HATS-29 b
Astrophysical Synthesis & Habitability Characterization
HATS-29 b is a confirmed gas giant exoplanet orbiting the star HATS-29, located approximately 1154.2 light-years (353.89 parsecs) from the Solar System. First announced in 2016 by HATSouth using the Transit detection technique (producing an estimated primary transit depth of 1.4354% across the stellar disk), this world measures 14.022 Earth radii (1.25 Jupiter radii) and has a measured mass of 207.543 Earth masses (0.65 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.42 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 43 km/s.
In its orbital architecture around HATS-29, HATS-29 b completes one full revolution every 4.606 Earth days at a semi-major axis of 0.05475 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 129.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.158 carries the world between 0.0461 AU at periapsis and 0.0634 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1212 K (+939°C / +1722°F) and receiving 356.00 S⊕ (~484,516 W/m²), HATS-29 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HATS-29 is classified as a solar-type yellow star of spectral type G with an effective photospheric temperature of 5,670 K, a radius of 1.073 R☉, a mass of 1.032 M☉, an estimated bolometric luminosity of 1.068 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.5 Gyr and a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, HATS-29 shines at apparent V-band magnitude 12.62 (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-29 |
| Spectral Type | G |
| Effective Temp (Teff) | 5,670 K |
| Stellar Radius | 1.0730 R☉ |
| Stellar Mass | 1.0320 M☉ |
| Bolometric Luminosity | 1.068 L☉ |
| Metallicity [Fe/H] | 0.160 dex |
| Stellar Age | 5.500 Gyr |
| Apparent Magnitude | V: 12.620 · G: 12.459 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.054750 AU |
| Orbital Period | 4.606 days |
| Mean Orbital Velocity | 129.3 km/s |
| Orbital Eccentricity (e) | 0.15800 |
| Orbital Inclination (i) | 87.3700° |
| Mean Bulk Density | 0.42 g/cm³ (43 km/s vesc) |
| Insolation Flux | 356.0000 S⊕ (~484,516 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1154.200 LY (353.891 pc) |