Here is an incredible simulation from NASA's Swift satellite, showing a black hole devouring a star. In late March 2011, NASA's Swift satellite alerted astronomers to intense and unusual high-energy flares from a new source in the constellation Draco. They soon realized that the source, which is now known as Swift J1644+57, was the result of a truly extraordinary event - the awakening of a distant galaxy's dormant black hole as it shredded and consumed a star. The galaxy is so far away that the radiation from the blast has traveled 3.9 billion years before reaching Earth. This is how the story goes:
As a star falls toward a black hole, it is ripped apart by intense tides. The gas is corralled into a disk that swirls around the black hole and becomes rapidly heated to temperatures of millions of degrees. The innermost gas in the disk spirals toward the black hole, where rapid motion and magnetism creates dual, oppositely directed "funnels" through which some particles may escape. Particle jets driving matter at velocities greater than 80-90 percent the speed of light form along the black hole's spin axis. In the case of Swift J1644+57, one of these jets happened to point straight at Earth.