2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4912The O VIII phenomenon describes the occurrence of ultra-high ionization absorption lines of the CNO elements (e.g. O VIII, N VII, C VI, and even Ne X) in the optical spectra hot of DO WDs.To be published in: Proceedings 13th European Workshop on White Dwarfs, NATO Science Series, 2 pages, 1 figureAstrophysicstext