Evidence for a new phase of matter measured with the STAR experiment at RHIC

I will show recent results of the STAR experiment measured in p-p, d-Au and Au-Au collisions at RHIC energies. Evidence for collective behavior of a new phase of matter is shown based on bulk properties. The characterization of the new matter, using high momentum particles produced in the same collisions, indicates that partons are indeed the relevant degrees of freedom in the produced state. Surprisingly the medium exhibits strong coupling, though, and seems to behave more like an ideal fluid than a weakly interacting plasma. Unique features such as strong partonic flow and jet quenching will be discussed in detail.