Confirmed Exoplanet Discovered 2008

WASP-11 b

A gas giant orbiting the k-type orange WASP-11, located approximately 406.8 light-years from Earth.

Key parameters at a glance

  • A radius of 12.44 Earth radii
  • A mass of 251.09 Earth masses
  • Surface gravity around 1.62 g
  • An orbital period of 3.722 days
  • Semi-major axis 0.0435 AU
  • Equilibrium temperature 992 K (719 °C)
  • Distance from Earth 406.81 light-years
  • Earth Similarity Index 0.137
  • Travel time at Voyager 1 speed 7,174,171 years
  • Almost certainly tidally locked to its host star given the close orbit

WASP-11 b Planet Profile

Physical Specs

Radius
12.44 R⊕
Radius (Jupiter)
1.110 R♃
Mass
251.09 M⊕
Mass (Jupiter)
0.790 M♃
Density
0.63 g/cm³
Surface Gravity
1.62 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.137
HZ Position Inner
Controversial No

Discovery

Year 2008
Method Transit
Facility SuperWASP
Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#1287of 1771

top 72.6%

This planet

12.44R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth WASP-11 b Jupiter
Radius (R⊕)1.0012.4411.21
Mass (M⊕)1.00251.09317.83
Density (g/cm³)5.510.631.33
Surface Gravity (g)1.001.622.53
Insolation (S⊕)1.00184.990.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 251.086 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 85593751

Gaia DR2

Gaia DR2 123376685084303360

Gaia DR3

Gaia DR3 123376685084303360

System

WASP-11

Percentile among Gas Giant cohort

Radius 12.442 R⊕ · percentile 27 / cohort 1771
Mass 251.086 M⊕ · percentile 27 / cohort 1747
Orbital period 3.72 d · percentile 26 / cohort 1533
Distance 124.73 pc · percentile 40 / cohort 1759
ESI 0.137 · percentile 34 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
3.722 days
Semi-major axis
0.0435 AU
Eccentricity
0.000
Inclination
89.80 °

Year Length

A year here lasts approximately 3.72 Earth days (1.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0435 AU.

Transit Fingerprint

Depth

1.600 %

Duration

2.556 h

Impact parameter b

0.054

Rp / R★

0.131000

Transit midpoint (BJD)

2,456,933.6153

Photometric dip

Transit produces a flux drop of 16,000 ppm lasting ≈ 2.56 h.

Extended Orbital Architecture

Planet / star radius ratio

0.131000

Semi-major axis / stellar radius

12.710

Impact parameter (b)

0.054

RV semi-amplitude (K)

82.100 m/s

Transit mid-time (BJD)

2,456,933.6153

Long. of periastron (ω)

146.00°

Sky-projected obliquity (λ)

7.00°

Angular separation (arcsec)

0.34900

Eq. Temperature

992K

(719 °C)

Insolation (S⊕)

184.99

Earth = 1.00

Earth Similarity (ESI)

0.137

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

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

West et al. 2009

Instrument

iKon-L CCD Camera

Publication

2009-07

Observation locale

Ground

Host System: WASP-11

Spectral Class

K-type orange

Effective Temperature

4,800 K — cooler than the Sun (5,778 K)

Estimated Age

7.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.890 R☉

Stellar Mass

1.420 M☉

Metallicity [Fe/H]

0.00

Extended Stellar Properties

Surface gravity (log g)

4.450 dex

Stellar density

2.800 g/cm³

Systemic radial velocity

4.91 km/s

Rotational v·sin i

1.04 km/s

Metallicity ratio

[Fe/H]

Distance
124.73 parsec
Light-years 406.81 ly
V-band magnitude
11.57 mag
Voyager-speed travel 7,174,171 yr

Multi-band Host Photometry — 11 bands

8.612.612.58B11.57V11.55Gaia10.93TESS10.02J9.56H9.42K9.37W19.44W29.40W38.62W4

Astrometric Data

Parallax

7.992 mas

Total Proper Motion

44.991 mas/yr

PM Right Ascension

3.86 mas/yr

PM Declination

-44.83 mas/yr

Galactic Cartesian (pc)

x = 0.583 · y = 0.633 · z = 0.510

Equatorial (J2000)

RA 47.36895° · Dec 30.67338°

Galactic ℓ, b

155.018° · -23.463°

Ecliptic λ, β

53.366° · 12.494°

HTM-20 index

1781384296

Observation Record

Photometric series

5

RV measurements

3

Emission spectra

6

Archive notes

3

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