Key parameters at a glance
- A radius of 4.74 Earth radii
- A mass of 30.20 Earth masses
- Surface gravity around 1.34 g
- An orbital period of 6.771 days
- Semi-major axis 0.0670 AU
- Equilibrium temperature 836 K (563 °C)
- Distance from Earth 814.23 light-years
- Earth Similarity Index 0.251
- Travel time at Voyager 1 speed 14,358,983 years
K2-27 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#422of 574
top 73.3%
This planet
4.74R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | K2-27 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.74 | 11.21 |
| Mass (M⊕) | 1.00 | 30.20 | 317.83 |
| Density (g/cm³) | 5.51 | 1.71 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.34 | 2.53 |
| Insolation (S⊕) | 1.00 | 116.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 30.200 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 363548415
Gaia DR2
Gaia DR2 3798552815560689792
Gaia DR3
Gaia DR3 3798552815560689792
System
K2-27
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.77 Earth days (1.9% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0670 AU.
Transit Fingerprint
Depth
0.293 %
Duration
2.802 h
Impact parameter b
0.300
Rp / R★
0.047400
Transit midpoint (BJD)
2,456,812.8447
Photometric dip
Transit produces a flux drop of 2,930 ppm lasting ≈ 2.80 h.
Extended Orbital Architecture
Planet / star radius ratio
0.047400
Semi-major axis / stellar radius
16.500
Impact parameter (b)
0.300
RV semi-amplitude (K)
11.800 m/s
Transit mid-time (BJD)
2,456,812.8447
Angular separation (arcsec)
0.26800
Eq. Temperature
836K
(563 °C)
Insolation (S⊕)
116.00
Earth = 1.00
Earth Similarity (ESI)
0.251
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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
Van Eylen et al. 2016Instrument
Kepler CCD Array
Publication
2016-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at K2 (12 shown).
Host System: K2-27
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,246 K — cooler than the Sun (5,778 K)
Estimated Age
10.30 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.876 R☉
Stellar Mass
0.880 M☉
Metallicity [Fe/H]
0.12
Extended Stellar Properties
Surface gravity (log g)
4.480 dex
Stellar density
2.040 g/cm³
Systemic radial velocity
-37.77 km/s
Rotational v·sin i
1.60 km/s
Activity index (log R'HK)
-5.037
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
3.977 mas
Total Proper Motion
27.195 mas/yr
PM Right Ascension
3.43 mas/yr
PM Declination
-26.98 mas/yr
Galactic Cartesian (pc)
x = -0.989 · y = 0.148 · z = 0.021
Equatorial (J2000)
RA 171.51519° · Dec 1.23062°
Galactic ℓ, b
261.027° · 56.987°
Ecliptic λ, β
171.717° · -2.234°
HTM-20 index
349284805
Similar Worlds
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Kepler-20 g
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