One of the brightest parts of the Milky Way is located in the constellation Carina (the keel). Known as the Carina Nebula, it is mostly composed of hydrogen gas. The red colour in the image represents emission radiation from interactions between the hydrogen gas and ultraviolet light from nearby stars. The brightest star in the nebula, known as Eta Carinae, is one of the most luminous stars in the Milky Way.
Credit: Capella-observatory / Ciel et Espace.