A Black Hole Consumed a Star and Released the Light of a Trillion Suns

A star is being consumed by a distant supermassive black hole. Astronomers call this a tidal disruption event (TDE). As the black hole rips apart the star, two jets of material moving with almost the speed of light are launched in opposite directions. One of the jets was aimed directly at Earth. Image credit: Carl Knox (OzGrav, ARC Centre of Excellence for Gravitational Wave Discovery, Swinburne University of Technology)

When a flash of light appears somewhere in the sky, astronomers notice. When it appears in a region of the sky not known to host a stellar object that’s flashed before, they really sit up and take notice. In astronomical parlance, objects that emit flashing light are called transients.

Earlier this year, astronomers spotted a transient that flashed with the light of a trillion Suns.

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Astronomers Discover a Mysterious Star That Flashes Every 20 Minutes. But What is it?

A radio map of the Milky Way showing the location of the new transient. Credit: Dr Natasha Hurley-Walker (ICRAR/Curtin) and the GLEAM Team

Just 4,000 light-years from Earth is a strange, star-sized object. It’s been observed by radio telescopes, but astronomers aren’t sure what it is. They call it a long period transient.

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What’s Causing the Mysterious Radio Waves Coming From the Center of the Milky Way?

An artist's impression of ASKAP J173608.2-321635, the mysterious radio source at the center of the Milky Way. Image Credit: Sebastian Zentilomo.

The center of the Milky Way is a mysterious place. Astronomers think there’s a supermassive black hole there, though it could be dark matter instead. The region is densely packed with stars, dominated by red giants. And because of all the dust between Earth and the galactic center, we can’t see anything with visible light, ultraviolet light, or low-energy x-rays.

But we can detect radio waves, and there are some unexplained ones coming from the center of the galaxy, and adding to the mystery.

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Astronomy Cast Ep. 519: Transients: What They Are and Why They Matter

Astronomers have found that sometimes the Universe changes. Things move, things explode, things get brighter or dimmer. In fact, knowing this has helped astronomers discover some very important aspects of the Universe. Today we begin a two part series on Transients and their role in astronomy.
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