Looks like an Erigeron. I don’t know which ones would be in your region.

Compare to Erigeron species. There are many of them.

Thanks! I decided to pull them up. There might be a place for them somewhere in my yard, but definitely not where they sowed themselves.

This is Erigeron canadensis. The only species in New York that has tightly packed serated leaves at the top near the flowers. The others, anuus, philidelphicus, pulchellus, and strigosus have fewer leaves near the top with smooth margins.