can anyone help?

hi all, i am looking to go to oslo for the first time in feb. I hear that oslo torp airport is miles away from central oslo. i am looking to stay at the Sentrum Pensjonat which i gather is close to the central station. my flight lands late at 21:00 and i wondered if anyone new if there is a train from the aiport to the central station that would operate at this time?

I would appreciate anything that anyone know about this and thanks again