Pr0211 b
Astrophysical Synthesis & Habitability Characterization
Pr0211 b is a confirmed gas giant exoplanet orbiting the star Pr0211, located approximately 595.9 light-years (182.71 parsecs) from the Solar System. First announced in 2012 by Fred Lawrence Whipple Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.4 Earth radii (1.2 Jupiter radii) and has a measured mass of 597.52 Earth masses (1.88 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.37 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.33 g⊕ (32.66 m/s²), and an escape velocity of 74.7 km/s.
In its orbital architecture around Pr0211, Pr0211 b completes one full revolution every 2.146 Earth days at a semi-major axis of 0.03176 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 161 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.011 (ranging from 0.0314 AU at periapsis to 0.0321 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1304 K (+1031°C / +1888°F) and receiving 457.31 S⊕ (~622,396 W/m²), Pr0211 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Pr0211 is classified as a stellar host with an effective photospheric temperature of 5,300 K, a radius of 0.827 R☉, a mass of 0.935 M☉, an estimated bolometric luminosity of 0.484 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.578 Gyr and a metallicity of [Fe/H] = 0.18 dex (metal-rich relative to the Sun). From Earth, Pr0211 shines at apparent V-band magnitude 12.163 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Pr0211 system is a multi-planet architecture hosting 2 confirmed worlds, with Pr0211 b sharing its stellar neighborhood alongside Pr0211 c.
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: Fred Lawrence Whipple Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Pr0211 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,300 K |
| Stellar Radius | 0.8270 R☉ |
| Stellar Mass | 0.9350 M☉ |
| Bolometric Luminosity | 0.484 L☉ |
| Metallicity [Fe/H] | 0.180 dex |
| Stellar Age | 0.578 Gyr |
| Apparent Magnitude | V: 12.163 · G: 11.928 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.031760 AU |
| Orbital Period | 2.146 days |
| Mean Orbital Velocity | 161 km/s |
| Orbital Eccentricity (e) | 0.01100 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.37 g/cm³ (74.7 km/s vesc) |
| Insolation Flux | 457.3078 S⊕ (~622,396 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 595.900 LY (182.714 pc) |