The Motion of RX J185635-3754

This photograph is the sum of three Hubble Space Telescope images. North is down, east is to the right.

All stars line up in this composite picture, except the neutron star, which moves across the image in a direction 10 degrees south of east. The three images of the neutron star are labeled by date. The proper motion is 1/3 of a second of arc per year.