Confirmed Exoplanet Discovered 2011

WASP-45 b

A gas giant orbiting the k-type orange WASP-45, located approximately 688.8 light-years from Earth.

Key parameters at a glance

  • A radius of 10.60 Earth radii
  • A mass of 306.39 Earth masses
  • Surface gravity around 2.72 g
  • An orbital period of 3.126 days
  • Semi-major axis 0.0396 AU
  • Equilibrium temperature 1,153 K (880 °C)
  • Distance from Earth 688.83 light-years
  • Earth Similarity Index 0.139
  • Travel time at Voyager 1 speed 12,147,489 years
  • Almost certainly tidally locked to its host star given the close orbit

WASP-45 b Planet Profile

Physical Specs

Radius
10.60 R⊕
Radius (Jupiter)
0.946 R♃
Mass
306.39 M⊕
Mass (Jupiter)
0.964 M♃
Density
1.42 g/cm³
Surface Gravity
2.72 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.139
HZ Position Inner
Controversial No

Discovery

Year 2011
Method Transit
Facility SuperWASP
Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#1712of 1771

top 96.6%

This planet

10.60R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth WASP-45 b Jupiter
Radius (R⊕)1.0010.6011.21
Mass (M⊕)1.00306.39317.83
Density (g/cm³)5.511.421.33
Surface Gravity (g)1.002.722.53
Insolation (S⊕)1.00294.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 306.388 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 305.435 M⊕ Lower bound from radial-velocity fitting.
Computed mass 306.592 M⊕ Model-computed mass (e.g. from mass-radius relation).

Star Catalogue Identifiers

TIC

TIC 120610833

Gaia DR2

Gaia DR2 2308834780352875904

Gaia DR3

Gaia DR3 2308834780352875904

System

WASP-45

Percentile among Gas Giant cohort

Radius 10.604 R⊕ · percentile 3 / cohort 1771
Mass 306.388 M⊕ · percentile 34 / cohort 1747
Orbital period 3.13 d · percentile 18 / cohort 1533
Distance 211.20 pc · percentile 51 / cohort 1759
ESI 0.139 · percentile 35 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
3.126 days
Semi-major axis
0.0396 AU
Eccentricity
0.000
Inclination
85.02 °

Year Length

A year here lasts approximately 3.13 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0396 AU.

Transit Fingerprint

Depth

1.290 %

Duration

1.682 h

Impact parameter b

0.866

Rp / R★

0.113700

Transit midpoint (BJD)

2,458,339.1430

Photometric dip

Transit produces a flux drop of 12,900 ppm lasting ≈ 1.68 h.

Extended Orbital Architecture

Planet / star radius ratio

0.113700

Semi-major axis / stellar radius

9.970

Impact parameter (b)

0.866

RV semi-amplitude (K)

149.000 m/s

Transit mid-time (BJD)

2,458,339.1430

Angular separation (arcsec)

0.18800

Eq. Temperature

1,153K

(880 °C)

Insolation (S⊕)

294.00

Earth = 1.00

Earth Similarity (ESI)

0.139

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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

Anderson et al. 2011

Instrument

iKon-L CCD Camera

Publication

2012-05

Observation locale

Ground

Host System: WASP-45

Spectral Class

K-type orange

Effective Temperature

5,150 K — cooler than the Sun (5,778 K)

Estimated Age

12.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.855 R☉

Stellar Mass

0.850 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.503 dex

Stellar density

1.920 g/cm³

Systemic radial velocity

4.55 km/s

Rotational v·sin i

2.30 km/s

Metallicity ratio

[Fe/H]

Distance
211.20 parsec
Light-years 688.83 ly
V-band magnitude
11.80 mag
Voyager-speed travel 12,147,489 yr

Multi-band Host Photometry — 11 bands

9.013.313.33B11.80V12.05Gaia11.50TESS10.75J10.37H10.29K10.21W110.28W210.18W38.95W4

Astrometric Data

Parallax

4.706 mas

Total Proper Motion

70.685 mas/yr

PM Right Ascension

52.90 mas/yr

PM Declination

-46.89 mas/yr

Galactic Cartesian (pc)

x = 0.806 · y = 0.074 · z = -0.588

Equatorial (J2000)

RA 5.23776° · Dec -35.99847°

Galactic ℓ, b

337.206° · -79.016°

Ecliptic λ, β

348.351° · -34.655°

HTM-20 index

-1537433228

Observation Record

RV measurements

1

Transmission spectra

3

Archive notes

2

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