HD 82943

HD 82943 is a G-type main-sequence star located approximately 89 light-years away in the constellation Hydra. It is notable for hosting two confirmed extrasolar planets, HD 82943 b and HD 82943 c.

The star is slightly more massive and luminous than the Sun. Its spectral type is G0V, indicating that it is a yellow dwarf star similar to our Sun. HD 82943 exhibits a high lithium abundance, an unusual characteristic for a star of its age. The reason for this high lithium abundance is currently debated, with possible explanations including recent accretion of planetary material or tidal engulfment of a planet.

The two discovered planets are both gas giants. HD 82943 b has a minimum mass of approximately 2.01 Jupiter masses and an orbital period of about 441 days. HD 82943 c has a minimum mass of approximately 1.73 Jupiter masses and an orbital period of about 221 days. These planets are in a near 2:1 orbital resonance, meaning that HD 82943 c completes approximately two orbits for every one orbit of HD 82943 b. This orbital resonance provides important insights into the formation and dynamical evolution of planetary systems.

The presence of the two Jupiter-sized planets has led to investigations into the possibility of smaller, terrestrial planets existing within the system's habitable zone, although none have been confirmed to date. Observations continue to be made to further characterize the star and its planetary system.