Astronomers have studied rings from X-ray light echoes, which were captured using NASA’s Chandra X-ray Observatory. With the help of these, astronomers determined how far Circinus X-1 is from Earth. It is a double star system in the plane of our galaxy.

According to co-author Michael Burton of the University of New South Wales in Sydney, Australia, they prefer to call this system the 'Lord of the Rings’ however this is not associated with Sauron.

According to Sebastian Heinz of the University of Wisconsin in Madison, who led the study, “It’s really hard to get accurate distance measurements in astronomy and we only have a handful of methods. But just as bats use sonar to triangulate their location, we can use the X-rays from Circinus X-1 to figure out exactly where it is”.

The space agency said in a statement that the rings are echoes from an explosion of X-rays emitted by Circinus X-1 in late 2013. It added that the explosion reflected off overriding clouds of dust and created the observed rings. Some reflected X-rays also reached Earth from different angles with a delay of nearly one to three months.

According to NASA, astronomers were able to find out the distance of Circinus X-1 from Earth by comparing the Chandra data to previous images of dust clouds that were detected by the Mopra radio telescope in Australia, and by using simple geometry. The distance was found to be 30,700 light years.