HATS-70 b
Astrophysical Synthesis & Habitability Characterization
HATS-70 b is a confirmed gas giant exoplanet orbiting the star HATS-70, located approximately 4758.1 light-years (1458.83 parsecs) from the Solar System. First announced in 2019 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 0.5717% across the stellar disk), this world measures 15.513 Earth radii (1.38 Jupiter radii) and has a measured mass of 4100.007 Earth masses (12.9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 6.06 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 17.04 g⊕ (167.11 m/s²), and an escape velocity of 181.9 km/s.
In its orbital architecture around HATS-70, HATS-70 b completes one full revolution every 1.888 Earth days at a semi-major axis of 0.03632 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 209.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.18 carries the world between 0.0298 AU at periapsis and 0.0429 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2730 K (+2457°C / +4455°F) and receiving 9,110.00 S⊕ (~12,398,710 W/m²), HATS-70 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-70 is classified as a stellar host with an effective photospheric temperature of 7,930 K, a radius of 1.881 R☉, a mass of 1.78 M☉, an estimated bolometric luminosity of 12.553 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.81 Gyr and a metallicity of [Fe/H] = 0.041 dex (near-solar heavy-element abundance). From Earth, HATS-70 shines at apparent V-band magnitude 12.227 (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-70 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 7,930 K |
| Stellar Radius | 1.8810 R☉ |
| Stellar Mass | 1.7800 M☉ |
| Bolometric Luminosity | 12.553 L☉ |
| Metallicity [Fe/H] | 0.041 dex |
| Stellar Age | 0.810 Gyr |
| Apparent Magnitude | V: 12.227 · G: 12.586 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.036320 AU |
| Orbital Period | 1.888 days |
| Mean Orbital Velocity | 209.3 km/s |
| Orbital Eccentricity (e) | 0.18000 |
| Orbital Inclination (i) | 86.7000° |
| Mean Bulk Density | 6.06 g/cm³ (181.9 km/s vesc) |
| Insolation Flux | 9110.0000 S⊕ (~12,398,710 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4758.100 LY (1458.830 pc) |