Sometimes, there are questions on here about undergraduate students publishing research (see here, here, and here). The answers don't seem particularly surprised that this is happening or try to dissuade the asker, they treat it like a normal question.
In my entire life, I've never heard of undergraduates publishing results apart from a handful of examples from famous science prodigies.
Furthermore, my experience of undergraduate was not conducive at all to publishing. I graduated from a mediocre UK university, and there was no original research done at all. Undergraduate is for getting you up to speed on the foundations of a field, preparing you for postgraduate where you study one sub-field, then a PhD where you push the boundaries of a sub-sub-field.
The questions linked above give advice like, "Discuss it with your supervisor". But as far as I'm aware undergraduates don't have supervisors.
Is this really as common as it would seem from questions on here? Is it a regional thing? Something that happens only at top universities?