I am looking for references on the automorphism group $\mathrm{Aut}(X)$ of a compact abelian group $X$. By automorphisms I mean topological group automorphisms. Some particular questions are as follows. How can $\mathrm{Aut}(X)$ be given topological structure? With this structure, can one approximate an automorphism by periodic automorphisms? When is a conjugacy class dense in $\mathrm{Aut}(X)$? Noting that automorphisms of $X$ preserve Haar measure, what ergodic-theoretic properties are generic in $\mathrm{Aut}(X)$?
I am most concerned with the case of a general abstract compact abelian group $X$, but I would also be very interested in references for specific $X$, even the circle.