Evolution of large-scale magnetic fields of chemically peculiar stars

We studied the magnetic field of chemically peculiar stars in the young Orion OB1 association and in other five older clusters. We have found new evidence of the validity of the relic origin of the magnetic field. In the Orion OB1 association, the magnetic field values and the occurrence frequency of magnetic stars are systematically higher than in older groups. There is no magnetic field generation during the life of a star on the main sequence. The observations were carried out using the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We studied the magnetic field of about 80 stars. More than 1000 spectra were obtained with the circular polarization analyzer on the BTA Main Stellar Spectrograph.