The way in which black holes suck in matter from neighbouring stars is a fundamentally magnetic process and not just caused by gravity. That's the conclusion from new measurements of the X-rays emitted by the gas surrounding a nearby black hole in the Milky Way.

Although predicted by theory over 30 years ago, this is the first time that this effect has been seen. The result -- based on measurements from the Chandra X-ray observatory -- could affect theories on how matter falls onto black holes and other compact objects (Nature 441 953).