Key parameters at a glance
- A radius of 17.90 Earth radii
- A mass of 1,175.97 Earth masses
- Surface gravity around 3.67 g
- An orbital period of 2.149 days
- Semi-major axis 0.0404 AU
- Equilibrium temperature 2,594 K (2321 °C)
- Distance from Earth 594.49 light-years
- Earth Similarity Index 0.047
- Travel time at Voyager 1 speed 10,483,907 years
MASCARA-1 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#79of 1771
top 4.4%
This planet
17.90R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | MASCARA-1 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 17.90 | 11.21 |
| Mass (M⊕) | 1.00 | 1,175.97 | 317.83 |
| Density (g/cm³) | 5.51 | 1.50 | 1.33 |
| Surface Gravity (g) | 1.00 | 3.67 | 2.53 |
| Insolation (S⊕) | 1.00 | 38,711.50 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 1,175.971 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
HD
HD 201585
HIP
HIP 104513
TIC
TIC 354619337
Gaia DR2
Gaia DR2 1744911763437512064
Gaia DR3
Gaia DR3 1744911763437512064
System
MASCARA-1
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 2.15 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0404 AU.
Transit Fingerprint
Depth
0.622 %
Duration
4.226 h
Impact parameter b
0.113
Rp / R★
0.078840
Transit midpoint (BJD)
2,458,833.4882
Photometric dip
Transit produces a flux drop of 6,216 ppm lasting ≈ 4.23 h.
Extended Orbital Architecture
Planet / star radius ratio
0.078840
Semi-major axis / stellar radius
4.168
Impact parameter (b)
0.113
RV semi-amplitude (K)
400.000 m/s
Occultation depth
0.013 ppm
Transit mid-time (BJD)
2,458,833.4882
Long. of periastron (ω)
-16.00°
Sky-projected obliquity (λ)
-69.20°
True obliquity (ψ)
72.10°
Angular separation (arcsec)
0.22100
Eq. Temperature
2,594K
(2321 °C)
Insolation (S⊕)
38,711.50
Earth = 1.00
Earth Similarity (ESI)
0.047
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
Talens et al. 2017Instrument
Multiple Instruments
Publication
2017-10
Observation locale
Ground
Discovery cohort
Planets confirmed in 2017 at Multiple Observatories (12 shown).
Host System: MASCARA-1
Spectral Class
A-type white
Effective Temperature
7,490 K — hotter than the Sun (5,778 K)
Estimated Age
0.80 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
2.082 R☉
Stellar Mass
1.900 M☉
Metallicity [Fe/H]
0.15
Extended Stellar Properties
Surface gravity (log g)
4.105 dex
Stellar density
0.297 g/cm³
Rotational v·sin i
101.70 km/s
Rotation period
0.85 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
5.458 mas
Total Proper Motion
7.852 mas/yr
PM Right Ascension
-5.72 mas/yr
PM Declination
5.38 mas/yr
Galactic Cartesian (pc)
x = 0.725 · y = -0.663 · z = 0.186
Equatorial (J2000)
RA 317.55153° · Dec 10.73890°
Galactic ℓ, b
60.448° · -24.375°
Ecliptic λ, β
323.607° · 25.768°
HTM-20 index
1436350654
Observation Record
Photometric series
1
Emission spectra
2
Archive notes
1
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