Key parameters at a glance
- A radius of 6.03 Earth radii
- A mass of 41.80 Earth masses
- Surface gravity around 1.15 g
- An orbital period of 3.836 days
- Semi-major axis 0.0458 AU
- Equilibrium temperature 935 K (661 °C)
- Distance from Earth 398.13 light-years
- Earth Similarity Index 0.194
- Travel time at Voyager 1 speed 7,020,944 years
- Almost certainly tidally locked to its host star given the close orbit
WASP-156 b Planet Profile
Physical Specs
Classification
Planet Type
Neptune-like
Discovery
Size rank in cohort
Rank by radius
#282of 574
top 49.0%
This planet
6.03R⊕
Neptune-like median
6.39R⊕
Nearest-size peers
| Metric | Earth | WASP-156 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 6.03 | 11.21 |
| Mass (M⊕) | 1.00 | 41.80 | 317.83 |
| Density (g/cm³) | 5.51 | 1.05 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.15 | 2.53 |
| Insolation (S⊕) | 1.00 | 150.00 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 41.800 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 270380593
Gaia DR2
Gaia DR2 2514360548993901312
Gaia DR3
Gaia DR3 2514360548993901312
System
WASP-156
Percentile among Neptune-like cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 3.84 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0458 AU.
Transit Fingerprint
Depth
0.536 %
Duration
2.404 h
Impact parameter b
0.228
Rp / R★
0.066841
Transit midpoint (BJD)
2,458,414.1361
Photometric dip
Transit produces a flux drop of 5,358 ppm lasting ≈ 2.40 h.
Extended Orbital Architecture
Planet / star radius ratio
0.066841
Semi-major axis / stellar radius
12.748
Impact parameter (b)
0.228
RV semi-amplitude (K)
18.700 m/s
Transit mid-time (BJD)
2,458,414.1361
Long. of periastron (ω)
90.00°
Sky-projected obliquity (λ)
105.70°
Angular separation (arcsec)
0.37500
Eq. Temperature
935K
(661 °C)
Insolation (S⊕)
150.00
Earth = 1.00
Earth Similarity (ESI)
0.194
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
Demangeon et al. 2018Instrument
iKon-L CCD Camera
Publication
2018-03
Observation locale
Ground
Host System: WASP-156
Spectral Class
K-type orange
Effective Temperature
4,987 K — cooler than the Sun (5,778 K)
Estimated Age
5.60 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.827 R☉
Stellar Mass
0.871 M☉
Metallicity [Fe/H]
0.31
Extended Stellar Properties
Surface gravity (log g)
4.541 dex
Stellar density
2.154 g/cm³
Systemic radial velocity
9.30 km/s
Rotational v·sin i
3.17 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
8.164 mas
Total Proper Motion
84.313 mas/yr
PM Right Ascension
74.19 mas/yr
PM Declination
40.06 mas/yr
Galactic Cartesian (pc)
x = 0.840 · y = 0.541 · z = 0.042
Equatorial (J2000)
RA 32.78209° · Dec 2.41819°
Galactic ℓ, b
159.091° · -54.760°
Ecliptic λ, β
31.415° · -10.164°
HTM-20 index
706281606
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