The Life Cycle of a Star
Free printable life cycle of a star diagram — from a nebula to a main-sequence star, and the two paths for average and massive stars. Download a high-resolution PDF or PNG for Letter paper.
The stages in a star's life
Stars are born, live for millions or billions of years, and then die. How a star ends its life depends on how big it is. Here is what happens at each labeled part of the diagram:
| Stage | What it does |
|---|---|
| Nebula | A giant cloud of gas and dust in space where stars are born. |
| Protostar | The gas and dust pull together and heat up, forming a young star. |
| Main-sequence star | A stable, shining star — like our Sun — that burns for billions of years. |
| Red giant or supergiant | As it runs out of fuel the star swells up: average stars become red giants, massive stars become red supergiants. |
| Planetary nebula → white dwarf | An average star gently sheds its outer layers, leaving behind a small, dense white dwarf. |
| Supernova → black hole | A massive star explodes in a supernova, and its core can collapse into a black hole. |
Companion worksheet
A free fill-in worksheet with an answer key, built from the labels above — students match each stage to its description, then answer a couple of short questions. Great for a quick check after using the diagram.
How to print
Choose Download PDF for a ready-to-print file that fits US Letter paper (8.5 × 11") in landscape, or Download PNG for the high-resolution image.
Frequently asked questions
What is the life cycle of a star?
A star begins in a nebula, becomes a protostar, then a main-sequence star. An average star later becomes a red giant, then a planetary nebula and a white dwarf. A massive star becomes a red supergiant, explodes as a supernova, and may form a black hole.
What will happen to our Sun?
The Sun is an average star. In billions of years it will become a red giant, then shed its layers as a planetary nebula, leaving behind a white dwarf.
What paper size should I print this on?
The diagram is sized for standard US Letter paper (8.5 × 11") in landscape orientation. Use "Download PDF" for a print-ready file that fits the page automatically.