HAT-P-36 b
Astrophysical Synthesis & Habitability Characterization
HAT-P-36 b is a confirmed gas giant exoplanet orbiting the star HAT-P-36, located approximately 960.3 light-years (294.42 parsecs) from the Solar System. First announced in 2011 by HATNet using the Transit detection technique (producing an estimated primary transit depth of 1.5891% across the stellar disk), this world measures 14.314 Earth radii (1.28 Jupiter radii) and has a measured mass of 587.413 Earth masses (1.85 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.1 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.87 g⊕ (28.15 m/s²), and an escape velocity of 71.7 km/s.
In its orbital architecture around HAT-P-36, HAT-P-36 b completes one full revolution every 1.327 Earth days at a semi-major axis of 0.0241 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 197.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.063 carries the world between 0.0226 AU at periapsis and 0.0256 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1781 K (+1508°C / +2746°F) and receiving 1,821.00 S⊕ (~2,478,381 W/m²), HAT-P-36 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HAT-P-36 is classified as a solar-type yellow star of spectral type G5 V with an effective photospheric temperature of 5,620 K, a radius of 1.041 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 0.97 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.6 Gyr and a metallicity of [Fe/H] = 0.25 dex (metal-rich relative to the Sun). From Earth, HAT-P-36 shines at apparent V-band magnitude 12.146 (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: HATNet · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HAT-P-36 |
| Spectral Type | G5 V |
| Effective Temp (Teff) | 5,620 K |
| Stellar Radius | 1.0410 R☉ |
| Stellar Mass | 1.0300 M☉ |
| Bolometric Luminosity | 0.97 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 6.600 Gyr |
| Apparent Magnitude | V: 12.146 · G: 12.093 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.024100 AU |
| Orbital Period | 1.327 days |
| Mean Orbital Velocity | 197.5 km/s |
| Orbital Eccentricity (e) | 0.06300 |
| Orbital Inclination (i) | 87.1300° |
| Mean Bulk Density | 1.1 g/cm³ (71.7 km/s vesc) |
| Insolation Flux | 1821.0000 S⊕ (~2,478,381 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 960.300 LY (294.419 pc) |