Crux – the Southern Cross
Constellation
Crux is the smallest constellation but one of the most famous. Its four bright stars form a cross that points towards the south celestial pole, guiding travellers in the Southern Hemisphere.
- Smallest of the 88Size
- AcruxBrightest star
- Australia, NZ, Brazil…On flags of
Take a closer look
Acrux is a team
To the eye, Acrux at the foot of the cross looks like one star. A small telescope splits it into two blue-white stars, and one of those is itself a close pair. Each of them is much hotter and brighter than our Sun.
The Jewel Box
Next to the star Mimosa lies a young star cluster called the Jewel Box. In the 1830s John Herschel described it as a casket of coloured precious stones. Through a telescope you see dozens of blue-white stars with one striking orange-red star among them.
Pointers and false cross
A bigger, dimmer “False Cross” nearby often fools beginners. To be sure you have the real one, find the two bright Pointer stars, Alpha and Beta Centauri, which point straight at it. Alpha Centauri is the nearest star system to us, about 4.4 light-years away.
How we found out
- Ancient times
Visible from Greece and the Middle East thousands of years ago, but Earth’s wobble slowly moved it out of sight there.
- 1500s
European sailors exploring the southern oceans use it to navigate.
- Today
It appears on the flags of Australia, New Zealand, Brazil, Papua New Guinea and Samoa.
How do you find south using the Southern Cross?
Extend the long arm of the cross about four and a half times its length – that point is near the south celestial pole. Drop straight down to the horizon: that’s south.
See it yourself
Best from the Southern Hemisphere, and from southern India and the tropics in spring.
From the encyclopedia
Read the full article on Wikipedia ↗Got it?
Mark Crux – the Southern Cross as explored to earn 10 XP.