The formation of planets
About a decade ago, in the year 1995, the first extrasolar planet around a solar-type star has been discovered. By now more than 290 extrasolar planets in over 240 planetary systems are known. Although the applied planet detection techniques cause strong selection effects, it is now obvious that the solar system planets cover a small region in the parameter space of possible planetary characteristics only. In order to better understand the observed diversity of planets, one has to go back into the history of the planetary systems - studying the formation and evolution.
In these lectures we will discuss the process of planet formation from two perspectives. One the one side findings from our Solar system and the new constraints derived from observations of exoplanetary systems will be collected. On the other side, the formation of planets is tightly connected with the formation of stars. Here, we will first discuss the question where, under which conditions and how stars form. Subsequently we will analyze the potential place of planet formation - circumstellar disks - and outline the process planet formation therein.