GJ 3512 b
Astrophysical Synthesis & Habitability Characterization
GJ 3512 b is a confirmed gas giant exoplanet orbiting the star GJ 3512, located approximately 30.9 light-years (9.49 parsecs) from the Solar System. First announced in 2019 by Calar Alto Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14.3 Earth radii (1.28 Jupiter radii) and has a measured mass of 146.519 Earth masses (0.46 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.28 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.72 g⊕ (7.06 m/s²), and an escape velocity of 35.8 km/s.
In its orbital architecture around GJ 3512, GJ 3512 b completes one full revolution every 203.109 Earth days at a semi-major axis of 0.3376 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 18.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.4279, swinging from 0.1931 AU at periapsis out to 0.4821 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 97 K (-176°C / -285°F) and an incident flux of 0.01 S⊕ (~19 W/m²), surface water and volatile species on GJ 3512 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star GJ 3512 is classified as a low-mass red dwarf of spectral type M5.5 V with an effective photospheric temperature of 3,141 K, a radius of 0.139 R☉, a mass of 0.123 M☉, an estimated bolometric luminosity of 0.00169 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.5 Gyr and a metallicity of [Fe/H] = -0.07 dex (near-solar heavy-element abundance). From Earth, GJ 3512 shines at apparent V-band magnitude 15.18 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The GJ 3512 system is a multi-planet architecture hosting 2 confirmed worlds, with GJ 3512 b sharing its stellar neighborhood alongside GJ 3512 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: Calar Alto Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 3512 |
| Spectral Type | M5.5 V |
| Effective Temp (Teff) | 3,141 K |
| Stellar Radius | 0.1390 R☉ |
| Stellar Mass | 0.1230 M☉ |
| Bolometric Luminosity | 0.00169 L☉ |
| Metallicity [Fe/H] | -0.070 dex |
| Stellar Age | 5.500 Gyr |
| Apparent Magnitude | V: 15.180 · G: 13.112 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.337600 AU |
| Orbital Period | 203.109 days |
| Mean Orbital Velocity | 18.1 km/s |
| Orbital Eccentricity (e) | 0.42790 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.28 g/cm³ (35.8 km/s vesc) |
| Insolation Flux | 0.0138 S⊕ (~19 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 30.900 LY (9.486 pc) |