Stardeath

**Why Do Stars Burn and What Happens When They Die? **
[] It starts off talking about how a star is formed by hydrogen being brought together by the force of gravity. This section finished by talking about nucleosynthesis before moving on to "The Burning of a Star" and "The Cooling of a Star". It finishes by explaining how a star will collapse in on itself, becoming a white dwarf or even a neutron star, depending on its size. After this occurs, the white dwarf may become a supernova, and eventually becomes a black hole.
 * Author:** Andrew Zimmerman Jones
 * Overview:** This is a great website that starts with the birth of stars and explains the steps until star death.
 * Updated**: 4/3/2018
 * Reviewed by:** Jenna Boeger 5/15/2018
 * Accuracy:** Very accurate as it was updated just a few months ago.
 * Readability/Clarity:** This article is brief but informative because it pinpoints the most important parts of the process of star death without using too many technical phrases that may be difficult for a student or even someone unfamiliar with astronomy to understand.
 * Navigation:** Easily maneuverable because everything is on a single page.

** Cool Cosmos: Star Death **
[] **Author:** Unknown **Overview:** This article is brief but covers a variety of topics related to star death. It starts will an introduction before talking about "Cosmic Recycling", Small Stars: Planetary Nebulae", "Cosmic Soccerballs", and finally "Big Stars: Supernova Remnants". The article starts with a brief discussion about nuclear fusion and how that relates to the life of a star. Next, it talks about how when a star dies, particles from it are sent back into the universe and used again, thus creating a new cycle. After, it discusses how when a star is about to die, it releases its outer layer creating planetary nebulae, a term coined when an astronomy believed he was looking at something similar to Uranus. Following this section, it mentions a type of carbon particle found inside the planetary nebulae called Buckminsterfullerene, or "Buckyballs" for short. Finally, it talks about supernovas and how they pertain to star death. **Updated:** 6/13/2014 **Reviewed by** Jenna Boeger 5/15/2018 **Accuracy:** Fairly accurate since it is only a few years old.
 * Readability/Clarity: **This is a great article that is clearly written and fairly easy to follow. Some of the terminologies are difficult to follow, but most of the information is written in simpler terms.
 * Navigation:** Easily navigated since it is a single page.

 The Death of Stars I: Solar Mass Stars
[]

**Author**: NASA and Hubble Heritage Team
 * Overview:** It starts off talking about the technical parts of planetary nebulae and even provides a few pictures to help with understanding since the description is quite complicated. Next, it discusses white dwarfs and offers a detailed graph depicting temperature differences, color, and size by using absolute magnitude. This graph is easy to use if you know what absolute magnitude is and how each color correlates with a different temperature. The last section is about "The Chandrasekhar Limit" and is more technical than the rest of the article, making it difficult to comprehend unless you are familiar with the terminology.
 * Updated:** Unknown
 * Reviewed by** Jenna Boeger 5/15/2018
 * Accuracy:** Very accurate since it was written by NASA and one of its Hubble Heritage Teams
 * Readability/Clarity:** This article is quite a bit more technical than the previous ones so it is more difficult to read. If you can understand the astronomy jargon, this article will be really helpful if you're writing a technical paper or just need a more in-depth understanding.
 * Navigation:** Easily navigated because it is one page.

 The Death of Stars ll: High Mass Stars
 [] **Author:** ESO **Overview:** This article is on the same website as the previous so many of the elements are the same. Unlike the previous article, it discusses what happens to larger stars and dives deeper into the science behind the process. It talks heavily about supernovae and the energy related to the process of their creation. Later on, it talks about hypernovae as well as pulsars and neutron stars, which are all part of the star death process. The last topic it discusses is black holes, which is the last stage in star death. What's helpful about this page is how it provides several diagrams, pictures, and animations to help the reader visualize the process they are reading about. **Updated:** Unknown <span style="font-family: Arial,Helvetica,sans-serif;">**Reviewed by** Jenna Boeger 5/15/2018 <span style="font-family: Arial,Helvetica,sans-serif;"><span style="font-family: arial,helvetica,sans-serif;">[] <span style="font-family: Arial,Helvetica,sans-serif;">**Author:** ESA, NASA, Hubble, Judy Schmidt <span style="font-family: Arial,Helvetica,sans-serif;">**Overview:** <span style="font-family: Arial,Helvetica,sans-serif;"> It features an image taken by the HUBBLE telescope and depicts a red giant becoming a planetary nebula. The description of what exactly is occurring is brief and simplified so it's easy to understand and comprehend. This article provides a detailed description of the nebula and includes things such as smell, sight, and chemical composition that aid greatly in the understanding of nebulae. <span style="font-family: Arial,Helvetica,sans-serif;">**Updated:** 10/5/2017 <span style="font-family: Arial,Helvetica,sans-serif;">**Reviewed by** Jenna Boeger 5/15/201 <span style="font-family: Arial,Helvetica,sans-serif;">**Readability/Clarity:** <span style="font-family: Arial,Helvetica,sans-serif;">This article is very short but is very useful if you're having a hard time picturing what the star death looks like. Good descriptions for visual learners and very little use of technical jargon.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Accuracy: **Very accurate because this a teaching source and the terms are very technical.
 * Readability/Clarity:** The information is written in highly technical terms and equations are given to explain certain subjects, so a high level of comprehension will be required. Like with the previous article, this information would be best for writing technical papers or furthering your understanding of astronomy.
 * Navigation:** Easily navigated due to the single page format.<span style="font-family: "Times New Roman",Times,serif; font-size: 130%;">Death of a Star
 * <span style="font-family: Arial,Helvetica,sans-serif;">Accuracy: **<span style="font-family: Arial,Helvetica,sans-serif;"> Very accurate as it was written by NASA, Hubble, and other credible sources.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Navigation: **<span style="font-family: Arial,Helvetica,sans-serif;">Easily navigated.

