This red bubble is made of gas that is being shocked by the expanding blast wave from a supernova explosion. Called SNR 0509-67.5, the bubble is 23 light-years across and is expanding at more than 11 million miles per hour.
In this segment of our “How far away is it” video book, we cover the Andromeda galaxy along with our local group of galaxies, including some of the dwarf galaxies orbiting the Milky Way.
We begin with Edwin Hubble’s discovery of a Cepheid variable star in what was thought to be a Milky Way nebula. We cover 5 of the dwarf galaxies orbiting the Milky Way including Sagittarius Dwarf, Sculptor Dwarf and Fornax Dwarf along with the Large Magellanic Cloud and the Small Magellanic Cloud. Then we examine some of the amazing nebula within these two dwarf galaxies including: Supernova Remnant N 63A, SN 0509-67.5.