Bp stars in Orion OB1 association

A total of 85 CP stars of various types are identified among 814 members of the Orion OB1 association. We selected 59 Bp stars, which account for 13.4% of the total number of B type stars in the association. The fraction of peculiar B type stars in the association is found to be twice higher than that of peculiar A type stars.

Magnetic field are found in 22 stars, 17 of them are objects with anomalous helium lines. No significant differences are found between the field strengths in the Bp type stars of the association and Bp type field stars. We identified 17 binaries, which make up 20% of the total number of peculiar stars studied which is the standard ratio for CP stars.