Astronomers spot giant 'blinking star', 100 times size of Sun, near the heart of Milky Way

On Friday, June 11, astronomers spotted a giant 'blinking' star towards the centre of the Milky Way, more than 25,000 light-years away. Telescopic observations revealed that the star, VVV-WIT-08, decreased in brightness by a factor of 30 so that it nearly disappeared from the sky, making it an exceptionally rare star to become 97% fainter over a period of several months and then return to its former brightness. Dr Leigh Smith from Cambridge's Institute of Astronomy, working with scientists at the University of Edinburgh, the University of Hertfordshire, the University of Warsaw in Poland and Universidad Andres Bello in Chile discovered the 'Blinking star'. 

Blinking star system

According to a study published 'Monthly Notices of the Royal Astronomical Society,' VVV-WIT-08 may belong to a new class of 'blinking giant' binary star system. In this binary star system, a giant star around 100 times larger than the Sun is eclipsed once every few decades by an as-yet-unseen orbital companion. The companion, which may be another star or a planet, is surrounded by an opaque disc, which covers the giant star, causing it to disappear and reappear in the sky. 

The VISTA Variables in the Via Lactea Survey (VVV), a project using the British-built VISTA telescope in Chile and operated by the European Southern Observatory, found the VVV-WIT-08. For the past decade, the observatory has been observing the same one billion stars to search for examples with varying brightness in the infrared part of the spectrum.

Two more of these peculiar giant stars in addition to VVV-WIT-08, are found by the UK- based team, suggesting that these may be a new class of 'blinking giant' stars for astronomers to investigate.

Image credit: ESO

The other theory of blinking star

The researchers considered whether some unknown dark object could have simply drifted in front of the giant star by chance as the star is located in a dense region of the Milky Way. However, simulations showed that there would have to be an implausibly large number of dark bodies floating around the Galaxy for this scenario to be likely. 

Dr Leigh Smith from Cambridge's Institute of Astronomy said, "There are certainly more to be found, but the challenge now is in figuring out what the hidden companions are, and how they came to be surrounded by discs, despite orbiting so far from the giant star". 

(With The Guardian input)

(Image Credit: AMANDA SMITH/UNIVERSITY OF CAMBRIDGE)