InGreek mythology,Phaethusa orPhaëthusa/ˌfeɪəˈθjuːzə/ (Ancient Greek:ΦαέθουσαPhaéthousa, "radiance") was a daughter ofHelios andNeaera, the personification of the brilliant, blinding rays of thesun.[1] With her twin sister,Lampetia, she guarded the cattle ofThrinacia. She carried a copper staff with which she tended to her father's herd of sheep. She is sometimes listed as among theHeliades, daughters of Helios andClymene who mourned for their brotherPhaethon and were transformed into poplar trees. In theArgonautica however, set explicitly after Phaethon's death, she and her sister are still tending to their father's flock.