Stock 1 is an open cluster in Vulpecula. It isn’t a common target for amateur astronomers and that seems a bit of a shame since between the hot blue photogenic stars and the dense star field with dust int he background it makes an interesting subject!

Being relatively obscure to amateurs there isn’t much reference data. According to this paper it is estimated to be around 300 million years old. The paper does not give a distance t the cluster, at least not in any units I know how to interpret.

This is 9h of RGB data. For all the technical details, see astrobin.