HAT-P-44 b
Astrophysical Synthesis & Habitability Characterization
HAT-P-44 b is a confirmed gas giant exoplanet orbiting the star HAT-P-44, located approximately 1134.5 light-years (347.85 parsecs) from the Solar System. First announced in 2014 by HATNet using the Transit detection technique (producing an estimated primary transit depth of 1.8089% across the stellar disk), this world measures 13.922 Earth radii (1.24 Jupiter radii) and has a measured mass of 111.871 Earth masses (0.35 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.23 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.58 g⊕ (5.69 m/s²), and an escape velocity of 31.7 km/s.
In its orbital architecture around HAT-P-44, HAT-P-44 b completes one full revolution every 4.301 Earth days at a semi-major axis of 0.0507 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 128.2 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.044 (ranging from 0.0485 AU at periapsis to 0.0529 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1108 K (+835°C / +1535°F) and receiving 185.12 S⊕ (~251,947 W/m²), HAT-P-44 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HAT-P-44 is classified as a stellar host with an effective photospheric temperature of 5,295 K, a radius of 0.949 R☉, a mass of 0.942 M☉, an estimated bolometric luminosity of 0.635 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.5 Gyr and a metallicity of [Fe/H] = 0.33 dex (metal-rich relative to the Sun). From Earth, HAT-P-44 shines at apparent V-band magnitude 13.225 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The HAT-P-44 system is a multi-planet architecture hosting 2 confirmed worlds, with HAT-P-44 b sharing its stellar neighborhood alongside HAT-P-44 c.
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-44 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,295 K |
| Stellar Radius | 0.9490 R☉ |
| Stellar Mass | 0.9420 M☉ |
| Bolometric Luminosity | 0.635 L☉ |
| Metallicity [Fe/H] | 0.330 dex |
| Stellar Age | 7.500 Gyr |
| Apparent Magnitude | V: 13.225 · G: 12.973 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050700 AU |
| Orbital Period | 4.301 days |
| Mean Orbital Velocity | 128.2 km/s |
| Orbital Eccentricity (e) | 0.04400 |
| Orbital Inclination (i) | 89.1000° |
| Mean Bulk Density | 0.23 g/cm³ (31.7 km/s vesc) |
| Insolation Flux | 185.1190 S⊕ (~251,947 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1134.500 LY (347.850 pc) |