The Milky Way from the constellations of Canis Major (top centre) through Puppis (centre), Vela (bottom centre) and Carina (bottom right). The field is dominated by Sirius (the Dog Star, top centre) in Canis Major, which is the brightest star in the sky with a visual magnitude of -1.5. The faint and pink areas seen scattered in the frame are emission nebulae; they are interstellar clouds, mainly formed by hydrogen, lit up and ionised by the ultraviolet radiation of young, hot stars embedded in them.