Callisto
Καλλιστώ
A companion of Artemis, turned into a bear and then into stars.
She belonged to Artemis's band of sworn virgins — until she was made pregnant by Zeus.
Changed into a bear, she roamed the woods, and at the moment her grown son's spear nearly pierced her, Zeus lifted them both into the sky.
They are the Great Bear and the Little Bear. Jupiter's moon Callisto bears the same name.
SourcesOvid, Metamorphoses