Astronomers uncover ‘blinking large’ star close to the middle of the Milky Manner


One thing handed in entrance of a star in a distant a part of the Milky Manner — however astronomers aren’t positive what.

Amanda Smith/College of Cambridge

In 2012, an enormous star some 25,000 light-years away blinked on the Earth, and we stared again, a little bit confused.

Astronomers utilizing the VISTA telescope in Chile watched the star dramatically lower in brightness after which mild up once more over a interval of round 200 days. The crew has a hunch that a big object, orbiting the large star, obscured our view of it briefly — however the nature of the occulting object is unsure. They’ve dubbed the occasion VVV-WIT-08.

“It is wonderful that we simply noticed a darkish, giant and elongated object cross between us and the distant star and we are able to solely speculate what its origin is,” mentioned Sergey Koposov, an astronomer on the College of Edinburgh and co-author of the brand new examine.

The examine, printed within the journal Month-to-month Notices of the Royal Astronomical Society, suggests a few potentialities, however the dip does not seem like as a consequence of options inherent to the star itself — it have to be a gravitationally sure companion. 

The occasion was found within the VISTA Variables within the Through Lactea survey (VVV). The WIT acronym that stands for “What is that this?” and is used when astronomers aren’t clear on why these large stars is likely to be blinking.

An animation of the mysterious object that handed in entrance of VVV-WIT-08?

Leigh Smith, Sergey Koposov

A variety of WIT objects have been found earlier than, with a handful of explanations: violent quasars, star collisions and novas. The crew state this one is sort of actually an occultation occasion — one thing has handed in entrance of the star from our view within the universe — and it have to be faint, with a thickness better than 23 million miles (or about one-quarter of the gap between the Earth and the solar).

They thought of quite a lot of totally different objects, ruling out an opportunity object wandering the cosmos simply passing in entrance of the star. It is also unlikely big discs of particles round white dwarfs and neutron stars prompted the occultation, although the crew say {that a} cloud of dusty, messy gasoline and particles round a black gap — a “black gap fallback disc” — could also be accountable.

The crew have additionally recognized two different candidate occasions, VVV-WIT-10 and VVV-WIT-11, suggesting there could also be extra of those “blinking giants” to find and describe.

“There are actually extra to be discovered, however the problem now could be in determining what the hidden companions are, and the way they got here to be surrounded by discs, regardless of orbiting so removed from the large star,” mentioned Leigh Smith, an astronomer at Cambridge’s Institute of Astronomy and first creator of the examine.

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