Key parameters at a glance
- A radius of 22.03 Earth radii
- A mass of 467.21 Earth masses
- Surface gravity around 0.96 g
- An orbital period of 1.091 days
- Semi-major axis 0.0234 AU
- Equilibrium temperature 2,601 K (2328 °C)
- Distance from Earth 1,393.49 light-years
- Earth Similarity Index 0.033
- Travel time at Voyager 1 speed 24,574,168 years
WASP-12 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#16of 1771
top 0.8%
This planet
22.03R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WASP-12 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 22.03 | 11.21 |
| Mass (M⊕) | 1.00 | 467.21 | 317.83 |
| Density (g/cm³) | 5.51 | 0.27 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.96 | 2.53 |
| Insolation (S⊕) | 1.00 | 8,220.58 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 467.210 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 464.032 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 467.156 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 86396382
Gaia DR2
Gaia DR2 3435282862461427072
Gaia DR3
Gaia DR3 3435282862461427072
System
WASP-12
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.09 Earth days (0.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0234 AU.
Transit Fingerprint
Depth
1.538 %
Duration
3.001 h
Impact parameter b
0.424
Rp / R★
0.117000
Transit midpoint (BJD)
2,457,607.5193
Photometric dip
Transit produces a flux drop of 15,378 ppm lasting ≈ 3.00 h.
Extended Orbital Architecture
Planet / star radius ratio
0.117000
Semi-major axis / stellar radius
3.000
Impact parameter (b)
0.424
RV semi-amplitude (K)
219.900 m/s
Transit mid-time (BJD)
2,457,607.5193
Long. of periastron (ω)
272.70°
Sky-projected obliquity (λ)
59.00°
Angular separation (arcsec)
0.05480
Eq. Temperature
2,601K
(2328 °C)
Insolation (S⊕)
8,220.58
Earth = 1.00
Earth Similarity (ESI)
0.033
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.
Orbital-brightness modulation
Host star brightness varies with the planet's orbit.
Discovery Paper
Primary reference
Hebb et al. 2009Instrument
iKon-L CCD Camera
Publication
2009-03
Observation locale
Ground
Discovery cohort
Planets confirmed in 2008 at SuperWASP (5 shown).
Host System: WASP-12
Spectral Class
F-type yellow-white
Effective Temperature
6,265 K — hotter than the Sun (5,778 K)
Estimated Age
3.05 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.690 R☉
Stellar Mass
1.325 M☉
Metallicity [Fe/H]
0.12
Extended Stellar Properties
Surface gravity (log g)
4.110 dex
Stellar density
0.386 g/cm³
Systemic radial velocity
19.08 km/s
Rotational v·sin i
1.90 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
2.312 mas
Total Proper Motion
7.135 mas/yr
PM Right Ascension
-1.58 mas/yr
PM Declination
-6.96 mas/yr
Galactic Cartesian (pc)
x = -0.115 · y = 0.861 · z = 0.495
Equatorial (J2000)
RA 97.63665° · Dec 29.67227°
Galactic ℓ, b
184.083° · 8.936°
Ecliptic λ, β
96.668° · 6.410°
HTM-20 index
1282409282
Observation Record
Photometric series
7
RV measurements
2
Transmission spectra
8
Emission spectra
26
Archive notes
8
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