HIP 67537 b
Astrophysical Synthesis & Habitability Characterization
HIP 67537 b is a confirmed gas giant exoplanet orbiting the star HIP 67537, located approximately 378.5 light-years (116.05 parsecs) from the Solar System. First announced in 2017 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.3 Earth radii (1.1 Jupiter radii) and has a measured mass of 4309.118 Earth masses (13.56 Jupiter masses). Combining its mass and radius yields a mean bulk density of 12.77 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 28.48 g⊕ (279.29 m/s²), and an escape velocity of 209.4 km/s.
In its orbital architecture around HIP 67537, HIP 67537 b completes one full revolution every 2523.647 Earth days (6.91Julian years) at a semi-major axis of 4.807 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 20.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.586, swinging from 1.9901 AU at periapsis out to 7.6239 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.300 R⊕, HIP 67537 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 67537 is classified as an orange K-type star of spectral type K1 III with an effective photospheric temperature of 4,985 K, a radius of 8.69 R☉, a mass of 2.316 M☉, an estimated bolometric luminosity of 41.84 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.15 dex (metal-rich relative to the Sun). From Earth, HIP 67537 shines at apparent V-band magnitude 6.43 (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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 67537 |
| Spectral Type | K1 III |
| Effective Temp (Teff) | 4,985 K |
| Stellar Radius | 8.6900 R☉ |
| Stellar Mass | 2.3160 M☉ |
| Bolometric Luminosity | 41.84 L☉ |
| Metallicity [Fe/H] | 0.150 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 6.430 · G: 6.171 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 4.807000 AU |
| Orbital Period | 2523.647 days |
| Mean Orbital Velocity | 20.7 km/s |
| Orbital Eccentricity (e) | 0.58600 |
| Orbital Inclination (i) | 82.1070° |
| Mean Bulk Density | 12.77 g/cm³ (209.4 km/s vesc) |
| Insolation Flux | 1.7903 S⊕ (~2,437 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 378.500 LY (116.046 pc) |