Key parameters at a glance
- A radius of 13.49 Earth radii
- A mass of 324.20 Earth masses
- Surface gravity around 1.78 g
- An orbital period of 114.736 days
- Semi-major axis 0.4810 AU
- Equilibrium temperature 478 K (205 °C)
- Distance from Earth 4,021.18 light-years
- Earth Similarity Index 0.284
- Travel time at Voyager 1 speed 70,913,458 years
1 sibling around Kepler-87
Kepler-87 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-87 b this | Gas Giant | 13.49 | 324.20 | 114.736 | 478 | 2013 |
| Kepler-87 c | Neptune-like | 6.14 | 6.40 | 191.232 | 403 | 2013 |
Kepler-87 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#721of 1771
top 40.7%
This planet
13.49R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | Kepler-87 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 13.49 | 11.21 |
| Mass (M⊕) | 1.00 | 324.20 | 317.83 |
| Density (g/cm³) | 5.51 | 0.73 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.78 | 2.53 |
| Insolation (S⊕) | 1.00 | 9.20 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 324.200 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 273592336
Gaia DR2
Gaia DR2 2086306584816171392
Gaia DR3
Gaia DR3 2086306584816171392
System
Kepler-87
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 114.74 Earth days (31.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.4810 AU.
Transit Fingerprint
Depth
0.485 %
Duration
11.878 h
Impact parameter b
0.727
Rp / R★
0.068550
Transit midpoint (BJD)
2,454,998.1507
Photometric dip
Transit produces a flux drop of 4,850 ppm lasting ≈ 11.88 h.
Extended Orbital Architecture
Planet / star radius ratio
0.068550
Semi-major axis / stellar radius
57.400
Impact parameter (b)
0.727
Transit mid-time (BJD)
2,454,998.1507
Long. of periastron (ω)
238.60°
Angular separation (arcsec)
0.39000
Eq. Temperature
478K
(205 °C)
Insolation (S⊕)
9.20
Earth = 1.00
Earth Similarity (ESI)
0.284
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.
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
Ofir et al. 2014Instrument
Kepler CCD Array
Publication
2014-01
Observation locale
Space
Discovery cohort
Planets confirmed in 2013 at Kepler (12 shown).
Host System: Kepler-87
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,600 K — cooler than the Sun (5,778 K)
Estimated Age
7.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.820 R☉
Stellar Mass
1.100 M☉
Metallicity [Fe/H]
-0.17
Extended Stellar Properties
Surface gravity (log g)
3.960 dex
Stellar density
0.385 g/cm³
Systemic radial velocity
-9.35 km/s
Rotational v·sin i
4.30 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
0.783 mas
Total Proper Motion
4.530 mas/yr
PM Right Ascension
-4.43 mas/yr
PM Declination
-0.93 mas/yr
Galactic Cartesian (pc)
x = 0.320 · y = -0.603 · z = 0.731
Equatorial (J2000)
RA 297.91684° · Dec 46.96511°
Galactic ℓ, b
80.911° · 10.108°
Ecliptic λ, β
320.589° · 65.574°
HTM-20 index
1093666933
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