It's a presentation that talks about the Life, Development and Death of the stars

1. By: Gonzalo Herrero, Donato Fuejo , Celso Galvan

2. In space, gas and dust
gather one another
because of the collision
of its particles and a
chemical reaction takes
place. This occurs along
millions of years and it
foms a huge dust cloud.

3.  Inside of it there are the “Creation Pillars” where new stars are
formed.
They are seven thousand light
year far way of the Earth. They
are formed of interstellar gas
and they are few light years
wide and they have enough
density to allow stars to be
create.
Stars are formed at the bottom
of the pillars and while they are
getting bigger they rise until
the top of the pillars

4.  A process of concentration starts and protostars are formed.
These protostars much bigger than our solar system and
they are relatively cold. You can only see them using the
infrared spectrum .
 While the process of
concentration the protostar
gets smaller.
When it reduces its size it
starts burning because the
fusion reactions that
transforms the hydrogen
Into helium start

6. The star was born, is generating light by
internal nuclear reactions converting
hydrogen to helium. Hydrogen accumulated
on the nucleus is limited. More mass of the
star means more pressure on the nucleus,
more temperature and more internal nuclear
reactions. The higher the temperature, the
more numbers of nuclear reactions and less
time of life because the hydrogen runs out.

8. They are three principals types of stars:
Blue stars- it´s big, very hot and very young.
Blue stars live shortly.
Yellow stars- it´s warm, has a longer life,
about ten billions years, are mediu sized and
are very common.
Red stars- small and cold, can have such long
lives as the age of the universe.

10. At the stage of evolution of the stars are
extremely stable, it´s surface temperature
does not change, it´s diameter is constant
and that is when they can have planets
around and can developed live on these
planets.

12. When the energy of the stars run out (its life depends on
how was its amount of mass) its death relies on, again,
how big the star was.
A star can end in two different ways: the light ones
consume themselves and became dwarf white stars and
the big ones formed what it is called a supernova, an
enormous explosion.

13. 
When the light stars are near to their end, progressively they rise their size
until the reaches a size a hundred times bigger than they was at the
beginning (they are called Red Giants).

The red giants suddenly start to shrink until they get a size that it is much
slower than the size they had before becoming a red giant.
This is because they had run out all of its nuclear fuel and they
get colder (meanwhile his light also disappears).

14. • Depending of the amount of mass the star had it could turns into a neutron star or
a dark hole. I’m going to take the Sun as a reference to determine the quantity of
mass.
• All heavy stars when their nuclear fuel runs out, don’t have any inner pressure that
can hold the gravitational attraction. This provoke that in the inside, protons and
electrons begin to fusion themselves and neutrons were formed so huge amounts
of energy are spread out.
Because of the energy spread, the outer parts of the stars explode to the space
while the nucleus it collapsing. This is known as a supernova
The outer parts spelled formed nebulas and from now on two different things can
happen:
1. If the star was between six and thirty times the Sun, the collapsed can stabilize,
but, because there’s no other thing that neutrons in the nucleus it becomes what is
known as a neutron star. (they turn very very quickly).
2. But, if the stars was more than thirty times the Sun, the nucleus collapse more
than the neutron stars and becomes a dark hole (a limited space where there’s so
high density than even the light can’t scape)

15. Supernova
Neutron Star Dark Hole