Key parameters at a glance
- A radius of 0.86 Earth radii
- A mass of 0.57 Earth masses
- Surface gravity around 0.77 g
- An orbital period of 13.297 days
- Semi-major axis 0.0930 AU
- Equilibrium temperature 515 K (242 °C)
- Distance from Earth 1,386.16 light-years
- Earth Similarity Index 0.600
- Travel time at Voyager 1 speed 24,444,983 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around Kepler-388
Kepler-388 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-388 b | Rocky Terrestrial | 0.81 | 0.46 | 3.173 | 830 | 2014 |
| Kepler-388 c this | Rocky Terrestrial | 0.86 | 0.57 | 13.297 | 515 | 2014 |
Kepler-388 c Planet Profile
Physical Specs
Classification
Planet Type
Rocky Terrestrial
Discovery
Size rank in cohort
Rank by radius
#444of 570
top 77.7%
This planet
0.86R⊕
Rocky Terrestrial median
1.01R⊕
Nearest-size peers
| Metric | Earth | Kepler-388 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 0.86 | 11.21 |
| Mass (M⊕) | 1.00 | 0.57 | 317.83 |
| Density (g/cm³) | 5.51 | 4.89 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.77 | 2.53 |
| Insolation (S⊕) | 1.00 | 16.64 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 164786156
Gaia DR2
Gaia DR2 2106711424679833984
Gaia DR3
Gaia DR3 2106711424679833984
System
Kepler-388
Percentile among Rocky Terrestrial cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 13.30 Earth days (3.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0930 AU.
Transit Fingerprint
Depth
0.022 %
Duration
3.277 h
Impact parameter b
0.180
Rp / R★
0.013131
Transit midpoint (BJD)
2,454,973.9479
Photometric dip
Transit produces a flux drop of 220 ppm lasting ≈ 3.28 h.
Extended Orbital Architecture
Planet / star radius ratio
0.013131
Semi-major axis / stellar radius
31.340
Impact parameter (b)
0.180
Transit mid-time (BJD)
2,454,973.9479
Angular separation (arcsec)
0.21900
Eq. Temperature
515K
(242 °C)
Insolation (S⊕)
16.64
Earth = 1.00
Earth Similarity (ESI)
0.600
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
Rowe et al. 2014Instrument
Kepler CCD Array
Publication
2014-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2014 at Kepler (12 shown).
Host System: Kepler-388
Spectral Class
K-type orange
Effective Temperature
4,498 K — cooler than the Sun (5,778 K)
Estimated Age
13.90 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.586 R☉
Stellar Mass
0.635 M☉
Metallicity [Fe/H]
0.00
Extended Stellar Properties
Surface gravity (log g)
4.690 dex
Stellar density
3.169 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.636 mas
Total Proper Motion
19.234 mas/yr
PM Right Ascension
0.42 mas/yr
PM Declination
-19.23 mas/yr
Galactic Cartesian (pc)
x = 0.182 · y = -0.688 · z = 0.702
Equatorial (J2000)
RA 284.82806° · Dec 44.60865°
Galactic ℓ, b
74.732° · 17.365°
Ecliptic λ, β
297.357° · 66.645°
HTM-20 index
1004160293
Similar Worlds
Kepler-290 d
Rocky Terrestrial · K-type orange
Radius 0.86 R⊕ · 2,265.6 ly
Kepler-1361 b
Rocky Terrestrial · K-type orange
Radius 0.86 R⊕ · 1,269.2 ly
Kepler-102 f
Rocky Terrestrial · K-type orange
Radius 0.86 R⊕ · 351.6 ly
K2-209 b
Rocky Terrestrial · K-type orange
Radius 0.87 R⊕ · 249.5 ly
Kepler-1907 b
Rocky Terrestrial · K-type orange
Radius 0.87 R⊕ · 952.7 ly
Kepler-1152 b
Rocky Terrestrial · K-type orange
Radius 0.87 R⊕ · 702.0 ly