Key parameters at a glance
- A radius of 16.98 Earth radii
- A mass of 532.36 Earth masses
- Surface gravity around 1.85 g
- An orbital period of 2.824 days
- Semi-major axis 0.0474 AU
- Equilibrium temperature 2,250 K (1977 °C)
- Distance from Earth 556.74 light-years
- Earth Similarity Index 0.046
- Travel time at Voyager 1 speed 9,818,026 years
MASCARA-4 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#110of 1771
top 6.2%
This planet
16.98R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | MASCARA-4 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 16.98 | 11.21 |
| Mass (M⊕) | 1.00 | 532.36 | 317.83 |
| Density (g/cm³) | 5.51 | 0.48 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.85 | 2.53 |
| Insolation (S⊕) | 1.00 | 4,913.69 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 532.363 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HD
HD 85628
TIC
TIC 371443216
Gaia DR2
Gaia DR2 5245968236116294016
Gaia DR3
Gaia DR3 5245968236116294016
System
MASCARA-4
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.82 Earth days (0.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0474 AU.
Transit Fingerprint
Depth
0.897 %
Duration
3.970 h
Impact parameter b
0.309
Rp / R★
0.086900
Transit midpoint (BJD)
2,458,909.6642
Photometric dip
Transit produces a flux drop of 8,970 ppm lasting ≈ 3.97 h.
Extended Orbital Architecture
Planet / star radius ratio
0.086900
Semi-major axis / stellar radius
5.704
Impact parameter (b)
0.309
RV semi-amplitude (K)
165.900 m/s
Transit mid-time (BJD)
2,458,909.6642
Sky-projected obliquity (λ)
250.34°
Angular separation (arcsec)
0.27800
Eq. Temperature
2,250K
(1977 °C)
Insolation (S⊕)
4,913.69
Earth = 1.00
Earth Similarity (ESI)
0.046
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
Dorval et al. 2020Instrument
Multiple Instruments
Publication
2020-03
Observation locale
Ground
Discovery cohort
Planets confirmed in 2020 at Multiple Observatories (12 shown).
Host System: MASCARA-4
Spectral Class
A-type white
Effective Temperature
7,800 K — hotter than the Sun (5,778 K)
Estimated Age
0.80 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
1.790 R☉
Stellar Mass
1.750 M☉
Metallicity [Fe/H]
0.00
Extended Stellar Properties
Surface gravity (log g)
4.100 dex
Stellar density
0.355 g/cm³
Systemic radial velocity
-18.31 km/s
Rotational v·sin i
43.00 km/s
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
5.830 mas
Total Proper Motion
16.544 mas/yr
PM Right Ascension
6.05 mas/yr
PM Declination
-15.40 mas/yr
Galactic Cartesian (pc)
x = -0.342 · y = 0.217 · z = -0.914
Equatorial (J2000)
RA 147.58007° · Dec -66.11393°
Galactic ℓ, b
285.976° · -9.402°
Ecliptic λ, β
205.701° · -67.707°
HTM-20 index
-1629552361
Similar Worlds
KOI-13 b
Gas Giant · A-type white
Radius 16.95 R⊕ · 1,693.1 ly
KELT-17 b
Gas Giant · A-type white
Radius 17.09 R⊕ · 738.7 ly
HIP 65426 b
Gas Giant · A-type white
Radius 16.81 R⊕ · 355.1 ly
TOI-1431 b
Gas Giant · A-type white
Radius 16.70 R⊕ · 485.7 ly
HD 135344 A b
Gas Giant · A-type white
Radius 16.25 R⊕ · 461.8 ly
KELT-21 b
Gas Giant · A-type white
Radius 17.78 R⊕ · 1,535.8 ly