The smallest ever star has been discovered. Astronomers led by the University of Cambridge spotted the body while hunting for exoplanets, and are intrigued by its existence at the lowest limits of stardom. The tiny twinkler is called EBLM J0555-57Ab, and is located about 600 light years away. It has just enough mass for the gravitational pressure inside it to enable the fusion of hydrogen nuclei into helium, the process that gives out light and heat, and defines a heavenly body as a star. The reason it was discovered is that it is actually part of what’s known as a binary system, meaning it is twinned with a much larger star.