HD 218108

HD 218108 is a G-type main-sequence star located approximately 193 light-years away in the constellation Cassiopeia. It is slightly larger and more massive than the Sun, with an estimated age older than the Sun as well. The star is also more luminous than the Sun.

HD 218108 is notable for hosting at least two confirmed extrasolar planets, designated HD 218108 b and HD 218108 c. These planets were discovered using the radial velocity method, which detects variations in a star's velocity caused by the gravitational pull of orbiting planets.

HD 218108 b is a gas giant with a minimum mass about twice that of Jupiter. It orbits the star at a distance of approximately 1.31 astronomical units (AU) with a period of around 597 days.

HD 218108 c is another gas giant, with a minimum mass of around 0.34 times that of Jupiter (roughly the mass of Saturn). It orbits much farther out, at a distance of about 2.7 AU, with an orbital period of approximately 1425 days.

The HD 218108 system is of interest to astronomers studying planetary formation and the diversity of exoplanetary systems. Further observations and analysis may reveal additional planets or provide more detailed information about the existing ones. The star's characteristics and planetary system contribute to our understanding of stellar and planetary evolution.