You are now the proud owner of Star In A Box.
Inside this box you can animate the different stages in a star's life and see how its brightness, size, and mass change with time.
Once you've opened the box just click the play button to start animating.
Star in a Box allows you to explore one of the most enigmatic tools in astronomy - the Hertzsprung-Russell diagram.
When you first open the box you start with a star with the same mass as the Sun. The tracks that you see on the diagram to the left map the lifecycle of the star. You can use the Star Properties tab to choose a star with a different starting mass or to jump to particular stages. You can play the animation of the star moving around the diagram, and see how its brightness, size, surface temperature, and mass change in the panels on the right.
Stars can take billions of years to go through their lives with the dramatic events taking place in relatively short periods of time. In the animation we speed up time when the star is not really changing much and slow things down for the dramatic phases of the star's life.