O5III

Walborn71 standard:  HD 15558 - O5III(f)
Walborn73 standard:  HD 15558 - O5III(f) 
Garrison77 standard: HD 150136 - O5III

# No standard

Hiltner69 does not list a O5III standard.

# Primary standard

HD 15558
   O5III(f): Walborn71(stan),Walborn73(stan)

# Secondary standard

HD 150136 (J1641-4845; V=5.6)
  *O5III:n(f): Walborn72(non-standard)
   O5III: Garrison77(stan),Garmany82
   O5(f): Conti77(SB2)
   O(5/7): Houk78
   O7: : Hoffleit56
   Oe5: Cannon
   O5:V: + O6: : Arnal88

   Companion to HD 150135 9.6" away.