The most infamous concentration camp was located at berlin hamburg auschwitz warsaw

The correct answer is Aushwitz. That's the camp from all the pictures with the famous sign on the doorway. Other famous ones were Mathausen, Dahau, and many more, but none were as famous for their cruelty as Aushwitz. There are many movies that faithfuly replicate the horrors seen in there.

Pilgrims is the answer

White dwarf is very hot, but also very small and that is why it may appear dim.