Prior to the 20th century, the constellation was also known as Piscis Notius, a name used to distinguish it from Pisces and the later introduced Piscis Volans (the flying fish).
Fomalhaut represents the mouth of the fish. It is a well known binary star, the companion being a white dwarf. Beta PsA is the only other star in the constellation to have been named, being Tien Kang (heavenly rope) in China. It is also a binary, although of two more nearly equal stars.
It is thought that originally Piscis Austrinus was the only constellation representing a fish, Pisces becoming fish only later.
* Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.
Aquarius, Piscis Australis and Ballon Aerostatique (an older constellation)
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