Key parameters at a glance
- A radius of 2.78 Earth radii
- A mass of 8.15 Earth masses
- Surface gravity around 1.05 g
- An orbital period of 29.885 days
- Semi-major axis 0.1745 AU
- Equilibrium temperature 453 K (180 °C)
- Distance from Earth 824.40 light-years
- Earth Similarity Index 0.519
- Travel time at Voyager 1 speed 14,538,265 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-531 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#768of 1978
top 38.8%
This planet
2.78R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-531 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.78 | 11.21 |
| Mass (M⊕) | 1.00 | 8.15 | 317.83 |
| Density (g/cm³) | 5.51 | 2.08 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.05 | 2.53 |
| Insolation (S⊕) | 1.00 | 10.01 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 243272677
Gaia DR2
Gaia DR2 2131181055955983232
Gaia DR3
Gaia DR3 2131181055955983232
System
Kepler-531
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 29.88 Earth days (8.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1745 AU.
Transit Fingerprint
Depth
0.128 %
Duration
4.561 h
Impact parameter b
0.710
Rp / R★
0.033897
Transit midpoint (BJD)
2,455,006.1944
Photometric dip
Transit produces a flux drop of 1,276 ppm lasting ≈ 4.56 h.
Extended Orbital Architecture
Planet / star radius ratio
0.033897
Semi-major axis / stellar radius
37.000
Impact parameter (b)
0.710
Transit mid-time (BJD)
2,455,006.1944
Angular separation (arcsec)
0.69000
Eq. Temperature
453K
(180 °C)
Insolation (S⊕)
10.01
Earth = 1.00
Earth Similarity (ESI)
0.519
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-531
Spectral Class
K-type orange
Effective Temperature
4,893 K — cooler than the Sun (5,778 K)
Estimated Age
7.76 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.750 R☉
Stellar Mass
0.780 M☉
Metallicity [Fe/H]
-0.03
Extended Stellar Properties
Surface gravity (log g)
4.580 dex
Stellar density
1.960 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
3.927 mas
Total Proper Motion
32.590 mas/yr
PM Right Ascension
-29.95 mas/yr
PM Declination
-12.84 mas/yr
Galactic Cartesian (pc)
x = 0.188 · y = -0.633 · z = 0.751
Equatorial (J2000)
RA 286.52466° · Dec 48.68355°
Galactic ℓ, b
79.158° · 17.753°
Ecliptic λ, β
303.660° · 70.198°
HTM-20 index
-712486960
Similar Worlds
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Kepler-1669 b
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Kepler-1840 b
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TOI-444 b
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HD 73583 b
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Kepler-152 b
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Radius 2.79 R⊕ · 1,438.6 ly