Confirmed Exoplanet Discovered 2018

WASP-170 b

A gas giant orbiting the g-type yellow (sun-like) WASP-170, located approximately 996.7 light-years from Earth.

Key parameters at a glance

  • A radius of 12.29 Earth radii
  • A mass of 508.53 Earth masses
  • Surface gravity around 3.37 g
  • An orbital period of 2.345 days
  • Semi-major axis 0.0337 AU
  • Equilibrium temperature 1,422 K (1149 °C)
  • Distance from Earth 996.74 light-years
  • Earth Similarity Index 0.107
  • Travel time at Voyager 1 speed 17,577,553 years

WASP-170 b Planet Profile

Physical Specs

Radius
12.29 R⊕
Radius (Jupiter)
1.096 R♃
Mass
508.53 M⊕
Mass (Jupiter)
1.600 M♃
Density
1.60 g/cm³
Surface Gravity
3.37 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.107
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

#1389of 1771

top 78.4%

This planet

12.29R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth WASP-170 b Jupiter
Radius (R⊕)1.0012.2911.21
Mass (M⊕)1.00508.53317.83
Density (g/cm³)5.511.601.33
Surface Gravity (g)1.003.372.53
Insolation (S⊕)1.00680.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 508.528 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 118956453

Gaia DR2

Gaia DR2 5656184406542140032

Gaia DR3

Gaia DR3 5656184406542140032

System

WASP-170

Percentile among Gas Giant cohort

Radius 12.285 R⊕ · percentile 22 / cohort 1771
Mass 508.528 M⊕ · percentile 49 / cohort 1747
Orbital period 2.34 d · percentile 10 / cohort 1533
Distance 305.60 pc · percentile 61 / cohort 1759
ESI 0.107 · percentile 28 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
2.345 days
Semi-major axis
0.0337 AU
Eccentricity
Inclination
84.87 °

Year Length

A year here lasts approximately 2.34 Earth days (0.6% of a terrestrial year) at a mean orbital distance of 0.0337 AU.

Transit Fingerprint

Depth

1.382 %

Duration

2.040 h

Impact parameter b

0.689

Rp / R★

0.117500

Transit midpoint (BJD)

2,457,802.3915

Photometric dip

Transit produces a flux drop of 13,820 ppm lasting ≈ 2.04 h.

Extended Orbital Architecture

Planet / star radius ratio

0.117500

Semi-major axis / stellar radius

7.710

Impact parameter (b)

0.689

RV semi-amplitude (K)

255.000 m/s

Transit mid-time (BJD)

2,457,802.3915

Angular separation (arcsec)

0.11000

Eq. Temperature

1,422K

(1149 °C)

Insolation (S⊕)

680.00

Earth = 1.00

Earth Similarity (ESI)

0.107

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

Barkaoui et al. 2019

Instrument

iKon-L CCD Camera

Publication

2019-02

Observation locale

Ground

Host System: WASP-170

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,600 K — cooler than the Sun (5,778 K)

Estimated Age

Stellar Radius

0.938 R☉

Stellar Mass

0.930 M☉

Metallicity [Fe/H]

0.22

Extended Stellar Properties

Surface gravity (log g)

4.466 dex

Stellar density

1.580 g/cm³

Systemic radial velocity

33.08 km/s

Rotational v·sin i

5.60 km/s

Metallicity ratio

[Fe/H]

Distance
305.60 parsec
Light-years 996.74 ly
V-band magnitude
12.61 mag
Voyager-speed travel 17,577,553 yr

Multi-band Host Photometry — 11 bands

8.713.513.46B12.61V12.47Gaia11.94TESS11.13J10.84H10.72K10.64W110.68W210.52W38.71W4

Astrometric Data

Parallax

3.244 mas

Total Proper Motion

10.048 mas/yr

PM Right Ascension

-9.98 mas/yr

PM Declination

1.13 mas/yr

Galactic Cartesian (pc)

x = -0.666 · y = 0.657 · z = -0.354

Equatorial (J2000)

RA 135.41630° · Dec -20.72037°

Galactic ℓ, b

247.559° · 16.656°

Ecliptic λ, β

145.275° · -35.857°

HTM-20 index

-148507608

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