Key parameters at a glance
- A radius of 2.30 Earth radii
- A mass of 5.90 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 2.628 days
- Semi-major axis 0.0310 AU
- Equilibrium temperature 737 K (464 °C)
- Distance from Earth 1,268.75 light-years
- Earth Similarity Index 0.355
- Travel time at Voyager 1 speed 22,374,349 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-621 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1499of 1978
top 75.7%
This planet
2.30R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-621 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.30 | 11.21 |
| Mass (M⊕) | 1.00 | 5.90 | 317.83 |
| Density (g/cm³) | 5.51 | 2.66 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 69.56 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 122706051
Gaia DR2
Gaia DR2 2053067935992494848
Gaia DR3
Gaia DR3 2053067935992494848
System
Kepler-621
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.63 Earth days (0.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0310 AU.
Transit Fingerprint
Depth
0.094 %
Duration
1.855 h
Impact parameter b
0.580
Rp / R★
0.031073
Transit midpoint (BJD)
2,455,002.7197
Photometric dip
Transit produces a flux drop of 937 ppm lasting ≈ 1.85 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031073
Semi-major axis / stellar radius
9.000
Impact parameter (b)
0.580
Transit mid-time (BJD)
2,455,002.7197
Angular separation (arcsec)
0.07970
Eq. Temperature
737K
(464 °C)
Insolation (S⊕)
69.56
Earth = 1.00
Earth Similarity (ESI)
0.355
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-621
Spectral Class
K-type orange
Effective Temperature
4,521 K — cooler than the Sun (5,778 K)
Estimated Age
3.63 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.680 R☉
Stellar Mass
0.720 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.630 dex
Stellar density
2.075 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.990 mas
Total Proper Motion
11.169 mas/yr
PM Right Ascension
-9.79 mas/yr
PM Declination
-5.37 mas/yr
Galactic Cartesian (pc)
x = 0.274 · y = -0.716 · z = 0.642
Equatorial (J2000)
RA 290.92725° · Dec 39.91412°
Galactic ℓ, b
72.167° · 11.348°
Ecliptic λ, β
304.266° · 60.887°
HTM-20 index
1585861569
Similar Worlds
K2-59 c
Sub-Neptune · K-type orange
Radius 2.30 R⊕ · 1,015.4 ly
Kepler-224 d
Sub-Neptune · K-type orange
Radius 2.30 R⊕ · 2,550.8 ly
Kepler-156 b
Sub-Neptune · K-type orange
Radius 2.30 R⊕ · 1,446.4 ly
TOI-2093 c
Sub-Neptune · K-type orange
Radius 2.30 R⊕ · 270.1 ly
TOI-178 e
Sub-Neptune · K-type orange
Radius 2.30 R⊕ · 204.5 ly
K2-57 b
Sub-Neptune · K-type orange
Radius 2.31 R⊕ · 861.7 ly