Key parameters at a glance

A radius of 11.88 Earth radii
A mass of 95.35 Earth masses
Surface gravity around 0.68 g
An orbital period of 10.022 days
Semi-major axis 0.0946 AU
Equilibrium temperature 1,001 K (728 °C)
Distance from Earth 515.21 light-years
Earth Similarity Index 0.126
Travel time at Voyager 1 speed 9,085,654 years

WASP-117 b Planet Profile

Physical Specs

Radius

11.88 R⊕

Radius (Jupiter)

1.060 R♃

Mass

95.35 M⊕

Mass (Jupiter)

0.300 M♃

Density

0.34 g/cm³

Surface Gravity

0.68 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.126

HZ Position Inner

Controversial No

Discovery

Year 2014

Method Transit

Facility SuperWASP

Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#1547of 1771

top 87.3%

This planet

11.88R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HAT-P-15 b 11.88 R⊕ TOI-628 b 11.88 R⊕ K2-31 b 11.88 R⊕

Metric	Earth	WASP-117 b	Jupiter
Radius (R⊕)	1.00	11.88	11.21
Mass (M⊕)	1.00	95.35	317.83
Density (g/cm³)	5.51	0.34	1.33
Surface Gravity (g)	1.00	0.68	2.53
Insolation (S⊕)	1.00	211.79	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	95.349 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 166739520

Gaia DR2

Gaia DR2 4746157737910069888

Gaia DR3

Gaia DR3 4746157737910069888

System

WASP-117

Percentile among Gas Giant cohort

Radius 11.882 R⊕ · percentile 12 / cohort 1771

Mass 95.349 M⊕ · percentile 5 / cohort 1747

Orbital period 10.02 d · percentile 44 / cohort 1533

Distance 157.96 pc · percentile 45 / cohort 1759

ESI 0.126 · percentile 33 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

10.022 days

Semi-major axis

0.0946 AU

Eccentricity

0.300

Inclination

89.14 °

Year Length

A year here lasts approximately 10.02 Earth days (2.7% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0946 AU.

Transit Fingerprint

Depth

0.800 %

Duration

5.851 h

Impact parameter b

0.435

Rp / R★

0.086500

Transit midpoint (BJD)

2,458,728.3342

Photometric dip

Transit produces a flux drop of 8,000 ppm lasting ≈ 5.85 h.

Extended Orbital Architecture

Planet / star radius ratio

0.086500

Semi-major axis / stellar radius

17.430

Impact parameter (b)

0.435

RV semi-amplitude (K)

25.200 m/s

Transit mid-time (BJD)

2,458,728.3342

Long. of periastron (ω)

242.00°

Sky-projected obliquity (λ)

44.00°

True obliquity (ψ)

69.60°

Angular separation (arcsec)

0.59900

Eq. Temperature

1,001K

(728 °C)

Insolation (S⊕)

211.79

Earth = 1.00

Earth Similarity (ESI)

0.126

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

Lendl et al. 2014

Instrument

iKon-L CCD Camera

Publication

2014-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2014 at SuperWASP (12 shown).

WASP-94 B b · Gas Giant WASP-84 b · Gas Giant WASP-106 b · Gas Giant WASP-69 b · Gas Giant WASP-98 b · Gas Giant WASP-99 b · Gas Giant WASP-104 b · Gas Giant WASP-96 b · Gas Giant WASP-97 b · Gas Giant WASP-70 A b · Gas Giant WASP-28 b · Gas Giant WASP-68 b · Gas Giant

Host System: WASP-117

Spectral Class

F-type yellow-white

Effective Temperature

6,040 K — hotter than the Sun (5,778 K)

Estimated Age

4.60 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.220 R☉

Stellar Mass

1.290 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

4.280 dex

Stellar density

1.000 g/cm³

Systemic radial velocity

-16.03 km/s

Rotational v·sin i

1.67 km/s

Metallicity ratio

[Fe/H]

Distance

157.96 parsec

Light-years 515.21 ly

V-band magnitude

10.14 mag

Voyager-speed travel 9,085,654 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

6.302 mas

Total Proper Motion

64.863 mas/yr

PM Right Ascension

59.96 mas/yr

PM Declination

24.74 mas/yr

Galactic Cartesian (pc)

x = 0.512 · y = 0.383 · z = -0.769

Equatorial (J2000)

RA 36.77581° · Dec -50.28442°

Galactic ℓ, b

271.160° · -60.529°

Ecliptic λ, β

5.021° · -59.084°

HTM-20 index

1568204929