Here is a labelled sketch for those who want to know which star is which.
The primary star Regor as it is commonly known is actually itself a spectroscopic binary With it being a Blue supergiant of spectral class o9 and its very close companion at a distnace of only 1 au is a Massive wolf-rayet star,the heaviest known.The binary has a orbital period of 78.5 days
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Regors next nearest companion (Gamma velorum B)is a blue-white B-type subgiant it is seperated from the Wolf-Rayet binary by 41.2''.
Gamma velorum has several fainter companions.The magnitude +8.5 Gamma velorum C a white A-type star which is 62.3 arcseconds from the primary Regor.
Gamma velorum D a A-type star of +9.4 magnitude is itself a binary system but its companion is 13th magnitude and i was unable to see it.
Regards Orestis