HD 134606 b
Astrophysical Synthesis & Habitability Characterization
HD 134606 b is a confirmed sub-neptune exoplanet orbiting the star HD 134606, located approximately 87.4 light-years (26.79 parsecs) from the Solar System. First announced in 2024 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 2.97 Earth radii and has a measured mass of 9.09 Earth masses. Combining its mass and radius yields a mean bulk density of 1.91 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.03 g⊕ (10.1 m/s²), and an escape velocity of 19.6 km/s.
In its orbital architecture around HD 134606, HD 134606 b completes one full revolution every 12.089 Earth days at a semi-major axis of 0.1046 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 94.1 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.092 carries the world between 0.095 AU at periapsis and 0.1142 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 895 K (+622°C / +1152°F) and receiving 106.11 S⊕ (~144,420 W/m²), HD 134606 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 134606 is classified as a solar-type yellow star of spectral type G5IV with an effective photospheric temperature of 5,576 K, a radius of 1.158 R☉, a mass of 1.046 M☉, an estimated bolometric luminosity of 1.163 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.3 Gyr and a metallicity of [Fe/H] = 0.343 dex (metal-rich relative to the Sun). From Earth, HD 134606 shines at apparent V-band magnitude 6.86 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 134606 system is a multi-planet architecture hosting 5 confirmed worlds, with HD 134606 b sharing its stellar neighborhood alongside HD 134606 e, HD 134606 f, HD 134606 c, HD 134606 d.
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 134606 |
| Spectral Type | G5IV |
| Effective Temp (Teff) | 5,576 K |
| Stellar Radius | 1.1580 R☉ |
| Stellar Mass | 1.0460 M☉ |
| Bolometric Luminosity | 1.163 L☉ |
| Metallicity [Fe/H] | 0.343 dex |
| Stellar Age | 7.300 Gyr |
| Apparent Magnitude | V: 6.860 · G: 6.678 |
| System Architecture | 1 Star, 5 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.104600 AU |
| Orbital Period | 12.089 days |
| Mean Orbital Velocity | 94.1 km/s |
| Orbital Eccentricity (e) | 0.09200 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.91 g/cm³ (19.6 km/s vesc) |
| Insolation Flux | 106.1131 S⊕ (~144,420 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 87.400 LY (26.791 pc) |