The Suns next stage is to get hotter and slightly increase in size.
In about 4.5 -> 5 billion years, it will have used up all of it's hydrogen, and will begin to fuse helium in it's core. Due to this, it's outer envelope will have expanded almost to the edge of the Earth.
Don't worry - we will all be dead by then.
After another billion years, the Sun will shed it's outer envelope as a planetary nebula and settle down to a retirement as a white dwarf for quite a few billions of years.
red giant
it is fusion of hydrogen into helium. (like our sun) if it is a red giant (the next stage of our suns life) it is burning helium into denser things.
The next stage in the Sun's evolution is the red giant phase. This occurs when the Sun runs out of hydrogen fuel in its core and starts burning helium. During this phase, the Sun will expand and become larger, eventually engulfing Mercury, Venus, and possibly Earth.
For a star like ours, the black dwarf stage For an immensely massive star, a back hole.
The next stage of the Sun's life cycle will be its transformation into a red giant. As the Sun exhausts its hydrogen fuel in the core, it will begin to fuse helium and expand significantly, engulfing the inner planets, including possibly Earth. Eventually, it will shed its outer layers, creating a planetary nebula, while the core will remain as a white dwarf, marking the final stage of its evolution.
White Dwarf then Black Dwarf=Dead Star
next stage
Alan Rickman's next appearance on stage should be the next harry potter book.
Basically there is no "next stage". Well, it is believed that a black hole will evaporate, but that will take a long, long time.
Plumage
It will expand and become a red giant
For a star like ours, the black dwarf stage For an immensely massive star, a back hole.