HR 5183 b
Astrophysical Synthesis & Habitability Characterization
HR 5183 b is a confirmed gas giant exoplanet orbiting the star HR 5183, located approximately 102.6 light-years (31.46 parsecs) from the Solar System. First announced in 2019 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.1 Earth radii (1.17 Jupiter radii) and has a measured mass of 1052.012 Earth masses (3.31 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.58 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.13 g⊕ (60.11 m/s²), and an escape velocity of 100.2 km/s.
In its orbital architecture around HR 5183, HR 5183 b completes one full revolution every 27000 Earth days (73.92Julian years) at a semi-major axis of 18 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 7.3 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.84, swinging from 2.88 AU at periapsis out to 33.12 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 171 K (-102°C / -152°F) and an incident flux of 0.01 S⊕ (~10 W/m²), surface water and volatile species on HR 5183 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HR 5183 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 5,794 K, a radius of 1.53 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 2.367 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.7 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, HR 5183 shines at apparent V-band magnitude 6.334 (accessible to binoculars and small amateur telescopes) 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HR 5183 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 5,794 K |
| Stellar Radius | 1.5300 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 2.367 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 7.700 Gyr |
| Apparent Magnitude | V: 6.334 · G: 6.175 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 18.000000 AU |
| Orbital Period | 27000 days |
| Mean Orbital Velocity | 7.3 km/s |
| Orbital Eccentricity (e) | 0.84000 |
| Orbital Inclination (i) | 80.3000° |
| Mean Bulk Density | 2.58 g/cm³ (100.2 km/s vesc) |
| Insolation Flux | 0.0077 S⊕ (~10 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 102.600 LY (31.461 pc) |