Constellations are groups of stars that represent mythological figures, fanciful beasts or old scientific instruments. Some have been used for millennia as a tool to share significant cultural stories and to track the passage of the weeks and months. Today they also help astronomers mark out portions of the sky and locate astronomical objects. Those listed below have been selected for their visibility in the evening up to 2 hours after sunset as seen from the southern hemisphere.
The summer constellation Orion is lying on its side low in the western sky. Above and to the left or south is the brightest star in the sky, Sirius, while above and to the right or north is Procyon. Farther north we see Pollux and Castor, the twin stars of Gemini. Due north is Regulus, the brightest star in the constellation Leo, the Lion. Regulus lies on the ecliptic, the line traced out by the planets, the Sun and the Moon in their journeys around the sky. Hence Regulus is often occulted, or covered, by the Moon.
Low in the east, we have the welcome return of the favourite constellation of the Australian winter sky, Scorpius, the Scorpion. It is easily recognisable, consisting of a line of bright stars, including the bright red star Antares. Scorpius rises as Orion is setting, recalling the ancient Greek story of the Scorpion chasing the giant Orion.
The Southern Cross, Crux, is well placed for observation, as it is now high in the south-east. The brightest star of the Cross, Acrux, is the closest to the horizon, while the next brightest, Beta Crucis or Mimosa, is to the left or east.
If we extend a line through the top two stars of the Southern Cross to the right or west, we reach Canopus, the brightest star in the constellation Carina, the Keel. This constellation was once part of a much larger constellation called Argo Navis, the Ship, that was broken up into three parts: Carina; Puppis, the Stern; and Vela, the Sails. Canopus appears to us as the second-brightest star in the sky, behind only Sirius. In reality, it is 36 times farther away than Sirius and is intrinsically a much brighter star.
