I can give you an overall idea of the poem's course of events, but you'll have to do some of the work on your own. The poem's narrator is sitting in a lecture, listening to an educated astronomer discuss the analytical and mathematical subjects of stars. He looks at charts and diagrams and proofs and figures, and essentially finds it all to be a bore. He doesn't feel connected to the contents of the lecture until he is able to leave at the end of the lecture and sit outside, staring at the stars silently. There, he is able to experience something that you couldn't learn in a lecture, as the learned astronomers only account mathematical figures. Overall, it's an experiential learning that he is connected to. A matter of wisdom over knowledge.
I hope this helped, even if it's just a little bit. Good luck!