Key parameters at a glance

A radius of 14.91 Earth radii
A mass of 197.69 Earth masses
Surface gravity around 0.89 g
An orbital period of 2.710 days
Semi-major axis 0.0410 AU
Equilibrium temperature 1,671 K (1398 °C)
Distance from Earth 1,747.18 light-years
Earth Similarity Index 0.064
Travel time at Voyager 1 speed 30,811,550 years

WASP-102 b Planet Profile

Physical Specs

Radius

14.91 R⊕

Radius (Jupiter)

1.330 R♃

Mass

197.69 M⊕

Mass (Jupiter)

0.622 M♃

Density

0.32 g/cm³

Surface Gravity

0.89 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.064

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

#242of 1771

top 13.6%

This planet

14.91R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

NGTS-21 b 14.91 R⊕ WASP-7 b 14.91 R⊕ WASP-184 b 14.91 R⊕

Metric	Earth	WASP-102 b	Jupiter
Radius (R⊕)	1.00	14.91	11.21
Mass (M⊕)	1.00	197.69	317.83
Density (g/cm³)	5.51	0.32	1.33
Surface Gravity (g)	1.00	0.89	2.53
Insolation (S⊕)	1.00	1,293.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	197.689 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 51637609

System

WASP-102

Percentile among Gas Giant cohort

Radius 14.908 R⊕ · percentile 86 / cohort 1771

Mass 197.689 M⊕ · percentile 19 / cohort 1747

Orbital period 2.71 d · percentile 12 / cohort 1533

Distance 535.69 pc · percentile 77 / cohort 1759

ESI 0.064 · percentile 10 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

2.710 days

Semi-major axis

0.0410 AU

Eccentricity

0.000

Inclination

89.06 °

Year Length

A year here lasts approximately 2.71 Earth days (0.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0410 AU.

Transit Fingerprint

Depth

0.995 %

Duration

3.282 h

Impact parameter b

0.110

Rp / R★

0.099700

Transit midpoint (BJD)

2,457,109.4558

Photometric dip

Transit produces a flux drop of 9,949 ppm lasting ≈ 3.28 h.

Extended Orbital Architecture

Planet / star radius ratio

0.099700

Semi-major axis / stellar radius

6.430

Impact parameter (b)

0.110

RV semi-amplitude (K)

86.160 m/s

Transit mid-time (BJD)

2,457,109.4558

Angular separation (arcsec)

0.07650

Eq. Temperature

1,671K

(1398 °C)

Insolation (S⊕)

1,293.00

Earth = 1.00

Earth Similarity (ESI)

0.064

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-188 b · Gas Giant WASP-197 b · Gas Giant WASP-194 b · Gas Giant WASP-195 b · Gas Giant WASP-149 b · Gas Giant

Host System: WASP-102

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,990 K — hotter than the Sun (5,778 K)

Estimated Age

0.67 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.375 R☉

Stellar Mass

1.080 M☉

Metallicity [Fe/H]

-0.20

Extended Stellar Properties

Surface gravity (log g)

4.200 dex

Stellar density

0.684 g/cm³

Metallicity ratio

[Fe/H]

Distance

535.69 parsec

Light-years 1,747.18 ly

V-band magnitude

12.67 mag

Voyager-speed travel 30,811,550 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.839 mas

Total Proper Motion

27.471 mas/yr

PM Right Ascension

-13.63 mas/yr

PM Declination

-23.85 mas/yr

Galactic Cartesian (pc)

x = 0.882 · y = -0.384 · z = 0.273

Equatorial (J2000)

RA 336.46430° · Dec 15.85664°

Galactic ℓ, b

79.182° · -34.370°

Ecliptic λ, β

344.547° · 23.796°

HTM-20 index

-636838754