Transcript Well, My Stars!! Brief Look at the Stars

Well, My Stars!!
a Brief Look at the Stars
His Excellency, Michael J. Coyle XV
Elementary Study of the Earth and Her Distant Neighbors
42 Montview, Dortshire
England
Evolution of Stars
Stars begin in nebulas, clouds of gas and
dust
Nebulas: 70% H, 28% He and 2% heavy
elements
Very little gravity until…
Nearby activity causes particles to contract
(star explosion, collision, etc.)
Protostars
Shrinking nebulas, faster speed
Example: ice skaters spinning
The center of this spinning disk is called a
protostar
Pressure (up), heat (up)  nuclear fusion
Nebulas can produce more than one star
Main Sequence Stars
2nd and longest stage in star life
Energy from nuclear fusion moves
outward, gravity holds matter inward
Maintains a stable size
It is in a state of equilibrium
Red Giants and Supergiants
3rd stage, when all of the H is used up
No longer in equilibrium, gravity forces the
core to contract
He creates more energy and the star gets
HUGE in size  Red Giant/Supergiant
Our sun: main sequence star has used
only 5% of its original hydrogen
White Dwarf Stars
A final stage, no energy left
Outer gases are lost, revealing a dense
core of matter inside: white dwarf
Exterior ring of gases appears as a
planetary nebula
millions of years to cool and become a
black dwarf or dead star
supernova
Novas and Supernovas
nova- a white dwarf that explodes
huge stars have tremendous explosions
called super novas
stars contract  dense iron core
 explosion
energy made over life of star = amount of
energy released during supernova
Neutron Stars and Pulsars
Neutron: subatomic particle, along with
protons are the mass in an atom
Neutron star: super dense ball of neutrons
left after an explosion
A spoonful would weigh 100 million tons
on Earth
Pulsar: a neutron star that emits light like a
lighthouse
Neutron star
pulsars
Black holes
Some massive stars contract with even
greater force…
condensing even the core of the star,
astronomers think: leaves a hole in space
or a black hole
gravity is so great that not even light can
escape it