Darren KongFall 2012
Stellar Evolution:The process by which a star undergoes a sequence of radical changes during its lifetime.

"The story of a star's life is in many ways the story of a battle between two opposing forces; pressure and gravity. A star is born when gravity becomes strong enough over come pressure within a gas cloud and compress it until nuclear fusion begins. A star lives while energy generated by fusion can keep pressure and gravity in steady balance. A star dies as it exhausts its fuel for fusion and goes out of balance again..."

-The Cosmic Perspective Fundamentals

By Bennett


The process of stellar evolution is the process in which things such as gravity effect a star and alter the composition of a star. These changes in the star can be seen and viewed quite dramatically in the different stages the star goes through. All stars eventually run out of fuel and will disappear which is referred to as it's death. The importance of stellar formation is in understanding the star in our own galaxy, which is the sun. It also aids in understanding under what conditions in which new planetary systems and galaxies may be formed. Stellar formation causes many important things to occur within are universe and so understanding the process that stars go through over time is of great importance.

Stellar Evolution:
external image hrdiagram_th.jpg
Stellar evolution chart.
Stellar evolution chart.





Website Name: the Astronomical UnitURL: http://www.astunit.com/astunit_tutorial.php?topic=stellarAuthor:Stephen TonkinLast Update: July 19, 1998[[#|Date]] Reviewed: November 27, 2012Reviewed By: Darren KongAccuracy: The information on the page seems to be fairly accurate although some of its information may be outdated as the page has not been updated in over a decade. Most of the information on the page agrees with other sources online.Readability and Clarity: Information and writing style of the page seems more targeted towards young adults that have little or limited knowledge on astronomy. The Page is written with many definitions on the more vague or complicated astronomy terms, it is also spaced out clearly on each subject making it fairly easy to read.Ease of Navigation: The rest of the website the page is on is simple to navigate with tabs and a search function for any visitor to use. However this page is the only section on stellar evolution the other pages would work to improve you knowledge in other areas of astronomy.

Dark nebulae, located in in the constellation of Orion. Also called the 'Horsehead Nebula'.
Dark nebulae, located in in the constellation of Orion. Also called the 'Horsehead Nebula'.

Name of Website: tufts.edu
URL:http://cosmos.phy.tufts.edu/~zirbel/ast9/handouts/StellarEvolution.PDF
Author: The author is not know however the page is hosted on Tuft [[#|university]], so the information on this page should be very reliable.
Last Update:N/A
[[#|Date]] Reviewed:11/28/12
Reviewed By:Darren Kong
Accuracy: All the information on this link is quite accurate, and there do not seem to be an contradicts with other sources.
Readability and Clarity: The link has all it's information in written in an orderly order. It does not seem however that this should not be read by children as the terms used in the page are confusing and the page is fairly wordy, although there are diagrams that can work to explain things to it's readers.
Ease Navigation: The link leads only to a few pages of information, so there is nothing to explore in the link one merely scrolls down the page to view the information. The page is part of a website where more information can be found.



Name of Website: http://chandra.harvard.edu
URL: http://chandra.harvard.edu/edu/formal/stellar_ev/
Author:
Last Update:September 24, 2008
[[#|Date]] Reviewed: 11/28/12
Reviewed By: Darren Kong
Accuracy: The website should be accurate as it is hosted on a site that shares a relation with NASA. the page was last updated four years ago so the informarion should also be up to [[#|date]].
Readability and Clarity: The page has a very small amount of information in it making it fairly simple to read, the information is also a brief overview so the audience does not have to know much about astronomy. So the page is more for people that would like a small look into stellar evolution.
Ease Navigation:The web page gives links to many other different resources that someone can go to further their knowledge on stellar evolution.


external image 167321main_image_feature_741_ys_full.jpg
Name of Website: http://www.historyoftheuniverse.com/
URL: http://historyoftheuniverse.com/index.php?p=star.html
Author: David Christian
Last Update:N/A
Date Reviewed:11/28/12
Reviewed By: Darren Kong
Accuracy: The site contains accurate and well written information that gives you an explanation of the evolution of the stars.
Readability and Clarity: The information is given in small pieces on each page so the page is pretty readable. the page seems to use some more advanced astronomy terms but it is fairly readable for a most ages.
Ease Navigation: The link leads to one page that gives an explanation of stars. You can click on the tab on the bottom of the page that can let you go through the pages which give more explanations to the life a star.


Bubble-like shock wave still expanding from a supernova explosion 15,000 years ago.
Bubble-like shock wave still expanding from a supernova explosion 15,000 years ago.

Name of Website: alcyone.com
URL:http://www.alcyone.com/max/writing/essays/stellar-evolution.html
Author: Erik Max Francis
Last Update: January 1, 2012
Date Reviewed:11/30/12
Reviewed By:Darren Kong
Accuracy: The information on the site seems to be accurate and the page was last updated on January 1st so the page should be updated or checked on fairly recently.
Readability and Clarity: The page gives it's information an essay form so the main audience would be intellectuals or anyone that is knowledgeable in stellar evolution. the footnotes at the bottom of the essay make it a bit easier to understand the writing.
Ease Navigation: The bottom of the page gives more links to other essays done by this author, however these essays deal with different subjects within astronomy and do not talk about stellar evolution.



