HATS-46 b
Astrophysical Synthesis & Habitability Characterization
HATS-46 b is a confirmed gas giant exoplanet orbiting the star HATS-46, located approximately 1480.1 light-years (453.81 parsecs) from the Solar System. First announced in 2018 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 1.195% across the stellar disk), this world measures 10.66 Earth radii (0.95 Jupiter radii) and has a measured mass of 50.217 Earth masses (0.16 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.23 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.44 g⊕ (4.31 m/s²), and an escape velocity of 24.3 km/s.
In its orbital architecture around HATS-46, HATS-46 b completes one full revolution every 4.742 Earth days at a semi-major axis of 0.05272 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 120.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.559, swinging from 0.0232 AU at periapsis out to 0.0822 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1082 K (+809°C / +1488°F) and receiving 209.77 S⊕ (~285,497 W/m²), HATS-46 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-46 is classified as a stellar host with an effective photospheric temperature of 5,451 K, a radius of 0.894 R☉, a mass of 0.869 M☉, an estimated bolometric luminosity of 0.633 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.4 Gyr and a metallicity of [Fe/H] = -0.029 dex (near-solar heavy-element abundance). From Earth, HATS-46 shines at apparent V-band magnitude 13.783 (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: HATSouth · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HATS-46 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,451 K |
| Stellar Radius | 0.8940 R☉ |
| Stellar Mass | 0.8690 M☉ |
| Bolometric Luminosity | 0.633 L☉ |
| Metallicity [Fe/H] | -0.029 dex |
| Stellar Age | 8.400 Gyr |
| Apparent Magnitude | V: 13.783 · G: 13.527 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.052720 AU |
| Orbital Period | 4.742 days |
| Mean Orbital Velocity | 120.9 km/s |
| Orbital Eccentricity (e) | 0.55900 |
| Orbital Inclination (i) | 86.9700° |
| Mean Bulk Density | 0.23 g/cm³ (24.3 km/s vesc) |
| Insolation Flux | 209.7699 S⊕ (~285,497 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1480.100 LY (453.808 pc) |