Introduction
The Life Cycle of a Star
to find out about Star Birth
to find out about the Main Sequence
to find out about the Death of a Star
Task
Classify pictures of BIG stars from birth formation to stellar death and write a detailed description of how you determined this sequence.
Process
- (unsequenced large star cycle page) shows eight NASA images from the Hubble Space Telescope (HST). These are pictures of the formation sequence of really BIG stars.
- Your FIRST task is to figure out and record the correct sequence of pictures from birth formation to stellar death. Pay careful attention to how you determine the sequence because your SECOND task is to write a detailed description so clear that other students will understand it, and be able to use it as a model to come up with the same sequence. Each picture is hyperlinked to a description of the picture for background information IF you need it.
- THIRD, check your sequence with the expert sequence (sequenced large star cycle page) and propose reasons for any discrepancies.
- FOURTH, and most important, write a paragraph or two that describes the sequence of stellar formation, life cycle, and death. Use sketches or pictures from the WWW to support your description.
Evaluation
Conclusion
Stars are born in nebulae. Huge clouds of dust and gas collapse under gravitational forces, forming protostars. These young stars undergo further collapse, forming main sequence stars.
Stars expand as they grow old. As the core runs out of hydrogen and then helium, the core contacts and the outer layers expand, cool, and become less bright. This is a red giant or a red super giant (depending on the initial mass of the star). It will eventually collapse and explode. Its fate is determined by the original mass of the star; it will become either a black dwarf, neutron star, or black hole.