Name of Website: Astronomy Today
URL: http://www.astronomytoday.com/cosmology/evol.html
Author: Marc Delhanty
Last Update: N/A
Date Reviewed: 11/30/12
Reviewed By: Darren Kong
Accuracy: The information is accurate and has nothing that would contradict the information of another source.
Readability and Clarity: The page is more of an introduction to the evolution to stars so it is suitable for all ages. The the information is broken up into many readable junks so that they are not too wordy to read.
Ease Navigation: The page gives out several other links to subjects regarding space and astronomy, which lead to different parts of the home site.


external image Ring.jpg

Name of Website: cass.ucsd.edu
URL: http://cass.ucsd.edu/archive/public/tutorial/StevI.html
Author: Gene Smith
Last Update: April 12, 1999
Date Reviewed: 11/30/12
Reviewed By: Darren Kong
Accuracy: The information given in the page is the same as many other pages with no contradictions between it and other sources. Although the information was updated a decade ago so some of it might be outdated
Readability and Clarity: The information of the page is very readable and is split into several easy to read sections. People that are teenagers or older should have no trouble reading this page as the many graphs and images make it manageable to read.
Ease Navigation: The URL links is connected to another explanation that is linked on the bottom of the first part. Besides this there are few parts that the page can link you too without going to the main host site.


M42, the Great Nebula in Orion.
M42, the Great Nebula in Orion.


Name of Website: Australia Telescope National Facility
URL: http://outreach.atnf.csiro.au/education/senior/astrophysics/stellarevolution_links.html#stellevolgeneral
Author: N/A
Last Update: April 29, 2005
Date Reviewed: 11/30/12
Reviewed By: Darren Kong
Accuracy: There is no information on this page however most of the links still work although half are broken this is still a good place for one to find information about stars.
Readability and Clarity: Each of the links give a short description which makes it easy to understand what you are looking at before you follow the link. The site is good for all ages to learn about astronomy as the links are good for children and adults.
Ease Navigation: This page itself gives no information on Stellar evolution, it instead gives several links that can help one learn about stellar evolution. These links lead to a different sites but some lead to the host site as well.



Name of Website: Aspire
URL: http://aspire.cosmic-ray.org/labs/star_life/starlife_main.html
Author: N/A
Last Update: N/A
Date Reviewed: 11/30/12
Reviewed By: Darren Kong
Accuracy: The information is accurate and nothing from other sources contradicts the information within the page.
Readability and Clarity: The page is suitable for children and is not very wordy. The many diagrams in the page make it easy even for children to read and learn about astronomy.
Ease Navigation: The page has arrows which can link you to the different parts making it easy to navigate as the site explains the process of a star. All of the link on the page lead to the main site and do note give out links to external sites.


Neutron Star
Neutron Star


Name of Website: University of Michigan
URL: http://www.umich.edu/~gs265/star.htm
Author: Arthur Holland and Mark Williams
Last Update: N/A
Date Reviewed: 12/01/12
Reviewed By: Darren Kong
Accuracy: All the information on the site seems to be accurate giving an correct depiction of all the forms a star may take in it's life such as a neutron star and black holes.As this site is hosted on the University of Michigan's site the chances that the information would be wrong. Nothing from this page contradicts the information of other pages.
Readability and Clarity: The information would be more suited towards the older teenagers and adults as the language and concepts talked about may be foreign to someone with limited knowledge in astronomy. although the bottom of the page includes a glossary for the terms used it is still not something that a younger teenager would be able to read easily.
Ease Navigation: The page contains no other links that one could further explore or go to to learn about stellar evolution.




Remnant of a supernova
Remnant of a supernova


Name of Website: NASA science
URL: http://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve/
Author: N/A
Last Update: N/A
Date Reviewed: 12/01/12
Reviewed By: Darren Kong
Accuracy: All the information on the page is accurate. Showing all the different stages of a stars life to be the same as other sources which talk about a star's stages in life. Even though is no update date for the site I could find, it seems to be updated as there are many links for new discoveries on the page.
Readability and Clarity: The page gives a good basic introduction to stars in general and then moves on to the different types of stars and when those stars occur. The information is given in a very organized matter using tables to explain different parts of the star's life cycle. The page should be more geared toward young adults, though there should be much of a problem for for someone who is new to astronomy understanding
Ease Navigation: The page is gives several links at the bottom of the page which gives out recent discoveries of different types of stars. This works very well to further one's knowledge on stars and to give a good perspective on what they are reading. The links lead to external sites, one could also use the navigation tabs to search about stellar evolution on the NASA site.


external image supernova%201987A%20Rings.gif

Name of Website: Thinkquest.org
URL: http://library.thinkquest.org/26220/stars/formation.html
Author: Oracle Corporation
Last Update: N/A
Date Reviewed: 12/02/12
Reviewed By: Darren Kong
Accuracy: All the information on the site is accurate and does not contradict the information on stellar evolution on other sources. The last date this site was updated is not known but the information seems to be the same as other sources and pages that have been updated.
Readability and Clarity: The page is very easy to read is more suited towards children readers that are just beginning to learn about stars. The information is very basic and easy to understand. The page also has a list of important terms to know while reading so one can understand the information even if they are not familiar to the more complicated terms.
Ease Navigation: The Thinkquest site has several different links and pages that can be explored on the site to learn about different types of stars, galaxies, and the universe. This makes it easy for one to gain more information on astronomy using this site.


Name of Website: http://www.maa.mhn.de/scholar.html
URL: http://www.maa.mhn.de/Scholar/star_evol.html#INDEXA1.1
Author: Nick Strobel
Last Update: August 29, 1995
Date Reviewed: 12/02/12
Reviewed By: Darren Kong
Accuracy: The information on this page discusses the general idea on what star evolution is and the several stages of life that the star goes through in a lifetime. The information is fairly general and the information matches with what other sources have said.
Readability and Clarity: The page is clearly not written for children and is more likely created for more adult users to read. Thinking on this audience it is fairly y straight forward and not difficult to read.
Ease Navigation: The top of the page contains several links as an index to help you navigate the page while reading with ease.