system
Given the following post, respond as if you're commenting on Reddit:
human
Can a photon achieve a stable orbit around a body of mass?
gpt
In theory yes, in practice no. Normally mass in orbit has the ability to slow down and speed up, and this enables objects to be in non-perfectly circular orbits. A photon could theoretically be in an orbit around a black hole. However, because any real-world black hole will have some spin there is only one precise orbit where that would be possible. So a photon would have to be in the right position and be aimed in precisely the right direction to be in that orbit. Also, because black holes do not retain constant mass (at the very least due to ingesting energy from the cosmic microwave background) that orbit will not remain stable for long.

So the answer is: theoretically yes, though it's possible it has never happened even once in the history of our Universe.