April 14, 2009: In our violent, discordant, and effervescent universe, reality always seems to be stranger than fiction. Case in point: there is a galaxy 54 million light-years away that is shooting out a 5,000-light-year-long, narrow beam of radiation and plasma that is as opulent as a Star Wars light saber and as destructive as the film's Death Star. This extragalactic jet is being fueled and ejected from the vicinity of a monster black hole that is 3 billion times the mass of our Sun. The disk around a rapidly spinning black hole has magnetic field lines that entrap ionized gas falling toward the black hole. These particles, along with radiation, flow rapidly away from the black hole along the magnetic field lines. The rotational energy of the spinning accretion disk adds momentum to the outflowing jet.
NASA's Hubble Space Telescope has been used to keep an eye on these million-degree fireworks for more than a decade. Hubble has caught the jet flickering. In particular, a glowing knot in the outflowing stream has gotten as bright as the galaxy's star-crowded nucleus, only to dim and then brighten again. Astronomers don't know why the black-hole torch is fluctuating, but it may be similar to the physics that causes flares to explode on the Sun. Plasma trapped in the Sun's magnetic field gets pinched and heated as the lines collapse and put the squeeze on it. Or, more simply, the jet may be plowing into an unseen clump of interstellar matter -- at more than half the speed of light!See the rest: