The paper presents magnetic field measurements for 15 chemically peculiar (CP) stars of subgroup 1b in the Orion OB1 association. We have found that the proportion of stars with strong magnetic fields among these 15 CP stars is almost twice as large as in subgroup 1a. Along with this, the age of subgroup 1b is estimated as 2 Myr, and the age of subgroup 1a is in the order of 10 Myr. The average root-mean-square magnetic field \(\left\langle {{{B}_{e}}} \right\rangle \) (all) for stars in subgroup 1b is 2.3 times higher than that for stars in subgroup 1a. The conclusions obtained fall within the concept of the fossil origin of large-scale magnetic fields in B and A stars, but the rate of field weakening with age appears anomalously high. We present our results as an important observational test for calibrating the theory of stellar magnetic field formation and evolution.

本文介绍了Orion OB1关联中15b亚群1b的化学特异（CP）恒星的磁场测量结果。我们发现，在这15个CP恒星中，具有强磁场的恒星所占比例几乎是1a亚组的两倍。随之，子组1b的年龄估计为2 Myr，子组1a的年龄大约为10 Myr。平均均方根磁场\（\ left \ langle {{{B} _ {e}}} \ right \ rangle \）（全部）子组1b中的恒星比子组1a中的恒星高2.3倍。得出的结论属于B和A恒星大磁场的化石起源概念，但随着年龄的增长，磁场减弱的速度异常高。我们将我们的结果作为校准恒星磁场形成和演化理论的重要观察测试。