#septuple star

Crux, which is Latin for "cross," is the smallest of the 88 constellations, but probably one of the most recognizable. That probably explains why it appears on the flags of Australia, Brazil, New Zealand, Papua New Guinea, and Samoa!

Although it was probably known to the Ancient Greeks since Ptolemy included these stars are part of Centaurus, Earth's precession slowly moved Crux below the horizon for most of Europe. The first more modern person to notice the Cross was the Portuguese astronomer João Faras in 1500 while he was accompanying an expedition to Brazil. However, it was Dutch cartographer Petrus Plancius who made it its own constellation in 1598, nearly a century later!

The named stars, in order of brightness, are:

Mimosa (β Crucis), a binary star system consisting of two blue giant stars separated by only about 9 AU (about the distance between the Sun and Saturn). The system lies about 280 light years away. Its name does not come from the drink, but comes from the Latin word mimosa meaning "actor."

Acrux (α Crucis) is a septuple star system consisting of several blue giants and at least one red dwarf. The entire system lies about 348 light years away. The name is an Americanism of Alpha Crucis.

Gacrux (γ Crucis) is a red giant star about 89 light years away, making this the nearest red giant to Earth. Its name is again an Americanism of Gamma Crucis.

Imai (δ Crucis) is a blue giant star about 345 light years away. Its name was given by the Mursi people of Ethiopia: when Imai stops appearing in the evening sky right at dusk, it is said that the Omo river rises high enough to flatten the imai grass along its banks.

Ginan (ε Crucis) is a solitary orange giant star about 230 light years away. Its name was given by the Wardaman people of Australia: this refers to a dillybag, a woven bag used to gather and carry food.

Lumbung (39 Crucis) is a solitary blue giant star about 840 light years away. Its name was given this year, coming from Bali. Lumbung was the name of this constellation in Indonesian astronomy, referring to a rice barn or granary.