HD 89744 b
Astrophysical Synthesis & Habitability Characterization
HD 89744 b is a confirmed gas giant exoplanet orbiting the star HD 89744, located approximately 126 light-years (38.64 parsecs) from the Solar System. First announced in 1999 by Fred Lawrence Whipple Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.6 Earth radii (1.12 Jupiter radii) and has a measured mass of 2653.881 Earth masses (8.35 Jupiter masses). Combining its mass and radius yields a mean bulk density of 7.32 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 16.72 g⊕ (163.97 m/s²), and an escape velocity of 162.3 km/s.
In its orbital architecture around HD 89744, HD 89744 b completes one full revolution every 256.78 Earth days at a semi-major axis of 0.917 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 38.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.677, swinging from 0.2962 AU at periapsis out to 1.5378 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 463 K (+190°C / +374°F) and receiving 7.43 S⊕ (~10,114 W/m²), HD 89744 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 89744 is classified as a warm F-type star of spectral type F7 V with an effective photospheric temperature of 6,291 K, a radius of 2.1326 R☉, a mass of 1.86 M☉, an estimated bolometric luminosity of 6.391 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.88 Gyr and a metallicity of [Fe/H] = 0.224 dex (metal-rich relative to the Sun). From Earth, HD 89744 shines at apparent V-band magnitude 5.735 (visible to the unaided human eye under dark skies) 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: Fred Lawrence Whipple Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 89744 |
| Spectral Type | F7 V |
| Effective Temp (Teff) | 6,291 K |
| Stellar Radius | 2.1326 R☉ |
| Stellar Mass | 1.8600 M☉ |
| Bolometric Luminosity | 6.391 L☉ |
| Metallicity [Fe/H] | 0.224 dex |
| Stellar Age | 1.880 Gyr |
| Apparent Magnitude | V: 5.735 · G: 5.606 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.917000 AU |
| Orbital Period | 256.78 days |
| Mean Orbital Velocity | 38.9 km/s |
| Orbital Eccentricity (e) | 0.67700 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 7.32 g/cm³ (162.3 km/s vesc) |
| Insolation Flux | 7.4311 S⊕ (~10,114 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 126.000 LY (38.636 pc) |