This is a picture of the Crab pulsar taken at the Leuschner Observatory by Dick Treffers. The image was taken through a 30-inch reflector with a CCD camera equipped with a rotating wheel. The wheel has a 90-degree clear sector, and was spun at the same frequency as the pulsar flashes (29.9 Hz). Each sub-image shows the pulsar at one particular phase, and the phase is advanced by 45 degrees from sub-frame to sub-frame. Each sub-image took one minute of integration time. You can also look at a FITS version of the image.