Upload
matthew-moore
View
214
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Hi, my name is Ben Ten living in North America. I am a student of Bachelors Part – II and a book wormer. I interested in astronomy and I prefer to search for information about astronomy. I want to have some necessary knowledge about astronomy. I especially draw my attention in Planet Star. I introduce my website, which contain the useful information about Star planet and some Facts about planet Star. There are also some pictures of Star. I hope that, they will provide to you useful knowledge about astronomy in general and STAR in particular.
Citation preview
Life Cycle of a Star – Birth through to Death The life cycle of a star is an amazing scientific phenomenon that takes
billions and billions of years to occur and involves several stages each with its
own interesting characteristics. Before we delve deeply into the various process
involved in the creation of a star, let us first try to define what a star actually is. A
start is a luminous globe of gas that is capable of producing its own heat and light
through nuclear fusion. It is created from a nebula, which is a cloud of hydrogen
and helium gas as well as dust existing in space.
The life cycle of a star
begins with the nebula. It is
known as the birthplace of
stars, the nebula is known to
have several kinds. Basically,
stars are formed from the gases
that are contained within the
nebula. These clouds of gases
– hydrogen and helium – and
dust collapse due to
gravitational forces resulting to the formation of protostars.
Protostars which are known as young stars eventually collapse in order to
form main sequence stars or also called dwarf stars. A red dwarf star is small and
faint approximately tenth of the diameter of the Sun. These burn slowly and live to
about a hundred billion years.
These would eventually expand as they begin to grow old; as time goes on;
its core runs of hydrogen and helium gases. This results in the cooling of the star
and a decrease in its brightness, this star is now known as the red giant.
The red giant or can also be called the red super giant is a large bright star
that has a cooler surface temperature – 2,000 to 3,000oC. They are considered
bright due to their size although the core temperature is quite low. The red giant
collapses in time leading to a massive explosion known as the Supernova. The
white dwarf star is part of the last stage of the life cycle of a star after the red
giant. A perfect example of this would be the Sun.
Depending on the star’s original mass, it can have several fates:
Black dwarf
The black dwarf is
considered as a stellar
remnant that has lost its
heat due to the depletion
of the helium and
hydrogen gases from its
core. It commonly arises
from the white dwarf star.
Neutron Star
This type of star
occurs after a supernova.
It results from the
combination of protons
and electrons leading to the formation of the neutron star. According to studies, if
the mass of a neutron star further decreases, there is a possibility that the increase
in gravitational pull can result to the creation of a black hole.
Black Hole
These are believed to form from massive sized stars when their lifespan ends.
It is believed that due to the intense gravitational pull within the black hole, not
even light can escape it. The density of matter within a black hole is immeasurable
since they can distort the space surrounding them and suck in the matter nearby.
Stars – Celestial Objects On Sea and Sky For as long as mankind can remember, stars have been those celestial objects
on sea and sky that have stirred up a lot of theories with regards to what they are
and how they came to be. Constellations are known as the chance aligning of the
stars that form several various icons coming from the ancient times. These
constellations are utilized by astronomers in order to provide organization to the
skies at night and to properly
locate the stars.
Stars are considered as the
most numerous visible objects in
the universe. The light and
energy emitted by these objects
are considered as a power source
for the solar system. Also
coming from the star are the
heavy elements that are essential
components in the formation of life forms. They are a keystone piece in the
creation of life in the universe. Without them, the universe would cease to exist as
is.
A perfect example of a star that provides energy to life forms would be the
Sun. The Sun as we know, gives life to Earth through the energy and heat it
provides for all the living species on the planet. Energy and heat are essential
factors for the survival of our species against the coldness of outer space.
So it brings us to the question, does the brightness of a star have any relation
to its core temperature? The measure of the stars brightness is termed as its
magnitude and identifying the colour to determine the temperature. Astronomers
have developed a scale to determine the magnitude and temperature of a star based
on its characteristics.
For the magnitude, the lower the value of the number given, the brighter the
star is. As for the colour and temperature, stars are divided among their colour and
ranked in what is called a spectral
class. This is an array of various
stars beginning from Class O
which is blue to the Class M that
are red. The hotter and higher the
temperature of the star, the more
intense shade of blue it is. While
stars that are red in colour, fall
under the category of cooler
temperatures.
Contrary to popular belief, stars in the sky do not really twinkle. The
occurrence of the phenomenon that makes stars seem to twinkle is a direct effect
from the interference in atmosphere. Air emitted rises, which causes images we
see to wave and blur. Stars that are lower in position in the sky have more
tendencies to twinkle in comparison to those that are in a higher location.
The twinkling effects of celestial objects on sea and sky are more likely to
occur in lower located stars since more light is required to pass through the
planet’s atmosphere. A good analogy or comparison would be in the case of a hot
summer day. Upon gazing far out into the pavement, there is a tendency for the
road to blur or seem to move. It is actually the hot air escaping from the pavement
and into the atmosphere.
