Key parameters at a glance
- A radius of 11.55 Earth radii
- A mass of 425.89 Earth masses
- Surface gravity around 3.20 g
- An orbital period of 2.799 days
- Semi-major axis 0.0370 AU
- Equilibrium temperature 1,160 K (887 °C)
- Distance from Earth 489.04 light-years
- Earth Similarity Index 0.138
- Travel time at Voyager 1 speed 8,624,305 years
- Almost certainly tidally locked to its host star given the close orbit
WASP-91 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1585of 1771
top 89.4%
This planet
11.55R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | WASP-91 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 11.55 | 11.21 |
| Mass (M⊕) | 1.00 | 425.89 | 317.83 |
| Density (g/cm³) | 5.51 | 1.59 | 1.33 |
| Surface Gravity (g) | 1.00 | 3.20 | 2.53 |
| Insolation (S⊕) | 1.00 | 332.56 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 425.892 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 238176110
Gaia DR2
Gaia DR2 6386751579018596864
Gaia DR3
Gaia DR3 6386751579018596864
System
WASP-91
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.80 Earth days (0.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0370 AU.
Transit Fingerprint
Depth
1.500 %
Duration
2.342 h
Impact parameter b
0.510
Rp / R★
0.122500
Transit midpoint (BJD)
2,456,297.7190
Photometric dip
Transit produces a flux drop of 15,000 ppm lasting ≈ 2.34 h.
Extended Orbital Architecture
Planet / star radius ratio
0.122500
Semi-major axis / stellar radius
9.100
Impact parameter (b)
0.510
RV semi-amplitude (K)
217.000 m/s
Transit mid-time (BJD)
2,456,297.7190
Angular separation (arcsec)
0.24700
Eq. Temperature
1,160K
(887 °C)
Insolation (S⊕)
332.56
Earth = 1.00
Earth Similarity (ESI)
0.138
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. Close-orbiting tidally-locked around a cool host.
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. 2017Instrument
iKon-L CCD Camera
Publication
2017-08
Observation locale
Ground
Discovery cohort
Planets confirmed in 2017 at SuperWASP-South (3 shown).
Host System: WASP-91
Spectral Class
K-type orange
Effective Temperature
4,920 K — cooler than the Sun (5,778 K)
Estimated Age
—
Stellar Radius
0.860 R☉
Stellar Mass
0.840 M☉
Metallicity [Fe/H]
0.19
Extended Stellar Properties
Surface gravity (log g)
4.300 dex
Stellar density
1.830 g/cm³
Systemic radial velocity
2.78 km/s
Rotational v·sin i
2.40 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
6.640 mas
Total Proper Motion
96.200 mas/yr
PM Right Ascension
96.18 mas/yr
PM Declination
-1.75 mas/yr
Galactic Cartesian (pc)
x = 0.339 · y = -0.013 · z = -0.941
Equatorial (J2000)
RA 357.84643° · Dec -70.15286°
Galactic ℓ, b
310.221° · -46.116°
Ecliptic λ, β
311.320° · -59.083°
HTM-20 index
689672360
Similar Worlds
KPS-1 b
Gas Giant · K-type orange
Radius 11.55 R⊕ · 856.8 ly
Wendelstein-1 b
Gas Giant · K-type orange
Radius 11.56 R⊕ · 995.8 ly
HATS-74 A b
Gas Giant · K-type orange
Radius 11.57 R⊕ · 976.5 ly
Kepler-553 c
Gas Giant · K-type orange
Radius 11.58 R⊕ · 2,376.1 ly
TOI-6303 b
Gas Giant · K-type orange
Radius 11.59 R⊕ · 496.5 ly
TOI-2384 b
Gas Giant · K-type orange
Radius 11.49 R⊕ · 624.6 ly