Execute this command from the Process menu or from the Animation Pane by
right-clicking the 
button and then
using the menu command.
Align on Point
The Align on Point command accurately registers an Image Set by shifting the images relative to a point source, such as a star. Images aligned by this method should have no significant field rotation or difference in image scale. If these requirements are not satisfied by the Image Set, or you need to align on an extended object, see the other alignment tools listed below.
Execute this command from the Process menu or from the Animation Pane by
right-clicking the button and then
using the menu command.
This command has no dialog and is available only when an Image Set is opened in the top-most window.
This command aligns on a precise coordinate by computing the centroid position near where you click on the first image. It then tracks the centroid position through the image stack in order to determine the offsets needed to bring the images into alignment. This uses the "global" centroid command, which is the same one used in the Measure menu and the Image Toolbar. Therefore, the centroid settings are taken from the current parameter profile in the Default Centroid Properties dialog.
Make the target image window the top-most window.
Execute this command from the Process menu.
Click the mouse on the reference point that is to be aligned in all images.
If you do not like the result, use the Undo command to remove the alignment.
There are two other image alignment methods available:
Align on Object: Use this command when the alignment object is extended, such as a planet, galaxy, or nebula.
Register Images: Use this command when one or more of the images differ in scale or rotation, or have other deformations like non-square pixels or non-perpendicular axes.
Image Geometry Commands, Align on Object, Register Images, Aligning Images