Key parameters at a glance
- A radius of 1.88 Earth radii
- A mass of 4.19 Earth masses
- Surface gravity around 1.19 g
- An orbital period of 12.001 days
- Semi-major axis 0.0906 AU
- Equilibrium temperature 632 K (359 °C)
- Distance from Earth 2,979.92 light-years
- Earth Similarity Index 0.444
- Travel time at Voyager 1 speed 52,550,962 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1221 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#153of 1176
top 12.9%
This planet
1.88R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-1221 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.88 | 11.21 |
| Mass (M⊕) | 1.00 | 4.19 | 317.83 |
| Density (g/cm³) | 5.51 | 3.47 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.19 | 2.53 |
| Insolation (S⊕) | 1.00 | 37.81 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 279912260
Gaia DR2
Gaia DR2 2106498767960692480
System
Kepler-1221
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 12.00 Earth days (3.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0906 AU.
Transit Fingerprint
Depth
0.048 %
Duration
3.433 h
Impact parameter b
0.595
Rp / R★
0.021361
Transit midpoint (BJD)
2,454,975.0415
Photometric dip
Transit produces a flux drop of 480 ppm lasting ≈ 3.43 h.
Extended Orbital Architecture
Planet / star radius ratio
0.021361
Semi-major axis / stellar radius
19.980
Impact parameter (b)
0.595
Transit mid-time (BJD)
2,454,975.0415
Angular separation (arcsec)
0.09920
Eq. Temperature
632K
(359 °C)
Insolation (S⊕)
37.81
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-1221
Spectral Class
K-type orange
Effective Temperature
5,194 K — cooler than the Sun (5,778 K)
Estimated Age
4.57 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.820 R☉
Stellar Mass
0.870 M☉
Metallicity [Fe/H]
0.09
Extended Stellar Properties
Surface gravity (log g)
4.550 dex
Stellar density
1.047 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Total Proper Motion
9.667 mas/yr
PM Right Ascension
2.10 mas/yr
PM Declination
-9.44 mas/yr
Galactic Cartesian (pc)
x = 0.190 · y = -0.672 · z = 0.716
Equatorial (J2000)
RA 285.82236° · Dec 45.71184°
Galactic ℓ, b
76.075° · 17.115°
Ecliptic λ, β
299.856° · 67.518°
HTM-20 index
-1228699211
Similar Worlds
Kepler-48 b
Super-Earth · K-type orange
Radius 1.88 R⊕ · 1,000.4 ly
TOI-286 c
Super-Earth · K-type orange
Radius 1.88 R⊕ · 193.2 ly
Kepler-137 c
Super-Earth · K-type orange
Radius 1.88 R⊕ · 988.2 ly
TOI-2322 c
Super-Earth · K-type orange
Radius 1.87 R⊕ · 195.2 ly
K2-47 b
Super-Earth · K-type orange
Radius 1.89 R⊕ · 1,141.2 ly
Kepler-1032 b
Super-Earth · K-type orange
Radius 1.87 R⊕ · 2,195.1 ly