Why is that ironic?
replyYou're just pointing out that there are tools to automate this.
Why any less effort? Masking the stars out and masking them in should take the same amount of time and effort.
replyFrom the article:
reply> Much of the time was spent painstakingly erasing stars, to reveal the satellites.
Many more stars than satellites in every frame. Erasing a couple satellites at most is quick. Erasing every star in the sky and keeping a couple satellites is not.