Key parameters at a glance
- A radius of 2.80 Earth radii
- A mass of 8.25 Earth masses
- Surface gravity around 1.05 g
- An orbital period of 8.115 days
- Semi-major axis 0.0790 AU
- Equilibrium temperature 879 K (606 °C)
- Distance from Earth 3,268.54 light-years
- Earth Similarity Index 0.275
- Travel time at Voyager 1 speed 57,640,695 years
1 sibling around Kepler-259
Kepler-259 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-259 b this | Sub-Neptune | 2.80 | 8.25 | 8.115 | 879 | 2014 |
| Kepler-259 c | Sub-Neptune | 2.70 | 7.75 | 36.925 | 530 | 2014 |
Kepler-259 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#742of 1978
top 37.5%
This planet
2.80R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-259 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.80 | 11.21 |
| Mass (M⊕) | 1.00 | 8.25 | 317.83 |
| Density (g/cm³) | 5.51 | 2.07 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.05 | 2.53 |
| Insolation (S⊕) | 1.00 | 113.45 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 158664318
Gaia DR2
Gaia DR2 2130405041264941184
Gaia DR3
Gaia DR3 2130405041264941184
System
Kepler-259
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 8.12 Earth days (2.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0790 AU.
Transit Fingerprint
Depth
0.083 %
Duration
2.954 h
Impact parameter b
0.750
Rp / R★
0.027648
Transit midpoint (BJD)
2,455,007.5196
Photometric dip
Transit produces a flux drop of 835 ppm lasting ≈ 2.95 h.
Extended Orbital Architecture
Planet / star radius ratio
0.027648
Semi-major axis / stellar radius
9.220
Impact parameter (b)
0.750
Transit mid-time (BJD)
2,455,007.5196
Angular separation (arcsec)
0.07880
Eq. Temperature
879K
(606 °C)
Insolation (S⊕)
113.45
Earth = 1.00
Earth Similarity (ESI)
0.275
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-259
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,938 K — hotter than the Sun (5,778 K)
Estimated Age
0.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.898 R☉
Stellar Mass
0.867 M☉
Metallicity [Fe/H]
-0.09
Extended Stellar Properties
Surface gravity (log g)
4.532 dex
Stellar density
1.220 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.969 mas
Total Proper Motion
9.021 mas/yr
PM Right Ascension
6.32 mas/yr
PM Declination
6.44 mas/yr
Galactic Cartesian (pc)
x = 0.215 · y = -0.652 · z = 0.727
Equatorial (J2000)
RA 288.21197° · Dec 46.61505°
Galactic ℓ, b
77.600° · 15.924°
Ecliptic λ, β
304.737° · 67.870°
HTM-20 index
1712803069
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Kepler-276 d
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Kepler-66 b
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HD 21693 b
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Kepler-912 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.80 R⊕ · 6,538.5 ly