ChatGPT said:

Kallisto was a nymph of extraordinary beauty, often described as a follower of Artemis, the virgin goddess of the hunt. Bound by her devotion to Artemis, Kallisto took a vow of chastity and lived freely in the forests, hunting alongside the goddess and her companions. However, her beauty attracted the attention of Zeus, who desired her deeply. In many versions of the myth, Zeus disguised himself as Artemis to approach Kallisto, gaining her trust before revealing his true identity and seducing her. When her pregnancy was discovered, Artemis—furious at what she believed to be a betrayal of their vow—banished her from the sacred company of maidens.

Kallisto later gave birth to a son, Arcas, but her misfortune did not end there. Hera, jealous of her husband’s infidelity, punished Kallisto by transforming her into a bear. Condemned to roam the wild forests in this form, she lived in fear and sorrow, unable to communicate or reveal her true identity. Years later, her grown son Arcas encountered her while hunting. Unaware that the bear before him was his mother, he raised his spear to strike her down. At the last moment, Zeus intervened to prevent the tragedy. To preserve both mother and son, he placed them among the stars as constellations: Kallisto became Ursa Major, the Great Bear, and Arcas became Ursa Minor, the Little Bear.