Key parameters at a glance
- A radius of 3.20 Earth radii
- A mass of 7.90 Earth masses
- Surface gravity around 0.77 g
- An orbital period of 5.341 days
- Semi-major axis 0.0553 AU
- Equilibrium temperature 854 K (581 °C)
- Distance from Earth 357.95 light-years
- Earth Similarity Index 0.256
- Travel time at Voyager 1 speed 6,312,500 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around K2-36
K2-36 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 |
|---|---|---|---|---|---|---|
| K2-36 b | Super-Earth | 1.43 | 4.30 | 1.423 | 1,328 | 2016 |
| K2-36 c this | Sub-Neptune | 3.20 | 7.90 | 5.341 | 854 | 2016 |
K2-36 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#348of 1978
top 17.5%
This planet
3.20R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-36 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.20 | 11.21 |
| Mass (M⊕) | 1.00 | 7.90 | 317.83 |
| Density (g/cm³) | 5.51 | 1.30 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.77 | 2.53 |
| Insolation (S⊕) | 1.00 | 89.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 7.900 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 363445121
Gaia DR2
Gaia DR2 3811989156889528320
Gaia DR3
Gaia DR3 3811989156889528320
System
K2-36
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.34 Earth days (1.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0553 AU.
Transit Fingerprint
Depth
0.155 %
Duration
1.153 h
Impact parameter b
0.935
Rp / R★
0.039300
Transit midpoint (BJD)
2,456,812.8400
Photometric dip
Transit produces a flux drop of 1,545 ppm lasting ≈ 1.15 h.
Extended Orbital Architecture
Planet / star radius ratio
0.039300
Semi-major axis / stellar radius
16.010
Impact parameter (b)
0.935
RV semi-amplitude (K)
3.400 m/s
Transit mid-time (BJD)
2,456,812.8400
Angular separation (arcsec)
0.50400
Eq. Temperature
854K
(581 °C)
Insolation (S⊕)
89.00
Earth = 1.00
Earth Similarity (ESI)
0.256
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
Sinukoff et al. 2016Instrument
Kepler CCD Array
Publication
2016-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-36
Spectral Class
K-type orange
Effective Temperature
4,916 K — cooler than the Sun (5,778 K)
Estimated Age
1.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.718 R☉
Stellar Mass
0.790 M☉
Metallicity [Fe/H]
-0.05
Extended Stellar Properties
Surface gravity (log g)
4.621 dex
Stellar density
2.990 g/cm³
Systemic radial velocity
13.25 km/s
Rotational v·sin i
2.70 km/s
Rotation period
17.13 days
Activity index (log R'HK)
-4.594
Metallicity ratio
[M/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
9.083 mas
Total Proper Motion
33.275 mas/yr
PM Right Ascension
-20.52 mas/yr
PM Declination
26.19 mas/yr
Galactic Cartesian (pc)
x = -0.981 · y = 0.183 · z = 0.067
Equatorial (J2000)
RA 169.44901° · Dec 3.86650°
Galactic ℓ, b
254.976° · 57.738°
Ecliptic λ, β
168.783° · -0.619°
HTM-20 index
-1765363968
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