HIP 67522 c
Astrophysical Synthesis & Habitability Characterization
HIP 67522 c is a confirmed gas giant exoplanet orbiting the star HIP 67522, located approximately 415.1 light-years (127.28 parsecs) from the Solar System. First announced in 2024 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.278% across the stellar disk), this world measures 7.936 Earth radii (0.71 Jupiter radii) and has a measured mass of 22 Earth masses. Combining its mass and radius yields a mean bulk density of 0.24 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.35 g⊕ (3.43 m/s²), and an escape velocity of 18.6 km/s.
In its orbital architecture around HIP 67522, HIP 67522 c completes one full revolution every 14.335 Earth days at a semi-major axis of 0.1228 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 93.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.077 carries the world between 0.1133 AU at periapsis and 0.1323 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 917 K (+644°C / +1191°F) and receiving 116.05 S⊕ (~157,943 W/m²), HIP 67522 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HIP 67522 is classified as a solar-type yellow star of spectral type G1 V with an effective photospheric temperature of 5,675 K, a radius of 1.38 R☉, a mass of 1.22 M☉, an estimated bolometric luminosity of 1.772 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.017 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, HIP 67522 shines at apparent V-band magnitude 9.79 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HIP 67522 system is a multi-planet architecture hosting 2 confirmed worlds, with HIP 67522 c sharing its stellar neighborhood alongside HIP 67522 b.
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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 67522 |
| Spectral Type | G1 V |
| Effective Temp (Teff) | 5,675 K |
| Stellar Radius | 1.3800 R☉ |
| Stellar Mass | 1.2200 M☉ |
| Bolometric Luminosity | 1.772 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 0.017 Gyr |
| Apparent Magnitude | V: 9.790 · G: 9.633 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.122800 AU |
| Orbital Period | 14.335 days |
| Mean Orbital Velocity | 93.2 km/s |
| Orbital Eccentricity (e) | 0.07700 |
| Orbital Inclination (i) | 89.2000° |
| Mean Bulk Density | 0.24 g/cm³ (18.6 km/s vesc) |
| Insolation Flux | 116.0490 S⊕ (~157,943 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 415.100 LY (127.280 pc) |