White dwarfs with carbon bands

Lick Observatory spectrophotometry is presented for three recognized 4670-A stars (G47-18, G99-37, and G257-38) and the DC star L1363-3. New C I features are reported for G47-18; G257-38 has no C I but definite C2; weak bands are also noted in L1363-3, which is a Wolf 219 group member. The magnetic CH star G99-37 is examined in greater detail. Model-atmosphere calculations show that it must have a helium-dominated atmosphere, since stringent upper limits on H-alpha and H-beta central Zeeman components are found. The CH 'G' band profile is compared with the theoretical calculations of Angel and Landstreet (1974). Other upper limits for atomic lines are discussed.