LP 261-75 b
Astrophysical Synthesis & Habitability Characterization
LP 261-75 b is a confirmed gas giant exoplanet orbiting the star LP 261-75 A, located approximately 110.7 light-years (33.93 parsecs) from the Solar System. First announced in 2006 by Apache Point Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 12.1 Earth radii (1.08 Jupiter radii) and has a measured mass of 6674.397 Earth masses (21 Jupiter masses). Combining its mass and radius yields a mean bulk density of 20.77 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 45.59 g⊕ (447.09 m/s²), and an escape velocity of 262.7 km/s.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1500 K (+1227°C / +2241°F), LP 261-75 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star LP 261-75 A is classified as a low-mass red dwarf of spectral type M4.5 V with an effective photospheric temperature of 3,138 K, a radius of 0.308 R☉, a mass of 0.22 M☉, an estimated bolometric luminosity of 0.00825 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.15 Gyr. From Earth, LP 261-75 A shines at apparent V-band magnitude 15.436 (faint and requiring research-grade or CCD telescopic photometry) 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: Apache Point Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | LP 261-75 A |
| Spectral Type | M4.5 V |
| Effective Temp (Teff) | 3,138 K |
| Stellar Radius | 0.3080 R☉ |
| Stellar Mass | 0.2200 M☉ |
| Bolometric Luminosity | 0.00825 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 0.150 Gyr |
| Apparent Magnitude | V: 15.436 · G: 13.833 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 450.000000 AU |
| Orbital Period | — |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 20.77 g/cm³ (262.7 km/s vesc) |
| Insolation Flux | 0.0000 S⊕ |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 110.700 LY (33.928 pc) |