Huge magnetic fields criss-cross the Andromeda galaxy
With the 100-meter radio telescope near Effelsberg, Bonn astronomers found magnetic fields in our neighboring galaxy that form a gigantic ring around their center.

Astronomers from the Max Planck Institute for Radio Astronomy in Bonn have used the 100-meter radio telescope near Bad Münstereifel-Effelsberg to undertake the most comprehensive and precise measurement to date of the magnetic fields in the Andromeda galaxy, a neighbor of our Milky Way system. The magnetic fields form a wide ring at a distance of between 20,000 and 50,000 light-years from the galaxy's core. The direction of the field runs almost along the ring, as predicted by the dynamo theory of field formation. Such gigantic magnetic fields play an important role in the formation and development of galaxies.
The Andromeda galaxy, number 31 in Charles Messier's (1730 –1817) catalogue, M 31 for short, is the closest spiral galaxy at a distance of only 2.5 million light years and exceeds the Milky Way system in size and total mass. M 31 can be seen with the naked eye on a clear night and can be found as a nebula in old Arabian star charts. With modern telescopes, their stars, gas and dust can be studied with great precision. In the field of radio waves, another, often neglected part of the galaxies opens up: …