The Fate of Stars 1

Went on my evening walk re-listening to another astronomy lecture on “The Fate of Stars”, about what happens to a star when it leaves the main sequence of the HR Diagram, and also emission and reflective nebulae: Young hot stars with temps of 13,900C excite the atoms and cause them to re-emit the UV light that they absorb when they cascade down to a lower energy state drive emission nebulas. Reflective nebulas, on the other hand, are particle clouds near a star with a temp less than 13,900C and the light is reflected. The emission nebulas are the most colorful.