http://bbms.bigbear.k12.ca.us/KASTLE/derekk/starhp.html |
 Thanks to http://bbms.bigbear.k12.ca.us/KASTLE/derekk/starhp.html Short animation movie with captions of a stars life cycle up to the point where the star could either explode and form a supernova or collapse into a white dwarf or a neutron star. |
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This image shows the life cycle of stellar evolution. We'll start with the
image in the middle of this diagram. Stars form in
nebulae
across the universe. The hot and cool gases inside the nebulae evolve into stars.
The stars live for millions of years, burning hydrogen in their cores. Once all
of the hydrogen is used up, the core starts to use helium as its fuel. In turn,
the star gets bigger and bigger. The hydrogen is now around the core in a shell.
The helium in the core is converted to carbon, and when there is no more helium
to convert, the helium forms another shell around the core. Now the star starts
to shrink and the density gets greater at the core.
The star has expanded again and has gotten bigger than the first expansion phase.
It is now a Red supergiant star. The star now has two possible paths; either
explode or keep condensing until it becomes a
white dwarf. In this picture, on the right side, the star ends its life in a huge supernova explosion scattering matter all over the place. When the explosion takes place, the matter may recombine and new stars can form. In the picture, on the left side, after the red giant phase occurs the star keeps condensing and collapsing onto itself. The shells of hydrogen and helium form a planetary nebula, leaving the core exposed. The hydrogen and helium of the planetary nebula eventually break away from the white dwarf and drift into the interstellar medium. A supernova explosion will only occur in high-mass star, while in low-mass stars no explosion will occur and the star will collapse form the planetary nebula and result in a tiny white or black dwarf. |
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