Key parameters at a glance
- A radius of 2.60 Earth radii
- A mass of 7.27 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 16.013 days
- Semi-major axis 0.1148 AU
- Equilibrium temperature 593 K (320 °C)
- Distance from Earth 1,998.81 light-years
- Earth Similarity Index 0.418
- Travel time at Voyager 1 speed 35,248,975 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-665 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1017of 1978
top 51.4%
This planet
2.60R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-665 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.60 | 11.21 |
| Mass (M⊕) | 1.00 | 7.27 | 317.83 |
| Density (g/cm³) | 5.51 | 2.27 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 20.72 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 27988995
Gaia DR2
Gaia DR2 2086734157398583424
Gaia DR3
Gaia DR3 2086734157398583424
System
Kepler-665
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 16.01 Earth days (4.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1148 AU.
Transit Fingerprint
Depth
0.126 %
Duration
3.065 h
Impact parameter b
0.187
Rp / R★
0.031693
Transit midpoint (BJD)
2,455,009.3596
Photometric dip
Transit produces a flux drop of 1,263 ppm lasting ≈ 3.07 h.
Extended Orbital Architecture
Planet / star radius ratio
0.031693
Semi-major axis / stellar radius
40.490
Impact parameter (b)
0.187
Transit mid-time (BJD)
2,455,009.3596
Angular separation (arcsec)
0.18700
Eq. Temperature
593K
(320 °C)
Insolation (S⊕)
20.72
Earth = 1.00
Earth Similarity (ESI)
0.418
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Morton et al. 2016Instrument
Kepler CCD Array
Publication
2016-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at Kepler (12 shown).
Host System: Kepler-665
Spectral Class
K-type orange
Effective Temperature
4,913 K — cooler than the Sun (5,778 K)
Estimated Age
4.68 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.740 R☉
Stellar Mass
0.790 M☉
Metallicity [Fe/H]
-0.03
Extended Stellar Properties
Surface gravity (log g)
4.600 dex
Stellar density
4.898 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.604 mas
Total Proper Motion
4.578 mas/yr
PM Right Ascension
-1.54 mas/yr
PM Declination
-4.31 mas/yr
Galactic Cartesian (pc)
x = 0.301 · y = -0.591 · z = 0.749
Equatorial (J2000)
RA 297.02559° · Dec 48.47857°
Galactic ℓ, b
81.967° · 11.362°
Ecliptic λ, β
320.991° · 67.193°
HTM-20 index
2146307014
Similar Worlds
K2-155 c
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 237.4 ly
Kepler-505 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 924.4 ly
K2-90 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 437.7 ly
HD 48948 c
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 55.1 ly
Kepler-1362 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 2,385.2 ly
HD 18599 b
Sub-Neptune · K-type orange
Radius 2.60 R⊕ · 125.8 ly