It is a star 100 times the size of the Sun and located 25,000 light years away.
The dimming was probably caused by it was probably caused by an orbiting planet or companion star, which was surrounded by a disk of opaque dust.
It is not clear when the star will dim again, but astronomers believe it will happen in the next 20 to 200 years.
The exploration of the sky continues to give surprises. A group of astronomers have discovered a giant blinking star, 100 times the size of the Sun, lurking near the very center of the Milky Way. Observations from the Vista telescope in Chile revealed that, over a few hundred days, the huge star, which is more than 25,000 light-years away, dimmed by 97% and then slowly returned to its former brightness.
When scientists find different stars that don’t fall into established categories, they call them “what is this” or “WIT” objects (literally translated as “what is this”). This latest discovery is called VVV-WIT-08.
The unexpected and dramatic dimming was likely caused by an orbiting planet or companion star, which was surrounded by a disk of opaque dust. It blocks the light that would otherwise have reached Earth. “It seemed to come out of nowhere,” he explains. Leigh smith from the Institute of Astronomy at the University of Cambridge to The Guardian, about the star’s sudden darkening.
VVV-WIT-08 began to fade in early 2012 and almost disappeared in April of that year, before recovering for the next 100 days. It is exceptionally rare for a star to fade for months and then shine again.
Astronomers noticed the mysterious phenomenon in data collected by the Vista telescope, operated by the European Southern Observatory in Chile. The instrument has been observing a billion stars for almost a decade, looking for examples that vary in brightness within the infrared range of the electromagnetic spectrum.
Because the huge star was in such a dense region of the galaxy, the researchers they wondered if an unknown dark object could have strayed versus VVV-WIT-08 by chance. Simulations suggested that this was highly unlikely and the dust disk theory emerged. It is not clear when the star will dim again, but astronomers believe it will happen in the next 20 to 200 years.
The astronomers’ calculations, published in ‘Monthly Notices of the Royal Astronomical Society’, suggested that the dust disk would be tilted to resemble an ellipse of the Earth and that it had to be gigantic, with a radius of at least a quarter of a the distance from the Earth to the Sun.
Other “blinking giants”
Not the first flickering star discovered by astronomers. A huge disk of dust causes the giant star Epsilon Aurigae to dim by about 50% every 27 years. Another star known as TYC 2505-672-1, which is part of a binary system, is dwarfed by the disk around its companion star every 69 years. Two stars with similar characteristics have also been observed near VVV-WIT-08 itself.
The cluster of discoveries will help astronomers understand what appears to be a new class of “blinking giants” stars. “Once you start accumulating collections of various of these things, you can look at their properties together and unravel the mysteries of where these records come from,” Smith details. “It allows us to learn how these systems evolve and what they do at the end of their lives.”