A series of three images taken of the Crab pulsar and surrounding region. If you look closely at the images, you will see a couple of features that change over this time frame. Note especially the thin white streak a little over one-third from the bottom of the middle image, and a little over one-fourth from the bottom of the lower right image. It appears much like a wave in a pond.

A close-up of the Crab Nebula pulsar and a diagram identifying the features seen. Note that these images have been rotated 90 degrees clockwise from the above images.