Amateur astronomer Victor Buso was testing his camera-telescope setup in Argentina back in September 2016, pointing his Newtonian telescope at a spiral galaxy called NGC613. He collected light from the galaxy for the next hour and a half, taking short exposures to keep out the Santa Fe city lights. When he looked at his images, he realised he'd captured a potential supernova - an enormous flash of light and energy bursting off of a distant star.