In 2010 scientists discovered four ‘monster’ sized stars, with the heaviest more than 300 times as massive as our Sun. Despite their incredible luminosity, these exotic objects, located in the giant star cluster R136 in the nearby galaxy the Large Magellanic Cloud; have oddly so far been found nowhere else. An image of the Wolf-Rayet star R136a1, the most massive star known. An image of the Wolf-Rayet star R136a1, the most massive star known. Credit: Wikipedia.