The Whirlpool Galaxy (also known as Messier 51a, M51a, or NGC 5194) is an interacting grand-design spiral galaxy that is estimated to be 23 ± 4 million light-years from the Milky Way Galaxy in the constellation Canes Venatici. It is one of the most famous galaxies in the sky. The galaxy and its companion (NGC 5195) are easily observed by amateur astronomers, and the two galaxies may even be seen with binoculars. (Wikipedia)

Note the blue star in the upper right part of M 51. This is Supernova SN 2011dh which was discovered on May 31st. As of Midnight June 2nd through the early hours of June 3rd it shines brightly. This is actually a single star that is now visible from over 23 million light-years away!