HD 154672 b
Astrophysical Synthesis & Habitability Characterization
HD 154672 b is a confirmed gas giant exoplanet orbiting the star HD 154672, located approximately 205.6 light-years (63.05 parsecs) from the Solar System. First announced in 2008 by Las Campanas Observatory 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 1706.747 Earth masses (5.37 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.49 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 10.42 g⊕ (102.19 m/s²), and an escape velocity of 129.2 km/s.
In its orbital architecture around HD 154672, HD 154672 b completes one full revolution every 163.94 Earth days at a semi-major axis of 0.6 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 39.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.61, swinging from 0.234 AU at periapsis out to 0.966 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 411 K (+138°C / +280°F) and receiving 5.02 S⊕ (~6,836 W/m²), HD 154672 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 154672 is classified as a solar-type yellow star of spectral type G3 IV with an effective photospheric temperature of 5,743 K, a radius of 1.32 R☉, a mass of 1.18 M☉, an estimated bolometric luminosity of 1.701 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 154672 shines at apparent V-band magnitude 8.21 (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: Las Campanas Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 154672 |
| Spectral Type | G3 IV |
| Effective Temp (Teff) | 5,743 K |
| Stellar Radius | 1.3200 R☉ |
| Stellar Mass | 1.1800 M☉ |
| Bolometric Luminosity | 1.701 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 8.000 Gyr |
| Apparent Magnitude | V: 8.210 · G: 8.037 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.600000 AU |
| Orbital Period | 163.94 days |
| Mean Orbital Velocity | 39.8 km/s |
| Orbital Eccentricity (e) | 0.61000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.49 g/cm³ (129.2 km/s vesc) |
| Insolation Flux | 5.0225 S⊕ (~6,836 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 205.600 LY (63.048 pc) |