Not necessarily - as Fractal said, they can be moved now - but make sure you keep it well watered, especially if you don't get rain soon.

The best time to divide and transplant Asters is March before new growth starts. This applies to most herbacious plants.

If the ground, is ok and not frozen, then this task can be carried out from now untill March/April, i have some large herbacious borders on my allotments and has a rule i always do mine in November, but on other occaisions have divided many different perennials in the winter months. julien