Astronomers have gotten one of their best looks yet at a black hole devouring a star and spitting out its remains at a quarter of the speed of light.
In 2005, a team noticed a bright flare of infrared light in a pair of colliding galaxies 134 million light-years away. The source turned out to be a star falling into a gigantic black hole that weighs 20 million times the mass of our sun.
While a few similar events have been seen before, they have always been either too far away or viewed with telescopes that weren鈥檛 powerful enough to tease out their specifics. 鈥淥ur result precisely fills this gap,鈥� says Miguel P茅rez-Torres, an astronomer at the Institute of Astrophysics of Andalusia in Granada, Spain.
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Over the course of 10 years, P茅rez-Torres and his colleagues closely monitored the region using both infrared and radio telescopes, which could peer through the dusty environment surrounding the black hole.
They were able to observe a jet-like structure that is thought to arise when a black hole breaks apart a star, leading to half the material falling into the black hole and half being shot outward at incredible speeds. The team compared their observations to simulations of these jets, and found they looked similar.
The researchers also calculated the total energy produced by the event, which was more than the output of 15 supernova explosions, and estimated the mass of the devoured star, which was between 1.9 and 6.5 times as massive as the sun.
The findings bolster the idea that galactic mergers provide the shakeup necessary to push stars toward the maw of supermassive black holes, which would otherwise remain fairly quiet, says Enrico Ramirez-Ruiz at the University of California, Santa Cruz. He adds that it remains possible a gigantic chunk of gas and dust fell into the black hole, rather than a star, mimicking a stellar digestion event.
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