Key parameters at a glance
- A radius of 3.53 Earth radii
- A mass of 15.68 Earth masses
- Surface gravity around 1.26 g
- An orbital period of 7.138 days
- Semi-major axis 0.0824 AU
- Equilibrium temperature 741 K (468 °C)
- Distance from Earth 505.41 light-years
- Earth Similarity Index 0.308
- Travel time at Voyager 1 speed 8,912,986 years
- Almost certainly tidally locked to its host star given the close orbit
3 siblings around K2-285
K2-285 c shares its host star with 3 other confirmed planets. Side-by-side measurements below.
K2-285 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#164of 1978
top 8.2%
This planet
3.53R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-285 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.53 | 11.21 |
| Mass (M⊕) | 1.00 | 15.68 | 317.83 |
| Density (g/cm³) | 5.51 | 1.95 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.26 | 2.53 |
| Insolation (S⊕) | 1.00 | 50.35 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 15.680 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 262715204
Gaia DR2
Gaia DR2 2657374606238804992
Gaia DR3
Gaia DR3 2657374606238804992
System
K2-285
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.14 Earth days (2.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0824 AU.
Transit Fingerprint
Depth
0.210 %
Duration
2.520 h
Impact parameter b
0.050
Rp / R★
0.041148
Transit midpoint (BJD)
2,457,744.5391
Photometric dip
Transit produces a flux drop of 2,100 ppm lasting ≈ 2.52 h.
Extended Orbital Architecture
Planet / star radius ratio
0.041148
Semi-major axis / stellar radius
22.510
Impact parameter (b)
0.050
RV semi-amplitude (K)
5.900 m/s
Transit mid-time (BJD)
2,457,744.5391
Angular separation (arcsec)
0.53200
Eq. Temperature
741K
(468 °C)
Insolation (S⊕)
50.35
Earth = 1.00
Earth Similarity (ESI)
0.308
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
Palle et al. 2019Instrument
Kepler CCD Array
Publication
2019-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-285
Spectral Class
K-type orange
Effective Temperature
4,975 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.787 R☉
Stellar Mass
0.830 M☉
Metallicity [Fe/H]
0.00
Extended Stellar Properties
Surface gravity (log g)
4.400 dex
Stellar density
2.512 g/cm³
Systemic radial velocity
15.88 km/s
Rotational v·sin i
3.90 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
6.425 mas
Total Proper Motion
37.056 mas/yr
PM Right Ascension
15.02 mas/yr
PM Declination
-33.87 mas/yr
Galactic Cartesian (pc)
x = 0.983 · y = -0.184 · z = 0.023
Equatorial (J2000)
RA 349.38435° · Dec 1.30015°
Galactic ℓ, b
80.675° · -53.685°
Ecliptic λ, β
350.751° · 5.398°
HTM-20 index
204873357
Similar Worlds
TOI-2076 c
Sub-Neptune · K-type orange
Radius 3.54 R⊕ · 136.7 ly
K2-283 b
Sub-Neptune · K-type orange
Radius 3.52 R⊕ · 1,314.1 ly
Kepler-687 b
Sub-Neptune · K-type orange
Radius 3.52 R⊕ · 2,066.7 ly
TOI-1246 e
Sub-Neptune · K-type orange
Radius 3.51 R⊕ · 552.6 ly
KOBE-1 c
Sub-Neptune · K-type orange
Radius 3.56 R⊕ · 78.2 ly
HIP 54373 c
Sub-Neptune · K-type orange
Radius 3.57 R⊕ · 61.0 ly