We report follow-up observations of the Crab Nebula with the PolarLight X-ray polarimeter, which revealed a possible variation in polarization associated with a pulsar glitch in 2019. The new observations confirm that the polarization has recovered roughly 100 days after the glitch. With the new observations, we find that the polarization angle (PA) measured with PolarLight from the total nebular emission has a difference of 18.0 4.6 from that measured 42 yr ago with OSO-8, indicating a secular evolution of polarization with either the Crab Nebula or pulsar. The long-term variation in PA could be a result of multiple glitches in the history, magnetic reconnection, or movement of synchrotron emitting structures in the nebula, or secular evolution of the pulsar magnetic geometry.

我们报告了使用 PolarLight X 射线偏振计对蟹状星云的后续观测，这揭示了与 2019 年脉冲星故障相关的偏振可能发生的变化。新的观测证实，偏振在故障发生大约 100 天后已恢复。通过新的观测，我们发现使用 PolarLight 测量的总星云发射的偏振角 (PA) 与 42 年前使用 OSO-8 测量的偏振角相差 18.0 4.6，表明蟹状星云的偏振长期演变或脉冲星。PA 的长期变化可能是由于历史上的多次故障、磁重联或星云中同步加速器发射结构的移动，或脉冲星磁几何结构的长期演化。