A giant star is playing an interesting game of hide and seek.
In 2012, a massive star some 25,000 light-years away blinked at Earth, and we looked back a little confused.
Astronomers using the VISTA telescope in Chile observed a dramatic decrease in the star’s brightness and then re-lighted over a period of about 200 days. The team believes that a large object orbiting the massive star obscured our view of it for some time – but the nature of the occult object remains uncertain. He has dubbed the event VVV-WIT-08.
Sergei Koposov, an astronomer at the University of Edinburgh and co-author of the new study, said, “It is surprising that we saw a dark, large and elongated object between ourselves and a distant star and we can only guess what its origin is.” ” Study.
The study, published in the journal Monthly Notices of the Royal Astronomical Society, suggests some possibilities, but the dip does not appear to be due to the star’s inherent characteristics – it must be a gravitationally bound companion.
The phenomenon was traced to the Via Lactea Survey (VVV) in Vista Char. WIT acronym which means “what is it?” And it is used when astronomers are not clear why these giant stars are blinking.
Several WIT objects have been discovered before with several explanations: violent quasars, star collisions and novae. The team says it’s almost certainly a cryptic event—something has passed in front of the star in the universe we think—and it must be faint, with a thickness of more than 23 million miles (or about one-quarter). distance between the Earth and the Sun).
He considered many different objects, ruling out a chance object wandering the universe as it passed in front of the star. It is also unlikely the giant disk of debris around white dwarfs and neutron stars, although the team says that a cloud of dusty, dirty gas and debris around the black hole – a “black hole fallback disk” – is to blame. can be given .
The team also identified two other candidate events, VVV-WIT-10 and VVV-WIT-11, suggesting that there may be more of these “blinking giants” to discover and describe.
“There are more to be found, of course, but the challenge now is to figure out what the hidden companions are, and how they are surrounded by disks, despite orbiting so far away from the giant star,” said Leigh Smith, an astronomer. said. Cambridge Institute of Astronomy and first author of the study.