BELLWORKBELLWORK

•Are stars BORN???Are stars BORN???•Take a moment to think Take a moment to think

about our own Sun, and write about our own Sun, and write down an idea about how it down an idea about how it was formed using what we was formed using what we have learned so far. have learned so far.

Life Cycle of STARSLife Cycle of STARS

The Stellar NurseryThe Stellar Nursery

Birth of a StarBirth of a Star•Stars are born out of a ball of Stars are born out of a ball of

gas, called a Nebula. This is the gas, called a Nebula. This is the stellar nursery. stellar nursery.

•Gas and particles are pulled Gas and particles are pulled together, their mass together, their mass condenses condenses ..

• The main ingredient is The main ingredient is Hydrogen.Hydrogen.

What Causes the Collapse?What Causes the Collapse?

•What did we say about all What did we say about all matter before?matter before?

•All matter is attracted to All matter is attracted to other matter = gravity.other matter = gravity.

Different Types of StarsDifferent Types of Stars

•Stars can become different Stars can become different types after the nursery.types after the nursery.

•Main-Sequence starsMain-Sequence stars•GiantsGiants•SupergiantsSupergiants•White DwarfWhite Dwarf

Stars Get OLDStars Get OLD

•Stars start out of the Stars start out of the nursery.nursery.

•Gain material slowly.Gain material slowly.•Stars lose material through Stars lose material through

nuclear fusion, over billions nuclear fusion, over billions of years.of years.

•Sometimes they lose material Sometimes they lose material REALLY FAST!REALLY FAST!

Example of SupernovaExample of Supernova

End stages of a StarEnd stages of a Star

•After middle age, retirement.After middle age, retirement.•Our Sun will become a red Our Sun will become a red

giant eventually, then a giant eventually, then a white dwarf most likely.white dwarf most likely.

•More massive stars explodeMore massive stars explode–Supernova!!!!!!!!!!!!!Supernova!!!!!!!!!!!!!

SupernovaSupernova

•The mass of a star collapses.The mass of a star collapses.• It explodes violently as seen It explodes violently as seen

in the animation.in the animation.•The result: The result: –Neutron StarsNeutron Stars–PulsarsPulsars–Black HolesBlack Holes

Death of a StarDeath of a Star• Supernovas A supernova is a Supernovas A supernova is a

gigantic explosion in which a gigantic explosion in which a massive star collapses.massive star collapses.

• Neutron Stars and Pulsars A star Neutron Stars and Pulsars A star that has collapsed under gravity to that has collapsed under gravity to the point at which all of its particles the point at which all of its particles are neutrons is called a neutron star. are neutrons is called a neutron star. If a neutron star is spinning, it is If a neutron star is spinning, it is called a pulsar.called a pulsar.

• Black Holes A black hole is an object Black Holes A black hole is an object that is so massive that even light that is so massive that even light cannot escape its gravity.cannot escape its gravity.

Different Types of StarsDifferent Types of Stars

•Your book walks you through Your book walks you through the different types of stars.the different types of stars.

•Pages 40-45Pages 40-45•Were going to create a Were going to create a

concept map of this process.concept map of this process.•What is a concept map?What is a concept map?

Concept MapConcept Map

Stellar Nursery: Nebula’s are giant clouds of gas