Blue supergiant star, illustration. This blue supergiant star once existed inside a cluster of young stars in the spiral galaxy NGC 3938. This galaxy is located 65 million light-years from earth. In 2017, this star exploded as a supernova and was named SN 2017EIN. SN 2017EIN was categorised as a Type Ic supernova because of the lack of hydrogen and helium in the supernova's spectrum. Using archival Hubble Space Telescope photos from 2007, astronomers were able to locate the star before it exploded. The star may have been as massive as 50 suns and burned hotter and bluer.