Research over the last 200 years suggests that half or more of visible stars are part of multiple star systems.
I apologise for the number of assumptions in my question but, because of the numbers of binary systems involved, I feel this "what if" type question may be a plausible physical outcome in some binary star systems.
Assume both stars were born at the same time, with approximately the same mass, but spinning in opposite directions. I don't know enough about stellar evolution to say whether this is feasible, but we do know binary star systems exist and they must have some chance, over time, of reaching similar angular momentum values, occasionally in oppositely rotating directions.
My questions are, assuming they are close enough, will this eventually result in a slowdown in their rotations, followed by mutual tidal locking?
If this occurs, and the mass of at least one star is large enough, could we then have a stationary neutron star or black hole?
I realise that the process of creating the dense star will occur after a supernova explosion, which will most likely vaporise the other star in the system.
I note there are related questions such as Binary Star System but I can't immediately see a duplicate of my question.