CHXR 73 b
Astrophysical Synthesis & Habitability Characterization
CHXR 73 b is a confirmed gas giant exoplanet orbiting the star CHXR 73, located approximately 620.9 light-years (190.37 parsecs) from the Solar System. First announced in 2006 by Hubble Space Telescope using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 12.3 Earth radii (1.1 Jupiter radii) and has a measured mass of 3994.486 Earth masses (12.57 Jupiter masses). Combining its mass and radius yields a mean bulk density of 11.84 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 26.4 g⊕ (258.9 m/s²), and an escape velocity of 201.6 km/s.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.300 R⊕, CHXR 73 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 CHXR 73 is classified as a low-mass red dwarf of spectral type M3.5 with an effective photospheric temperature of 3,099 K, a mass of 0.35 M☉. Stellar evolution modeling indicates an estimated stellar age of 0.002 Gyr. From Earth, CHXR 73 shines at apparent Gaia G-band magnitude 17.293 (faint and requiring research-grade or CCD telescopic photometry) 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: Hubble Space Telescope · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | CHXR 73 |
| Spectral Type | M3.5 |
| Effective Temp (Teff) | 3,099 K |
| Stellar Radius | — |
| Stellar Mass | 0.3500 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 0.002 Gyr |
| Apparent Magnitude | · G: 17.293 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 210.000000 AU |
| Orbital Period | — |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 11.84 g/cm³ (201.6 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 620.900 LY (190.374 pc) |