HD 183579 b
Astrophysical Synthesis & Habitability Characterization
HD 183579 b is a confirmed sub-neptune exoplanet orbiting the star HD 183579, located approximately 186.8 light-years (57.27 parsecs) from the Solar System. First announced in 2021 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 0.1111% across the stellar disk), this world measures 3.49 Earth radii (0.31 Jupiter radii) and has a measured mass of 20.4 Earth masses. Combining its mass and radius yields a mean bulk density of 2.65 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.67 g⊕ (16.38 m/s²), and an escape velocity of 27 km/s.
In its orbital architecture around HD 183579, HD 183579 b completes one full revolution every 17.471 Earth days at a semi-major axis of 0.1322 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 82.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.061 carries the world between 0.1241 AU at periapsis and 0.1403 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 752 K (+479°C / +894°F) and receiving 58.10 S⊕ (~79,074 W/m²), HD 183579 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 183579 is classified as a solar-type yellow star of spectral type G2 V with an effective photospheric temperature of 5,784 K, a radius of 0.96 R☉, a mass of 0.996 M☉, an estimated bolometric luminosity of 0.925 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.1 Gyr and a metallicity of [Fe/H] = -0.038 dex (near-solar heavy-element abundance). From Earth, HD 183579 shines at apparent V-band magnitude 8.67 (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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 183579 |
| Spectral Type | G2 V |
| Effective Temp (Teff) | 5,784 K |
| Stellar Radius | 0.9600 R☉ |
| Stellar Mass | 0.9960 M☉ |
| Bolometric Luminosity | 0.925 L☉ |
| Metallicity [Fe/H] | -0.038 dex |
| Stellar Age | 3.100 Gyr |
| Apparent Magnitude | V: 8.670 · G: 8.515 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.132200 AU |
| Orbital Period | 17.471 days |
| Mean Orbital Velocity | 82.3 km/s |
| Orbital Eccentricity (e) | 0.06100 |
| Orbital Inclination (i) | 89.1100° |
| Mean Bulk Density | 2.65 g/cm³ (27 km/s vesc) |
| Insolation Flux | 58.1000 S⊕ (~79,074 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 186.800 LY (57.265 pc) |