HAT-P-29 b
Astrophysical Synthesis & Habitability Characterization
HAT-P-29 b is a confirmed gas giant exoplanet orbiting the star HAT-P-29, located approximately 1022.7 light-years (313.58 parsecs) from the Solar System. First announced in 2011 by HATNet using the Transit detection technique (producing an estimated primary transit depth of 0.8554% across the stellar disk), this world measures 13.115 Earth radii (1.17 Jupiter radii) and has a measured mass of 279.69 Earth masses (0.88 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 1.63 g⊕ (15.98 m/s²), and an escape velocity of 51.7 km/s.
In its orbital architecture around HAT-P-29, HAT-P-29 b completes one full revolution every 5.723 Earth days at a semi-major axis of 0.0667 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 126.8 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.09 carries the world between 0.0607 AU at periapsis and 0.0727 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1281 K (+1008°C / +1846°F) and receiving 433.00 S⊕ (~589,313 W/m²), HAT-P-29 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HAT-P-29 is classified as a warm F-type star of spectral type F8 with an effective photospheric temperature of 6,087 K, a radius of 1.3 R☉, a mass of 1.45 M☉, an estimated bolometric luminosity of 2.082 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.2 Gyr and a metallicity of [Fe/H] = 0.21 dex (metal-rich relative to the Sun). From Earth, HAT-P-29 shines at apparent V-band magnitude 11.825 (faint and requiring research-grade or CCD telescopic photometry) in the Northern 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: HATNet · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HAT-P-29 |
| Spectral Type | F8 |
| Effective Temp (Teff) | 6,087 K |
| Stellar Radius | 1.3000 R☉ |
| Stellar Mass | 1.4500 M☉ |
| Bolometric Luminosity | 2.082 L☉ |
| Metallicity [Fe/H] | 0.210 dex |
| Stellar Age | 2.200 Gyr |
| Apparent Magnitude | V: 11.825 · G: 11.734 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.066700 AU |
| Orbital Period | 5.723 days |
| Mean Orbital Velocity | 126.8 km/s |
| Orbital Eccentricity (e) | 0.09000 |
| Orbital Inclination (i) | 87.1000° |
| Mean Bulk Density | 0.68 g/cm³ (51.7 km/s vesc) |
| Insolation Flux | 433.0000 S⊕ (~589,313 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1022.700 LY (313.576 pc) |