Key parameters at a glance
- A radius of 2.27 Earth radii
- A mass of 5.79 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 44.299 days
- Semi-major axis 0.2348 AU
- Equilibrium temperature 463 K (190 °C)
- Distance from Earth 2,441.50 light-years
- Earth Similarity Index 0.550
- Travel time at Voyager 1 speed 43,055,898 years
Kepler-1817 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1552of 1978
top 78.4%
This planet
2.27R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1817 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.27 | 11.21 |
| Mass (M⊕) | 1.00 | 5.79 | 317.83 |
| Density (g/cm³) | 5.51 | 2.71 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 10.85 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 351804260
Gaia DR2
Gaia DR2 2105396099534835456
Gaia DR3
Gaia DR3 2105396099534835456
System
Kepler-1817
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 44.30 Earth days (12.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2348 AU.
Transit Fingerprint
Depth
0.080 %
Duration
4.367 h
Impact parameter b
0.683
Rp / R★
0.028427
Transit midpoint (BJD)
2,454,974.2788
Photometric dip
Transit produces a flux drop of 798 ppm lasting ≈ 4.37 h.
Extended Orbital Architecture
Planet / star radius ratio
0.028427
Semi-major axis / stellar radius
64.800
Impact parameter (b)
0.683
Transit mid-time (BJD)
2,454,974.2788
Angular separation (arcsec)
0.31400
Eq. Temperature
463K
(190 °C)
Insolation (S⊕)
10.85
Earth = 1.00
Earth Similarity (ESI)
0.550
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
Valizadegan et al. 2022Instrument
Kepler CCD Array
Publication
2022-02
Observation locale
Space
Discovery cohort
Planets confirmed in 2021 at Kepler (12 shown).
Host System: Kepler-1817
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,316 K — cooler than the Sun (5,778 K)
Estimated Age
0.40 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.915 R☉
Stellar Mass
0.878 M☉
Metallicity [Fe/H]
0.16
Extended Stellar Properties
Surface gravity (log g)
4.459 dex
Stellar density
2.626 g/cm³
Systemic radial velocity
-19.26 km/s
Rotational v·sin i
6.60 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.307 mas
Total Proper Motion
9.367 mas/yr
PM Right Ascension
9.34 mas/yr
PM Declination
-0.77 mas/yr
Galactic Cartesian (pc)
x = 0.149 · y = -0.698 · z = 0.701
Equatorial (J2000)
RA 282.03334° · Dec 44.47800°
Galactic ℓ, b
73.871° · 19.186°
Ecliptic λ, β
292.360° · 66.985°
HTM-20 index
-243677618
Similar Worlds
K2-398 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · 1,979.7 ly
TOI-5788 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · 318.4 ly
K2-222 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.28 R⊕ · 330.5 ly
Kepler-1985 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · —
Kepler-166 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · 1,968.4 ly
Kepler-759 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 2.27 R⊕ · 3,501.2 ly