Key parameters at a glance
- A radius of 2.49 Earth radii
- A mass of 4.90 Earth masses
- Surface gravity around 0.79 g
- An orbital period of 6.482 days
- Semi-major axis 0.0701 AU
- Equilibrium temperature 1,276 K (1003 °C)
- Distance from Earth 1,548.79 light-years
- Earth Similarity Index 0.182
- Travel time at Voyager 1 speed 27,312,869 years
1 sibling around Kepler-109
Kepler-109 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-109 b this | Sub-Neptune | 2.49 | 4.90 | 6.482 | 1,276 | 2014 |
| Kepler-109 c | Sub-Neptune | 2.65 | 8.20 | 21.223 | 859 | 2014 |
Kepler-109 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1191of 1978
top 60.2%
This planet
2.49R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-109 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.49 | 11.21 |
| Mass (M⊕) | 1.00 | 4.90 | 317.83 |
| Density (g/cm³) | 5.51 | 1.70 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.79 | 2.53 |
| Insolation (S⊕) | 1.00 | 442.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 4.900 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 4.554 M⊕ | Lower bound from radial-velocity fitting. |
Star Catalogue Identifiers
TIC
TIC 122441003
Gaia DR2
Gaia DR2 2101175933393051008
Gaia DR3
Gaia DR3 2101175933393051008
System
Kepler-109
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 6.48 Earth days (1.8% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0701 AU.
Transit Fingerprint
Depth
0.030 %
Duration
3.649 h
Impact parameter b
0.580
Rp / R★
0.016860
Transit midpoint (BJD)
2,454,955.9779
Photometric dip
Transit produces a flux drop of 302 ppm lasting ≈ 3.65 h.
Extended Orbital Architecture
Planet / star radius ratio
0.016860
Semi-major axis / stellar radius
13.655
Impact parameter (b)
0.580
RV semi-amplitude (K)
1.600 m/s
Transit mid-time (BJD)
2,454,955.9779
Angular separation (arcsec)
0.14800
Eq. Temperature
1,276K
(1003 °C)
Insolation (S⊕)
442.00
Earth = 1.00
Earth Similarity (ESI)
0.182
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
Discovery Paper
Primary reference
Marcy et al. 2014Instrument
Kepler CCD Array
Publication
2014-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2014 at Kepler (12 shown).
Host System: Kepler-109
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,950 K — hotter than the Sun (5,778 K)
Estimated Age
6.20 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.387 R☉
Stellar Mass
1.094 M☉
Metallicity [Fe/H]
-0.02
Extended Stellar Properties
Surface gravity (log g)
4.210 dex
Stellar density
0.430 g/cm³
Rotational v·sin i
1.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
2.077 mas
Total Proper Motion
13.364 mas/yr
PM Right Ascension
-7.74 mas/yr
PM Declination
10.90 mas/yr
Galactic Cartesian (pc)
x = 0.266 · y = -0.715 · z = 0.647
Equatorial (J2000)
RA 290.39268° · Dec 40.28491°
Galactic ℓ, b
72.326° · 11.878°
Ecliptic λ, β
303.679° · 61.361°
HTM-20 index
-1016689703
Similar Worlds
HD 88986 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 108.5 ly
Kepler-265 d
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 4,175.6 ly
Kepler-184 d
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 1,990.6 ly
Kepler-11 f
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 2,108.1 ly
Kepler-289 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 2,297.6 ly
Kepler-865 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.49 R⊕ · 1,911.7 ly