What is the Southern Cross constellation?

The Southern Cross is a constellation of five stars on the Australian flag that represents the country's location in the southern hemisphere. The five stars are arranged in the shape of a kite or cross and appear in white on the blue field on the right-hand side of the flag, opposite the Union Jack and Commonwealth Star.

Astronomers know the Southern Cross as Crux, the smallest of the 88 modern constellations. Its four brightest stars are Alpha Crucis (Acrux), Beta Crucis (Mimosa), Gamma Crucis (Gacrux), and Delta Crucis. A fifth, fainter star, Epsilon Crucis, sits inside the cross shape. On the flag, the four main stars are drawn with seven points each, while Epsilon Crucis is shown with five points, reflecting its lower brightness.

The constellation is visible from anywhere south of about 25 degrees north latitude and is circumpolar from most of Australia, meaning it never sets below the horizon. Indigenous Australians have used the Southern Cross in navigation, ceremony, and seasonal calendars for tens of thousands of years. European settlers used it to find south, since Australia has no bright pole star equivalent to Polaris in the northern hemisphere.

The Southern Cross also appears on the flags of New Zealand, Papua New Guinea, Samoa, and Brazil, and it featured on the Eureka Flag flown by rebel miners at the 1854 Eureka Stockade. Because it is shared with other southern hemisphere nations, the constellation is sometimes proposed as a neutral symbol that could anchor a redesigned Australian flag if the Union Jack were ever removed. For now, the five stars of Crux on the right of the current flag remain the most distinctively Australian element.