The flowers are about 1 to 2 inches wide.
About 2 to 3 feet off the ground.
Edited: my memory is going. I originally claimed the flowers were 2 to 3 inches wide when in fact they are maybe 1-1/2 inches wide! Sorry for any confusion.
I've seen pics of asters and thought mine had too many petals to be one. But now that I've searched specifically for asters, there seem to be lots of pics of them with this many petals.