HD 5583 b
Astrophysical Synthesis & Habitability Characterization
HD 5583 b is a confirmed gas giant exoplanet orbiting the star HD 5583, located approximately 715 light-years (219.22 parsecs) from the Solar System. First announced in 2016 by Roque de los Muchachos Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1837.057 Earth masses (5.78 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.83 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 11.21 g⊕ (109.93 m/s²), and an escape velocity of 134 km/s.
In its orbital architecture around HD 5583, HD 5583 b completes one full revolution every 139.35 Earth days at a semi-major axis of 0.53 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 41.4 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.076 carries the world between 0.4897 AU at periapsis and 0.5703 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 965 K (+692°C / +1278°F) and receiving 145.03 S⊕ (~197,381 W/m²), HD 5583 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 5583 is classified as a stellar host with an effective photospheric temperature of 4,830 K, a radius of 9.09 R☉, a mass of 1.01 M☉, an estimated bolometric luminosity of 40.347 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.41 Gyr and a metallicity of [Fe/H] = -0.5 dex (metal-poor relative to the Sun). From Earth, HD 5583 shines at apparent V-band magnitude 7.604 (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: Roque de los Muchachos Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 5583 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,830 K |
| Stellar Radius | 9.0900 R☉ |
| Stellar Mass | 1.0100 M☉ |
| Bolometric Luminosity | 40.347 L☉ |
| Metallicity [Fe/H] | -0.500 dex |
| Stellar Age | 7.410 Gyr |
| Apparent Magnitude | V: 7.604 · G: 7.308 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.530000 AU |
| Orbital Period | 139.35 days |
| Mean Orbital Velocity | 41.4 km/s |
| Orbital Eccentricity (e) | 0.07600 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.83 g/cm³ (134 km/s vesc) |
| Insolation Flux | 145.0268 S⊕ (~197,381 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 715.000 LY (219.216 pc) |