Key parameters at a glance
- A radius of 2.59 Earth radii
- A mass of 9.68 Earth masses
- Surface gravity around 1.44 g
- An orbital period of 3.472 days
- Semi-major axis 0.0382 AU
- Equilibrium temperature 1,089 K (816 °C)
- Distance from Earth 505.41 light-years
- Earth Similarity Index 0.233
- 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 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.
K2-285 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1043of 1978
top 52.7%
This planet
2.59R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-285 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.59 | 11.21 |
| Mass (M⊕) | 1.00 | 9.68 | 317.83 |
| Density (g/cm³) | 5.51 | 3.07 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.44 | 2.53 |
| Insolation (S⊕) | 1.00 | 234.31 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 9.680 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 3.47 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0382 AU.
Transit Fingerprint
Depth
0.097 %
Duration
2.180 h
Impact parameter b
0.570
Rp / R★
0.030130
Transit midpoint (BJD)
2,457,743.3755
Photometric dip
Transit produces a flux drop of 970 ppm lasting ≈ 2.18 h.
Extended Orbital Architecture
Planet / star radius ratio
0.030130
Semi-major axis / stellar radius
10.430
Impact parameter (b)
0.570
RV semi-amplitude (K)
4.620 m/s
Transit mid-time (BJD)
2,457,743.3755
Angular separation (arcsec)
0.24600
Eq. Temperature
1,089K
(816 °C)
Insolation (S⊕)
234.31
Earth = 1.00
Earth Similarity (ESI)
0.233
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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 b
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 136.7 ly
Kepler-1388 b
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 1,480.1 ly
K2-110 b
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 379.9 ly
Kepler-1854 b
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 1,380.8 ly
TOI-836.01
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 89.7 ly
TOI-1064 b
Sub-Neptune · K-type orange
Radius 2.59 R⊕ · 222.0 ly