Key parameters at a glance
- A radius of 2.26 Earth radii
- A mass of 5.73 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 16.088 days
- Semi-major axis 0.1220 AU
- Equilibrium temperature 668 K (395 °C)
- Distance from Earth 1,881.74 light-years
- Earth Similarity Index 0.394
- Travel time at Voyager 1 speed 33,184,554 years
1 sibling around Kepler-209
Kepler-209 b 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-209 b this | Sub-Neptune | 2.26 | 5.73 | 16.088 | 668 | 2014 |
| Kepler-209 c | Sub-Neptune | 3.10 | 9.80 | 41.750 | 486 | 2014 |
Kepler-209 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1572of 1978
top 79.4%
This planet
2.26R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-209 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.26 | 11.21 |
| Mass (M⊕) | 1.00 | 5.73 | 317.83 |
| Density (g/cm³) | 5.51 | 2.73 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 48.66 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 159652365
Gaia DR2
Gaia DR2 2101964558106974848
Gaia DR3
Gaia DR3 2101964558106974848
System
Kepler-209
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 16.09 Earth days (4.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1220 AU.
Transit Fingerprint
Depth
0.061 %
Duration
2.878 h
Impact parameter b
0.080
Rp / R★
0.022863
Transit midpoint (BJD)
2,455,005.8134
Photometric dip
Transit produces a flux drop of 613 ppm lasting ≈ 2.88 h.
Extended Orbital Architecture
Planet / star radius ratio
0.022863
Semi-major axis / stellar radius
11.350
Impact parameter (b)
0.080
Transit mid-time (BJD)
2,455,005.8134
Angular separation (arcsec)
0.21100
Eq. Temperature
668K
(395 °C)
Insolation (S⊕)
48.66
Earth = 1.00
Earth Similarity (ESI)
0.394
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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-209
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,513 K — cooler than the Sun (5,778 K)
Estimated Age
1.95 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.935 R☉
Stellar Mass
0.971 M☉
Metallicity [Fe/H]
0.11
Extended Stellar Properties
Surface gravity (log g)
4.472 dex
Stellar density
1.340 g/cm³
Metallicity ratio
[M/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.705 mas
Total Proper Motion
20.569 mas/yr
PM Right Ascension
-10.14 mas/yr
PM Declination
-17.90 mas/yr
Galactic Cartesian (pc)
x = 0.266 · y = -0.686 · z = 0.677
Equatorial (J2000)
RA 291.16946° · Dec 42.64073°
Galactic ℓ, b
74.756° · 12.372°
Ecliptic λ, β
306.427° · 63.427°
HTM-20 index
349126560
Similar Worlds
Kepler-649 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 1,675.6 ly
HD 28471 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 142.4 ly
Kepler-154 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 2,985.0 ly
Kepler-163 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 2,249.9 ly
K2-159 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 557.7 ly
Kepler-1863 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.26 R⊕ · 2,823.0 ly