Key parameters at a glance

A radius of 15.13 Earth radii
A mass of 283.50 Earth masses
Surface gravity around 1.24 g
An orbital period of 2.676 days
Equilibrium temperature 1,589 K (1316 °C)
Distance from Earth 844.02 light-years
Earth Similarity Index 0.074
Travel time at Voyager 1 speed 14,884,234 years

WASP-108 b Planet Profile

Physical Specs

Radius

15.13 R⊕

Radius (Jupiter)

1.350 R♃

Mass

283.50 M⊕

Mass (Jupiter)

0.892 M♃

Density

0.48 g/cm³

Surface Gravity

1.24 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.074

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility Transiting Exoplanet Survey Satellite (TESS)

Telescope 0.1 m TESS Telescope

Size rank in cohort

Rank by radius

#221of 1771

top 12.4%

This planet

15.13R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

WASP-123 b 15.13 R⊕ KELT-11 b 15.13 R⊕ KELT-2 A b 15.13 R⊕

Metric	Earth	WASP-108 b	Jupiter
Radius (R⊕)	1.00	15.13	11.21
Mass (M⊕)	1.00	283.50	317.83
Density (g/cm³)	5.51	0.48	1.33
Surface Gravity (g)	1.00	1.24	2.53
Insolation (S⊕)	1.00	1,360.16	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	283.503 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 404340025

Gaia DR2

Gaia DR2 6084610490990144512

Gaia DR3

Gaia DR3 6084610486697803008

System

WASP-108

Percentile among Gas Giant cohort

Radius 15.132 R⊕ · percentile 87 / cohort 1771

Mass 283.503 M⊕ · percentile 31 / cohort 1747

Orbital period 2.68 d · percentile 12 / cohort 1533

Distance 258.78 pc · percentile 56 / cohort 1759

ESI 0.074 · percentile 15 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

2.676 days

Semi-major axis

— AU

Eccentricity

0.000

Inclination

89.20 °

Year Length

A year here lasts approximately 2.68 Earth days (0.7% of a terrestrial year) on a nearly circular orbit.

Transit Fingerprint

Depth

1.434 %

Duration

3.228 h

Impact parameter b

0.100

Rp / R★

0.111650

Transit midpoint (BJD)

2,456,413.7949

Photometric dip

Transit produces a flux drop of 14,341 ppm lasting ≈ 3.23 h.

Extended Orbital Architecture

Planet / star radius ratio

0.111650

Semi-major axis / stellar radius

7.030

Impact parameter (b)

0.100

Transit mid-time (BJD)

2,456,413.7949

Eq. Temperature

1,589K

(1316 °C)

Insolation (S⊕)

1,360.16

Earth = 1.00

Earth Similarity (ESI)

0.074

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.

Direct imaging

The planet has been imaged directly (rare).

Discovery Paper

Primary reference

Bohn et al. 2020

Instrument

TESS CCD Array

Publication

2020-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at Transiting Exoplanet Survey Satellite (TESS) (12 shown).

TOI-700 d · Rocky Terrestrial TOI-237 b · Super-Earth TOI-700 b · Rocky Terrestrial TOI-1266 c · Super-Earth LTT 3780 c · Sub-Neptune TOI-700 c · Sub-Neptune TOI-776 c · Sub-Neptune TOI-942 c · Neptune-like TOI-776 b · Super-Earth TOI-1266 b · Sub-Neptune TOI-540 b · Rocky Terrestrial LHS 1815 b · Rocky Terrestrial

Host System: WASP-108

Spectral Class

F-type yellow-white

Effective Temperature

6,783 K — hotter than the Sun (5,778 K)

Estimated Age

4.64 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.344 R☉

Stellar Mass

1.167 M☉

Metallicity [Fe/H]

0.15

Extended Stellar Properties

Surface gravity (log g)

4.243 dex

Stellar density

0.639 g/cm³

Metallicity ratio

[M/H]

Distance

258.78 parsec

Light-years 844.02 ly

V-band magnitude

11.21 mag

Voyager-speed travel 14,884,234 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

3.836 mas

Total Proper Motion

34.285 mas/yr

PM Right Ascension

25.81 mas/yr

PM Declination

-22.57 mas/yr

Galactic Cartesian (pc)

x = -0.623 · y = -0.177 · z = -0.762

Equatorial (J2000)

RA 195.82816° · Dec -49.63977°

Galactic ℓ, b

304.906° · 13.186°

Ecliptic λ, β

216.741° · -38.965°

HTM-20 index

-699121234