A Star Passing The Black Hole at The Centre of Our Galaxy Is About to Test Einstein's Theory

In a few months, astronomers are going to be pointing their telescopes to Sagittarius A, the supermassive black hole at the centre of our galaxy.
That's because it's going to be buzzed by a closely orbiting star - providing another context for testing Einstein's theory of general relativity.
The star is called S0-2, one of a class of stars known as S-stars (not to be confused with S-type stars) that closely orbit Sgr A, which has an estimated mass of around 4.3 million Suns.
But S0-2 is special. It's one of two stars that zoom in closest to the black hole in its elliptical orbit, which means it's likely to show the effects of the black hole's gargantuan gravitational pull when it swings around once every 16 years.