Phæthon

English Proper noun en Phaëthon. Usage notes Two conventions are found in English for representing the sequences ⟨ae⟩ and ⟨æ⟩. In the older convention, ⟨æ⟩ represents a diphthong while ⟨ae⟩ represents two vowels in hiatus; under this convention, the spelling en Phaethon reflects the Greek spelling Φαέθων, which contains ⟨αε⟩ rather than the diphthong ⟨αι⟩. In a later convention, ⟨ae⟩ is used for both hiatus and diphthongs unless a diaeresis is added, yielding en Phaëthon. The use of ⟨æ⟩ in en Phæthon, though historically attested, is considered incorrect by both conventions.