HD 102272 b
Astrophysical Synthesis & Habitability Characterization
HD 102272 b is a confirmed gas giant exoplanet orbiting the star HD 102272, located approximately 1132.1 light-years (347.1 parsecs) from the Solar System. First announced in 2008 by McDonald Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.9 Earth radii (1.15 Jupiter radii) and has a measured mass of 1570.08 Earth masses (4.94 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.03 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 9.44 g⊕ (92.57 m/s²), and an escape velocity of 123.4 km/s.
In its orbital architecture around HD 102272, HD 102272 b completes one full revolution every 127.58 Earth days at a semi-major axis of 0.51 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 43.5 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.05 carries the world between 0.4845 AU at periapsis and 0.5355 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1038 K (+765°C / +1409°F) and receiving 176.41 S⊕ (~240,096 W/m²), HD 102272 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 102272 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 4,790 K, a radius of 10.3 R☉, a mass of 1.45 M☉, an estimated bolometric luminosity of 50.108 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.41 dex (metal-poor relative to the Sun). From Earth, HD 102272 shines at apparent V-band magnitude 8.69 (accessible to binoculars and small amateur telescopes) 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: McDonald Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 102272 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 4,790 K |
| Stellar Radius | 10.3000 R☉ |
| Stellar Mass | 1.4500 M☉ |
| Bolometric Luminosity | 50.108 L☉ |
| Metallicity [Fe/H] | -0.410 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.690 · G: 8.405 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.510000 AU |
| Orbital Period | 127.58 days |
| Mean Orbital Velocity | 43.5 km/s |
| Orbital Eccentricity (e) | 0.05000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.03 g/cm³ (123.4 km/s vesc) |
| Insolation Flux | 176.4116 S⊕ (~240,096 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1132.100 LY (347.097 pc) |