HATS-16 b
Astrophysical Synthesis & Habitability Characterization
HATS-16 b is a confirmed gas giant exoplanet orbiting the star HATS-16, located approximately 2469.1 light-years (757.04 parsecs) from the Solar System. First announced in 2016 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 1.1645% across the stellar disk), this world measures 14.572 Earth radii (1.3 Jupiter radii) and has a measured mass of 1039.304 Earth masses (3.27 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.85 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 4.89 g⊕ (47.95 m/s²), and an escape velocity of 94.5 km/s.
In its orbital architecture around HATS-16, HATS-16 b completes one full revolution every 2.687 Earth days at a semi-major axis of 0.03744 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 151.6 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 1592 K (+1319°C / +2406°F) and receiving 994.81 S⊕ (~1,353,936 W/m²), HATS-16 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-16 is classified as a solar-type yellow star of spectral type G3 V with an effective photospheric temperature of 5,738 K, a radius of 1.238 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 1.491 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.5 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, HATS-16 shines at apparent V-band magnitude 13.957 (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-16 |
| Spectral Type | G3 V |
| Effective Temp (Teff) | 5,738 K |
| Stellar Radius | 1.2380 R☉ |
| Stellar Mass | 0.9700 M☉ |
| Bolometric Luminosity | 1.491 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 9.500 Gyr |
| Apparent Magnitude | V: 13.957 · G: 13.686 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.037440 AU |
| Orbital Period | 2.687 days |
| Mean Orbital Velocity | 151.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 83.5300° |
| Mean Bulk Density | 1.85 g/cm³ (94.5 km/s vesc) |
| Insolation Flux | 994.8095 S⊕ (~1,353,936 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2469.100 LY (757.044 pc) |