Key parameters at a glance

A radius of 14.82 Earth radii
A mass of 458.63 Earth masses
Surface gravity around 2.09 g
An orbital period of 5.749 days
Semi-major axis 0.0720 AU
Equilibrium temperature 1,666 K (1393 °C)
Distance from Earth 2,202.47 light-years
Earth Similarity Index 0.076
Travel time at Voyager 1 speed 38,840,547 years

WASP-188 b Planet Profile

Physical Specs

Radius

14.82 R⊕

Radius (Jupiter)

1.322 R♃

Mass

458.63 M⊕

Mass (Jupiter)

1.443 M♃

Density

0.78 g/cm³

Surface Gravity

2.09 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.076

HZ Position Inner

Controversial No

Discovery

Year 2025

Method Transit

Facility SuperWASP

Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#250of 1771

top 14.1%

This planet

14.82R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Gaia-2 b 14.82 R⊕ KELT-23 A b 14.83 R⊕ WASP-68 b 14.80 R⊕

Metric	Earth	WASP-188 b	Jupiter
Radius (R⊕)	1.00	14.82	11.21
Mass (M⊕)	1.00	458.63	317.83
Density (g/cm³)	5.51	0.78	1.33
Surface Gravity (g)	1.00	2.09	2.53
Insolation (S⊕)	1.00	1,278.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	458.626 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 289574465

Gaia DR2

Gaia DR2 2095929368839731072

Gaia DR3

Gaia DR3 2095929368839731072

System

WASP-188

Percentile among Gas Giant cohort

Radius 14.818 R⊕ · percentile 86 / cohort 1771

Mass 458.626 M⊕ · percentile 46 / cohort 1747

Orbital period 5.75 d · percentile 39 / cohort 1533

Distance 675.28 pc · percentile 81 / cohort 1759

ESI 0.076 · percentile 16 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

5.749 days

Semi-major axis

0.0720 AU

Eccentricity

0.000

Inclination

85.88 °

Year Length

A year here lasts approximately 5.75 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0720 AU.

Transit Fingerprint

Depth

0.551 %

Duration

4.412 h

Impact parameter b

0.610

Rp / R★

0.074200

Transit midpoint (BJD)

2,457,033.1214

Photometric dip

Transit produces a flux drop of 5,509 ppm lasting ≈ 4.41 h.

Extended Orbital Architecture

Planet / star radius ratio

0.074200

Semi-major axis / stellar radius

8.460

Impact parameter (b)

0.610

RV semi-amplitude (K)

124.630 m/s

Transit mid-time (BJD)

2,457,033.1214

Angular separation (arcsec)

0.10700

Eq. Temperature

1,666K

(1393 °C)

Insolation (S⊕)

1,278.00

Earth = 1.00

Earth Similarity (ESI)

0.076

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

Schanche et al. 2025

Instrument

e2v CCD Camera

Publication

2025-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2025 at SuperWASP (8 shown).

WASP-154 b · Gas Giant WASP-155 b · Gas Giant WASP-116 b · Gas Giant WASP-197 b · Gas Giant WASP-194 b · Gas Giant WASP-195 b · Gas Giant WASP-102 b · Gas Giant WASP-149 b · Gas Giant

Host System: WASP-188

Spectral Class

F-type yellow-white

Effective Temperature

6,850 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.830 R☉

Stellar Mass

1.500 M☉

Metallicity [Fe/H]

0.00

Extended Stellar Properties

Surface gravity (log g)

4.100 dex

Stellar density

0.345 g/cm³

Metallicity ratio

[Fe/H]

Distance

675.28 parsec

Light-years 2,202.47 ly

V-band magnitude

12.17 mag

Voyager-speed travel 38,840,547 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

1.452 mas

Total Proper Motion

1.415 mas/yr

PM Right Ascension

-0.35 mas/yr

PM Declination

-1.37 mas/yr

Galactic Cartesian (pc)

x = 0.123 · y = -0.793 · z = 0.596

Equatorial (J2000)

RA 278.78198° · Dec 36.61563°

Galactic ℓ, b

65.164° · 18.830°

Ecliptic λ, β

284.023° · 59.628°

HTM-20 index

-1454147301