Agree - those attributes are definitely “low level” and not idiomatic in most situations. I must have missed them skimming that file.

For the particular case of n-body you could argue you are already in a pretty extreme HPC world and doing it without vectors would basically be a toy calculator. The problem then of course that C# isn’t really ever idiomatic for that. The question (as alaways) becomes about what to compare. Typical or pushed to the limit.