Of course there are both stars and bats. Electromagnetic radiation is emitted, mosquitoes are eaten, and it doesn't matter the tiniest bit that we say so. I don't fully understand how the North American power grid works--nobody does in full--but that doesn't mean there is no North American power grid.

Stars are there, completely independent of our necessarily limited conceptualization of them. They go on converting elements without us needing to name them. You're completely mistaking the map for the territory when you say that there are "no stars".

Furthermore, you botch all of objectivity when you equate objectivity with "collective conceptions". There are lots of ways to have a collective conception that doesn't involve anything objective at all (save us objectively agreeing: but it is the fact of the agreement which is objectively the case, not that whatever we agree on is objectively true). The point of objectivity isn't that everyone agrees--indeed, piles of people fail to accept all kinds of objectively true things. However, because most of us have extensive experience with things like walls, appeal to objective reality (e.g. walls) is one of the best ways to get a collective conception.

Science is like art in the same way that a paintbrush is like the store of human knowledge. The choice of how to use the paintbrush to create art has a subjective component, just as does the choice of how to use science to enlarge the store of human knowledge. But the knowledge generated by the tool (if applied well) is no more subjective than the paint on the canvas is.

The subjectivity lies in decisions like, "We want to recover a tiny dangerous radioactive capsule lost who knows where, just in case it ended up somewhere where it could hurt someone." We could just as well say, "Nah, who cares?" Or "If it badly injures someone, that's how we'll find it!" But collective agreement isn't what lets you find a one-in-a-trillion tiny little rock-like-thing lost somewhere in a vast area among all the others. It's actual impartial human-independent objectivity that we used to construct tools that exploit those regularities and allow us to do things indistinguishable from magic: https://www.bbc.com/news/world-australia-64483271

For all your words about enslaving nature, you sure don't do a very reliable job at relating why the method works to enable enslavement, if that's what we decide to do with it.