Key parameters at a glance
- A radius of 3.88 Earth radii
- A mass of 21.80 Earth masses
- Surface gravity around 1.45 g
- An orbital period of 1.674 days
- Semi-major axis 0.0301 AU
- Equilibrium temperature 1,841 K (1568 °C)
- Distance from Earth 616.30 light-years
- Earth Similarity Index 0.110
- Travel time at Voyager 1 speed 10,868,470 years
K2-100 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#34of 1978
top 1.7%
This planet
3.88R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | K2-100 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.88 | 11.21 |
| Mass (M⊕) | 1.00 | 21.80 | 317.83 |
| Density (g/cm³) | 5.51 | 2.04 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.45 | 2.53 |
| Insolation (S⊕) | 1.00 | 1,915.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 21.800 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 307733361
Gaia DR2
Gaia DR2 664337230586013312
Gaia DR3
Gaia DR3 664337230586013312
System
K2-100
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.67 Earth days (0.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0301 AU.
Transit Fingerprint
Depth
0.012 %
Duration
1.606 h
Impact parameter b
0.791
Rp / R★
0.028670
Transit midpoint (BJD)
2,457,140.7194
Photometric dip
Transit produces a flux drop of 123 ppm lasting ≈ 1.61 h.
Extended Orbital Architecture
Planet / star radius ratio
0.028670
Semi-major axis / stellar radius
5.210
Impact parameter (b)
0.791
RV semi-amplitude (K)
10.600 m/s
Transit mid-time (BJD)
2,457,140.7194
Long. of periastron (ω)
0.00°
Angular separation (arcsec)
0.15900
Eq. Temperature
1,841K
(1568 °C)
Insolation (S⊕)
1,915.00
Earth = 1.00
Earth Similarity (ESI)
0.110
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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
Mann et al. 2017Instrument
Kepler CCD Array
Publication
2017-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-100
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,945 K — hotter than the Sun (5,778 K)
Estimated Age
0.75 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.240 R☉
Stellar Mass
1.150 M☉
Metallicity [Fe/H]
0.22
Extended Stellar Properties
Surface gravity (log g)
4.330 dex
Stellar density
0.850 g/cm³
Systemic radial velocity
33.60 km/s
Rotational v·sin i
14.00 km/s
Rotation period
4.30 days
Activity index (log R'HK)
-4.526
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 13 bands
Astrometric Data
Parallax
5.264 mas
Total Proper Motion
38.416 mas/yr
PM Right Ascension
-36.14 mas/yr
PM Declination
-13.01 mas/yr
Galactic Cartesian (pc)
x = -0.599 · y = 0.724 · z = 0.344
Equatorial (J2000)
RA 129.60109° · Dec 20.10601°
Galactic ℓ, b
205.240° · 32.195°
Ecliptic λ, β
126.782° · 1.581°
HTM-20 index
-2005768867
Similar Worlds
Kepler-368 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.88 R⊕ · 2,514.6 ly
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HD 20003 c
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HD 51608 c
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HD 42618 b
Sub-Neptune · G-type yellow (Sun-like)
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