HD 10180 g

Astrophysical Synthesis & Habitability Characterization

HD 10180 g is a confirmed gas giant exoplanet orbiting the star HD 10180, located approximately 127.1 light-years (38.96 parsecs) from the Solar System. First announced in 2010 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world has a minimum or true mass of 3375.338 Earth masses (10.62 M♃), while its physical transit radius has not yet been geometrically observed.

In its orbital architecture around HD 10180, HD 10180 g completes one full revolution every 604.67 Earth days (1.66Julian years) at a semi-major axis of 1.427 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 25.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.263, swinging from 1.0517 AU at periapsis out to 1.8023 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.

✓ Classified as a Temperate Habitable Zone Candidate.

With an estimated equilibrium temperature of 251 K (-22°C / -8°F) and an incident stellar irradiance of 0.73 S⊕ (~996 W/m²), HD 10180 g orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.

The host star HD 10180 is classified as a solar-type yellow star of spectral type G1 V with an effective photospheric temperature of 5,911 K, a radius of 1.109 R☉, a mass of 1.06 M☉, an estimated bolometric luminosity of 1.347 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.3 Gyr and a metallicity of [Fe/H] = 0.08 dex (metal-rich relative to the Sun). From Earth, HD 10180 shines at apparent V-band magnitude 7.33 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 10180 system is a multi-planet architecture hosting 6 confirmed worlds, with HD 10180 g sharing its stellar neighborhood alongside HD 10180 c, HD 10180 d, HD 10180 e, HD 10180 f, HD 10180 h.

Discovery Facility: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).