Key parameters at a glance
- A radius of 20.96 Earth radii
- A mass of 247.91 Earth masses
- Surface gravity around 0.56 g
- An orbital period of 3.735 days
- Semi-major axis 0.0515 AU
- Equilibrium temperature 1,755 K (1482 °C)
- Distance from Earth 1,323.89 light-years
- Earth Similarity Index 0.041
- Travel time at Voyager 1 speed 23,346,857 years
WASP-17 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#23of 1771
top 1.2%
This planet
20.96R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WASP-17 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 20.96 | 11.21 |
| Mass (M⊕) | 1.00 | 247.91 | 317.83 |
| Density (g/cm³) | 5.51 | 0.08 | 1.33 |
| Surface Gravity (g) | 1.00 | 0.56 | 2.53 |
| Insolation (S⊕) | 1.00 | 1,292.19 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 247.907 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 66818296
Gaia DR2
Gaia DR2 6042793005779654656
Gaia DR3
Gaia DR3 6042793005779654656
System
WASP-17
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.74 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0515 AU.
Transit Fingerprint
Depth
1.700 %
Duration
4.423 h
Impact parameter b
0.400
Rp / R★
0.124720
Transit midpoint (BJD)
2,454,592.8015
Photometric dip
Transit produces a flux drop of 17,000 ppm lasting ≈ 4.42 h.
Extended Orbital Architecture
Planet / star radius ratio
0.124720
Semi-major axis / stellar radius
8.970
Impact parameter (b)
0.400
RV semi-amplitude (K)
59.200 m/s
Transit mid-time (BJD)
2,454,592.8015
Long. of periastron (ω)
-82.60°
Sky-projected obliquity (λ)
-148.50°
Angular separation (arcsec)
0.12700
Eq. Temperature
1,755K
(1482 °C)
Insolation (S⊕)
1,292.19
Earth = 1.00
Earth Similarity (ESI)
0.041
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
Anderson et al. 2010Instrument
iKon-L CCD Camera
Publication
2010-01
Observation locale
Ground
Discovery cohort
Planets confirmed in 2009 at SuperWASP (6 shown).
Host System: WASP-17
Spectral Class
F-type yellow-white
Effective Temperature
6,550 K — hotter than the Sun (5,778 K)
Estimated Age
2.65 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.490 R☉
Stellar Mass
2.280 M☉
Metallicity [Fe/H]
-0.25
Extended Stellar Properties
Surface gravity (log g)
4.200 dex
Stellar density
0.980 g/cm³
Systemic radial velocity
-49.51 km/s
Rotational v·sin i
9.92 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
2.437 mas
Total Proper Motion
12.591 mas/yr
PM Right Ascension
-8.10 mas/yr
PM Declination
-9.64 mas/yr
Galactic Cartesian (pc)
x = -0.442 · y = -0.764 · z = -0.470
Equatorial (J2000)
RA 239.96225° · Dec -28.06179°
Galactic ℓ, b
345.960° · 18.668°
Ecliptic λ, β
243.549° · -7.339°
HTM-20 index
-609292101
Observation Record
Photometric series
3
RV measurements
2
Transmission spectra
25
Emission spectra
8
Similar Worlds
TOI-1518 b
Gas Giant · F-type yellow-white
Radius 21.05 R⊕ · 736.7 ly
WASP-76 b
Gas Giant · F-type yellow-white
Radius 20.78 R⊕ · 634.2 ly
HAT-P-33 b
Gas Giant · F-type yellow-white
Radius 20.74 R⊕ · 1,291.9 ly
BD-14 3065 b
Gas Giant · F-type yellow-white
Radius 21.59 R⊕ · 1,922.4 ly
WASP-78 b
Gas Giant · F-type yellow-white
Radius 21.63 R⊕ · 2,460.1 ly
KELT-12 b
Gas Giant · F-type yellow-white
Radius 19.95 R⊕ · 1,200.4 ly