 1,604.7 ly
TOI-712 c
Sub-Neptune · K-type orange
Radius 2.70 R⊕ · 191.2 ly
Kepler-1539 b
Sub-Neptune · K-type orange
Radius 2.70 R⊕ · 2,440.7 ly
Kepler-290 c
Sub-Neptune · K-type orange
Radius 2.70 R⊕ · 2,265.6 ly