Excuse me if this question is too elementary for this forum, or in the wrong forum - I'm a newbie here.
How do astronomers initially determine the RA of a star, for star catalogues and nautical almanacs for example? While I believe I understand RA, I don't know how it is figured to begin with. I was surprised that I can't find the specific answer to this anywhere using google.
Is it done with transit telescopes and measuring meridian crossing times? And if so, as a secondary question, how can astronomers catalogue so many millions of stars with their accurate RA and Dec? It would appear to be almost impossible to do this manually.