I did an imaging session last night at a clear sky. The session was aborted by a post meridian flip align failure, I had not the align log activated, so I cannot say what the root cause might have been.

My question to the experts: Is a meridian flip ALWAYS needed if the object starts east and ends west of meridian or can it be avoided under specific circumstances? If so, which are the prerequisites under which the flip can be avoided (geometry/equipment setup)?

Thanks for your insights!