HD 83443 b
Astrophysical Synthesis & Habitability Characterization
HD 83443 b is a confirmed gas giant exoplanet orbiting the star HD 83443, located approximately 133.4 light-years (40.9 parsecs) from the Solar System. First announced in 2002 by Multiple Observatories 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 127.767 Earth masses (0.4 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.25 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.64 g⊕ (6.28 m/s²), and an escape velocity of 33.7 km/s.
In its orbital architecture around HD 83443, HD 83443 b completes one full revolution every 2.986 Earth days at a semi-major axis of 0.0406 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 147.9 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.012 (ranging from 0.0401 AU at periapsis to 0.0411 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1263 K (+990°C / +1814°F) and receiving 477.44 S⊕ (~649,802 W/m²), HD 83443 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 83443 is classified as an orange K-type star of spectral type K0 V with an effective photospheric temperature of 5,442 K, a radius of 0.94 R☉, a mass of 1 M☉, an estimated bolometric luminosity of 0.695 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.64 Gyr and a metallicity of [Fe/H] = 0.34 dex (metal-rich relative to the Sun). From Earth, HD 83443 shines at apparent V-band magnitude 8.23 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 83443 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 83443 b sharing its stellar neighborhood alongside HD 83443 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 83443 |
| Spectral Type | K0 V |
| Effective Temp (Teff) | 5,442 K |
| Stellar Radius | 0.9400 R☉ |
| Stellar Mass | 1.0000 M☉ |
| Bolometric Luminosity | 0.695 L☉ |
| Metallicity [Fe/H] | 0.340 dex |
| Stellar Age | 2.640 Gyr |
| Apparent Magnitude | V: 8.230 · G: 8.027 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.040600 AU |
| Orbital Period | 2.986 days |
| Mean Orbital Velocity | 147.9 km/s |
| Orbital Eccentricity (e) | 0.01200 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.25 g/cm³ (33.7 km/s vesc) |
| Insolation Flux | 477.4442 S⊕ (~649,802 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 133.400 LY (40.899 pc) |