Do all stars in the universe shine?
No. Not a stellar expert here, but stars come in all sizes and colors. Red giants, main sequences, blue normals, white dwarves, super novas, and others. White dwarves are smaller than planets and invisible without a telescope. The Dog Star is an example of this, but somehow the Dogon tribesmen of Africa have known of its existence without telescopes for some time, and its exact position in earth’s sky. Black holes are invisible even with the most powerful telescope, and their exisistence was proved mathematically by Stephen Hawking.
