This movie shows 10,000 stars of various masses evolving together to create a fireworks display of novas and supernovas, leading to a lovely flow into a population of white dwarfs below the main sequence.   To learn more, visit the Digital Demo Room (DDR) created by Charles Gammie and friends, which includes a stellar structure and evolution simulator that achieves great speed by replacing detailed simulations with analytic formulae for approximating the evolution of a wide range of initial masses.   As a result, you can get an overview of the simultaneous evolution of a large number of stars by looking at movies showing them dancing over the H-R diagram.   It is wonderful for getting a general feel for the global flow of stellar evolution.   Then if you want more details about the inner workings of some particular star, you can use EZ to get at them.   By the way, one of my favorite features of the site is the ability to get very fast turnaround on new movies created to your request.   For example, go to the "Intermediate Level" page and enter star masses of 7, 8, and 9 for a combined run.   After you hit submit, it takes less than a minute to generate a movie for the 3 stars, which you can then watch by clicking on the "View Movie Here" link.   Here's the result: 7-8-9 movie.   The stars move off the main sequence and take turns rushing across the Hertzsprung gap, backing up on a "blue loop", and then forming a nebula or exploding in a supernova.   What fun!   Then check out the pdf files I made with data from EZ for the same mass stars (7, 8, and 9).