Celestial Events SA
SOUTHERN CROSS (CRUX) - CONSTELLATION OF THE MONTH
SOUTHERN CROSS HISTORY
Crux, also known as the Southern Cross is probably the most recognisable constellation in the southern skies. Due to its southerly location, the constellation is not visible from the northern hemisphere and thus has no Greek mythology associated with it. The Greeks were aware of it but included it within the constellation of Centaurus.
The Bushmen saw Crux as a journey of giraffe, along with the 2 pointer stars, Hadar and Rigil Kentaurus (the Pointers). Other traditional African beliefs include the 4 brightest stars as lionesses, with the 5th, dimmer star, their lone cub. The pointers represent the 2 pride males following close behind.
Alpha Crusis is the brightest star in the Southern Cross and is the 13th brightest star in the sky. Its brightest is due to it being a multiple star system and even binoculars can split the 2 main components into a great example of a double star.
Beta Crusis is also known as ‘Mimosa’, possible named after the yellow/white globular flowerheads of the family of plant bearing the same name. Beta Crusis is in the top 20 brightest stars in the sky and thought to be one of the hottest in the galaxy due to its relatively young age of around 10 million years.
DEEP SKY OBJECTS
The Jewel Box is small open cluster of stars found close to Beta Crusis. To the naked eye it can easily be mistaken as a faint star but binoculars will reveal the cluster. An amateur telescope will reveal the varied colours of the stars that give it is name, including the central 3 stars of differing colours that form a line known as the ‘Traffic Lights’
The Jewel Box is one of the youngest known clusters in the sky and was discovered by Nicolas De Lacaille from his observatory in the Cape of Good Hope in South Africa on March 25th 1752.
The Coal Sack is a Dark or Absorption Nebula occupying a large region of sky between Alpha and Beta Crusis. It is the most prominent nebula of its type visible from Earth.
The area looks devoid of stars to the naked eye but binoculars will resolve many stars hidden within. The area is a dense patch of interstellar dust and gas situated between the Earth and the stars of the Milky Way, thus blocking out the majority of their light. It is from areas like these that new stars can form under the correct conditions.
The Bushmen called the Coalsack the ‘Old Bag of the Night’ and other African cultures considered it a hole in the sky that once housed the Small Magellanic Cloud before the god’s became angry and kicked it out. Literally!