Key parameters at a glance
- A radius of 2.57 Earth radii
- A mass of 7.13 Earth masses
- Surface gravity around 1.08 g
- An orbital period of 9.274 days
- Semi-major axis 0.0759 AU
- Equilibrium temperature 649 K (376 °C)
- Distance from Earth 1,853.97 light-years
- Earth Similarity Index 0.386
- Travel time at Voyager 1 speed 32,694,791 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-660 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1074of 1978
top 54.2%
This planet
2.57R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-660 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.57 | 11.21 |
| Mass (M⊕) | 1.00 | 7.13 | 317.83 |
| Density (g/cm³) | 5.51 | 2.31 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.08 | 2.53 |
| Insolation (S⊕) | 1.00 | 44.09 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 158662352
Gaia DR2
Gaia DR2 2130882023153533184
Gaia DR3
Gaia DR3 2130882023153533184
System
Kepler-660
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 9.27 Earth days (2.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0759 AU.
Transit Fingerprint
Depth
0.129 %
Duration
3.300 h
Impact parameter b
0.387
Rp / R★
0.033112
Transit midpoint (BJD)
2,455,006.2580
Photometric dip
Transit produces a flux drop of 1,288 ppm lasting ≈ 3.30 h.
Extended Orbital Architecture
Planet / star radius ratio
0.033112
Semi-major axis / stellar radius
21.600
Impact parameter (b)
0.387
Transit mid-time (BJD)
2,455,006.2580
Angular separation (arcsec)
0.13400
Eq. Temperature
649K
(376 °C)
Insolation (S⊕)
44.09
Earth = 1.00
Earth Similarity (ESI)
0.386
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.
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
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-660
Spectral Class
K-type orange
Effective Temperature
4,779 K — cooler than the Sun (5,778 K)
Estimated Age
4.57 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.710 R☉
Stellar Mass
0.750 M☉
Metallicity [Fe/H]
-0.07
Extended Stellar Properties
Surface gravity (log g)
4.610 dex
Stellar density
1.936 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.731 mas
Total Proper Motion
20.947 mas/yr
PM Right Ascension
3.08 mas/yr
PM Declination
20.72 mas/yr
Galactic Cartesian (pc)
x = 0.209 · y = -0.639 · z = 0.740
Equatorial (J2000)
RA 288.13830° · Dec 47.72456°
Galactic ℓ, b
78.646° · 16.398°
Ecliptic λ, β
305.626° · 68.931°
HTM-20 index
-1871953648
Similar Worlds
Kepler-532 b
Sub-Neptune · K-type orange
Radius 2.57 R⊕ · 1,020.2 ly
Kepler-241 c
Sub-Neptune · K-type orange
Radius 2.57 R⊕ · 1,669.9 ly
Kepler-580 b
Sub-Neptune · K-type orange
Radius 2.57 R⊕ · 1,056.4 ly
Kepler-245 b
Sub-Neptune · K-type orange
Radius 2.57 R⊕ · 2,809.9 ly
TOI-1174 b
Sub-Neptune · K-type orange
Radius 2.56 R⊕ · 308.7 ly
KOI-1833 d
Sub-Neptune · K-type orange
Radius 2.58 R⊕ · 946.9 ly