The cause? Scientists believe a supermassive black hole at the center of a galaxy nearly four billion light-years distant has wrapped its gravitational tendrils around a star the size of our sun, spawning a high-energy jet of gamma radiation.
On March 28th the gamma ray burst was equivalent to the brightness of a hundred billion suns—or as the paper published today in Science describes it, "An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy." It's believed that supermassive black holes lie at the heart of large galaxies.
"This burst produced a tremendous amount of energy over a fairly long period of time, and the event is still going on more than two and a half months later," says UC Berkeley astronomy professor and study lead Joshua Bloom.
The reason it's so bright? The energy jet is pointed directly at us. And instead of swallowing the star whole, the black hole is nibbling on it bit by bit, keeping the energy jet going.
"That's because as the black hole rips the star apart, the mass swirls around like water going down a drain, and this swirling process releases a lot of energy," explains Bloom.
Bloom surmises the black hole wasn't doing much until the star wandered by, causing a tidal disruption so violent it produced energy at never-before-seen gamma-ray levels.
Couple this with the likelihood of the jet angling in our direction, and you have a "once in 100 million years in any given galaxy” event, according to Bloom, who says he'd be surprised if another occurred "anywhere in the sky in the next decade."
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