Key parameters at a glance
- A radius of 1.26 Earth radii
- A mass of 2.13 Earth masses
- Surface gravity around 1.34 g
- An orbital period of 5.620 days
- Semi-major axis 0.0577 AU
- Equilibrium temperature 772 K (499 °C)
- Distance from Earth 1,850.76 light-years
- Earth Similarity Index 0.406
- Travel time at Voyager 1 speed 32,638,186 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1688 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#1148of 1176
top 97.5%
This planet
1.26R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-1688 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.26 | 11.21 |
| Mass (M⊕) | 1.00 | 2.13 | 317.83 |
| Density (g/cm³) | 5.51 | 5.83 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.34 | 2.53 |
| Insolation (S⊕) | 1.00 | 84.01 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 122068161
Gaia DR2
Gaia DR2 2101475241074002176
Gaia DR3
Gaia DR3 2101475241074002176
System
Kepler-1688
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 5.62 Earth days (1.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0577 AU.
Transit Fingerprint
Depth
0.020 %
Duration
2.751 h
Impact parameter b
0.179
Rp / R★
0.012664
Transit midpoint (BJD)
2,454,965.9556
Photometric dip
Transit produces a flux drop of 204 ppm lasting ≈ 2.75 h.
Extended Orbital Architecture
Planet / star radius ratio
0.012664
Semi-major axis / stellar radius
3.000
Impact parameter (b)
0.179
Transit mid-time (BJD)
2,454,965.9556
Angular separation (arcsec)
0.10200
Eq. Temperature
772K
(499 °C)
Insolation (S⊕)
84.01
Earth = 1.00
Earth Similarity (ESI)
0.406
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
Armstrong et al. 2021Instrument
Kepler CCD Array
Publication
2021-07
Observation locale
Space
Discovery cohort
Planets confirmed in 2020 at Kepler (12 shown).
Host System: Kepler-1688
Spectral Class
K-type orange
Effective Temperature
4,632 K — cooler than the Sun (5,778 K)
Estimated Age
14.00 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.746 R☉
Stellar Mass
0.814 M☉
Metallicity [Fe/H]
-0.05
Extended Stellar Properties
Surface gravity (log g)
4.600 dex
Stellar density
3.144 g/cm³
Metallicity ratio
[M/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.762 mas
Total Proper Motion
3.493 mas/yr
PM Right Ascension
1.69 mas/yr
PM Declination
3.06 mas/yr
Galactic Cartesian (pc)
x = 0.251 · y = -0.708 · z = 0.660
Equatorial (J2000)
RA 289.55301° · Dec 41.29785°
Galactic ℓ, b
72.985° · 12.885°
Ecliptic λ, β
303.007° · 62.514°
HTM-20 index
-1362503943
Similar Worlds
Kepler-755 c
Super-Earth · K-type orange
Radius 1.26 R⊕ · 1,301.5 ly
TOI-5789 b
Super-Earth · K-type orange
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Kepler-1029 b
Super-Earth · K-type orange
Radius 1.26 R⊕ · 1,195.9 ly
Kepler-211 b
Super-Earth · K-type orange
Radius 1.26 R⊕ · 1,009.0 ly
Kepler-1697 b
Super-Earth · K-type orange
Radius 1.26 R⊕ · 808.1 ly
K2-203 b
Super-Earth · K-type orange
Radius 1.27 R⊕ · 541.9 ly