NGC 6231

MK spectral classification

NoRefMK
020681O9.5 III
023481O9.5 IV
028881B0 IV
033481B1 V
034981B1 V
043481O9 V
050581O8 V
052181B0.5 V
061581O9 III
065181O7
071281B1 V
085381O9.5 IIIn
085481WC7
085581B0.5 Ia
085681O7 f
085781O9 Ib
085881O6
086281O9 III