Key parameters at a glance
- A radius of 3.34 Earth radii
- A mass of 11.10 Earth masses
- Surface gravity around 1.00 g
- An orbital period of 15.675 days
- Semi-major axis 0.1157 AU
- Equilibrium temperature 923 K (650 °C)
- Distance from Earth 653.60 light-years
- Earth Similarity Index 0.243
- Travel time at Voyager 1 speed 11,526,183 years
1 sibling around K2-111
K2-111 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| K2-111 b | Super-Earth | 1.84 | 5.35 | 5.352 | 1,293 | 2017 |
| K2-111 c this | Sub-Neptune | 3.34 | 11.10 | 15.675 | 923 | 2020 |
K2-111 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#256of 1978
top 12.9%
This planet
3.34R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-111 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.34 | 11.21 |
| Mass (M⊕) | 1.00 | 11.10 | 317.83 |
| Density (g/cm³) | 5.51 | 1.64 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.00 | 2.53 |
| Insolation (S⊕) | 1.00 | — | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Minimum mass (M sin i) | 11.100 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
TIC
TIC 14227229
Gaia DR2
Gaia DR2 53006669599267328
Gaia DR3
Gaia DR3 53006669599267328
System
K2-111
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 15.67 Earth days (4.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1157 AU.
Extended Orbital Architecture
Semi-major axis / stellar radius
19.910
RV semi-amplitude (K)
3.190 m/s
Transit mid-time (BJD)
2,458,119.6200
Long. of periastron (ω)
-79.60°
Angular separation (arcsec)
0.57700
Eq. Temperature
923K
(650 °C)
Insolation (S⊕)
—
Earth = 1.00
Earth Similarity (ESI)
0.243
0 = alien, 1 = Earth-identical
Insufficient insolation data — the surface is too hot to retain surface water.
Discovery Paper
Primary reference
Mortier et al. 2020Instrument
Multiple Instruments
Publication
2020-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2020 at Multiple Observatories (12 shown).
Host System: K2-111
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,775 K — cooler than the Sun (5,778 K)
Estimated Age
12.30 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.250 R☉
Stellar Mass
0.840 M☉
Metallicity [Fe/H]
-0.46
Extended Stellar Properties
Surface gravity (log g)
4.250 dex
Stellar density
0.600 g/cm³
Systemic radial velocity
-16.28 km/s
Rotational v·sin i
1.10 km/s
Rotation period
29.20 days
Activity index (log R'HK)
-5.133
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
4.963 mas
Total Proper Motion
127.366 mas/yr
PM Right Ascension
122.34 mas/yr
PM Declination
-35.44 mas/yr
Galactic Cartesian (pc)
x = 0.467 · y = 0.806 · z = 0.363
Equatorial (J2000)
RA 59.89031° · Dec 21.29853°
Galactic ℓ, b
170.979° · -23.551°
Ecliptic λ, β
62.128° · 0.725°
HTM-20 index
-771258425
Similar Worlds
Kepler-940 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.34 R⊕ · 4,112.1 ly
Kepler-728 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.34 R⊕ · 5,757.4 ly
Kepler-1468 d
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.33 R⊕ · 6,194.5 ly
TOI-261.02
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.35 R⊕ · 373.4 ly
Kepler-1451 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.35 R⊕ · 3,453.1 ly
Kepler-11 g
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.33 R⊕ · 2,108.1 ly