From the main menu, click "GMOS - MMS - Convert OT fits to Catalog - Load Fits from file".
A pop-up window will appear. Select the Object Table file corresponding to the current image displayed (e.g. mask_OT.fits) then click "OK" (this may take a few seconds).
Another window will appear (shown below) which contains the Object Table. Let us call this the catalog window. This window is like a standard Skycat display which an extra two rows of new buttons along the bottom.
As soon as the catalog window is loaded, shapes appear over objects in the displayed image. This maps the assigned priorities of the objects with different shapes and colors representing a different priority object. This will be explained in more detail later.
NOTE: Do not manually edit the catalog
file (*.cat) - always manipulate the FITS Object Table,
e.g. mask_OT.fits.