On November 11, 2014, astronomers everywhere were treated a rather rare case of cosmic fireworks. A very distant star ended its life in a giant explosion of light which we call a supernova. Â Supernovae have been spotted as ‘new’ or ‘guest stars’ by humans looking up into space since ancient times, and can be so bright that occasionally a supernova can be seen from half-way across the universe with the unaided eye.
What was rare about the supernova event on November 11, 2014, is not actually that the star exploded. Â All stars that are at least 2-3 times the mass of the Sun end their lives in this dramatic way. Â What is extremely lucky for us is that this supernova event happened to be situated behind an object which acts as a natural telescope in space. Â This natural telescope, also known as a lens, can play optical illusions on us. Â In this case, the lens boosted the brightness of this already bright stellar explosion. Â The lens also literally photocopied the image of the supernova into four different places on the sky. Â As a result, instead of spotting one bright and apparently new ‘star’ in the sky, a total of four bright lights are seen. Â A supernova which is photocopied on the sky is so rare that only a total of one event (this one) has ever been discovered. Â Astronomers everywhere are racing to observe the fading light of the four copies of this stellar explosion before the supernova disappears from view. Â On a historical note, such ‘lensed’ events were first predicted by Einstein as a natural consequence of the Theory of General Relativity.