Many years ago, I implemented star tracking for telescope alignment for auger.org. An actual basic version using libnova et al was pretty straightforward and a

Many years ago, I implemented star tracking for telescope alignment for auger.org. An actual basic version using libnova et al was pretty straightforward and a matter of days to prototype if I recall correctly (it was a project for a master student, so I had to do most of the work over a longer period of time). I think the accuracy was around a decimal fraction of a degree then. But the cameras of that thing have only 440 1.5° pixels (photomultipliers that sample at 5-20M samples/s). A higher resolution camera could probably do much better assuming you have a very accurate computer model of the optical properties of your telescope/lenses/camera.