HATS-68 b
Astrophysical Synthesis & Habitability Characterization
HATS-68 b is a confirmed gas giant exoplanet orbiting the star HATS-68, located approximately 1969.8 light-years (603.96 parsecs) from the Solar System. First announced in 2018 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 0.5245% across the stellar disk), this world measures 13.809 Earth radii (1.23 Jupiter radii) and has a measured mass of 410.001 Earth masses (1.29 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.86 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.15 g⊕ (21.08 m/s²), and an escape velocity of 61 km/s.
In its orbital architecture around HATS-68, HATS-68 b completes one full revolution every 3.586 Earth days at a semi-major axis of 0.05071 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 153.8 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.036 (ranging from 0.0489 AU at periapsis to 0.0525 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1741 K (+1468°C / +2674°F) and receiving 1,521.00 S⊕ (~2,070,081 W/m²), HATS-68 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-68 is classified as a stellar host with an effective photospheric temperature of 6,147 K, a radius of 1.748 R☉, a mass of 1.351 M☉, an estimated bolometric luminosity of 3.914 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.02 Gyr and a metallicity of [Fe/H] = 0.21 dex (metal-rich relative to the Sun). From Earth, HATS-68 shines at apparent V-band magnitude 12.312 (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-68 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,147 K |
| Stellar Radius | 1.7480 R☉ |
| Stellar Mass | 1.3510 M☉ |
| Bolometric Luminosity | 3.914 L☉ |
| Metallicity [Fe/H] | 0.210 dex |
| Stellar Age | 3.020 Gyr |
| Apparent Magnitude | V: 12.312 · G: 12.163 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050710 AU |
| Orbital Period | 3.586 days |
| Mean Orbital Velocity | 153.8 km/s |
| Orbital Eccentricity (e) | 0.03600 |
| Orbital Inclination (i) | 83.2100° |
| Mean Bulk Density | 0.86 g/cm³ (61 km/s vesc) |
| Insolation Flux | 1521.0000 S⊕ (~2,070,081 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1969.800 LY (603.955 pc) |