GJ 625 b
Astrophysical Synthesis & Habitability Characterization
GJ 625 b is a confirmed super-earth exoplanet orbiting the star GJ 625, located approximately 21.1 light-years (6.47 parsecs) from the Solar System. First announced in 2017 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.49 Earth radii and has a measured mass of 2.82 Earth masses. Combining its mass and radius yields a mean bulk density of 4.7 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.4 km/s.
In its orbital architecture around GJ 625, GJ 625 b completes one full revolution every 14.628 Earth days at a semi-major axis of 0.078361 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 58.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.13 carries the world between 0.0682 AU at periapsis and 0.0885 AU at apoapsis, driving measurable seasonal insolation cycles.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for GJ 625 b place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star GJ 625 is classified as a low-mass red dwarf of spectral type M2 with an effective photospheric temperature of 3,499 K, a radius of 0.31 R☉, a mass of 0.3 M☉, an estimated bolometric luminosity of 0.013 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.38 dex (metal-poor relative to the Sun). From Earth, GJ 625 shines at apparent V-band magnitude 10.066 (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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 625 |
| Spectral Type | M2 |
| Effective Temp (Teff) | 3,499 K |
| Stellar Radius | 0.3100 R☉ |
| Stellar Mass | 0.3000 M☉ |
| Bolometric Luminosity | 0.013 L☉ |
| Metallicity [Fe/H] | -0.380 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 10.066 · G: 9.137 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.078361 AU |
| Orbital Period | 14.628 days |
| Mean Orbital Velocity | 58.3 km/s |
| Orbital Eccentricity (e) | 0.13000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.7 g/cm³ (15.4 km/s vesc) |
| Insolation Flux | 2.0787 S⊕ (~2,829 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 21.100 LY (6.472 pc) |