Astronomers observed a giant star, about 25.000 light-years from Earth.
Over a period of about 200 days, astronomers in Chile observed using the telescope VISTA, the significant reduction of the brightness of the star and its reappearance. The team believes that a large object, orbiting the giant star, hid it for a while from Earth. However, astronomers can not be sure what exactly was this object that covered the star. The phenomenon was named VVV-WIT-08.
"It is amazing. We have just noticed a dark and large object passing between us and the distant star and we can only guess what its origin is"He said Sergey Koposov, astronomer at University of Edinburgh and co-author of the new study.
The study, published in the journal "Monthly Notices of the Royal Astronomical Society", Suggests some hypotheses about what happened, but the temporary disappearance and reappearance of the star does not seem to be due to its inherent characteristics. It was covered by something else.
The VVV-WIT-08 was discovered by VISTA Variables in the Via Lactea survey, a project using the VISTA telescope in Chile. The acronym WIT means “What is this?”And is used when astronomers are unsure of why these giant stars may flash.
In the past, many WIT objects have been discovered and various explanations have been given: quasars, star collisions and novas. Regarding this phenomenon, astronomers believe that something else has passed in front of the star, causing its temporary disappearance.
They thought of various objects, ruling out the possibility of a random object wandering in the space and passes in front of the star. However, the team says a cloud of dust, around a black hole, could be a possible cause.
Researchers also believe that VVV-WIT-08 may belong to a new category of "blinking giant binary star system", where a giant star hides once every few decades from another object. This object, which may be another star or a planet, is surrounded by an opaque disk, which covers the giant star, forcing it to disappear and reappear in the sky.
The team has also identified two other similar phenomena, the VVV-WIT-10 and VVV-WIT-11, suggesting that there may be more of these "flashing giants".
Leigh Smith, an astronomer at the Cambridge Institute of Astronomy and the study's first author, said there are certainly other such stars, but the challenge is to find the objects that make them disappear.