stars life .. how they are formed ... supernova , what is black hole, worm hole ..... very very interesting topic in very simple language and many images that make u understand easily
3. LIFE OF STAR
There are millions of star in our galaxy but now
the question arises HOW DOES THE STARS ARE
FORMED ??????????? OR WHERE DOES IT
COME FROM????
Basically these stars are formed in the clouds of
dust and gas ….
The massive clouds in the universe
experiences their own gravitational
forces and begin to collapse so it fall
on itself (DENSED AT THE CENTER)…..
5. Now as we move to the center of the cloud it become
denser and denser and hot too due to gravitational
forces.
Now because of the gravitational force the dust and
the gas particles are brought so close at the center so
that these particles begin to stick to each other.
Then result to form a star of hydrogen atom these
hydrogen atom fuses to form helium and it creates the
energy that powers every star.
The life of the star depends on the size of the star at its
birth.
When the star is small there is a balance between the
gravitational force and the pressure due to fusion of
particles.
6. Time goes on and the star becomes supergiant and
then the distance between the center and the edge
of star goes on increasing that results into weaker
gravitational force between them.
As the gravitational forces between the center and
the edge become weak the star is unable to hold
itself and the explosion of star take place that is
termed as supernova..
This explosion posses very high energy such that it
can light up our whole galaxy and we can also see it
through earth surface through naked eyes.
8. SUPERNOVA
A supernova is an explosion of a massive
supergiant star. It may shine with the brightness
of 10 billion suns.
The total energy output may be 1044 joules, as
much as the total output of the sun during its 10
billion year lifetime.
The likely scenario is that fusion proceeds to
build up a core of iron.
We can say it’s the end of star life.
9. On average, a supernova will occur about once
every 50 year in a galaxy the size of the Milky Way.
Supernova leads to the formation of the black hole.
11. Black hole where the
gravitational forces is so
high that even light
cannot escape out of it.
12. Black hole
If a star has three times or more the core mass of
the Sun and collapses, it can form a black hole.
Don't let the name fool you: a black hole is
anything but empty space.
Rather, it is a great amount of matter packed into
a very small area - think of a star ten times more
massive than the Sun squeezed into a sphere
approximately the diameter of New York City.
The result is a gravitational field so strong that
nothing, not even light, can escape.
13. Black holes were predicted by Einstein's theory of
general relativity, which showed that when a massive
star dies, it leaves behind a small, dense remnant core.
If the core's mass is more than about three times the
mass of the Sun, the equations showed, the force of
gravity overwhelms all other forces and produces a
black hole.
Most black holes form from the remnants of a large star
that dies in a supernova explosion.
Scientists can't directly observe black holes with telescopes
that detect x-rays, light, or other forms of electromagnetic
radiation
14. We can, however, infer the presence of black holes
and study them by detecting their effect on other
matter nearby.
If a black hole passes through a cloud of interstellar
matter, for example, it will draw matter inward in a
process known as accretion.
A similar process can occur if a normal star passes
close to a black hole. In this case, the black hole can
tear the star apart as it pulls it toward itself. As the
attracted matter accelerates and heats up, it emits
x-rays that radiate into space.
15. If the total mass of the star is large enough
(about three times the mass of the Sun), it can be
proven theoretically that no force can keep the
star from collapsing under the influence of
gravity.
However, as the star collapses, a strange thing
occurs. As the surface of the star nears an
imaginary surface called the "event horizon,"
time on the star slows relative to the time kept by
observers far away. When the surface reaches the
event horizon, time stands still, and the star can
collapse no more - it is a frozen collapsing object.