HD 72892 b
Astrophysical Synthesis & Habitability Characterization
HD 72892 b is a confirmed gas giant exoplanet orbiting the star HD 72892, located approximately 227.4 light-years (69.73 parsecs) from the Solar System. First announced in 2016 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1737.886 Earth masses (5.47 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.57 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 10.61 g⊕ (104.05 m/s²), and an escape velocity of 130.3 km/s.
In its orbital architecture around HD 72892, HD 72892 b completes one full revolution every 39.446 Earth days at a semi-major axis of 0.228 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 62.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.419, swinging from 0.1325 AU at periapsis out to 0.3235 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 634 K (+361°C / +682°F) and receiving 26.93 S⊕ (~36,654 W/m²), HD 72892 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 72892 is classified as a solar-type yellow star of spectral type G5 V with an effective photospheric temperature of 5,688 K, a radius of 1.22 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 1.398 L☉. Stellar evolution modeling indicates an estimated stellar age of 8 Gyr and a metallicity of [Fe/H] = 0.25 dex (metal-rich relative to the Sun). From Earth, HD 72892 shines at apparent V-band magnitude 8.83 (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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 72892 |
| Spectral Type | G5 V |
| Effective Temp (Teff) | 5,688 K |
| Stellar Radius | 1.2200 R☉ |
| Stellar Mass | 1.0100 M☉ |
| Bolometric Luminosity | 1.398 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 8.000 Gyr |
| Apparent Magnitude | V: 8.830 · G: 8.647 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.228000 AU |
| Orbital Period | 39.446 days |
| Mean Orbital Velocity | 62.9 km/s |
| Orbital Eccentricity (e) | 0.41900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.57 g/cm³ (130.3 km/s vesc) |
| Insolation Flux | 26.9314 S⊕ (~36,654 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 227.400 LY (69.731 pc) |