I know that stars somewhere btw 1-2 solar masses will go through a giant phase and then peter out into a white dwarf.
But there's a diagram that sort of looks like a toddler scribbled on a wall...
here: https://en.wikipedia.org/wiki/Stellar_e ... ack_1m.svg
... and it shows a star spiking in luminosity and then dropping back down again quickly, then wobbling its way back up.
My question is whether the star's radius is always proportional to its changing luminosity. Does it shrink in size during the "red clump" stage as listed on the diagram?
Also there's no sense of time associated with that diagram, so I'm not sure how long any of those sub-phases of the giant phase actually last.
One last interesting (to me) note: that a white dwarf is apparently the hottest phase of a star's life, if I'm reading that diagram correctly.