A Black Hole Shreds Star Into Pieces

This illustration of a recently observed tidal disruption named ASASSN-14li shows a disc of stellar debris around the black hole at the upper left. A long tail of ejected stellar debris extends to the right far from the black hole. The X-ray spectrum

A black holes is a dying star that has collapsed inward from its own weight. Astronomers think that ASASSN-14li has a mass that's about a few million times that of our own Sunday.

Jon Miller of the University of Michigan in Ann Arbor, who led the study, told Nature magazine about the significance of the findings. The researchers claimed that they have seen quite a number of tidal disruptions, however this is the best one, and it will allow them to fully understand what happens when a black hole shreds a star.

The tidal disruption event, named ASASSN-14li, resulted in two types of radiation - X-rays and optical light.

"When a star wanders too close to a black hole, intense tidal forces rip the star apart". Nearly the stellar debris on the side of the star farthest from the black hole was flung out into space; the rest was sucked down into the black hole.

Here's what we're seeing: The gravity of the black hole pulls most of the star's material down in a filament, heating it to millions of degrees and creating an X-ray flare that astronomers are able to catch via telescopes, such as NASA's Chandra X-ray Observatory. As the material falls into the black hole's event horizon - from which no light can escape - this flare disappears. Known as ASASSN-14li, this black hole-star interaction is located in the center of a galaxy 290 million light years away.

It's the closest tidal disruption event we've discovered in a decade, and astronomers are hopeful that it'll help us develop theories on the structure and evolution of such cosmic happenings.

The optical light All-Sky Automated Survey for Supernovae (ASAS-SN) originally discovered the tidal disruption, known as ASASSN-14li, in November 2014.

'In the future, tidal disruptions can provide us with laboratories to study the effects of extreme gravity'. But how this process starts has remained a mystery.

The data also revealed signs of X-ray absorbing material beyond the disc. This could either be outflowing gas, leaving the disc via a wind, or a stream of gas flowing towards the black hole but temporarily set on a different orbit, not having settled yet in the disc with most of the leftover matter from the destroyed star.


The researchers determined that most of the X-rays are produced by material that is extremely close to the black hole. Eventually, these filmants merge into a smooth, hot disk which glows from X-ray emissions. The wind is not moving fast enough to escape the black hole's gravitational grasp. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.



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