Key parameters at a glance
- A radius of 14.34 Earth radii
- A mass of 89.31 Earth masses
- Surface gravity around 0.43 g
- An orbital period of 4.055 days
- Semi-major axis 0.0483 AU
- Equilibrium temperature 1,166 K (893 °C)
- Distance from Earth 697.92 light-years
- Earth Similarity Index 0.087
- Travel time at Voyager 1 speed 12,307,733 years
WASP-39 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#299of 1771
top 16.8%
This planet
14.34R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WASP-39 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 14.34 | 11.21 |
| Mass (M⊕) | 1.00 | 89.31 | 317.83 |
| Density (g/cm³) | 5.51 | 0.17 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.43 | 2.53 |
| Insolation (S⊕) | 1.00 | 316.27 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 89.310 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 181949561
Gaia DR2
Gaia DR2 3643098875168270592
Gaia DR3
Gaia DR3 3643098875168270592
System
WASP-39
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 4.06 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0483 AU.
Transit Fingerprint
Depth
2.343 %
Duration
2.803 h
Impact parameter b
0.450
Rp / R★
0.145700
Transit midpoint (BJD)
2,455,342.9691
Photometric dip
Transit produces a flux drop of 23,435 ppm lasting ≈ 2.80 h.
Extended Orbital Architecture
Planet / star radius ratio
0.145700
Semi-major axis / stellar radius
11.390
Impact parameter (b)
0.450
RV semi-amplitude (K)
37.900 m/s
Transit mid-time (BJD)
2,455,342.9691
Long. of periastron (ω)
0.00°
Sky-projected obliquity (λ)
0.00°
Angular separation (arcsec)
0.22600
Eq. Temperature
1,166K
(893 °C)
Insolation (S⊕)
316.27
Earth = 1.00
Earth Similarity (ESI)
0.087
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
Faedi et al. 2011Instrument
iKon-L CCD Camera
Publication
2011-07
Observation locale
Ground
Discovery cohort
Planets confirmed in 2011 at SuperWASP (8 shown).
Host System: WASP-39
Spectral Class
G-type yellow (Sun-like)
Effective Temperature
5,485 K — cooler than the Sun (5,778 K)
Estimated Age
8.50 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.939 R☉
Stellar Mass
0.913 M☉
Metallicity [Fe/H]
0.01
Extended Stellar Properties
Surface gravity (log g)
4.453 dex
Stellar density
1.555 g/cm³
Systemic radial velocity
-58.44 km/s
Rotational v·sin i
1.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
4.645 mas
Total Proper Motion
19.056 mas/yr
PM Right Ascension
-19.05 mas/yr
PM Declination
0.35 mas/yr
Galactic Cartesian (pc)
x = -0.794 · y = -0.605 · z = -0.060
Equatorial (J2000)
RA 217.32665° · Dec -3.44450°
Galactic ℓ, b
344.403° · 51.371°
Ecliptic λ, β
216.115° · 10.698°
HTM-20 index
-779564604
Observation Record
RV measurements
2
Transmission spectra
27
Emission spectra
3
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