Frog Rock Observatory - Ring Removal

One method for ring removal

*NOTE: This method only works if there is black sky around the star with the halo.

Original image with halo around fairly bright star.
Using the Elliptical Marquee tool, select just enough to cover the halo. press Ctrl + C to copy the selection, press Ctrl + V to paste.
Set the layer blending mode to Linear Burn.
An option is the opacity slider to better match the background around the star.
Flatten the image before going on to the next halo or saving the final image. Use the clone or healing tool to clean up any residual noise that is left

A cool tip shown to me by
John Sarkissian , double click anywhere on the work area of Photoshop to bring up the Open dialog box.