Qatar-3 b
Astrophysical Synthesis & Habitability Characterization
Qatar-3 b is a confirmed gas giant exoplanet orbiting the star Qatar-3, located approximately 2399.2 light-years (735.6 parsecs) from the Solar System. First announced in 2017 by Qatar using the Transit detection technique (producing an estimated primary transit depth of 0.784% across the stellar disk), this world measures 12.285 Earth radii (1.1 Jupiter radii) and has a measured mass of 1369.847 Earth masses (4.31 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.07 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 9.08 g⊕ (89.04 m/s²), and an escape velocity of 118.1 km/s.
In its orbital architecture around Qatar-3, Qatar-3 b completes one full revolution every 2.508 Earth days at a semi-major axis of 0.03783 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 164.1 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 1681 K (+1408°C / +2566°F) and receiving 1,330.00 S⊕ (~1,810,130 W/m²), Qatar-3 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Qatar-3 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 6,007 K, a radius of 1.272 R☉, a mass of 1.145 M☉, an estimated bolometric luminosity of 1.89 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.31 Gyr and a metallicity of [Fe/H] = -0.041 dex (near-solar heavy-element abundance). From Earth, Qatar-3 shines at apparent V-band magnitude 12.929 (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-3 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 6,007 K |
| Stellar Radius | 1.2720 R☉ |
| Stellar Mass | 1.1450 M☉ |
| Bolometric Luminosity | 1.89 L☉ |
| Metallicity [Fe/H] | -0.041 dex |
| Stellar Age | 0.310 Gyr |
| Apparent Magnitude | V: 12.929 · G: 12.820 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037830 AU |
| Orbital Period | 2.508 days |
| Mean Orbital Velocity | 164.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.8000° |
| Mean Bulk Density | 4.07 g/cm³ (118.1 km/s vesc) |
| Insolation Flux | 1330.0000 S⊕ (~1,810,130 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2399.200 LY (735.601 pc) |