Confirmed Exoplanet Discovered 2018

WASP-145 A b

A gas giant orbiting the k-type orange WASP-145 A, located approximately 297.8 light-years from Earth.

Key parameters at a glance

  • A radius of 10.09 Earth radii
  • A mass of 282.87 Earth masses
  • Surface gravity around 2.78 g
  • An orbital period of 1.769 days
  • Semi-major axis 0.0261 AU
  • Equilibrium temperature 1,200 K (927 °C)
  • Distance from Earth 297.78 light-years
  • Earth Similarity Index 0.138
  • Travel time at Voyager 1 speed 5,251,300 years
  • Almost certainly tidally locked to its host star given the close orbit

WASP-145 A b Planet Profile

Physical Specs

Radius
10.09 R⊕
Radius (Jupiter)
0.900 R♃
Mass
282.87 M⊕
Mass (Jupiter)
0.890 M♃
Density
1.60 g/cm³
Surface Gravity
2.78 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.138
HZ Position Inner
Controversial No

Discovery

Year 2018
Method Transit
Facility SuperWASP-South
Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#1765of 1771

top 99.6%

This planet

10.09R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth WASP-145 A b Jupiter
Radius (R⊕)1.0010.0911.21
Mass (M⊕)1.00282.87317.83
Density (g/cm³)5.511.601.33
Surface Gravity (g)1.002.782.53
Insolation (S⊕)1.00313.400.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 282.869 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 381856447

Gaia DR2

Gaia DR2 6458529931463278848

Gaia DR3

Gaia DR3 6458529931463278848

System

WASP-145

Percentile among Gas Giant cohort

Radius 10.088 R⊕ · percentile 0 / cohort 1771
Mass 282.869 M⊕ · percentile 31 / cohort 1747
Orbital period 1.77 d · percentile 5 / cohort 1533
Distance 91.30 pc · percentile 33 / cohort 1759
ESI 0.138 · percentile 35 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
1.769 days
Semi-major axis
0.0261 AU
Eccentricity
0.000
Inclination
83.30 °

Year Length

A year here lasts approximately 1.77 Earth days (0.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0261 AU.

Transit Fingerprint

Depth

1.160 %

Duration

0.977 h

Impact parameter b

0.970

Rp / R★

0.108000

Transit midpoint (BJD)

2,456,844.1653

Photometric dip

Transit produces a flux drop of 11,600 ppm lasting ≈ 0.98 h.

Extended Orbital Architecture

Planet / star radius ratio

0.108000

Semi-major axis / stellar radius

8.740

Impact parameter (b)

0.970

RV semi-amplitude (K)

178.000 m/s

Transit mid-time (BJD)

2,456,844.1653

Angular separation (arcsec)

0.28600

Eq. Temperature

1,200K

(927 °C)

Insolation (S⊕)

313.40

Earth = 1.00

Earth Similarity (ESI)

0.138

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

Hellier et al. 2019

Instrument

iKon-L CCD Camera

Publication

2019-01

Observation locale

Ground

Host System: WASP-145 A

Spectral Class

K-type orange

Effective Temperature

4,900 K — cooler than the Sun (5,778 K)

Estimated Age

6.99 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.680 R☉

Stellar Mass

0.760 M☉

Metallicity [Fe/H]

-0.04

Extended Stellar Properties

Surface gravity (log g)

4.650 dex

Stellar density

3.360 g/cm³

Systemic radial velocity

3.35 km/s

Rotational v·sin i

2.10 km/s

Distance
91.30 parsec
Light-years 297.78 ly
V-band magnitude
11.64 mag
Voyager-speed travel 5,251,300 yr

Multi-band Host Photometry — 11 bands

8.312.612.62B11.64V11.36Gaia10.72TESS9.84J9.29H9.19K9.08W19.12W29.06W38.29W4

Astrometric Data

Parallax

10.924 mas

Total Proper Motion

107.689 mas/yr

PM Right Ascension

107.11 mas/yr

PM Declination

11.19 mas/yr

Galactic Cartesian (pc)

x = 0.409 · y = -0.317 · z = -0.856

Equatorial (J2000)

RA 322.25376° · Dec -58.83615°

Galactic ℓ, b

336.103° · -43.037°

Ecliptic λ, β

302.958° · -41.229°

HTM-20 index

1111696148

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