This does appear to be rust on your aster. This pathogen requires two host species to be present to survive. Pines and aster or golden rods. "Pine needle rust needs both pine and either golden rod or asters to complete its one-year life cycle. The spores that are produced on pine do not infect pine but will infect goldenrod or aster, and only spores produced on these alternate hosts can infect pine. Without the alternate host, the fungus will not be able to complete its life cycle." As long as you have both in proximity, you may be subject to this pathogen in the future. It's typically more impactful on young pines and Scotch pines.  Other than separating these hosts from each other, no management is necessary. You can read more on the topic here:

https://extension.umn.edu/plant-diseases/pine-needle-rust

https://www.canr.msu.edu/news/rust_on_pine

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/rusts/pine-needle-rusts