The Local Bubble. Map of a small portion of our Milky Way galaxy centred on the Sun (one of the yellow stars at centre). The Sun's neighbourhood is surrounded by a loop of gas (orange), the Local Bubble, some 500 light years in diameter. It was formed either by the blast wave of a supernova explosion or by the stellar winds of many young stars. Red circles with yellow cores are red giant stars, blue circles with white cores are blue giants. A nearby gas loop (out of picture at top right) is compressing the Local Bubble and pushing streamers of gas (upper centre) towards the Sun. The Henbest/Baum galaxy map is based on the locat- ion of 1500 stars, nebulae and other objects.