Could you have authority but not power? How?

It is possible. It's kind of like with presidency because even though he/she is the president. He/she will still have to go through others opinions to have the say on what their wanting to do. Being president doesn't mean you can do anything with the country. Your ideas/plans still have to go the Supreme Court or someone

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