The first exoplanet discovered (designated
HD 82943 b) was announced in 2000 by a team of French astronomers led by
Michel Mayor. The exoplanet orbits its parent star at a mean distance of 1.19
astronomical units (AU) and taking approximately 441
days to complete the orbit. Nearly a year later, a second exoplanet (designated
HD 82943 c) was announced by the same discoverers of the previous planet. This exoplanet orbits closer than the other, at a mean distance of 0.746 AU and taking 219 days to complete its orbit. The two known exoplanet appear to have a 2:1
resonance with one another. Further radial velocity analysis hinted at either long-period stellar activity or presence of a third Jovian exoplanet with an orbital period of 1,075 days. Announced in 2001, HD 82943 was found to contain an unusually high abundance of
lithium-6. Upon reaching a sufficient core temperature, young stars quickly burn through their initial allotment of lithium-6, whereas planets should retain their lithium-6. Thus the simplest and most convincing answer to explain this observation is that one or more planets, or at least planetary material, have fallen into the star sometime after it passed through its early evolutionary stage. A circumstellar
debris disk was discovered in 2003, based on an
infrared excess detected in the system. The inner edge of this disk orbits at a distance of from the host star. The distance to the outer edge is poorly constrained. == See also ==