Key parameters at a glance
- A radius of 14.73 Earth radii
- A mass of 186.25 Earth masses
- Surface gravity around 0.86 g
- An orbital period of 4.466 days
- Semi-major axis 0.0558 AU
- Equilibrium temperature 1,342 K (1069 °C)
- Distance from Earth 970.19 light-years
- Earth Similarity Index 0.085
- Travel time at Voyager 1 speed 17,109,303 years
WASP-55 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#258of 1771
top 14.5%
This planet
14.73R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WASP-55 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 14.73 | 11.21 |
| Mass (M⊕) | 1.00 | 186.25 | 317.83 |
| Density (g/cm³) | 5.51 | 0.34 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.86 | 2.53 |
| Insolation (S⊕) | 1.00 | 504.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 186.247 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 294301883
Gaia DR2
Gaia DR2 3603529272750802560
Gaia DR3
Gaia DR3 3603529272750802560
System
WASP-55
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.47 Earth days (1.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0558 AU.
Transit Fingerprint
Depth
1.836 %
Duration
3.533 h
Impact parameter b
0.235
Rp / R★
0.122300
Transit midpoint (BJD)
2,455,737.9392
Photometric dip
Transit produces a flux drop of 18,355 ppm lasting ≈ 3.53 h.
Extended Orbital Architecture
Planet / star radius ratio
0.122300
Semi-major axis / stellar radius
10.660
Impact parameter (b)
0.235
RV semi-amplitude (K)
68.700 m/s
Transit mid-time (BJD)
2,455,737.9392
Angular separation (arcsec)
0.18800
Eq. Temperature
1,342K
(1069 °C)
Insolation (S⊕)
504.00
Earth = 1.00
Earth Similarity (ESI)
0.085
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.
Detection Signatures
Transit photometry
A transit dip has been observed from at least one telescope.
Radial velocity
Stellar wobble has been measured spectroscopically.
Discovery Paper
Primary reference
Hellier et al. 2012Instrument
iKon-L CCD Camera
Publication
2012-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2012 at SuperWASP (12 shown).
Host System: WASP-55
Spectral Class
F-type yellow-white
Effective Temperature
6,096 K — hotter than the Sun (5,778 K)
Estimated Age
3.05 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.090 R☉
Stellar Mass
1.071 M☉
Metallicity [Fe/H]
-0.03
Extended Stellar Properties
Surface gravity (log g)
4.393 dex
Stellar density
1.159 g/cm³
Systemic radial velocity
-4.32 km/s
Rotational v·sin i
3.28 km/s
Rotation period
17.45 days
Activity index (log R'HK)
-4.844
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 12 bands
Astrometric Data
Parallax
3.334 mas
Total Proper Motion
12.667 mas/yr
PM Right Ascension
12.07 mas/yr
PM Declination
-3.84 mas/yr
Galactic Cartesian (pc)
x = -0.873 · y = -0.384 · z = -0.301
Equatorial (J2000)
RA 203.75820° · Dec -17.50350°
Galactic ℓ, b
317.483° · 44.133°
Ecliptic λ, β
208.406° · -7.072°
HTM-20 index
-1240417074
Similar Worlds
TOI-5386 A b
Gas Giant · F-type yellow-white
Radius 14.71 R⊕ · 1,286.6 ly
HAT-P-16 b
Gas Giant · F-type yellow-white
Radius 14.68 R⊕ · 739.2 ly
TOI-3474 b
Gas Giant · F-type yellow-white
Radius 14.67 R⊕ · 1,370.3 ly
WASP-193 b
Gas Giant · F-type yellow-white
Radius 14.78 R⊕ · 1,181.0 ly
XO-3 b
Gas Giant · F-type yellow-white
Radius 14.80 R⊕ · 694.9 ly
WASP-62 b
Gas Giant · F-type yellow-white
Radius 14.80 R⊕ · 572.8 ly