An Asteroid-Smashing Star Ground a Giant Rock to Bits and Covered Itself in the Remains

By Rafi Letzter - Staff Writer 2 days ago Space

It was a crunch visible light-years away.



An artist's illustration shows an asteroid cracking to pieces.(Image: © JPL-Caltech)

Somewhere in the galaxy, a white dwarf star suddenly started shining brightly. And now we understand the violent cataclysm that caused it: the star's gravitational field tore the asteroid to bits, scattering its metallic bits in a shiny halo around the star.

There's no telescope video of an asteroid shattering across space. But here's what we do know: There's a white dwarf star in our galaxy that, for years, emitted a consistent amount of mid-infrared (MIR) light. Then, in 2018, these emissions changed. Over the course of six months, the starlight from that point in space got about 10% more intense in the MIR spectrum — and that point is still getting brighter. The researchers think that's because of a newly formed cloud of metallic dust between Earth and the star, likely due to the recent breakup of the asteroid.

To an outsider, it may sound counterintuitive that a cloud of dust would make a star look brighter. But Tinggui Wang, an astronomer at the University of Science and Technology of China and lead author of a paper describing the event, said the brightening makes sense if you think about how the star and the cloud interact.

"When the debris are on our line of sight to the star, it would make the star dim," he told Live Science. "However, the [individual pieces of] debris cover only a small fraction of the sky, so the chance of being on the line of sight is small.

More:
https://www.livescience.com/white-dwarf-asteroid-smasher.html