I thought asters bloomed in FALL
I think your asters are Alpine Aster (Aster alpinus), which actually bloom in late May/June (April/May here in zone 9). I also bought a pink one recently (the variety is called Happy End).
Being spring bloomers, I don't think Alpine Asters will flower again in Fall. They will maybe do in Spring, but this is too a curiosity of mine.
Ciao!

I was forgetting. I don't see any reason why your asters won't bloom next Spring.

Grazie, Alchemilla! Now I'll move them where they will look good in the spring!

It's now Nov, my first-year dwarf asters (which didn't fare too well) are pitiful stalks of brown foliage with a very few spent blooms. Do I prune them down now?

Mine aren't dwarf but the regular ones. I just cut mine about 1 inch to the ground. No idea if that's the right way to do it but they looked so awful. If they don't come back, oh well.