Key parameters at a glance
- A radius of 3.65 Earth radii
- A mass of 15.50 Earth masses
- Surface gravity around 1.16 g
- An orbital period of 9.031 days
- Semi-major axis 0.0850 AU
- Equilibrium temperature 885 K (612 °C)
- Distance from Earth 863.60 light-years
- Earth Similarity Index 0.253
- Travel time at Voyager 1 speed 15,229,512 years
3 siblings around WASP-47
WASP-47 d shares its host star with 3 other confirmed planets. Side-by-side measurements below.
WASP-47 d Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#113of 1978
top 5.7%
This planet
3.65R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | WASP-47 d | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 3.65 | 11.21 |
| Mass (M⊕) | 1.00 | 15.50 | 317.83 |
| Density (g/cm³) | 5.51 | 1.80 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.16 | 2.53 |
| Insolation (S⊕) | 1.00 | 145.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 15.500 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 102264230
Gaia DR2
Gaia DR2 2613413008919918976
Gaia DR3
Gaia DR3 2613413008919918976
System
WASP-47
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 9.03 Earth days (2.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0850 AU.
Transit Fingerprint
Depth
0.107 %
Duration
4.288 h
Impact parameter b
0.192
Rp / R★
0.029310
Transit midpoint (BJD)
2,457,024.4301
Photometric dip
Transit produces a flux drop of 1,070 ppm lasting ≈ 4.29 h.
Extended Orbital Architecture
Planet / star radius ratio
0.029310
Semi-major axis / stellar radius
16.268
Impact parameter (b)
0.192
RV semi-amplitude (K)
4.260 m/s
Transit mid-time (BJD)
2,457,024.4301
Long. of periastron (ω)
83.00°
Angular separation (arcsec)
0.32100
Eq. Temperature
885K
(612 °C)
Insolation (S⊕)
145.00
Earth = 1.00
Earth Similarity (ESI)
0.253
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.
Radial velocity
Stellar wobble has been measured spectroscopically.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Becker et al. 2015Instrument
Kepler CCD Array
Publication
2015-08
Observation locale
Space
Discovery cohort
Planets confirmed in 2015 at K2 (12 shown).
Host System: WASP-47
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,565 K — cooler than the Sun (5,778 K)
Estimated Age
6.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
1.156 R☉
Stellar Mass
1.058 M☉
Metallicity [Fe/H]
0.43
Extended Stellar Properties
Surface gravity (log g)
4.344 dex
Stellar density
0.998 g/cm³
Systemic radial velocity
-27.06 km/s
Rotational v·sin i
1.80 km/s
Rotation period
39.40 days
Activity index (log R'HK)
-5.201
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
3.750 mas
Total Proper Motion
43.956 mas/yr
PM Right Ascension
15.02 mas/yr
PM Declination
-41.31 mas/yr
Galactic Cartesian (pc)
x = 0.857 · y = -0.471 · z = -0.208
Equatorial (J2000)
RA 331.20309° · Dec -12.01907°
Galactic ℓ, b
45.748° · -48.187°
Ecliptic λ, β
328.992° · -0.209°
HTM-20 index
-1742555658
Similar Worlds
Kepler-1128 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.65 R⊕ · 3,533.6 ly
Kepler-1775 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.65 R⊕ · 2,142.9 ly
K2-194 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.64 R⊕ · 2,053.2 ly
Kepler-1635 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.64 R⊕ · 3,488.1 ly
HD 164922 c
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.66 R⊕ · 71.8 ly
Kepler-565 b
Sub-Neptune · G-type yellow (Sun-like)
Radius 3.64 R⊕ · 3,395.3 ly