Key parameters at a glance
- A radius of 5.31 Earth radii
- A mass of 161.12 Earth masses
- Surface gravity around 5.71 g
- An orbital period of 36.337 days
- Semi-major axis 0.2150 AU
- Equilibrium temperature 513 K (240 °C)
- Distance from Earth 5,692.89 light-years
- Earth Similarity Index 0.081
- Travel time at Voyager 1 speed 100,394,108 years
2 siblings around Kepler-281
Kepler-281 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-281 b | Sub-Neptune | 2.82 | 324.00 | 14.646 | 694 | 2014 |
| Kepler-281 c this | Neptune-like | 5.31 | 161.12 | 36.337 | 513 | 2014 |
| Kepler-281 d | Neptune-like | 5.94 | 654.00 | 148.272 | 321 | 2021 |
Kepler-281 c Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#340of 574
top 59.1%
This planet
5.31R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | Kepler-281 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 5.31 | 11.21 |
| Mass (M⊕) | 1.00 | 161.12 | 317.83 |
| Density (g/cm³) | 5.51 | 0.01 | 1.33 |
| Surface Gravity (g) | 1.00 | 5.71 | 2.53 |
| Insolation (S⊕) | 1.00 | 35.20 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 161.124 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 270858032
Gaia DR2
Gaia DR2 2078404532186285568
Gaia DR3
Gaia DR3 2078404532186285568
System
Kepler-281
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 36.34 Earth days (9.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2150 AU.
Transit Fingerprint
Depth
0.283 %
Duration
6.809 h
Impact parameter b
0.770
Rp / R★
0.053910
Transit midpoint (BJD)
2,454,993.4009
Photometric dip
Transit produces a flux drop of 2,828 ppm lasting ≈ 6.81 h.
Extended Orbital Architecture
Planet / star radius ratio
0.053910
Semi-major axis / stellar radius
29.000
Impact parameter (b)
0.770
Transit mid-time (BJD)
2,454,993.4009
Angular separation (arcsec)
0.12300
Eq. Temperature
513K
(240 °C)
Insolation (S⊕)
35.20
Earth = 1.00
Earth Similarity (ESI)
0.081
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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-281
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,723 K — cooler than the Sun (5,778 K)
Estimated Age
0.60 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.899 R☉
Stellar Mass
0.950 M☉
Metallicity [Fe/H]
0.02
Extended Stellar Properties
Surface gravity (log g)
4.531 dex
Stellar density
0.248 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.545 mas
Total Proper Motion
11.298 mas/yr
PM Right Ascension
-6.44 mas/yr
PM Declination
-9.29 mas/yr
Galactic Cartesian (pc)
x = 0.290 · y = -0.648 · z = 0.704
Equatorial (J2000)
RA 294.10815° · Dec 44.77065°
Galactic ℓ, b
77.669° · 11.413°
Ecliptic λ, β
312.683° · 64.678°
HTM-20 index
-1670214005
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Kepler-82 c
Neptune-like · G-type yellow (Sun-like)
Radius 5.34 R⊕ · 2,949.5 ly