Key parameters at a glance
- A radius of 2.63 Earth radii
- A mass of 7.41 Earth masses
- Surface gravity around 1.07 g
- An orbital period of 5.721 days
- Semi-major axis 0.0501 AU
- Equilibrium temperature 509 K (236 °C)
- Distance from Earth 2,508.62 light-years
- Earth Similarity Index 0.479
- 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 d 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 this | Sub-Neptune | 2.63 | 7.41 | 5.721 | 509 | 2021 |
| Kepler-1321 b | Neptune-like | 4.92 | 21.50 | 11.128 | 408 | 2016 |
Kepler-1321 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#987of 1978
top 49.8%
This planet
2.63R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1321 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.63 | 11.21 |
| Mass (M⊕) | 1.00 | 7.41 | 317.83 |
| Density (g/cm³) | 5.51 | 2.24 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.07 | 2.53 |
| Insolation (S⊕) | 1.00 | 15.84 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 271165895
Gaia DR2
Gaia DR2 2128141834020807680
Gaia DR3
Gaia DR3 2128141834020807680
System
Kepler-1321
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.72 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0501 AU.
Transit Fingerprint
Depth
0.132 %
Duration
2.618 h
Impact parameter b
0.166
Rp / R★
0.032418
Transit midpoint (BJD)
2,454,967.6628
Photometric dip
Transit produces a flux drop of 1,316 ppm lasting ≈ 2.62 h.
Extended Orbital Architecture
Planet / star radius ratio
0.032418
Semi-major axis / stellar radius
16.240
Impact parameter (b)
0.166
Transit mid-time (BJD)
2,454,967.6628
Angular separation (arcsec)
0.06510
Eq. Temperature
509K
(236 °C)
Insolation (S⊕)
15.84
Earth = 1.00
Earth Similarity (ESI)
0.479
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
Valizadegan et al. 2022Instrument
Kepler CCD Array
Publication
2022-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Kepler (12 shown).
Host System: Kepler-1321
Spectral Class
M-type red dwarf
Effective Temperature
3,640 K — cooler than the Sun (5,778 K)
Estimated Age
6.26 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.503 R☉
Stellar Mass
0.513 M☉
Metallicity [Fe/H]
0.21
Extended Stellar Properties
Surface gravity (log g)
4.744 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
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