Key parameters at a glance

A radius of 15.52 Earth radii
A mass of 692.87 Earth masses
Surface gravity around 2.87 g
An orbital period of 1.683 days
Semi-major axis 0.0295 AU
Equilibrium temperature 2,050 K (1776 °C)
Distance from Earth 973.22 light-years
Earth Similarity Index 0.061
Travel time at Voyager 1 speed 17,162,794 years

WASP-87 b Planet Profile

Physical Specs

Radius

15.52 R⊕

Radius (Jupiter)

1.385 R♃

Mass

692.87 M⊕

Mass (Jupiter)

2.180 M♃

Density

1.02 g/cm³

Surface Gravity

2.87 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.061

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#196of 1771

top 11.0%

This planet

15.52R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HATS-70 b 15.51 R⊕ CoRoT-5 b 15.56 R⊕ TOI-3321 b 15.56 R⊕

Metric	Earth	WASP-87 b	Jupiter
Radius (R⊕)	1.00	15.52	11.21
Mass (M⊕)	1.00	692.87	317.83
Density (g/cm³)	5.51	1.02	1.33
Surface Gravity (g)	1.00	2.87	2.53
Insolation (S⊕)	1.00	4,170.10	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	692.869 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 15445551

Gaia DR2

Gaia DR2 6077185317188247936

Gaia DR3

Gaia DR3 6077185317188247936

System

WASP-87

Percentile among Gas Giant cohort

Radius 15.524 R⊕ · percentile 89 / cohort 1771

Mass 692.869 M⊕ · percentile 57 / cohort 1747

Orbital period 1.68 d · percentile 4 / cohort 1533

Distance 298.39 pc · percentile 60 / cohort 1759

ESI 0.061 · percentile 9 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1.683 days

Semi-major axis

0.0295 AU

Eccentricity

0.000

Inclination

81.07 °

Year Length

A year here lasts approximately 1.68 Earth days (0.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0295 AU.

Transit Fingerprint

Depth

0.765 %

Duration

3.031 h

Impact parameter b

0.604

Rp / R★

0.087460

Transit midpoint (BJD)

2,457,082.0766

Photometric dip

Transit produces a flux drop of 7,650 ppm lasting ≈ 3.03 h.

Extended Orbital Architecture

Planet / star radius ratio

0.087460

Semi-major axis / stellar radius

3.890

Impact parameter (b)

0.604

RV semi-amplitude (K)

325.000 m/s

Transit mid-time (BJD)

2,457,082.0766

Sky-projected obliquity (λ)

-8.00°

Angular separation (arcsec)

0.09870

Eq. Temperature

2,050K

(1776 °C)

Insolation (S⊕)

4,170.10

Earth = 1.00

Earth Similarity (ESI)

0.061

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

Addison et al. 2016

Instrument

UCLES Spectrograph

Publication

2016-05

Observation locale

Ground

Host System: WASP-87

Spectral Class

F-type yellow-white

Effective Temperature

6,450 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.627 R☉

Stellar Mass

1.204 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.320 dex

Stellar density

0.479 g/cm³

Systemic radial velocity

-14.18 km/s

Rotational v·sin i

9.90 km/s

Distance

298.39 parsec

Light-years 973.22 ly

V-band magnitude

10.73 mag

Voyager-speed travel 17,162,794 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

3.323 mas

Total Proper Motion

4.147 mas/yr

PM Right Ascension

-1.36 mas/yr

PM Declination

3.92 mas/yr

Galactic Cartesian (pc)

x = -0.601 · y = -0.056 · z = -0.797

Equatorial (J2000)

RA 185.32468° · Dec -52.84082°

Galactic ℓ, b

298.322° · 9.761°

Ecliptic λ, β

211.488° · -45.145°

HTM-20 index

1344496918