Sean Ono Lennon and Charlotte Kemp Muhl welcomed their first child. Their newborn son has been named Aurelius, marking a new generation. This event confirms earlier reports from Sean's half-brother, Julian Lennon. Aurelius is now the first grandchild of John Lennon and Yoko Ono. Sean and Kemp Muhl have collaborated musically as The Ghost of a Saber Tooth Tiger.