Key parameters at a glance
- A radius of 2.32 Earth radii
- A mass of 5.99 Earth masses
- Surface gravity around 1.11 g
- An orbital period of 11.085 days
- Semi-major axis 0.0901 AU
- Equilibrium temperature 665 K (392 °C)
- Distance from Earth 2,691.36 light-years
- Earth Similarity Index 0.392
- Travel time at Voyager 1 speed 47,462,149 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1208 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1469of 1978
top 74.2%
This planet
2.32R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1208 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.32 | 11.21 |
| Mass (M⊕) | 1.00 | 5.99 | 317.83 |
| Density (g/cm³) | 5.51 | 2.64 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.11 | 2.53 |
| Insolation (S⊕) | 1.00 | 37.66 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 63010574
Gaia DR2
Gaia DR2 2126563450717837056
Gaia DR3
Gaia DR3 2126563450717837056
System
Kepler-1208
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 11.09 Earth days (3.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0901 AU.
Transit Fingerprint
Depth
0.077 %
Duration
1.708 h
Impact parameter b
0.125
Rp / R★
0.027998
Transit midpoint (BJD)
2,455,188.0366
Photometric dip
Transit produces a flux drop of 772 ppm lasting ≈ 1.71 h.
Extended Orbital Architecture
Planet / star radius ratio
0.027998
Semi-major axis / stellar radius
29.100
Impact parameter (b)
0.125
Transit mid-time (BJD)
2,455,188.0366
Angular separation (arcsec)
0.10900
Eq. Temperature
665K
(392 °C)
Insolation (S⊕)
37.66
Earth = 1.00
Earth Similarity (ESI)
0.392
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-1208
Spectral Class
K-type orange
Effective Temperature
5,001 K — cooler than the Sun (5,778 K)
Estimated Age
4.47 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.760 R☉
Stellar Mass
0.800 M☉
Metallicity [Fe/H]
-0.03
Extended Stellar Properties
Surface gravity (log g)
4.590 dex
Stellar density
19.939 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.185 mas
Total Proper Motion
2.928 mas/yr
PM Right Ascension
1.53 mas/yr
PM Declination
-2.50 mas/yr
Galactic Cartesian (pc)
x = 0.266 · y = -0.661 · z = 0.702
Equatorial (J2000)
RA 291.88124° · Dec 44.55576°
Galactic ℓ, b
76.753° · 12.737°
Ecliptic λ, β
309.026° · 65.058°
HTM-20 index
594768966
Similar Worlds
Kepler-1643 b
Sub-Neptune · K-type orange
Radius 2.32 R⊕ · 1,114.7 ly
Kepler-954 b
Sub-Neptune · K-type orange
Radius 2.32 R⊕ · 703.9 ly
K2-69 b
Sub-Neptune · K-type orange
Radius 2.32 R⊕ · 589.4 ly
Kepler-1802 c
Sub-Neptune · K-type orange
Radius 2.32 R⊕ · 2,076.6 ly
Kepler-417 b
Sub-Neptune · K-type orange
Radius 2.31 R⊕ · 3,176.7 ly
Kepler-241 b
Sub-Neptune · K-type orange
Radius 2.33 R⊕ · 1,669.9 ly