1 / 29

The Star Life Cycle

The Star Life Cycle. Integrated Science. What is a star?. A mass of gas and plasma that is held together by its own gravity and uses chemical reactions to make its own light. . Where do stars come from?. Stars form from Nebulas. Nebula A cloud of dust, hydrogen, helium, and plasma.

dextra
Download Presentation

The Star Life Cycle

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Star Life Cycle Integrated Science

  2. What is a star? • A mass of gas and plasma that is held together by its own gravity and uses chemical reactions to make its own light.

  3. Where do stars come from? • Stars form from Nebulas. • Nebula • A cloud of dust, hydrogen, helium, and plasma. • A star forming region. • May be the source of planets and other bodies in space.

  4. What is a star made of? • Gravity causes Hydrogen and Helium to clump together until they are large enough to form a star. • Majority Hydrogen (97%) and some Helium (3%)

  5. Protostar • The first step in any star’s life • A spinning, flattening ball of hydrogen and helium that has enough gravity to keep all the matter pulled together. = Protostar = Baby Star

  6. Main Sequence Star • Once the protostar gets big enough, it starts to shine brightly. • They use hydrogen as fuel to make light. • Main Sequence Stars produce light by joining the nucleus of a hydrogen atom to other hydrogens or other elements. • Bonding a nucleus to another is a Fusion Reaction. • Atoms get bigger and bigger during fusion reactions.

  7. Main Sequence Stars • The majority of a star’s life is spent as a main sequence star. • Gravity pulls the particles that make up a star in even when they want to escape. • The temperature of the star increases as it gets older because the fusion reactions are exothermic. • Exothermic = gives off heat.

  8. Main Sequence Star Main Sequence Star = Kid to Adult

  9. Main Sequence Stars • When stars run out of hydrogen they leave the “main sequence” part of their life cycle. • With the hydrogen gone, all stars will start to use helium as fuel. • The star begins to heat up and expand when helium is burned.

  10. Red Giants • Red Giants use helium as fuel. • Helium is fused together to make carbon. • They are much larger and cooler than main sequence stars. • Becoming a Red Giant is the first step in star death.

  11. After Red Giant • The path of a star after a red giant depends on its size. • Large Stars • Become Supernovae, then neutron stars or black holes. • Medium Stars • Become White Dwarfs, then Black Dwarfs • Small Stars • Become White Dwarfs, then Black Dwarfs.

  12. Small and Medium Stars • Once all the Helium is gone they shrink and become very small, very dense white dwarf stars. • Most White Dwarfs are about the size of Earth. • One spoonful of a white dwarf star would weigh several tons!

  13. Small and Medium Stars • When White Dwarfs run out of fuel they become Black Dwarfs. • Black Dwarfs are very dense and produce very little or no light at all.

  14. Large Stars • Large Stars can explode in an explosion called a supernova. • Supernova explosions happen when the protons get too close to each other. • They begin to repel like magnets of the same charge would • What is left after the supernova explosion is called a neutron star.

  15. Large Stars • If the explosion is large enough, a neutron star does not form and a black hole forms instead. • Black holes are stars that have collapsed on themselves • Black holes are so dense and have such a strong gravitational force that light can’t even escape from them. • Anything that falls into a black hole is crushed.

More Related