The Crab nebula is so far the only celestial object with a statistically significant detection in soft X-ray polarimetry^1,2,3,4, a window that has not been explored in astronomy since the 1970s. However, soft X-ray polarimetry is expected to be a sensitive probe of magnetic fields in high-energy astrophysical objects, including rotation-powered pulsars^5,6,7 and pulsar wind nebulae⁸. Here we report the re-detection of soft X-ray polarization after 40 years from the Crab nebula and pulsar with PolarLight⁹, a miniature polarimeter utilizing a novel technique^10,11 onboard a CubeSat. The polarization fraction of the Crab in the on-pulse phases was observed to decrease after a glitch of the Crab pulsar on 23 July 2019, while that of the pure nebular emission remained constant within uncertainty. The phenomenon may have lasted about 100 days. If the association between the glitch and polarization change can be confirmed with future observations, it will place strong constraints on the physical mechanism of the high-energy emission^12,13,14 and glitch^15,16,17 of pulsars.

迄今为止，蟹状星云是唯一在软X射线旋光法^1,2,3,4中具有统计显着性的天体，这是自1970年代以来从未在天文学中探索的窗口。但是，软X射线极化法有望成为高能天体物体（包括旋转动力脉冲星^5、6、7和脉冲星云^8）中磁场的敏感探测器。在这里，我们报告了使用PolarLight ⁹（一种利用新技术^10,11的微型旋光仪）从蟹状星云和脉冲星重新探测了40年后的软X射线偏振在CubeSat上。在蟹脉冲星在2019年7月23日发生毛刺后，观察到在脉冲相中蟹的极化分数降低，而纯星云发射的极化分数在不确定性范围内保持恒定。这种现象可能已经持续了大约100天。如果毛刺和极化变化之间的关联可以通过未来的观察得到证实，它将对脉冲星的高能发射^12,13,14和毛刺^15,16,17的物理机制施加强大的约束。