HD 73344 d
Astrophysical Synthesis & Habitability Characterization
HD 73344 d is a confirmed gas giant exoplanet orbiting the star HD 73344, located approximately 115 light-years (35.26 parsecs) from the Solar System. First announced in 2025 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.2 Earth radii (1.18 Jupiter radii) and has a measured mass of 810.462 Earth masses (2.55 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.94 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 4.65 g⊕ (45.6 m/s²), and an escape velocity of 87.7 km/s.
In its orbital architecture around HD 73344, HD 73344 d completes one full revolution every 5823 Earth days (15.94Julian years) at a semi-major axis of 6.7 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 12.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.18 carries the world between 5.494 AU at periapsis and 7.906 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 127 K (-146°C / -231°F) and an incident flux of 0.04 S⊕ (~55 W/m²), surface water and volatile species on HD 73344 d would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 73344 is classified as a warm F-type star of spectral type F6 V with an effective photospheric temperature of 6,148 K, a radius of 1.22 R☉, a mass of 1.19 M☉, an estimated bolometric luminosity of 1.908 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.15 Gyr and a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, HD 73344 shines at apparent V-band magnitude 6.894 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 73344 system is a multi-planet architecture hosting 3 confirmed worlds, with HD 73344 d sharing its stellar neighborhood alongside HD 73344 b, HD 73344 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 73344 |
| Spectral Type | F6 V |
| Effective Temp (Teff) | 6,148 K |
| Stellar Radius | 1.2200 R☉ |
| Stellar Mass | 1.1900 M☉ |
| Bolometric Luminosity | 1.908 L☉ |
| Metallicity [Fe/H] | 0.160 dex |
| Stellar Age | 1.150 Gyr |
| Apparent Magnitude | V: 6.894 · G: 6.747 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 6.700000 AU |
| Orbital Period | 5823 days |
| Mean Orbital Velocity | 12.5 km/s |
| Orbital Eccentricity (e) | 0.18000 |
| Orbital Inclination (i) | 59.0000° |
| Mean Bulk Density | 1.94 g/cm³ (87.7 km/s vesc) |
| Insolation Flux | 0.0407 S⊕ (~55 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 115.000 LY (35.260 pc) |