Key parameters at a glance
- A radius of 12.81 Earth radii
- A mass of 411.27 Earth masses
- Surface gravity around 2.51 g
- An orbital period of 1.420 days
- Semi-major axis 0.0233 AU
- Equilibrium temperature 1,418 K (1145 °C)
- Distance from Earth 605.39 light-years
- Earth Similarity Index 0.100
- Travel time at Voyager 1 speed 10,676,131 years
- Almost certainly tidally locked to its host star given the close orbit
Qatar-1 b Planet Profile
Physical Specs
Classification
Planet Type
Gas Giant
Discovery
Size rank in cohort
Rank by radius
#1058of 1771
top 59.7%
This planet
12.81R⊕
Gas Giant median
13.52R⊕
Nearest-size peers
| Metric | Earth | Qatar-1 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 12.81 | 11.21 |
| Mass (M⊕) | 1.00 | 411.27 | 317.83 |
| Density (g/cm³) | 5.51 | 1.08 | 1.33 |
| Surface Gravity (g) | 1.00 | 2.51 | 2.53 |
| Insolation (S⊕) | 1.00 | 382.33 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 411.272 M⊕ | Direct mass measurement (not derived). |
| Minimum mass (M sin i) | 409.047 M⊕ | Lower bound from radial-velocity fitting. |
| Computed mass | 411.240 M⊕ | Model-computed mass (e.g. from mass-radius relation). |
Star Catalogue Identifiers
TIC
TIC 236887394
Gaia DR2
Gaia DR2 2244830490514284928
Gaia DR3
Gaia DR3 2244830490514284928
System
Qatar-1
Percentile among Gas Giant cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 1.42 Earth days (0.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0233 AU.
Transit Fingerprint
Depth
2.140 %
Duration
1.661 h
Impact parameter b
0.645
Rp / R★
0.146290
Transit midpoint (BJD)
2,456,234.1032
Photometric dip
Transit produces a flux drop of 21,400 ppm lasting ≈ 1.66 h.
Extended Orbital Architecture
Planet / star radius ratio
0.146290
Semi-major axis / stellar radius
6.247
Impact parameter (b)
0.645
RV semi-amplitude (K)
261.600 m/s
Occultation depth
0.196 ppm
Transit mid-time (BJD)
2,456,234.1032
Sky-projected obliquity (λ)
-8.40°
Angular separation (arcsec)
0.12600
Eq. Temperature
1,418K
(1145 °C)
Insolation (S⊕)
382.33
Earth = 1.00
Earth Similarity (ESI)
0.100
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched. 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.
Transit timing variations
Gravitational interactions from neighbours have been detected.
Discovery Paper
Primary reference
Alsubai et al. 2011Instrument
FLI ProLine 4K CCD Sensor
Publication
2011-10
Observation locale
Ground
Host System: Qatar-1
Spectral Class
K-type orange
Effective Temperature
5,013 K — cooler than the Sun (5,778 K)
Estimated Age
1.19 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.803 R☉
Stellar Mass
0.838 M☉
Metallicity [Fe/H]
0.17
Extended Stellar Properties
Surface gravity (log g)
4.552 dex
Stellar density
2.286 g/cm³
Systemic radial velocity
-38.06 km/s
Rotational v·sin i
1.76 km/s
Rotation period
23.70 days
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 11 bands
Astrometric Data
Parallax
5.359 mas
Total Proper Motion
59.526 mas/yr
PM Right Ascension
12.64 mas/yr
PM Declination
58.17 mas/yr
Galactic Cartesian (pc)
x = 0.231 · y = -0.351 · z = 0.908
Equatorial (J2000)
RA 303.38187° · Dec 65.16233°
Galactic ℓ, b
98.719° · 16.424°
Ecliptic λ, β
9.617° · 76.443°
HTM-20 index
-675469578
Observation Record
Transmission spectra
2
Emission spectra
9
Archive notes
2
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