Key parameters at a glance
- A radius of 2.69 Earth radii
- A mass of 7.70 Earth masses
- Surface gravity around 1.06 g
- An orbital period of 9.328 days
- Semi-major axis 0.0819 AU
- Equilibrium temperature 696 K (423 °C)
- Distance from Earth 1,069.08 light-years
- Earth Similarity Index 0.354
- Travel time at Voyager 1 speed 18,853,294 years
- Almost certainly tidally locked to its host star given the close orbit
4 siblings around K2-268
K2-268 c shares its host star with 4 other confirmed planets. Side-by-side measurements below.
K2-268 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#881of 1978
top 44.5%
This planet
2.69R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-268 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.69 | 11.21 |
| Mass (M⊕) | 1.00 | 7.70 | 317.83 |
| Density (g/cm³) | 5.51 | 2.17 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.06 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Star Catalogue Identifiers
TIC
TIC 444037742
Gaia DR2
Gaia DR2 604743013163971072
Gaia DR3
Gaia DR3 604743013163971072
System
K2-268
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 9.33 Earth days (2.6% of a terrestrial year) at a mean orbital distance of 0.0819 AU.
Transit Fingerprint
Depth
0.124 %
Duration
3.350 h
Impact parameter b
0.650
Rp / R★
0.031200
Transit midpoint (BJD)
2,457,140.8467
Photometric dip
Transit produces a flux drop of 1,239 ppm lasting ≈ 3.35 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031200
Semi-major axis / stellar radius
17.170
Impact parameter (b)
0.650
Transit mid-time (BJD)
2,457,140.8467
Angular separation (arcsec)
0.25000
Eq. Temperature
696K
(423 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.354
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Livingston et al. 2018Instrument
Kepler CCD Array
Publication
2018-12
Observation locale
Space
Discovery cohort
Planets confirmed in 2018 at K2 (12 shown).
Host System: K2-268
Spectral Class
K-type orange
Effective Temperature
5,106 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.780 R☉
Stellar Mass
0.840 M☉
Metallicity [Fe/H]
0.03
Extended Stellar Properties
Surface gravity (log g)
4.580 dex
Stellar density
2.299 g/cm³
Rotation period
24.87 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
3.022 mas
Total Proper Motion
8.195 mas/yr
PM Right Ascension
-8.19 mas/yr
PM Declination
0.12 mas/yr
Galactic Cartesian (pc)
x = -0.676 · y = 0.707 · z = 0.205
Equatorial (J2000)
RA 133.70949° · Dec 11.84827°
Galactic ℓ, b
216.073° · 32.703°
Ecliptic λ, β
132.779° · -5.338°
HTM-20 index
-1890003543
Similar Worlds
Kepler-417 c
Sub-Neptune · K-type orange
Radius 2.69 R⊕ · 3,176.7 ly
EPIC 212737443 c
Sub-Neptune · K-type orange
Radius 2.69 R⊕ · 1,096.7 ly
TOI-2134 b
Sub-Neptune · K-type orange
Radius 2.69 R⊕ · 73.8 ly
TOI-4504 b
Sub-Neptune · K-type orange
Radius 2.69 R⊕ · 1,117.4 ly
TOI-178 d
Sub-Neptune · K-type orange
Radius 2.70 R⊕ · 204.5 ly
Kepler-1539 b
Sub-Neptune · K-type orange
Radius 2.70 R⊕ · 2,440.7 ly