Key parameters at a glance

A radius of 15.47 Earth radii
A mass of 98.84 Earth masses
Surface gravity around 0.41 g
An orbital period of 4.900 days
Semi-major axis 0.0600 AU
Equilibrium temperature 1,362 K (1089 °C)
Distance from Earth 691.05 light-years
Earth Similarity Index 0.071
Travel time at Voyager 1 speed 12,186,658 years

WASP-20 b Planet Profile

Physical Specs

Radius

15.47 R⊕

Radius (Jupiter)

1.380 R♃

Mass

98.84 M⊕

Mass (Jupiter)

0.311 M♃

Density

0.16 g/cm³

Surface Gravity

0.41 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.071

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Transit

Facility SuperWASP

Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#204of 1771

top 11.5%

This planet

15.47R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

WASP-24 b 15.47 R⊕ WASP-14 b 15.47 R⊕ WASP-159 b 15.47 R⊕

Metric	Earth	WASP-20 b	Jupiter
Radius (R⊕)	1.00	15.47	11.21
Mass (M⊕)	1.00	98.84	317.83
Density (g/cm³)	5.51	0.16	1.33
Surface Gravity (g)	1.00	0.41	2.53
Insolation (S⊕)	1.00	259.86	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	98.841 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 211438925

Gaia DR2

Gaia DR2 2359978293136820864

Gaia DR3

Gaia DR3 2359978293137038720

System

WASP-20

Percentile among Gas Giant cohort

Radius 15.468 R⊕ · percentile 88 / cohort 1771

Mass 98.841 M⊕ · percentile 5 / cohort 1747

Orbital period 4.90 d · percentile 36 / cohort 1533

Distance 211.88 pc · percentile 52 / cohort 1759

ESI 0.071 · percentile 13 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.900 days

Semi-major axis

0.0600 AU

Eccentricity

0.000

Inclination

85.82 °

Year Length

A year here lasts approximately 4.90 Earth days (1.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0600 AU.

Transit Fingerprint

Depth

1.096 %

Duration

3.070 h

Impact parameter b

0.691

Rp / R★

0.099630

Transit midpoint (BJD)

2,455,715.6659

Photometric dip

Transit produces a flux drop of 10,957 ppm lasting ≈ 3.07 h.

Extended Orbital Architecture

Planet / star radius ratio

0.099630

Semi-major axis / stellar radius

9.500

Impact parameter (b)

0.691

RV semi-amplitude (K)

32.800 m/s

Transit mid-time (BJD)

2,455,715.6659

Sky-projected obliquity (λ)

12.70°

Angular separation (arcsec)

0.28300

Eq. Temperature

1,362K

(1089 °C)

Insolation (S⊕)

259.86

Earth = 1.00

Earth Similarity (ESI)

0.071

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

Anderson et al. 2015

Instrument

iKon-L CCD Camera

Publication

2015-03

Observation locale

Ground

Discovery cohort

Planets confirmed in 2015 at SuperWASP (5 shown).

WASP-89 b · Gas Giant WASP-83 b · Gas Giant WASP-135 b · Gas Giant WASP-74 b · Gas Giant WASP-82 b · Gas Giant

Host System: WASP-20

Spectral Class

F-type yellow-white

Effective Temperature

5,940 K — hotter than the Sun (5,778 K)

Estimated Age

7.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.242 R☉

Stellar Mass

1.200 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.231 dex

Stellar density

0.630 g/cm³

Systemic radial velocity

1.32 km/s

Rotational v·sin i

4.75 km/s

Metallicity ratio

[Fe/H]

Distance

211.88 parsec

Light-years 691.05 ly

V-band magnitude

10.68 mag

Voyager-speed travel 12,186,658 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Total Proper Motion

18.353 mas/yr

PM Right Ascension

-1.40 mas/yr

PM Declination

-18.30 mas/yr

Galactic Cartesian (pc)

x = 0.910 · y = 0.082 · z = -0.406

Equatorial (J2000)

RA 5.16056° · Dec -23.93579°

Galactic ℓ, b

55.915° · -82.357°

Ecliptic λ, β

354.602° · -23.887°

HTM-20 index

-1969977222