In Europe there are no or hardly any part-time PhDs in astronomy. There used to people that would be on the dole until they finished the PhD. Strickter funding and other rules put mostly an end to that.
Of course there is a PhD comic on the topic.
Not so in the USA where not only do the students pay for the classes but it strongly depends on year-to-year funding. So many people do a phd on the side. Next to a full time job.
So how to set that up? The research part of a phd is a lot harder to do part time. It’s deep work. Hard to get back into after distractions. The kind you do while concentrating on a topic for a long time.
I may now have one or two people who will do a phd with me over many years. Does anyone have experience with the part time PhD student? And how to help them over the finish line?
No idea yet.