Flag of Australia - Construction

Construction

Under the Flags Act, the Australian National Flag must meet the following specifications:

1. the Union Flag occupying the upper quarter next the staff;
2. a large white star (representing the 6 States of Australia and the Territories) in the centre of the lower quarter next the pye and pointing direct to the centre of St George's Cross in the Union Flag;
3. 5 white stars (representing the Southern Cross) in the half of the flag further from the staff.

The location of the stars is as follows:

• Commonwealth Star – 7 pointed star, centred in lower hoist.
• Alpha Crucis – 7 pointed star, straight below centre fly 1/6 up from bottom edge.
• Beta Crucis – 7 pointed star, 1/4 of the way left and 1/16 up from the centre fly.
• Gamma Crucis – 7 pointed star, straight above centre fly 1/6 down from top edge.
• Delta Crucis – 7 pointed star, 2/9 of the way right and 31/240 up from the centre fly.
• Epsilon Crucis – 5 pointed star, 1/10 of the way right and 1/24 down from the centre fly.

The outer diameter of the Commonwealth Star is 3/10 of the flag's width, while that of the stars in the Southern Cross is 1/7 of the flag's width, except for Epsilon, for which the fraction is 1/12. Each star's inner diameter is 4/9 of the outer diameter. The flag's width is the measurement of the hoist edge of the flag (the distance from top to bottom). The stars are named after the first five letters of the Greek alphabet, in decreasing order of brightness in the sky.