HIP 34222 b
Astrophysical Synthesis & Habitability Characterization
HIP 34222 b is a confirmed gas giant exoplanet orbiting the star HIP 34222, located approximately 74.5 light-years (22.84 parsecs) from the Solar System. First announced in 2021 by Cerro Tololo Inter-American Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.9 Earth radii (1.24 Jupiter radii) and has a measured mass of 263.798 Earth masses (0.83 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.54 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.37 g⊕ (13.44 m/s²), and an escape velocity of 48.7 km/s.
In its orbital architecture around HIP 34222, HIP 34222 b completes one full revolution every 159.986 Earth days at a semi-major axis of 0.492 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 33.5 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.305, swinging from 0.3419 AU at periapsis out to 0.6421 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.900 R⊕, HIP 34222 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 34222 is classified as an orange K-type star of spectral type K7 V with an effective photospheric temperature of 4,050 K, a radius of 0.6186 R☉, a mass of 0.62 M☉, an estimated bolometric luminosity of 0.092 L☉. From Earth, HIP 34222 shines at apparent V-band magnitude 10.14 (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: Cerro Tololo Inter-American Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 34222 |
| Spectral Type | K7 V |
| Effective Temp (Teff) | 4,050 K |
| Stellar Radius | 0.6186 R☉ |
| Stellar Mass | 0.6200 M☉ |
| Bolometric Luminosity | 0.092 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 10.140 · G: 9.577 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.492000 AU |
| Orbital Period | 159.986 days |
| Mean Orbital Velocity | 33.5 km/s |
| Orbital Eccentricity (e) | 0.30500 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.54 g/cm³ (48.7 km/s vesc) |
| Insolation Flux | 0.3832 S⊕ (~522 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 74.500 LY (22.839 pc) |