Key parameters at a glance
- A radius of 1.54 Earth radii
- A mass of 2.99 Earth masses
- Surface gravity around 1.26 g
- An orbital period of 0.577 days
- Semi-major axis 0.0119 AU
- Equilibrium temperature 1,757 K (1484 °C)
- Distance from Earth 1,681.18 light-years
- Earth Similarity Index 0.155
- Travel time at Voyager 1 speed 29,647,623 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1228 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#670of 1176
top 56.9%
This planet
1.54R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-1228 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.54 | 11.21 |
| Mass (M⊕) | 1.00 | 2.99 | 317.83 |
| Density (g/cm³) | 5.51 | 4.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.26 | 2.53 |
| Insolation (S⊕) | 1.00 | 1,598.66 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 272596598
Gaia DR2
Gaia DR2 2080534148769345408
Gaia DR3
Gaia DR3 2080534148769345408
System
Kepler-1228
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts roughly 13.9 hours long on a nearly circular orbit at a mean orbital distance of 0.0119 AU.
Transit Fingerprint
Depth
0.040 %
Duration
1.096 h
Impact parameter b
0.710
Rp / R★
0.018680
Transit midpoint (BJD)
2,454,965.4256
Photometric dip
Transit produces a flux drop of 400 ppm lasting ≈ 1.10 h.
Extended Orbital Architecture
Planet / star radius ratio
0.018680
Semi-major axis / stellar radius
4.138
Impact parameter (b)
0.710
Transit mid-time (BJD)
2,454,965.4256
Angular separation (arcsec)
0.02300
Eq. Temperature
1,757K
(1484 °C)
Insolation (S⊕)
1,598.66
Earth = 1.00
Earth Similarity (ESI)
0.155
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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-1228
Spectral Class
K-type orange
Effective Temperature
5,063 K — cooler than the Sun (5,778 K)
Estimated Age
5.13 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.740 R☉
Stellar Mass
0.780 M☉
Metallicity [Fe/H]
-0.18
Extended Stellar Properties
Surface gravity (log g)
4.590 dex
Stellar density
2.230 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.911 mas
Total Proper Motion
50.302 mas/yr
PM Right Ascension
-46.46 mas/yr
PM Declination
-19.28 mas/yr
Galactic Cartesian (pc)
x = 0.305 · y = -0.610 · z = 0.731
Equatorial (J2000)
RA 296.55276° · Dec 46.96619°
Galactic ℓ, b
80.457° · 10.925°
Ecliptic λ, β
318.557° · 65.988°
HTM-20 index
-2045468186
Similar Worlds
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Super-Earth · K-type orange
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Kepler-1805 b
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TOI-2431 b
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Kepler-1064 b
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Kepler-55 e
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Radius 1.55 R⊕ · 1,887.8 ly