Markarian 501

Radio image of Markarian 501Markarian 501 is more than 300 million light years distant from the earth. It has an active nucleus, the source of energy for the jet of fast-moving particles seen in this VLBA image. The image reveals a remarkable feature in the jet - a dramatic twisting in direction through nearly a right angle. VLBA images like this one help astronomers to understand the nature of jets, active galactic nuclei, and the black holes they may harbor.

Image by J.M. Wrobel and J.E. Conway