#Keyframer
There's no explicit way to delete elements in the KF, but here's a workaround
for you.
Once you've found a frame that lets you see a star element that you want to
remove, do an Object/Snapshot. This will make a new ROTATED object in the
Editor. Now, Hide your original star cluster object.
Next step is to position a cube object over the element in the new snapshotted
object that you want to delete. Go back to the Editor and the cube will act as
a 3D cursor for ya. Delete the element, go back to the KF, and Unhide the
original object. Now, copy the animation from the first star cluster object to
the new snapshotted object and you should be back in business.
– G