HD 44219 b
Astrophysical Synthesis & Habitability Characterization
HD 44219 b is a confirmed gas giant exoplanet orbiting the star HD 44219, located approximately 172.6 light-years (52.91 parsecs) from the Solar System. First announced in 2010 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14.1 Earth radii (1.26 Jupiter radii) and has a measured mass of 184.34 Earth masses (0.58 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.36 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 40.4 km/s.
In its orbital architecture around HD 44219, HD 44219 b completes one full revolution every 472 Earth days (1.29Julian years) at a semi-major axis of 1.26 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 29 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.41, swinging from 0.7434 AU at periapsis out to 1.7766 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 14.100 R⊕, HD 44219 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 44219 is classified as a solar-type yellow star of spectral type G3 V with an effective photospheric temperature of 5,752 K, a radius of 1.32 R☉, a mass of 1.2 M☉, an estimated bolometric luminosity of 1.711 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.4 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, HD 44219 shines at apparent V-band magnitude 7.69 (accessible to binoculars and small amateur telescopes) 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 44219 |
| Spectral Type | G3 V |
| Effective Temp (Teff) | 5,752 K |
| Stellar Radius | 1.3200 R☉ |
| Stellar Mass | 1.2000 M☉ |
| Bolometric Luminosity | 1.711 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 8.400 Gyr |
| Apparent Magnitude | V: 7.690 · G: 7.530 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.260000 AU |
| Orbital Period | 472 days |
| Mean Orbital Velocity | 29 km/s |
| Orbital Eccentricity (e) | 0.41000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 0.36 g/cm³ (40.4 km/s vesc) |
| Insolation Flux | 1.1462 S⊕ (~1,560 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 172.600 LY (52.905 pc) |