B1IV JM53, Garrison67, and MK73 do not list a B1IV standard MK43 standard: omi Per - B1IV bet Cep - B1IV alf Vir - B1III-IV MK78 standard: zet Tau - B1IV:((e))(shell) Mv(B1IV) = -3.9 ; GrayCorbally09 # Standards zet Tau = HR 1910 = HD 37202 B1IV:((e))(shell): MK78 B1IVe shell: Slettebak82 B4IIIp shell He-n: Lesh68 bet Cep B1IV: MK43 omi Per B1IV: MK43 alf Vir B1III-IV: MK43