A common feature of magnetars is the “glitch,” an event that causes a sudden increase in spin. Scientists have seen hundreds of glitches and have a plausible model for how they occur based on the frictionless neutron superfluid believed to be at their center.
On April 28, 2012, astronomers witnessed the first sudden slowdown from a magnetar, 1E 2259+586. It’s been dubbed the anti-glitch. It was wholly unexpected and doesn’t fit into any current theories.There are clues that may help. A week before its anti-glitch, the magnetar unleashed an intense burst of X-rays that is most likely connected to the slowdown.
One mystery that was recently solved was the existence of CXOU J164710.2-455216 in the cluster Westerlund 1. The supernova it came from was around 40 times the mass of the Sun, so it shouldn’t have left anything but a black hole. The leading theory was that there had been a binary system which interfered with the normal mechanisms. Scientists found a “runaway” star nearby that looked exactly as predicted.