How many Astronomy journals with no APC in Russian are there?

This directory lists 2 Astronomy journals with no APC in Russian. Every listing has been filtered to journals that charge no article processing charge.

Do these journals really charge nothing to publish?

Yes. Every journal listed charges no article processing charge. Some journals may still levy other fees such as submission or page charges — those are shown separately on each journal page, and you can filter to journals with no other fees at all.

How do I choose between these astronomy journals?

Start with scope fit — read the aims and scope and the two most recent issues. Then check the indexing databases your institution recognises, the peer review model, the licence, whether you keep copyright, and whether articles receive DOIs and are preserved long term. Every one of those is shown on each journal page here.