HD 153950 b
Astrophysical Synthesis & Habitability Characterization
HD 153950 b is a confirmed gas giant exoplanet orbiting the star HD 153950, located approximately 158 light-years (48.46 parsecs) from the Solar System. First announced in 2008 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.2 Earth radii (1.18 Jupiter radii) and has a measured mass of 937.599 Earth masses (2.95 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.25 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.38 g⊕ (52.76 m/s²), and an escape velocity of 94.3 km/s.
In its orbital architecture around HD 153950, HD 153950 b completes one full revolution every 499.4 Earth days (1.37Julian years) at a semi-major axis of 1.28 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 27.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.34, swinging from 0.8448 AU at periapsis out to 1.7152 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.200 R⊕, HD 153950 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 153950 is classified as a warm F-type star of spectral type F8 V with an effective photospheric temperature of 6,124 K, a radius of 1.28 R☉, a mass of 1.25 M☉, an estimated bolometric luminosity of 2.068 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.3 Gyr and a metallicity of [Fe/H] = -0.01 dex (near-solar heavy-element abundance). From Earth, HD 153950 shines at apparent V-band magnitude 7.39 (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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 153950 |
| Spectral Type | F8 V |
| Effective Temp (Teff) | 6,124 K |
| Stellar Radius | 1.2800 R☉ |
| Stellar Mass | 1.2500 M☉ |
| Bolometric Luminosity | 2.068 L☉ |
| Metallicity [Fe/H] | -0.010 dex |
| Stellar Age | 4.300 Gyr |
| Apparent Magnitude | V: 7.390 · G: 7.238 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.280000 AU |
| Orbital Period | 499.4 days |
| Mean Orbital Velocity | 27.9 km/s |
| Orbital Eccentricity (e) | 0.34000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.25 g/cm³ (94.3 km/s vesc) |
| Insolation Flux | 1.3550 S⊕ (~1,844 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 158.000 LY (48.455 pc) |