Piscis Austrinus (also known as Piscis Australis) is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish", in contrast with the larger constellation Pisces, which represents a pair of fishes. Prior to the 20th century, it was also known as Piscis Notius. Its only star brighter than 4th magnitude is Fomalhaut.
Piscis Austrinus was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. The stars of the modern constellation Grus once formed part of Piscis Austrinus. In 1597 (or 1598), Petrus Plancius carved out a separate constellation and named it after the crane.
In Greek mythology, this constellation is known as the Great Fish and it is portrayed as swallowing the water being poured out by Aquarius, the water-bearer constellation. The two fish of the constellation Pisces are said to be the offspring of the Great Fish. In Egyptian mythology, this fish saved the life of the Egyptian goddess Isis, so she placed this fish and its descendants into the heavens as constellations of stars.
Read more about Piscis Austrinus: Origins, Characteristics, Notable Features