Sky Guide March 2023

Constellations represent groups of stars that have been given a name and more recently a border. Think of them as suburbs in the sky. For millennia they have been used as a tool to share lore and events. Today, the 88 western constellations, as recognised by the International Astronomical Union (IAU) are used to map the sky and assist in the search for astronomical objects. Every March, these constellations dominate our sky as seen from the southern hemisphere:

Taurus the bull, possibly the oldest of all western constellations, is low in the northwest. It is home to M1 the crab nebula formed by a star that exploded in 1054, M45 the Pleiades, a striking open cluster and the dying red star Aldebaran. Aldebaran is 65 light years from the Sun and is 44 times wider but only a little more massive (+16%). It has exhausted its core supply of hydrogen fuel and is now ‘burning’ hydrogen in a shell around a helium core.

Orion the hunter, is descending into March’s north-western sky sitting above Taurus the bull and followed by the faithful Canis Major. One of the most famous non-zodiac constellations, its three-star belt, lies close to the celestial equator. These stars also make the base of what many Australians refer to as the saucepan. Within the handle of the saucepan, or the sword for the traditionalists, a star making cloud, or nebula at around 1,350 light years away is one of the first things to look at through any telescope. M42 or the Orion nebula, contains enough gas and dust to make as many as 2,000 stars like the Sun. It is a stunning object to view on a dark moonless night.