Life Cycle of the Stars

By Aiyana and Meredith

http://techcenter.davidson.k12.nc.us/spring026/images/OuterSpace.jpg

Nebula

• A nebula is made of gas and dust• The nebula is the birth place of a star• They get their light from nearby stars.

http://sunshine.chpc.uh.edu/labs/star_life/starlife_main.htmltahttp://www.windowsmoviemakers.net/PapaJohn/117/Blue-Screen_Outer_Space_Clips_files/image004.jpg

Protostar“Fetus”

• The protostar is the first stage of a star’s life

• Formed when gravity clumps the hydrogen and helium of a nebula together

• In order to grow in life it needs to maintain equilibrium– Balance between gravity pulling atoms towards center

and gas pushing heat and light away form center

http://sunshine.chpc.utah.edu/labs/star_life/starlife_proto.html

Main Sequence“Adulthood”

• Phase in which stars live out the majority of their lives

• Stars last in main sequence for billions of years

• During entire life the star battles gravity, trying to crush it

http://spaceflightnow.com/news/n0009/15supernova/supernova.jpg

http://www.presentationstation.com/Backgrounds/Miscellaneous_2/orange_spot.jpg

Red Giant“Middle Age”

• During this short phase the star starts cooling and the fusion fuel starts going away

• Core shrinks but fusion keeps on going• When our sun reaches the phase of a red

giant its diameter will expand to the size of the orbit of Mars

http://sunshine.chpc.utah.edu/labs/star_life/support/red_giant.html

http://www.awesomebackgrounds.com/templates/fire-on.JPG

White Dwarf/Black Hole“Old Age”

• When a star runs out of fuel to burn, gravity collapses it in

• Low mass stars, who have electrons that prevent the collapse of the core, shrink to a white dwarf

• When crushed by gravity high mass stars totally leave space become a black hole

http://spaceflightnow.com/news/n0005/22astronext10/000522blackhole.jpghttp://www.vgaplanets.com/v4doc/PLAN0020.gif

http://www.freestockfootage.com/Thumbs/t600-100-023.jpg

White Dwarf Black Hole

Brown Dwarf

• Star like objects in space that have masses less than .08 times that of the sun

• Unable to sustain hydrogen fusion• Brown dwarf is a protostar that didn’t have

enough dust and gas to achieve a temperature hot enough to ignite fusion

Arrow is pointing at a Brown Dwarf

http://www.universetoday.com/html/pictures/big2002-0109a.jpg

Planetary Nebula“After Life”

• When a star explodes a large cloud of gas is expelled called a Planetary Nebula

• The first planetary nebula ever seen was the Dumbbell Nebula M27

http://www.ask.com/bar?q=planetry+nebula&page=1&adt=0&qsrc=2417&ab=0&title=Planetary Nebula&u=http%3A%2F%2Fschmidling.com%2Fplanebs.htm

• After explosion the core remains extremely hot which emits high energetic radiation• One of the largest planetary Nebulae is NGC246

Helium fusion

• Nuclear fusion with the nuclei being involved with helium.

• Powered by fusing the element hydrogen into the element helium.

• When stars exhaust their hydrogen fuel and build up a lot of helium, they begin to fuse helium together to form carbon.

http://www.oufusion.org.uk/newsspring05/helium2carbon.jpg

http://www.awesomebackgrounds.com/ss-explosion.htm

Hydrogen Fusion

• Four hydrogen nuclei come together to make a nucleus.

• There are electrons, neutrinos, and photons involved in making fusion of hydrogen into helium.

• This fusion cycle generates energy in our Sun.

http://www.physics.uiowa.edu/~umallik/adventure/spangle/spangle_files/image018.gif

Neutron Star

• Neutron stars are objects created in the cores of massive stars.

• The core of a star collapses and crushes together every proton combined with electrons.

• Neutrons can stop the collapse and remain as neutron stars.

Supernova

• Most energetic explosion.• Occur at the end of a star’s life, when

nuclear fuel is exhausted and can no longer be supported by the nuclear energy.

• When the explosion occurs, the brightness can be as that of many millions of stars.

http://www.ask.com/bar?q=supernova+information&page=1&adt=0&qsrc=2417&ab=3&title=Supernovae&u=http%3A%2F%2Fimagine.gsfc.nasa.gov%2Fdocs%2Fscience%2Fknow_l2%2Fsupernovae.html

http://chandra.harvard.edu/photo/2004/rxj1242/rxj1242_still3.jpg