Qatar-1 b
Astrophysical Synthesis & Habitability Characterization
Qatar-1 b is a confirmed gas giant exoplanet orbiting the star Qatar-1, located approximately 605.4 light-years (185.62 parsecs) from the Solar System. First announced in 2010 by Qatar using the Transit detection technique (producing an estimated primary transit depth of 2.1397% across the stellar disk), this world measures 12.812 Earth radii (1.14 Jupiter radii) and has a measured mass of 411.272 Earth masses (1.29 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.08 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.51 g⊕ (24.61 m/s²), and an escape velocity of 63.4 km/s.
In its orbital architecture around Qatar-1, Qatar-1 b completes one full revolution every 1.42 Earth days at a semi-major axis of 0.02332 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 178.7 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1418 K (+1145°C / +2093°F) and receiving 382.33 S⊕ (~520,348 W/m²), Qatar-1 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Qatar-1 is classified as a stellar host with an effective photospheric temperature of 5,013 K, a radius of 0.803 R☉, a mass of 0.838 M☉, an estimated bolometric luminosity of 0.365 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.19 Gyr and a metallicity of [Fe/H] = 0.171 dex (metal-rich relative to the Sun). From Earth, Qatar-1 shines at apparent V-band magnitude 12.692 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: Qatar · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Qatar-1 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,013 K |
| Stellar Radius | 0.8030 R☉ |
| Stellar Mass | 0.8380 M☉ |
| Bolometric Luminosity | 0.365 L☉ |
| Metallicity [Fe/H] | 0.171 dex |
| Stellar Age | 1.190 Gyr |
| Apparent Magnitude | V: 12.692 · G: 12.476 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.023320 AU |
| Orbital Period | 1.42 days |
| Mean Orbital Velocity | 178.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 84.0800° |
| Mean Bulk Density | 1.08 g/cm³ (63.4 km/s vesc) |
| Insolation Flux | 382.3280 S⊕ (~520,348 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 605.400 LY (185.615 pc) |