Key parameters at a glance
- A radius of 6.18 Earth radii
- A mass of 31.60 Earth masses
- Surface gravity around 0.83 g
- An orbital period of 135.499 days
- Semi-major axis 0.4800 AU
- Equilibrium temperature 295 K (22 °C)
- Distance from Earth 3,160.45 light-years
- Earth Similarity Index 0.511
- Travel time at Voyager 1 speed 55,734,562 years
1 sibling around Kepler-397
Kepler-397 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-397 b | Sub-Neptune | 2.46 | 6.62 | 22.251 | 539 | 2014 |
| Kepler-397 c this | Neptune-like | 6.18 | 31.60 | 135.499 | 295 | 2014 |
Kepler-397 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#264of 574
top 45.8%
This planet
6.18R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-397 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 6.18 | 11.21 |
| Mass (M⊕) | 1.00 | 31.60 | 317.83 |
| Density (g/cm³) | 5.51 | 0.74 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.83 | 2.53 |
| Insolation (S⊕) | 1.00 | 1.80 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 271963778
System
Kepler-397
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 135.50 Earth days (37.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4800 AU.
Transit Fingerprint
Depth
0.504 %
Duration
6.901 h
Impact parameter b
0.840
Rp / R★
0.072673
Transit midpoint (BJD)
2,455,066.6904
Photometric dip
Transit produces a flux drop of 5,038 ppm lasting ≈ 6.90 h.
Extended Orbital Architecture
Planet / star radius ratio
0.072673
Semi-major axis / stellar radius
109.000
Impact parameter (b)
0.840
Transit mid-time (BJD)
2,455,066.6904
Angular separation (arcsec)
0.49500
Eq. Temperature
295K
(22 °C)
Insolation (S⊕)
1.80
Earth = 1.00
Earth Similarity (ESI)
0.511
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Transit timing variations
Gravitational interactions from neighbours have been detected.
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-397
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,307 K — cooler than the Sun (5,778 K)
Estimated Age
5.25 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.767 R☉
Stellar Mass
0.844 M☉
Metallicity [Fe/H]
-0.24
Extended Stellar Properties
Surface gravity (log g)
4.572 dex
Stellar density
1.317 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 15 bands
Astrometric Data
Total Proper Motion
5.179 mas/yr
PM Right Ascension
-5.12 mas/yr
PM Declination
-0.77 mas/yr
Galactic Cartesian (pc)
x = 0.323 · y = -0.665 · z = 0.674
Equatorial (J2000)
RA 295.89404° · Dec 42.38052°
Galactic ℓ, b
76.135° · 9.154°
Ecliptic λ, β
313.360° · 61.977°
HTM-20 index
-1603995579
Similar Worlds
K2-333 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.18 R⊕ · 1,121.9 ly
HD 49674 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.20 R⊕ · 140.4 ly
Kepler-453 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.20 R⊕ · 1,444.4 ly
TOI-1386 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.22 R⊕ · 479.0 ly
Kepler-696 b
Neptune-like · G-type yellow (Sun-like)
Radius 6.14 R⊕ · 4,619.8 ly
Kepler-87 c
Neptune-like · G-type yellow (Sun-like)
Radius 6.14 R⊕ · 4,021.2 ly