Esperanto letter Ŭ

The Esperanto letter Ŭ (called ŭo, ŭo luneta or u luneta in Esperanto and U-breve /juː briːv/ in English) represents IPA phoneme /u̯/. It can be used only after "a" or "e". "Aŭ" is pronounced /au̯/ and "eŭ" is pronounced /eu̯/. Some linguists accept /w/ at the end of a syllable. Using that notation "aŭ" is pronounced /aw/ and "eŭ" is pronounced /ew/. The name of the letter is an exception, because /wo/ (or worse /u̯o/) is not part of Esperanto phonetics.