The physics courses I took (in both high-school and college) didn't generally deal with astronomy. Not sure how common that is. Instead they covered mostly "foundational" topics: general & special relativity, electricity & magnetism, mechanics, atomic structure, etc.
I think your experience is pretty typical. I had the same. I took what was technically considered a college-level physics course in high school, and we never really delved into astronomy. Only in college itself did the subject start to come up, and that's because I selected those classes.
I suspect this is because the US high school education system has a fairly standardized, one-size-fits-all curriculum. There are some allowances and exceptions, of course. But, for the most part, everyone is going to be covering roughly the same material. And astronomy isn't deemed as necessary, for the beginner, as some other rudiments of physics. College, on the other hand, offers more opportunity for individual choice in one's curriculum.
I had the same situation in college as well, though that could be because I went to a somewhat unusually set up science/math uni (hmc.edu), in which all majors had to take a science/math "common core". There were 3 required physics classes for non-physics majors, which were these, going pretty in-depth into physics but still not covering any astronomy: http://physics.hmc.edu/course/3/, http://physics.hmc.edu/course/46/, http://physics.hmc.edu/course/4/
Astrophysics is generally popular among students, but afaict it hasn't been included basically because the physicists consider the above three courses to be higher priority.
