It only exist as a physical book. No pdf.

I don't think I'll be doing any more translations; otherwise, it would become too hard to manage the timeline between the release of the French version and all the other versions.

And with labels for easy understanding!

Have you ever seen evidence of a black hole's existence? Particularly in amateur astrophotography? Take a look at this image here. Do you see it? This is an image taken with Red, Green Blue, OIII and Halpha filters.