Key parameters at a glance
- A radius of 4.92 Earth radii
- A mass of 21.50 Earth masses
- Surface gravity around 0.89 g
- An orbital period of 11.128 days
- Semi-major axis 0.0781 AU
- Equilibrium temperature 408 K (135 °C)
- Distance from Earth 2,508.62 light-years
- Earth Similarity Index 0.444
- Travel time at Voyager 1 speed 44,239,438 years
- Almost certainly tidally locked to its host star given the close orbit
2 siblings around Kepler-1321
Kepler-1321 b shares its host star with 2 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-1321 c | Sub-Neptune | 2.40 | 6.35 | 2.226 | 697 | 2016 |
| Kepler-1321 d | Sub-Neptune | 2.63 | 7.41 | 5.721 | 509 | 2021 |
| Kepler-1321 b this | Neptune-like | 4.92 | 21.50 | 11.128 | 408 | 2016 |
Kepler-1321 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#393of 574
top 68.3%
This planet
4.92R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-1321 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 4.92 | 11.21 |
| Mass (M⊕) | 1.00 | 21.50 | 317.83 |
| Density (g/cm³) | 5.51 | 0.99 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.89 | 2.53 |
| Insolation (S⊕) | 1.00 | 13.55 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 271165895
Gaia DR2
Gaia DR2 2128141834020807680
Gaia DR3
Gaia DR3 2128141834020807680
System
Kepler-1321
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.13 Earth days (3.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0781 AU.
Transit Fingerprint
Depth
0.606 %
Duration
2.772 h
Impact parameter b
0.709
Rp / R★
0.085957
Transit midpoint (BJD)
2,454,972.5417
Photometric dip
Transit produces a flux drop of 6,057 ppm lasting ≈ 2.77 h.
Extended Orbital Architecture
Planet / star radius ratio
0.085957
Semi-major axis / stellar radius
23.200
Impact parameter (b)
0.709
Transit mid-time (BJD)
2,454,972.5417
Angular separation (arcsec)
0.10200
Eq. Temperature
408K
(135 °C)
Insolation (S⊕)
13.55
Earth = 1.00
Earth Similarity (ESI)
0.444
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
Morton et al. 2016Instrument
Kepler CCD Array
Publication
2016-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at Kepler (12 shown).
Host System: Kepler-1321
Spectral Class
K-type orange
Effective Temperature
4,094 K — cooler than the Sun (5,778 K)
Estimated Age
4.17 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.530 R☉
Stellar Mass
0.540 M☉
Metallicity [Fe/H]
-0.45
Extended Stellar Properties
Surface gravity (log g)
4.730 dex
Stellar density
2.475 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.275 mas
Total Proper Motion
21.696 mas/yr
PM Right Ascension
-4.05 mas/yr
PM Declination
-21.31 mas/yr
Galactic Cartesian (pc)
x = 0.285 · y = -0.625 · z = 0.727
Equatorial (J2000)
RA 294.52860° · Dec 46.64087°
Galactic ℓ, b
79.507° · 12.002°
Ecliptic λ, β
315.114° · 66.280°
HTM-20 index
-1101821351
Similar Worlds
Kepler-229 c
Neptune-like · K-type orange
Radius 4.92 R⊕ · 2,694.9 ly
TOI-544 c
Neptune-like · K-type orange
Radius 4.92 R⊕ · 134.1 ly
HIP 19976 b
Neptune-like · K-type orange
Radius 4.94 R⊕ · 131.3 ly
Kepler-257 d
Neptune-like · K-type orange
Radius 4.95 R⊕ · 2,544.9 ly
TOI-1272 c
Neptune-like · K-type orange
Radius 4.95 R⊕ · 448.7 ly
TOI-880 c
Neptune-like · K-type orange
Radius 4.95 R⊕ · 197.9 ly