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