Main sequence

On a graph of output power, also known as luminosity, versus the surface temperature, the sun currently lives here.

The sun's location is a fairly ordinary place to live, with many stars inhabiting this diagonal line which is known as the main sequence.

But as we march forward in time, the sun will eventually depart.

The sun began life with being about three quarters hydrogen by mass, much like the rest of the universe.

Now, many of you have probably heard that the sun will one day become a giant star.

But this is not that, at least not yet.

The Sun here is still classified as a normal star, moving slightly up the main sequence as it ages.

Flash forward 5 billion years into the future and the Sun finally starts to leave the main sequence.