Left-hand panel: average Hβ profile in quiescence plus superimposed WD spectrum models with effective temperatures of 25 000, 35 000 and 45 000 K (from bottom to top). Right-hand panel: comparison of the BB Dor average Hβ absorption (top) with the Hβ absorption profiles of three magnetic WDs with B₁ of 10.8, 5 (showing the narrow absorption characteristic of Zeeman splitting) and 4.1 MG (from top to bottom; see text for details).