HIP 38594 c
Astrophysical Synthesis & Habitability Characterization
HIP 38594 c is a confirmed gas giant exoplanet orbiting the star HIP 38594, located approximately 58 light-years (17.79 parsecs) from the Solar System. First announced in 2020 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 7.94 Earth radii (0.71 Jupiter radii) and has a measured mass of 48.4 Earth masses (0.15 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.53 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.77 g⊕ (7.55 m/s²), and an escape velocity of 27.6 km/s.
In its orbital architecture around HIP 38594, HIP 38594 c completes one full revolution every 3477.768 Earth days (9.52Julian years) at a semi-major axis of 3.805 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 11.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.16 carries the world between 3.1962 AU at periapsis and 4.4138 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 80 K (-193°C / -315°F) and an incident flux of 0.01 S⊕ (~8 W/m²), surface water and volatile species on HIP 38594 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HIP 38594 is classified as a low-mass red dwarf of spectral type M0 with an effective photospheric temperature of 4,086 K, a radius of 0.6266 R☉, a mass of 0.61 M☉, an estimated bolometric luminosity of 0.098 L☉. From Earth, HIP 38594 shines at apparent V-band magnitude 9.75 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HIP 38594 system is a multi-planet architecture hosting 2 confirmed worlds, with HIP 38594 c sharing its stellar neighborhood alongside HIP 38594 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HIP 38594 |
| Spectral Type | M0 |
| Effective Temp (Teff) | 4,086 K |
| Stellar Radius | 0.6266 R☉ |
| Stellar Mass | 0.6100 M☉ |
| Bolometric Luminosity | 0.098 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 9.750 · G: 9.085 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.805000 AU |
| Orbital Period | 3477.768 days |
| Mean Orbital Velocity | 11.9 km/s |
| Orbital Eccentricity (e) | 0.16000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.53 g/cm³ (27.6 km/s vesc) |
| Insolation Flux | 0.0060 S⊕ (~8 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 58.000 LY (17.789 pc) |