Many explanations are given in Greek mythology: (1) Phthia was a daughter of Niobe {see planet  (71)} and was killed by Artemis {see planet  (105)}. (2) Phthia was a mistress of Zeus, Apollo {see planets  (5731),  (1862)}, or Phoenix. It is also the name of a town in Thessaly where Achilles {see planet  (588)} was born. (Z 209) _ _.