Gl 725 B c
Astrophysical Synthesis & Habitability Characterization
Gl 725 B c is a confirmed super-earth exoplanet orbiting the star Gl 725 B, located approximately 22.3 light-years (6.84 parsecs) from the Solar System. First announced in 2026 by Mauna Kea Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.66 Earth radii and has a measured mass of 3.4 Earth masses. Combining its mass and radius yields a mean bulk density of 4.1 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16 km/s.
In its orbital architecture around Gl 725 B, Gl 725 B c completes one full revolution every 37.9 Earth days at a semi-major axis of 0.139 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 39.9 km/s (compared to Earth's 29.8 km/s).
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 215 K (-58°C / -72°F) and an incident stellar irradiance of 0.47 S⊕ (~645 W/m²), Gl 725 B c orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star Gl 725 B is classified as a low-mass red dwarf of spectral type M4 with an effective photospheric temperature of 3,379 K, a radius of 0.28 R☉, a mass of 0.25 M☉, an estimated bolometric luminosity of 0.00917 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.7 Gyr and a metallicity of [Fe/H] = -0.28 dex (metal-poor relative to the Sun). From Earth, Gl 725 B shines at apparent V-band magnitude 9.7 (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: Mauna Kea Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Gl 725 B |
| Spectral Type | M4 |
| Effective Temp (Teff) | 3,379 K |
| Stellar Radius | 0.2800 R☉ |
| Stellar Mass | 0.2500 M☉ |
| Bolometric Luminosity | 0.00917 L☉ |
| Metallicity [Fe/H] | -0.280 dex |
| Stellar Age | 8.700 Gyr |
| Apparent Magnitude | V: 9.700 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.139000 AU |
| Orbital Period | 37.9 days |
| Mean Orbital Velocity | 39.9 km/s |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.1 g/cm³ (16 km/s vesc) |
| Insolation Flux | 0.4742 S⊕ (~645 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 22.300 LY (6.842 pc) |