HAT-P-46 b
Astrophysical Synthesis & Habitability Characterization
HAT-P-46 b is a confirmed gas giant exoplanet orbiting the star HAT-P-46, located approximately 948.3 light-years (290.74 parsecs) from the Solar System. First announced in 2014 by HATNet using the Transit detection technique (producing an estimated primary transit depth of 0.8933% across the stellar disk), this world measures 14.392 Earth radii (1.28 Jupiter radii) and has a measured mass of 156.684 Earth masses (0.49 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.29 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.76 g⊕ (7.45 m/s²), and an escape velocity of 36.9 km/s.
In its orbital architecture around HAT-P-46, HAT-P-46 b completes one full revolution every 4.463 Earth days at a semi-major axis of 0.0577 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 140.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.123 carries the world between 0.0506 AU at periapsis and 0.0648 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1458 K (+1185°C / +2165°F) and receiving 1,405.48 S⊕ (~1,912,858 W/m²), HAT-P-46 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HAT-P-46 is classified as a stellar host with an effective photospheric temperature of 6,120 K, a radius of 1.396 R☉, a mass of 1.284 M☉, an estimated bolometric luminosity of 2.453 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.5 Gyr and a metallicity of [Fe/H] = 0.3 dex (metal-rich relative to the Sun). From Earth, HAT-P-46 shines at apparent V-band magnitude 11.997 (faint and requiring research-grade or CCD telescopic photometry) in the Southern 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-46 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,120 K |
| Stellar Radius | 1.3960 R☉ |
| Stellar Mass | 1.2840 M☉ |
| Bolometric Luminosity | 2.453 L☉ |
| Metallicity [Fe/H] | 0.300 dex |
| Stellar Age | 2.500 Gyr |
| Apparent Magnitude | V: 11.997 · G: 11.684 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.057700 AU |
| Orbital Period | 4.463 days |
| Mean Orbital Velocity | 140.6 km/s |
| Orbital Eccentricity (e) | 0.12300 |
| Orbital Inclination (i) | 85.5000° |
| Mean Bulk Density | 0.29 g/cm³ (36.9 km/s vesc) |
| Insolation Flux | 1405.4798 S⊕ (~1,912,858 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 948.300 LY (290.736 pc) |