Caption: The stellar evolution on the Hertzsprung-Russell (HR) diagram of a star of stellar mass ∼ 1 solar mass M_☉ = 1.98855(25)*10**30 kg (e.g., the Sun) from the zero-age main sequence (ZAMS) main sequence to the end of nuclear burning lifetime: i.e., the end of its post-main-sequence evolution.

Features:

1. The horizontal axis is photospheric temperature in kelvins. Following HR diagram convention, it is a wrong-way axis with photospheric temperature increasing to the left. Not following HR diagram convention, the horizontal axis is NOT a log scale.

2. The vertical axis is a log scale for luminosity in units of the solar luminosity L_☉ = 3.828*10**26 W.

3. The stellar evolution phases shown and some NOT shown on the HR diagram are:
   1. zero-age main sequence (ZAMS).
   2. main sequence.
   3. subgiant.
   4. red giant.
   5. core helium flash.
   6. horizontal branch.
   7. asymptotic giant branch.
   8. planetary nebula.
   9. white dwarf: The star moves to the blueward to higher temperature then dives to much lower luminosity and becomes a hot young white dwarf. Then it slowly cools moving redward to lower temperature.
   10. black dwarf: In the far future, billions of years (i.e., gigayears) from now, the white dwarf cools to be a nearly invisible black dwarf. One estimate (which has great uncertainty) gives 10**6 gigayears for a white dwarf to cool to 5 K which will make it very nearly invisibly dark (see Wikipedia: Black dwarf: Formation).

Credit/Permission: © User:Lithopsian, 2013 / Creative Commons CC BY-SA 3.0.
Image link: Wikipedia: File:Evolution of a sun-like star.png.
Local file: local link: sun_evolution_hr.html.
File: Sun file: sun_evolution_hr.html.