This assignment-Reach for the stars focuses on the life cycle of stars, the classification/types of the stars, the Hertz sprung-Russell diagram, the physical, chemical characteristics of size, ,ass, magnitude, radiation, temperature, luminosity, the spectral classes of stars, causes of the properti...
Assignment 4: Reach for the stars.
Introduction: Stars are most commonly known as the “natural
lights of night-time” however for people to be able to spot a star in
the sky, stars have to go through certain chemical processes for them
to be formed completely. This assignment will focus on the life cycle
of stars, the classification/types of the stars, the Hertz sprung-Russell
diagram, the physical, chemical characteristics of size, mass,
magnitude, radiation, temperature, luminosity, the spectral classes
of stars, causes of the properties, history of stars, the big bang
theory and the death of stars.
Figure 1 to the right shows
a picture of stars in the
night sky.
D.P.6: Explain current
knowledge and theories of
the life cycle of stars.
*In the 21st century it is now well
studied how exactly stars are formed
and what their characteristics are
like. It is now known that stars that
are much bigger burn their fuel more
rapidly and live for a shorter time
period. The mass of a star governs
,the conclusive fate of a star. Two of these facts were not known
100years back in the 20th century because at that time nuclear
processes were not well understood by then astronomers.
Astronomers back then believed stars were made by gases, nebulae
and dust because of the gravity conception. Astronomers theorized
that the stars where formed when terrains of the clouds subsided. It
was believed that as the region collapsed it would hasten and heat
up to construct a protostar that was heated up by gravity friction.
Before the atomic age officially by, no astronomer or researcher
knew where the origin of the heat in the stars came from. However
in the year 1913 two astronomers one Danish (Enjar Hertzspung) and
the other an English (Henry Norris Russell) astronomer developed
the now known diagram the Hertz sprung-Russell diagram (also
known as H-R diagram) which shows the absolute immensity
brightness of stars are arranged against their spectral types which is
the temperature.
Figure 2 above shows a detailed picture of the Hertzspung-Russell
Diagram.
*The diagram in figure two shows how hot or cool the star would be
at different temperatures. The blue parts representing that the stars
are really hot during that particular temperature period, orange
parts indicate that the temperature on that area is medium heat not
too hot or too cold. The red parts shows the cooler temperatures.
Stars are aligned in order of decreasing brightness from the right to
,the left and by spectral class on the Hertzspung-Russell diagram. The
relation between colour and the brightness of the star was a radical
proceeding in modern astronomy today. The different colour codes
of the stars on the diagram helped astronomers to be able to
estimate the distance of faraway stars from our home planet earth.
Most of the stars that exist today are in the Hertzspung- Russell
diagram sequence. The sun is in the middle of the diagram amidst
the yellow dwarf which are known as the medium sized stars.
Although the H-R diagram is still used in today’s astronomy and is
really helpful in modern astronomy, Russell’s reasoning behind the
movements of stars on the diagram where the opposite
understanding of the stellar evolution which is defined as the way
stars change depending with the time period. In 1910 Indian-
American astrophysicist Subrahmanyan Chandrasekhar was the first
physicist to classify the evolution of stars into supernova, neutron
stars and white dwarfs. He also predicted the conditions that are
essential for the formation of black holes that was first found in the
20th century. Over time the implementation of atomic fission and
fusion worked their way into astronomical theory and it became
apparent that stars spend about 90% of their lives as a main chain
before they die eventually. Today’s knowledge of the formation of
stars has been put in a number of stages with specific processes that
happen during the time and stage they are at for the formation.
,Figure 3 below shows a picture of the stages all stars in the universe
go through.
*Stars exist in a wide variety of masses and the mass helps
determine how radiantly the star will shine and how its lifetime will
come to an end. Average size stars for instance like the sun, come to
the end of their life as a white dwarf that would be nearby by
interstellar dust that is disappearing, bigger stars transform into
supernovae, neutron stars and black holes.
, D.P.7: Describe the evidence linked to theories of the
evolution of the universe. Over the centuries there have been
a number of theories about the origin of the universe and how it
formed and for it to be able to accommodate us as humans in this
universe. The most common theory that has been spoken about and
is believed by many scientists to have actually taken place billions of
years back is the Big Bang Theory.
*The Big Bang theory is known as the process which took place
13.8billion years ago when the universe started off as a murky , tiny
fireball that exploded with a lot of force that resulted in creating a lot
of different types of galaxies and matter of the extensive universe. In
the year 1927 an astronomer called Georges Lemaitre came up with
the idea of how years back the universe started as a single link. He
stated that the universe extended and stretched to get as massive as
it is today and it would keep extending on.
Figure 4 shows a picture of how it is believed the big bang looked like
when it was going through the formation stage.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller kiki24mona. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $45.79. You're not tied to anything after your purchase.
