as inconstant as the North Star?

Polaris (North Star) has a few setbacks, one of them is that it won't be in the same place every night, this is because Earth is wobbling on it's axis. The next time that anyone will see Polaris in the same spot in the sky is in 26,000 years! Polaris is always either brighter or less bright ever night it never stays at the same brightness, so one day you may not know that it is the north star, and other days you will know.

To measure celestial objects you use magnitude, in 120 BC they created the system and it is still used today! They created it by dividing the stars into 6 categories, or magnitudes, it ranged from dimmest to brightest. They called the brightest, magnitude 1, and the dimmest magnitude 6. In magnitude 1 the stars are 2.5 times brighter than he 2nd category every group is brighter than the next group.