Key parameters at a glance
- A radius of 1.87 Earth radii
- A mass of 4.16 Earth masses
- Surface gravity around 1.19 g
- An orbital period of 259.337 days
- Semi-major axis 0.7450 AU
- Equilibrium temperature 304 K (31 °C)
- Distance from Earth 4,975.58 light-years
- Earth Similarity Index 0.822
- Travel time at Voyager 1 speed 87,744,260 years
Context from the literature
Kepler-1638 is a G-type subgiant star located about 5,000 light years away in the constellation of Cygnus. One known exoplanet has been found orbiting the star: Kepler-1638b.As of January 2021, Kepler-1638 is the farthest star with a known exoplanet orbiting in the habitable zone.
Excerpted from Wikipedia · full article
Kepler-1638 b Planet Profile
Physical Specs
Classification
Planet Type
Super-Earth
Discovery
Size rank in cohort
Rank by radius
#169of 1176
top 14.3%
This planet
1.87R⊕
Super-Earth median
1.60R⊕
Nearest-size peers
| Metric | Earth | Kepler-1638 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 1.87 | 11.21 |
| Mass (M⊕) | 1.00 | 4.16 | 317.83 |
| Density (g/cm³) | 5.51 | 3.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.19 | 2.53 |
| Insolation (S⊕) | 1.00 | 2.76 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 27529656
Gaia DR2
Gaia DR2 2134726877877965568
Gaia DR3
Gaia DR3 2134726877877965568
System
Kepler-1638
Percentile among Super-Earth cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 259.34 Earth days (71.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.7450 AU.
Transit Fingerprint
Depth
0.035 %
Duration
15.979 h
Impact parameter b
0.014
Rp / R★
0.018301
Transit midpoint (BJD)
2,454,998.6905
Photometric dip
Transit produces a flux drop of 350 ppm lasting ≈ 15.98 h.
Extended Orbital Architecture
Planet / star radius ratio
0.018301
Semi-major axis / stellar radius
127.300
Impact parameter (b)
0.014
Transit mid-time (BJD)
2,454,998.6905
Angular separation (arcsec)
0.48800
Eq. Temperature
304K
(31 °C)
Insolation (S⊕)
2.76
Earth = 1.00
Earth Similarity (ESI)
0.822
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.
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-1638
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,710 K — cooler than the Sun (5,778 K)
Estimated Age
4.37 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.950 R☉
Stellar Mass
0.970 M☉
Metallicity [Fe/H]
-0.01
Extended Stellar Properties
Surface gravity (log g)
4.470 dex
Stellar density
0.404 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.627 mas
Total Proper Motion
7.792 mas/yr
PM Right Ascension
-5.14 mas/yr
PM Declination
5.86 mas/yr
Galactic Cartesian (pc)
x = 0.285 · y = -0.598 · z = 0.749
Equatorial (J2000)
RA 295.48233° · Dec 48.52447°
Galactic ℓ, b
81.522° · 12.288°
Ecliptic λ, β
318.676° · 67.703°
HTM-20 index
1852138202
Similar Worlds
Kepler-299 e
Super-Earth · G-type yellow (Sun-like)
Radius 1.87 R⊕ · 3,431.9 ly
Kepler-1683 b
Super-Earth · G-type yellow (Sun-like)
Radius 1.87 R⊕ · 2,391.2 ly
55 Cnc e
Super-Earth · G-type yellow (Sun-like)
Radius 1.88 R⊕ · 41.0 ly
Kepler-191 c
Super-Earth · G-type yellow (Sun-like)
Radius 1.86 R⊕ · 1,938.9 ly
Kepler-299 d
Super-Earth · G-type yellow (Sun-like)
Radius 1.86 R⊕ · 3,431.9 ly
Kepler-1471 c
Super-Earth · G-type yellow (Sun-like)
Radius 1.88 R⊕ · 3,192.0 ly