Download Zairamink_Lifecycle of a Star

Picture: http://upload.wikimedia.org/wikipedia/commons/4/4e/Pleiades_large.jpg
The Pleiades Star Cluster
Low and High Mass Stars
By Zairamink
A
Star of Lower Mass
Picture: http://en.wikipedia.org/wiki/File:Orion_Nebula_-_Hubble_2006_mosaic_18000.jpg
Orion Nebula
 Gas
and other particles is space cluster
together they form a mass that is called a
Interstellar Gas Cloud or Nebula.
 As more gas and particulate cluster the
gravitational pull of the Nebula
strengthens and pulls more particles to
gain more mass, thus strengthening it’s
gravitational pull further
Info: http://library.thinkquest.org/3103/nonshocked/topics/interstellar/interstellar.html
Picture: http://upload.wikimedia.org/wikipedia/commons/7/74/Triangulum.nebula.full.jpg
 Once
the Nebula gathers enough mass
the gravity starts to try and pull it
together while the atoms themselves try
to push apart.
 The actions of the atoms trying to push
apart and the gravity trying to push in
creates heat and pressure.
 At that point one of two things happen
Info: Notes
Picture: http://www.msnbc.msn.com/id/25959575/displaymode/1168/rstry/25959579/rpage/1/
 After
a ProtoStar one of two things can
happen, either it turns into a main
sequence star or a Brown Dwarf.
 A brown Dwarf is a Protostar that didn’t
gather enough mass to make enough
heat to start fusion, so in the end it just
shines dimly, never truly becoming a star.
Info: Notes
Picture: http://www.sciencedaily.com/releases/2008/04/080410101146.htm
 If
the ProtoStar gathers enough mass and
heat it starts to fuse Hydrogen into
Helium, once it starts fusing the it would
be declared a star
 This type of star would be called a Main
Sequence Star
 Most stars are Main sequence Stars
because this is one of the longest parts of
the stars life time.
Info: Notes
Picture: http://upload.wikimedia.org/wikipedia/commons/7/72/Pleiades_Spitzer_big.jpg
 When
the star starts to run out of
Hydrogen it starts to try and burn Helium
in a attempt to keep burning and not to
collapse upon it’s self.
 Helium burns a bright red and the star it’s
self expands, thus giving it the name ‘Red
Giant’
 When
a Red Giant stars to run out of
helium it once again try’s to gain heat by
radiating it’s outer layers out wards.
 As the outer layers dissipate away from
the core, the core it’s self becomes
incredibly hot and dense, trying to
sustain it’s self by fusing Helium into
carbon and that into heavier elements.
Info: http://fusedweb.llnl.gov/CPEP/Chart_Pages/5.Plasmas/Nebula.html
 A White
Dwarf happens after a Planetary
Nebula, a star uses all of it’s fuel, after
which all that is left is the very hot, very
dense core of the star.
 It cools down over Millions of years,
during which all it does is radiate lowenergy X-rays into space.
 A white dwarf has a low luminosity but
have about half the mass of the sun while
it is about the size of the earth.
Info: http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html
http://en.wikipedia.org/wiki/White_dwarf
A
black dwarf happens when a white
dwarf becomes cool to the point that it no
longer emits significant heat or light of
any kind.
 There are no documented sightings of a
black dwarf due to they’re low luminosity,
or it could be that our universe is simply
too young for us to have any black dwarf
yet
A
Star of Higher Mass
 Like
the low mass stars, high mass stars
Start the same way.
 Gas and other particles is space cluster
together they form a mass that is called a
Interstellar Gas Cloud or Nebula.
 As more gas and particulate cluster the
gravitational pull of the Nebula
strengthens and pulls more particles to
gain more mass, thus strengthening it’s
gravitational pull further
Info: http://library.thinkquest.org/3103/nonshocked/topics/interstellar/interstellar.html
Picture: http://upload.wikimedia.org/wikipedia/commons/7/74/Triangulum.nebula.full.jpg
 The
only difference between a low mass star
and a high mass star at this point is how
many atoms and mass they gain
 Once the Nebula gathers enough mass the
gravity starts to try and pull it together
while the atoms themselves try to push
apart.
 The actions of the atoms trying to push apart
and the gravity trying to push in creates
heat and pressure.
 As
the Protostar starts to burn hydrogen it
would now be called a star, but due to it’s
mass it would be declared a Massive
Main Sequence Star instead of a star of
small or standard size which would be
called a Main Sequence Star.
 Due to the mass of the star it has the
ability to burn hotter then most stars,
using it’s fuel faster and thus going into
the next stage of events faster.
A
Super nova is a stellar explosion
 They are extremely luminous and cause a
burst of radiation that often briefly
outshines an entire galaxy, before fading
over several weeks or months.
 During the time a Super Nova is around, it
radiates as much energy as the sun in it’s
entire life time.
 After a Super Nova one of two things can
happen.
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After a super nova, the remains of the star could become a
Neutron Star
To get a Neutron Star you need to have star that's larger than
about 1.5 solar masses and less than 5 times the mass of the
sun.
If you have some where around that mass then after the
super nova the protons and electrons of atoms are forced
together into neutrons.
When neutron stars form, they maintain the momentum of
the entire star, but now they're just a few kilometers across.
This causes them to spin at tremendous rates, sometimes as
fast as hundreds of times a second.
Just one teaspoon of a neutron star would have the mass of
over 5 x 1012 kilograms.
Info: http://www.universetoday.com/guide-to-space/stars/what-is-a-neutron-star/

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A black hole is an object which has such high gravitational pull
that not even light can escape. Hence it is black.
But in the black hole case the initial star was so massive that
nothing could stop its gravitational collapse. All the matter of
the star's core is crushed to an infinitely small point, a
singularity.
What would it be like to enter a black hole? Not pleasant. First,
as you approach the black hole the difference in the
gravitational pull on your head compared to your feet (known
as tidal forces) would rip you apart. But suppose you survived
that. Once you cross the event horizon there is no turning back.
Then the only thing to do is avoid the black hole itself at all
costs. If you run into that singularity it will crush your body
right out of existence.
Info: http://www.windows.ucar.edu/tour/link=/the_universe/BH.html