HD 11505 b
Astrophysical Synthesis & Habitability Characterization
HD 11505 b is a confirmed gas giant exoplanet orbiting the star HD 11505, located approximately 127.1 light-years (38.97 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories 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 2510.527 Earth masses (7.9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 6.92 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 15.81 g⊕ (155.04 m/s²), and an escape velocity of 157.9 km/s.
In its orbital architecture around HD 11505, HD 11505 b completes one full revolution every 32669.222 Earth days (89.44Julian years) at a semi-major axis of 20.247 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 6.7 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.144 carries the world between 17.3314 AU at periapsis and 23.1626 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 67 K (-206°C / -339°F) and an incident flux of 0.00 S⊕ (~5 W/m²), surface water and volatile species on HD 11505 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 11505 is classified as a stellar host with an effective photospheric temperature of 5,757 K, a radius of 1.1957 R☉, a mass of 1.03 M☉, an estimated bolometric luminosity of 1.409 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.22 dex (metal-poor relative to the Sun). From Earth, HD 11505 shines at apparent V-band magnitude 7.43 (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 11505 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,757 K |
| Stellar Radius | 1.1957 R☉ |
| Stellar Mass | 1.0300 M☉ |
| Bolometric Luminosity | 1.409 L☉ |
| Metallicity [Fe/H] | -0.220 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 7.430 · G: 7.258 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 20.247000 AU |
| Orbital Period | 32669.222 days |
| Mean Orbital Velocity | 6.7 km/s |
| Orbital Eccentricity (e) | 0.14400 |
| Orbital Inclination (i) | 87.5050° |
| Mean Bulk Density | 6.92 g/cm³ (157.9 km/s vesc) |
| Insolation Flux | 0.0035 S⊕ (~5 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 127.100 LY (38.968 pc) |