User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-6951062-20130314091404/@comment-3146930-20130319190625

That was how I see it. When she died, Artemis sent her up to the stars because she loved them so much. Perseus did die at some point and went to Elysium, but didn't become a constellation until later, or so the myths go. I wonder if Percy will ever meet Perseus.