Stars are hot and produce light before they start to burn Hydrogen into Helium using fusion. Variable Stars result from an instability in the way the shells where fusion is occuring in the star burn. State a way a variable star might change periodically that results in greater and lesser amounts of light coming from the star. Degenerate Electron pressure holds up white dwarf stars. Explain how this makes the star stable and not prone to the dramatic expansion and collapse phases that it underwent when it was still using fusion to produce energy.
Neutron stars are the size of mountains and weigh as much as a star.
For a very large black hole of the type thought to occupy the centres of galaxies the tides near the event horizon are too weak to harm a space traveller.