Key parameters at a glance
- A radius of 8.68 Earth radii
- A mass of 82.64 Earth masses
- Surface gravity around 1.10 g
- An orbital period of 12.455 days
- Semi-major axis 0.1016 AU
- Equilibrium temperature 650 K (377 °C)
- Distance from Earth 760.72 light-years
- Earth Similarity Index 0.239
- Travel time at Voyager 1 speed 13,415,234 years
K2-329 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#108of 574
top 18.6%
This planet
8.68R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | K2-329 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 8.68 | 11.21 |
| Mass (M⊕) | 1.00 | 82.64 | 317.83 |
| Density (g/cm³) | 5.51 | 0.69 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.10 | 2.53 |
| Insolation (S⊕) | 1.00 | 45.70 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 82.636 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 82.636 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 82.643 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 301258470
Gaia DR2
Gaia DR2 2632880927441296640
Gaia DR3
Gaia DR3 2632880927441296640
System
K2-329
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 12.46 Earth days (3.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1016 AU.
Transit Fingerprint
Depth
1.035 %
Duration
3.621 h
Impact parameter b
0.364
Rp / R★
0.096790
Transit midpoint (BJD)
2,457,773.1573
Photometric dip
Transit produces a flux drop of 10,353 ppm lasting ≈ 3.62 h.
Extended Orbital Architecture
Planet / star radius ratio
0.096790
Semi-major axis / stellar radius
26.620
Impact parameter (b)
0.364
RV semi-amplitude (K)
24.600 m/s
Transit mid-time (BJD)
2,457,773.1573
Long. of periastron (ω)
161.00°
Angular separation (arcsec)
0.43600
Eq. Temperature
650K
(377 °C)
Insolation (S⊕)
45.70
Earth = 1.00
Earth Similarity (ESI)
0.239
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
Sha et al. 2021Instrument
Kepler CCD Array
Publication
2021-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2020 at K2 (12 shown).
Host System: K2-329
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,282 K — cooler than the Sun (5,778 K)
Estimated Age
1.80 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.822 R☉
Stellar Mass
0.901 M☉
Metallicity [Fe/H]
0.10
Extended Stellar Properties
Surface gravity (log g)
4.566 dex
Stellar density
2.300 g/cm³
Systemic radial velocity
-19.25 km/s
Rotational v·sin i
1.90 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 17 bands
Astrometric Data
Parallax
4.259 mas
Total Proper Motion
18.821 mas/yr
PM Right Ascension
14.17 mas/yr
PM Declination
-12.39 mas/yr
Galactic Cartesian (pc)
x = 0.984 · y = -0.153 · z = -0.090
Equatorial (J2000)
RA 351.13538° · Dec -5.16415°
Galactic ℓ, b
75.766° · -59.822°
Ecliptic λ, β
349.821° · -1.234°
HTM-20 index
-1021963937
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