Key parameters at a glance
- A radius of 2.60 Earth radii
- A mass of 7.27 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 19.562 days
- Semi-major axis 0.1260 AU
- Equilibrium temperature 455 K (182 °C)
- Distance from Earth 325.93 light-years
- Earth Similarity Index 0.531
- Travel time at Voyager 1 speed 5,747,694 years
- Almost certainly tidally locked to its host star given the close orbit
K2-174 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1017of 1978
top 51.4%
This planet
2.60R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-174 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.60 | 11.21 |
| Mass (M⊕) | 1.00 | 7.27 | 317.83 |
| Density (g/cm³) | 5.51 | 2.27 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 10.96 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 243014114
Gaia DR2
Gaia DR2 46217666333148416
Gaia DR3
Gaia DR3 46217666333148416
System
K2-174
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 19.56 Earth days (5.4% of a terrestrial year) at a mean orbital distance of 0.1260 AU.
Transit Fingerprint
Depth
0.135 %
Duration
5.808 h
Impact parameter b
0.020
Rp / R★
0.036000
Transit midpoint (BJD)
2,457,083.7792
Photometric dip
Transit produces a flux drop of 1,350 ppm lasting ≈ 5.81 h.
Extended Orbital Architecture
Planet / star radius ratio
0.036000
Semi-major axis / stellar radius
26.600
Impact parameter (b)
0.020
Transit mid-time (BJD)
2,457,083.7792
Angular separation (arcsec)
1.26000
Eq. Temperature
455K
(182 °C)
Insolation (S⊕)
10.96
Earth = 1.00
Earth Similarity (ESI)
0.531
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
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: K2-174
Spectral Class
K-type orange
Effective Temperature
4,455 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.676 R☉
Stellar Mass
0.700 M☉
Metallicity [Fe/H]
0.11
Extended Stellar Properties
Surface gravity (log g)
4.625 dex
Stellar density
3.210 g/cm³
Systemic radial velocity
-0.67 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
9.978 mas
Total Proper Motion
69.870 mas/yr
PM Right Ascension
31.85 mas/yr
PM Declination
-62.19 mas/yr
Galactic Cartesian (pc)
x = 0.468 · y = 0.838 · z = 0.281
Equatorial (J2000)
RA 60.79297° · Dec 16.34717°
Galactic ℓ, b
175.582° · -26.349°
Ecliptic λ, β
61.990° · -4.298°
HTM-20 index
-62098271
Similar Worlds
K2-155 c
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 237.4 ly
Kepler-505 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 924.4 ly
K2-90 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 437.7 ly
HD 48948 c
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 55.1 ly
Kepler-1362 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 2,385.2 ly
Kepler-665 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 1,998.8 ly