GJ 680 b

Astrophysical Synthesis & Habitability Characterization

GJ 680 b is a confirmed gas giant exoplanet orbiting the star GJ 680, located approximately 31.5 light-years (9.67 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12 Earth radii (1.07 Jupiter radii) and has a measured mass of 7977.493 Earth masses (25.1 Jupiter masses). Combining its mass and radius yields a mean bulk density of 25.46 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 55.4 g⊕ (543.29 m/s²), and an escape velocity of 288.4 km/s.

In its orbital architecture around GJ 680, GJ 680 b completes one full revolution every 17281.665 Earth days (47.31Julian years) at a semi-major axis of 10.138 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 6.4 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.381, swinging from 6.2754 AU at periapsis out to 14.0006 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.

❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 37 K (-236°C / -393°F) and an incident flux of 0.00 S⊕ (~0 W/m²), surface water and volatile species on GJ 680 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.

The host star GJ 680 is classified as an orange K-type star of spectral type K5 with an effective photospheric temperature of 3,563 K, a radius of 0.4593 R☉, a mass of 0.456 M☉, an estimated bolometric luminosity of 0.031 L☉. From Earth, GJ 680 shines at apparent V-band magnitude 10.129 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere.

Discovery Facility: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).