HIP 66074 b
Astrophysical Synthesis & Habitability Characterization
HIP 66074 b is a confirmed gas giant exoplanet orbiting the star HIP 66074, located approximately 115.6 light-years (35.44 parsecs) from the Solar System. First announced in 2023 by European Space Agency (ESA) Gaia Satellite using the Astrometry detection technique, this world measures 12.9 Earth radii (1.15 Jupiter radii) and has a measured mass of 1589.142 Earth masses (5 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.08 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 9.55 g⊕ (93.65 m/s²), and an escape velocity of 124.2 km/s.
In its orbital architecture around HIP 66074, HIP 66074 b completes one full revolution every 310.9 Earth days at a semi-major axis of 0.799 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 28 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.948, swinging from 0.0415 AU at periapsis out to 1.5565 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.900 R⊕, HIP 66074 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 HIP 66074 is classified as a stellar host with an effective photospheric temperature of 4,300 K, a radius of 0.69 R☉, a mass of 0.705 M☉, an estimated bolometric luminosity of 0.146 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.9 Gyr and a metallicity of [Fe/H] = 0.12 dex (metal-rich relative to the Sun). From Earth, HIP 66074 shines at apparent V-band magnitude 10.25 (faint and requiring research-grade or CCD telescopic photometry) 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: European Space Agency (ESA) Gaia Satellite · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 66074 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,300 K |
| Stellar Radius | 0.6900 R☉ |
| Stellar Mass | 0.7050 M☉ |
| Bolometric Luminosity | 0.146 L☉ |
| Metallicity [Fe/H] | 0.120 dex |
| Stellar Age | 7.900 Gyr |
| Apparent Magnitude | V: 10.250 · G: 9.747 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.799000 AU |
| Orbital Period | 310.9 days |
| Mean Orbital Velocity | 28 km/s |
| Orbital Eccentricity (e) | 0.94800 |
| Orbital Inclination (i) | 13.0000° |
| Mean Bulk Density | 4.08 g/cm³ (124.2 km/s vesc) |
| Insolation Flux | 0.2381 S⊕ (~324 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 115.600 LY (35.444 pc) |