Five planets revealed after 20 years of observation
(PHYSorg.com Space & Earth)

Over 4000 exoplanets have been discovered since the first one in 1995, but the vast majority of them orbit their stars with relatively short periods of revolution. Indeed, to confirm the presence of a planet, it is necessary to wait until it has made one or more revolutions around its star. This can take from a few days for the closest to the star to decades for the furthest away: Jupiter for example takes 11 years to go around the sun. Only a telescope dedicated to the search for exoplanets can carry out such measurements over such long periods of time, which is the case of the EULER telescope of the Geneva University (UNIGE), Switzerland, located at the Silla Observatory in Chile. These planets with long periods of revolution are of particular interest to astronomers because they are part of a poorly known but unavoidable population to explain the formation and evolution of planets. An article published by the journal Astronomy & Astrophysics.