GJ 1061 d
Astrophysical Synthesis & Habitability Characterization
GJ 1061 d 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 1.16 Earth radii and has a measured mass of 1.67 Earth masses. Combining its mass and radius yields a mean bulk density of 5.9 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.24 g⊕ (12.16 m/s²), and an escape velocity of 13.4 km/s.
In its orbital architecture around GJ 1061, GJ 1061 d completes one full revolution every 13.066 Earth days at a semi-major axis of 0.054 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 45 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.04 (ranging from 0.0518 AU at periapsis to 0.0562 AU at apoapsis), the planet experiences minimal orbital distance variation.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 242 K (-31°C / -24°F) and an incident stellar irradiance of 0.60 S⊕ (~817 W/m²), GJ 1061 d orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
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 d sharing its stellar neighborhood alongside GJ 1061 b, GJ 1061 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: 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) | 0.054000 AU |
| Orbital Period | 13.066 days |
| Mean Orbital Velocity | 45 km/s |
| Orbital Eccentricity (e) | 0.04000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 5.9 g/cm³ (13.4 km/s vesc) |
| Insolation Flux | 0.6000 S⊕ (~817 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 12.000 LY (3.673 pc) |