HATS-63 b
Astrophysical Synthesis & Habitability Characterization
HATS-63 b is a confirmed gas giant exoplanet orbiting the star HATS-63, located approximately 2032.7 light-years (623.23 parsecs) from the Solar System. First announced in 2018 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 1.3437% across the stellar disk), this world measures 13.529 Earth radii (1.21 Jupiter radii) and has a measured mass of 305.117 Earth masses (0.96 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.68 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.67 g⊕ (16.38 m/s²), and an escape velocity of 53.1 km/s.
In its orbital architecture around HATS-63, HATS-63 b completes one full revolution every 3.057 Earth days at a semi-major axis of 0.04026 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 143.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.136 carries the world between 0.0348 AU at periapsis and 0.0457 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1398 K (+1125°C / +2057°F) and receiving 634.10 S⊕ (~863,010 W/m²), HATS-63 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-63 is classified as a stellar host with an effective photospheric temperature of 5,627 K, a radius of 1.07 R☉, a mass of 0.931 M☉, an estimated bolometric luminosity of 1.03 L☉. Stellar evolution modeling indicates an estimated stellar age of 10.3 Gyr and a metallicity of [Fe/H] = 0.081 dex (metal-rich relative to the Sun). From Earth, HATS-63 shines at apparent V-band magnitude 13.992 (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-63 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,627 K |
| Stellar Radius | 1.0700 R☉ |
| Stellar Mass | 0.9310 M☉ |
| Bolometric Luminosity | 1.03 L☉ |
| Metallicity [Fe/H] | 0.081 dex |
| Stellar Age | 10.300 Gyr |
| Apparent Magnitude | V: 13.992 · G: 13.721 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.040260 AU |
| Orbital Period | 3.057 days |
| Mean Orbital Velocity | 143.3 km/s |
| Orbital Eccentricity (e) | 0.13600 |
| Orbital Inclination (i) | 84.8600° |
| Mean Bulk Density | 0.68 g/cm³ (53.1 km/s vesc) |
| Insolation Flux | 634.1000 S⊕ (~863,010 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2032.700 LY (623.232 pc) |