Key parameters at a glance
- A radius of 8.37 Earth radii
- A mass of 52.90 Earth masses
- Surface gravity around 0.76 g
- An orbital period of 3.588 days
- Semi-major axis 0.0411 AU
- Equilibrium temperature 809 K (536 °C)
- Distance from Earth 2,315.70 light-years
- Earth Similarity Index 0.183
- Travel time at Voyager 1 speed 40,837,444 years
- Almost certainly tidally locked to its host star given the close orbit
K2-127 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#133of 574
top 23.0%
This planet
8.37R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | K2-127 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 8.37 | 11.21 |
| Mass (M⊕) | 1.00 | 52.90 | 317.83 |
| Density (g/cm³) | 5.51 | 0.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.76 | 2.53 |
| Insolation (S⊕) | 1.00 | 105.60 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 187309502
Gaia DR2
Gaia DR2 3613472293839371136
Gaia DR3
Gaia DR3 3613472293839371136
System
K2-127
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.59 Earth days (1.0% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0411 AU.
Transit Fingerprint
Depth
1.512 %
Duration
2.321 h
Impact parameter b
0.580
Rp / R★
0.116200
Transit midpoint (BJD)
2,457,223.9259
Photometric dip
Transit produces a flux drop of 15,120 ppm lasting ≈ 2.32 h.
Extended Orbital Architecture
Planet / star radius ratio
0.116200
Semi-major axis / stellar radius
11.460
Impact parameter (b)
0.580
Transit mid-time (BJD)
2,457,223.9259
Long. of periastron (ω)
-65.74°
Angular separation (arcsec)
0.05790
Eq. Temperature
809K
(536 °C)
Insolation (S⊕)
105.60
Earth = 1.00
Earth Similarity (ESI)
0.183
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.
Discovery Paper
Primary reference
Dressing et al. 2017Instrument
Kepler CCD Array
Publication
2017-11
Observation locale
Space
Discovery cohort
Planets confirmed in 2017 at K2 (12 shown).
Host System: K2-127
Spectral Class
K-type orange
Effective Temperature
4,575 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.660 R☉
Stellar Mass
0.720 M☉
Metallicity [Fe/H]
-0.11
Extended Stellar Properties
Surface gravity (log g)
4.650 dex
Stellar density
2.211 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
1.381 mas
Total Proper Motion
23.802 mas/yr
PM Right Ascension
-23.80 mas/yr
PM Declination
-0.07 mas/yr
Galactic Cartesian (pc)
x = -0.872 · y = -0.446 · z = -0.201
Equatorial (J2000)
RA 207.07829° · Dec -11.58899°
Galactic ℓ, b
324.402° · 48.897°
Ecliptic λ, β
209.274° · -0.397°
HTM-20 index
291762694
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