Stars – The Solar System and Outer Space Probably among all the famous stars within the solar system and outer
space, the most popular would have to be the sun. The sun actually comprises of
almost all the matter within the solar system, the remaining matter would be
composed of the planets Jupiter and
Saturn. Within the solar system and
outer space, there are numerous
astronomical objects that are bound to
the orbit through the force of gravity.
Stars are among the most
abundant astronomical objects that lay
within the entirety of the solar system.
Created from space formations termed
as nebula, these stars live for billions
of years as glowing structures of
burning gas. As the star ages, its core
temperature becomes cooler and the entire structure becomes unstable. The
instability of an aging star eventually leads to its death in a massive explosion
known as the supernova.
The particles and elements coming from these stars explosions are the core
ingredients that ultimately become new stars when they combine with other gases
and dust. This occurrence is a perfect example of where energy is neither
destroyed nor created. It only changes in form.
Eventually the increase of the pull of gravity forces the creation of brand new
stars. The increase in gravitational force is due to the spinning action created by
the clouds of dust, hydrogen and helium gases. These are the initial stages of the
formation of a new star.
If you wonder why stars are so bright, you can compare the mechanism of a
star to that of a nuclear reactor. A massive amount of energy is being produced by
stars through nuclear fusion involving helium and hydrogen gas molecules. This is
the source of the brightness of a star.
Surprisingly, there are about two hundred billion stars within the known
universe. That does not even include the sun! Since the sun is the nearest star to
our planet, we are able to observe its natural form as a glowing hot ball of gas.
While we look at other stars in the sky as small little dots resembling lights on a
Christmas tree. They seem tiny when in fact these stars can be as massive or even
much more in comparison to our Sun.
It is only due to their extreme
distance which makes them difficult
to see in their actual form. To give
you a better idea on how massive
another star can be, the Sun is
actually just a medium sized star.
While our planet, in terms of the
diameter is only a hundredth of that
of the Sun. So imagine another star
that is twice or more in size of the
Sun, big huh? Giant stars are about
one thousand times the diameter of the Sun. These are found in several different
galaxies that are billions of light years away.
So the next time you look up in that night sky and you see a star twinkle,
imagine how many light years it took for that light to travel. Imagine that the star
you’re looking at is only a minute part of an even bigger picture.
Interesting Facts about Stars The night sky is filled with a lot of mysteries and trivial information. There
are a lot of interesting facts about stars that you may not know of. Knowing
about these trivial facts can actually help you to appreciate the universe more or
can be an interesting topic for conversation between you and your peers. So here
are some interesting facts about stars:
1. The Sun is the closest star to Earth.
For those that don’t know, yes, the Sun is a star! It is the closest one to the
planet - approximately 150 million kilometers away. The Sun is classified under
the G2 yellow dwarf star class and is in the phase of its life cycle known as the
main sequence. Our Sun, like most other stars, emits energy and light through
conversion of hydrogen and helium atoms. This process – nuclear fusion – occurs
at the Sun’s core where it’s the hottest.
The Sun is estimated to be
about 4.5 billion years old and is
predicted to be in this phase for
another seven billion years or so.
Unfortunately, like most other stars,
when the time comes that it runs out
of fuel, it would become a red giant
star while increasing in size. There is
even a probability that it would
engulf Mercury, Venus and probably
even Earth as it expands.
2. All stars are in a perfect
state of balance.
Since they are billions of light years away, it would be difficult to know that
stars are actually in a constant battle or conflict with themselves. All the stars have
their own gravitational pull that pulls itself inward. This action, if not repelled by
another force would lead to the continuous collapse of a star until it becomes
minute in size. The amazing part is that the nuclear fusion occurring at the star’s
core actually repels the gravitational force by creating an outward push. This
phenomenon actually takes about 100,000 years to complete.
When a star loses its fuel at the core, there is no longer any action to repel the
pull of gravity hence a star collapses into smaller minute particles known as
dwarfs.
3. Everything is
equal.
With stars, the colour,
temperature and its mass
are all related. The actual
color of a star can indicate
its size and temperature.
The hottest stars are
surprisingly the smallest
ones and are blue in colour.
Their temperatures go to about 12,000 Kelvin. While the yellow coloured stars are
the medium sized ones just like the Sun. Their temperatures fall to about 6,000
Kelvin. And lastly, the coolest and biggest ones are coloured red and have
temperatures that are less than 3,500 Kelvin.
4. Stars are just like twins.
When looking at the night sky, it would seem like stars are up there all alone.
But don’t fret; these heavenly bodies actually come in pairs. These are termed
binary stars where in a set of two stars share a common center of gravity in an
orbit. In some other systems in space, stars can even come in groups of threes or
even four!