GJ 1061 b
Astrophysical Synthesis & Habitability Characterization
GJ 1061 b is a confirmed terrestrial exoplanet orbiting the star GJ 1061, located approximately 12 light-years (3.67 parsecs) from the Solar System. First announced in 2020 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.04 Earth radii and has a measured mass of 1.11 Earth masses. Combining its mass and radius yields a mean bulk density of 5.44 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.03 g⊕ (10.1 m/s²), and an escape velocity of 11.6 km/s.
In its orbital architecture around GJ 1061, GJ 1061 b completes one full revolution every 3.207 Earth days at a semi-major axis of 0.021 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 71.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.05 carries the world between 0.02 AU at periapsis and 0.0221 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 388 K (+115°C / +239°F) and receiving 3.80 S⊕ (~5,172 W/m²), GJ 1061 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star GJ 1061 is classified as a low-mass red dwarf of spectral type M5.5 V with an effective photospheric temperature of 2,953 K, a radius of 0.156 R☉, a mass of 0.12 M☉, an estimated bolometric luminosity of 0.00166 L☉. Stellar evolution modeling indicates an estimated stellar age of 7 Gyr and a metallicity of [Fe/H] = -0.08 dex (near-solar heavy-element abundance). From Earth, GJ 1061 shines at apparent V-band magnitude 12.7 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The GJ 1061 system is a multi-planet architecture hosting 3 confirmed worlds, with GJ 1061 b sharing its stellar neighborhood alongside GJ 1061 c, GJ 1061 d.
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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 1061 |
| Spectral Type | M5.5 V |
| Effective Temp (Teff) | 2,953 K |
| Stellar Radius | 0.1560 R☉ |
| Stellar Mass | 0.1200 M☉ |
| Bolometric Luminosity | 0.00166 L☉ |
| Metallicity [Fe/H] | -0.080 dex |
| Stellar Age | 7.000 Gyr |
| Apparent Magnitude | V: 12.700 · G: 10.989 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.021000 AU |
| Orbital Period | 3.207 days |
| Mean Orbital Velocity | 71.2 km/s |
| Orbital Eccentricity (e) | 0.05000 |
| Orbital Inclination (i) | 77.0000° |
| Mean Bulk Density | 5.44 g/cm³ (11.6 km/s vesc) |
| Insolation Flux | 3.8000 S⊕ (~5,172 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 12.000 LY (3.673 pc) |