While camping, I noticed that if you look long enough at almost any star, you start seeing some tiny, subtle colors in that star. Even crazier, they sometimes flicker between more colors. In my case orange, blue and something like cyan.
Besides constellations, what else could you observe regarding starts, with the naked eye?
That isn’t really observable to our naked eye though, that’s Doppler shift and is the same thing that makes a sound change pit h if it’s coming towards you or away from you (think of a siren as a cop car passes you). The Doppler shift, or redshift of stars and other celestial objects is how the expansion of the universe can be observed and measured.