Pulsar reveals strength of magnetic field of Milky Way's supermassiveblackhole

Also reveals why it's eating so slowly.

Giant magnet makes Milky Way black hole a slow eater - physics-math - 14
August 2013 - New Scientist
http://www.newscientist.com/article/...low-eater.html

The supermassive black hole at our galaxy's centre enjoys a slow dinner, thanks to a giant magnet.

The Milky Way's black hole, Sagittarius A*, is clearly sucking in hot gas because doing so makes it burp out radio waves that we can detect. But jets of matter streaming outwardsMovie Camera slow down its gas consumption. "The black hole is not feeding to its full potential," says Ralph Eatough at the Max Planck Institute for Radio Astronomy in Bonn, Germany.

The jets could be the result of a magnetic field produced by charged ions swirling around in the gas but it wasn't clear whether the field was strong enough. To find out, Eatough and colleagues turned to a nearby spinning star, called a pulsar

This particular pulsar was discovered earlier in the year, just 0.3 light years away from the black hole. Eatough's team realised that the strong bursts of radio waves emitted by the pulsar would be rotated by the black hole's magnetic field, and so could be used to measure the strength of the field.