HD 26161 b
Astrophysical Synthesis & Habitability Characterization
HD 26161 b is a confirmed gas giant exoplanet orbiting the star HD 26161, located approximately 133.4 light-years (40.91 parsecs) from the Solar System. First announced in 2021 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 11.9 Earth radii (1.06 Jupiter radii) and has a measured mass of 9045.396 Earth masses (28.46 Jupiter masses). Combining its mass and radius yields a mean bulk density of 29.6 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 63.88 g⊕ (626.45 m/s²), and an escape velocity of 308.4 km/s.
In its orbital architecture around HD 26161, HD 26161 b completes one full revolution every 10942.29 Earth days (29.96Julian years) at a semi-major axis of 10.087 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 10 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.922, swinging from 0.7868 AU at periapsis out to 19.3872 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 111 K (-162°C / -260°F) and an incident flux of 0.02 S⊕ (~33 W/m²), surface water and volatile species on HD 26161 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 26161 is classified as a stellar host with an effective photospheric temperature of 6,058 K, a radius of 1.456 R☉, a mass of 1.12 M☉, an estimated bolometric luminosity of 2.562 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, HD 26161 shines at apparent V-band magnitude 6.893 (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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 26161 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,058 K |
| Stellar Radius | 1.4560 R☉ |
| Stellar Mass | 1.1200 M☉ |
| Bolometric Luminosity | 2.562 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 6.893 · G: 6.743 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 10.087000 AU |
| Orbital Period | 10942.29 days |
| Mean Orbital Velocity | 10 km/s |
| Orbital Eccentricity (e) | 0.92200 |
| Orbital Inclination (i) | 59.5580° |
| Mean Bulk Density | 29.6 g/cm³ (308.4 km/s vesc) |
| Insolation Flux | 0.0243 S⊕ (~33 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 133.400 LY (40.913 pc) |