Key parameters at a glance
- A radius of 2.47 Earth radii
- A mass of 749.90 Earth masses
- Surface gravity around 122.92 g
- An orbital period of 5.371 days
- Semi-major axis 0.0610 AU
- Equilibrium temperature 1,096 K (823 °C)
- Distance from Earth 2,293.86 light-years
- Earth Similarity Index 0.078
- Travel time at Voyager 1 speed 40,452,248 years
2 siblings around Kepler-203
Kepler-203 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-203 b | Sub-Neptune | 2.57 | 7.13 | 3.163 | 1,308 | 2014 |
| Kepler-203 c this | Sub-Neptune | 2.47 | 749.90 | 5.371 | 1,096 | 2014 |
| Kepler-203 d | Super-Earth | 1.44 | 33.90 | 11.330 | 855 | 2014 |
Kepler-203 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1226of 1978
top 61.9%
This planet
2.47R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-203 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.47 | 11.21 |
| Mass (M⊕) | 1.00 | 749.90 | 317.83 |
| Density (g/cm³) | 5.51 | 273.00 | 1.33 |
| Surface Gravity (g) | 1.00 | 122.92 | 2.53 |
| Insolation (S⊕) | 1.00 | 329.79 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 749.900 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 169084431
Gaia DR2
Gaia DR2 2076792648144511104
Gaia DR3
Gaia DR3 2076792648144511104
System
Kepler-203
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.37 Earth days (1.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0610 AU.
Transit Fingerprint
Depth
0.052 %
Duration
2.014 h
Impact parameter b
0.100
Rp / R★
0.020870
Transit midpoint (BJD)
2,455,005.2370
Photometric dip
Transit produces a flux drop of 519 ppm lasting ≈ 2.01 h.
Extended Orbital Architecture
Planet / star radius ratio
0.020870
Semi-major axis / stellar radius
20.378
Impact parameter (b)
0.100
Transit mid-time (BJD)
2,455,005.2370
Angular separation (arcsec)
0.08670
Eq. Temperature
1,096K
(823 °C)
Insolation (S⊕)
329.79
Earth = 1.00
Earth Similarity (ESI)
0.078
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
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-203
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,821 K — hotter than the Sun (5,778 K)
Estimated Age
1.78 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.114 R☉
Stellar Mass
1.060 M☉
Metallicity [Fe/H]
0.08
Extended Stellar Properties
Surface gravity (log g)
4.358 dex
Stellar density
1.020 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.393 mas
Total Proper Motion
4.216 mas/yr
PM Right Ascension
-1.60 mas/yr
PM Declination
3.90 mas/yr
Galactic Cartesian (pc)
x = 0.342 · y = -0.668 · z = 0.661
Equatorial (J2000)
RA 297.08996° · Dec 41.38807°
Galactic ℓ, b
75.694° · 7.894°
Ecliptic λ, β
314.319° · 60.726°
HTM-20 index
-833794070
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Kepler-198 c
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Kepler-310 d
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Kepler-1307 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.47 R⊕ · 3,309.2 ly