HD 155193 b
Astrophysical Synthesis & Habitability Characterization
HD 155193 b is a confirmed gas giant exoplanet orbiting the star HD 155193, located approximately 188.5 light-years (57.8 parsecs) from the Solar System. First announced in 2021 by Haute-Provence Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14 Earth radii (1.25 Jupiter radii) and has a measured mass of 238.371 Earth masses (0.75 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.48 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 46.2 km/s.
In its orbital architecture around HD 155193, HD 155193 b completes one full revolution every 352.65 Earth days at a semi-major axis of 1.04 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 32.1 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.21 carries the world between 0.8216 AU at periapsis and 1.2584 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 392 K (+119°C / +246°F) and receiving 4.05 S⊕ (~5,507 W/m²), HD 155193 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 155193 is classified as a warm F-type star of spectral type F8 IV with an effective photospheric temperature of 6,239 K, a radius of 1.7644 R☉, a mass of 1.221 M☉, an estimated bolometric luminosity of 4.232 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, HD 155193 shines at apparent V-band magnitude 7.009 (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: Haute-Provence Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 155193 |
| Spectral Type | F8 IV |
| Effective Temp (Teff) | 6,239 K |
| Stellar Radius | 1.7644 R☉ |
| Stellar Mass | 1.2210 M☉ |
| Bolometric Luminosity | 4.232 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 7.009 · G: 6.867 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.040000 AU |
| Orbital Period | 352.65 days |
| Mean Orbital Velocity | 32.1 km/s |
| Orbital Eccentricity (e) | 0.21000 |
| Orbital Inclination (i) | 0.7112° |
| Mean Bulk Density | 0.48 g/cm³ (46.2 km/s vesc) |
| Insolation Flux | 4.0461 S⊕ (~5,507 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 188.500 LY (57.800 pc) |