1. Constellation Project Information
Life Cycle of Stars
Constellation Project
Information

2. How Stars Begin…
Inside vast clouds of gas and dust floating in space, gravity causes the denser areas to pull together, or coalesce.
These clouds are called nebulae.

3. Crab Nebula

4. Cat’s Eye Nebula

6. As the nebula starts to spin…
Gravity compresses the gas and dust into a spinning disk with a bulge in the middle.
A warm protostar forms as the center collapses under its own gravity.

7. The protostar radiates heat and ejects matter from its poles.
Eventually, fusion begins in hydrogen gas at the core and the star begins its life.

9. The disk either disperses or forms planets

11. Not all stars are the same:
Stars exist that are significantly larger and significantly smaller than our sun.
Not all stars have planets.
Some stars are older than our sun and some are younger.

12. The Hertzprung-Russell Diagram
Built to show the relationship between absolute magnitude, luminosity, classification and effective temperature of the stars.

13. Many variations exist..
Notice the spectral classes at the bottom and their relationship to surface temperature.

14. This version also includes the red and blue giant regions.
Be sure to compare your stars to the Sun.

15. How Stars End Stars burn until they use all their nuclear fuel.
Different size stars evolve differently.
The larger a star, the hotter, brighter and shorter lived it is.

16. A Star the Size of Our Sun
Burns for 10 billion years
Star exhausts its hydrogen and swells into a red giant.
Core collapses. Nuclear reaction blows off the star’s surface.

17. Blown-off gases form a glowing nebula.

18. The core of the star collapses into a white dwarf star.

20. When our Sun becomes a red giant its size will interfere with the Earth’s orbit.
We’re about 4 billion years from when that will occur.

21. A Star 10 x the size of our Sun
Burns out in 20 million years
Bright, hot, blue star uses up its hydrogen fuel, swells into a red supergiant.
It is 5000 x more luminous than our Sun (see comparison in the two pictures)

22. When nuclear reactions cease, the core collapses and the star explodes in a brilliant supernova.

25. If the star explodes with enough force, much of its mass is hurled into space, leaving behind a small, dense neutron star.

26. A Star 30 x the size of the Sun
These stars can exhaust their fuel in as little as 1 million years.
This large star is one of the most luminous in the universe.
It expands into a red supergiant and ends in a powerful supernova explosion.

27. Its huge core collapses past the neutron star stage and becomes a black hole
This is a dense, heavy structure whose gravity is so strong that not even light can escape from the interior.

28. An artists representation

29. I love this picture of a black hole seemingly devouring a nearby star.
Notice the X-ray emissions of the black hole showing how matter is changed into energy.

30. Works Cited Rand McNally New Concise Atlas of the
Universe, “The Universe Explained;
The Life and Death of Stars”