A Blue Ensign defaced with the Commonwealth Star (also known as the Federation Star) in the lower hoist quarter and the five stars of the Southern Cross in the fly half.
The flag of Australia is a defaced Blue Ensign: a blue field with the Union Jack in the canton (upper hoist quarter), and a large white seven-pointed star known as the Commonwealth Star in the lower hoist quarter. The fly contains a representation of the Southern Cross constellation, made up of five white stars – one small five-pointed star and four, larger, seven-pointed stars.