Confirmed Exoplanet Discovered 2010

WASP-38 b

A gas giant orbiting the f-type yellow-white WASP-38, located approximately 444.4 light-years from Earth.

Key parameters at a glance

  • A radius of 13.79 Earth radii
  • A mass of 1,093.34 Earth masses
  • Surface gravity around 5.75 g
  • An orbital period of 6.872 days
  • Semi-major axis 0.0752 AU
  • Equilibrium temperature 1,250 K (977 °C)
  • Distance from Earth 444.35 light-years
  • Earth Similarity Index 0.125
  • Travel time at Voyager 1 speed 7,836,199 years

WASP-38 b Planet Profile

Physical Specs

Radius
13.79 R⊕
Radius (Jupiter)
1.230 R♃
Mass
1,093.34 M⊕
Mass (Jupiter)
3.440 M♃
Density
2.30 g/cm³
Surface Gravity
5.75 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.125
HZ Position Unknown
Controversial No

Discovery

Year 2010
Method Transit
Facility SuperWASP
Telescope Canon 200mm f/1.8L

Size rank in cohort

Rank by radius

#540of 1771

top 30.4%

This planet

13.79R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth WASP-38 b Jupiter
Radius (R⊕)1.0013.7911.21
Mass (M⊕)1.001,093.34317.83
Density (g/cm³)5.512.301.33
Surface Gravity (g)1.005.752.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 1,093.335 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

HD

HD 146389

TIC

TIC 318696424

Gaia DR2

Gaia DR2 4453211899986180352

Gaia DR3

Gaia DR3 4453211899986180352

System

WASP-38

Percentile among Gas Giant cohort

Radius 13.787 R⊕ · percentile 69 / cohort 1771
Mass 1,093.335 M⊕ · percentile 69 / cohort 1747
Orbital period 6.87 d · percentile 41 / cohort 1533
Distance 136.24 pc · percentile 41 / cohort 1759
ESI 0.125 · percentile 33 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
6.872 days
Semi-major axis
0.0752 AU
Eccentricity
0.030
Inclination
89.50 °

Year Length

A year here lasts approximately 6.87 Earth days (1.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0752 AU.

Transit Fingerprint

Depth

0.690 %

Duration

4.807 h

Impact parameter b

0.350

Rp / R★

0.079600

Transit midpoint (BJD)

2,459,005.5124

Photometric dip

Transit produces a flux drop of 6,900 ppm lasting ≈ 4.81 h.

Extended Orbital Architecture

Planet / star radius ratio

0.079600

Semi-major axis / stellar radius

12.110

Impact parameter (b)

0.350

RV semi-amplitude (K)

252.000 m/s

Transit mid-time (BJD)

2,459,005.5124

Long. of periastron (ω)

-22.20°

Sky-projected obliquity (λ)

7.50°

Angular separation (arcsec)

0.55200

Eq. Temperature

1,250K

(977 °C)

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.125

0 = alien, 1 = Earth-identical

Insufficient insolation data — 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

Barros et al. 2010

Instrument

iKon-L CCD Camera

Publication

2011-01

Observation locale

Ground

Host System: WASP-38

Spectral Class

F-type yellow-white

Effective Temperature

6,180 K — hotter than the Sun (5,778 K)

Estimated Age

3.29 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.520 R☉

Stellar Mass

1.760 M☉

Metallicity [Fe/H]

-0.02

Extended Stellar Properties

Surface gravity (log g)

4.250 dex

Stellar density

0.710 g/cm³

Systemic radial velocity

-9.06 km/s

Rotational v·sin i

7.50 km/s

Metallicity ratio

[Fe/H]

Distance
136.24 parsec
Light-years 444.35 ly
V-band magnitude
9.39 mag
Voyager-speed travel 7,836,199 yr

Multi-band Host Photometry — 11 bands

7.99.99.86B9.39V9.21Gaia8.84TESS8.29J8.11H8.00K7.98W18.02W27.99W37.87W4

Astrometric Data

Parallax

7.311 mas

Total Proper Motion

49.999 mas/yr

PM Right Ascension

-31.07 mas/yr

PM Declination

-39.17 mas/yr

Galactic Cartesian (pc)

x = -0.432 · y = -0.885 · z = 0.174

Equatorial (J2000)

RA 243.95972° · Dec 10.03241°

Galactic ℓ, b

23.528° · 39.033°

Ecliptic λ, β

239.786° · 30.781°

HTM-20 index

429010222

Observation Record

RV measurements

1

Emission spectra

1

Archive notes

1

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