His brief definition of how stars of varying sizes die goes as follows: __**<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">"Stars Like the Sun **__ <span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">When the core runs out of hydrogen fuel, it will contract under the weight of gravity. However, some hydrogen fusion will occur in the upper layers. As the core contracts, it heats up. This heats the upper layers, causing them to expand. As the outer layers expand, the radius of the star will increase and it will become a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">red giant **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">. The radius of the red giant sun will be just beyond the Earth's orbit. At some point after this, the core will become hot enough to cause the helium to fuse into carbon. When the helium fuel runs out, the core will expand and cool. The upper layers will expand and eject material that will collect around the dying star to form a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">planetary nebula **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">. Finally, the core will cool into a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">white dwarf **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;"> and then eventually into a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">black dwarf **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">. This entire process will take a few billion years.
 * <span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">Craig Freudenrich, Ph.D., **<span style="background-color: #ffffff; font-family: Arial,Helvetica,sans-serif;">is a freelance science writer and former senior editor at HowStuffWorks.

__**<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">Stars More Massive Than the Sun **__
<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">When the core runs out of hydrogen, these stars fuse helium into carbon just like the Sun. However, after the helium is gone, their mass is enough to fuse carbon into heavier elements such as oxygen, neon, silicon, magnesium, sulfur, and iron. Once the core has turned to iron, it can no longer burn. The star collapses due to its own gravity and the iron core heats up. The core becomes so tightly packed that protons and electrons merge to form neutrons. In less than a second, the iron core, which is about the size of the Earth, shrinks to a neutron core with a radius of about 6 miles (10 kilometers). The outer layers of the star fall inward on the neutron core, thereby crushing it further. The core heats to billions of degrees and explodes ( **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">supernova **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">), thereby releasing large amounts of energy and material into space. The shock wave from the supernova can initiate star formation in other interstellar clouds. The remains of the core can form a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">neutron star **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;"> or a **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;">black hole **<span style="background-color: #ffffff; color: #333333; font-family: arial,helvetica,clean,sans-serif; font-size: 12px;"> depending upon the mass of the original star." //<span style="color: #800080; font-family: &#39;Comic Sans MS&#39;,cursive; font-size: 240%;">**Dylan Jensen: Fall 2012** //

**__ Stars: The End of a Star __**
@http://aspire.cosmic-ray.org/labs/star_life/starlife_end.html

Reviewed by Dylan Jensen: 11/13/12 Author: University of Utah This page gives an easy to read, accurate description and summary of a star's last phase of existence. It is written for the interested astronomy student in an interactive, picture-based form. The page describes the differences between low-mass, medium-mass, and massive stars and gives examples of each. This website also gives easy to find interactive labs on various topics. These topics are the carbon burning process, what happens to different size stars at the end of their life cycles, and how white dwarfs and neutron stars are formed. This site would be most useful for children or someone just starting off with astronomy.

__ The Spectacle of Star Death __
__ @http://www.youtube.com/watch?v=E6FpSOg2BxE __

Reviewed by Dylan Jensen: 11/19/12 Author: Uploaded by SpaceRip Updated/Uploaded: Jan 20, 2012 This is a valuable YouTube video for the aspiring astronomer. The death of a star is broken down into a few easily understandable steps with a multitude of magnificent pictures. The caption reads: " Take a breathtaking journey into the future, five billion years from now, to see the ultimate fate of the Solar System. This gem from HubbleCast showcases stunning Hubble imagery of the death throes of Sun-like stars. The wreckage of these dying stars form the building blocks of new generations of stars".

__ Star Death __
@http://www.esa.int/esaKIDSen/SEM976WJD1E_OurUniverse_0.html

Reviewed by Dylan Jensen: 11/19/12 Author: European Space Agency This website gives a lot of valuable information to children. The website not only has information in regards to star death, but also about the origins of our solar system, the sun, planets, and their moons, and finally comets and meteors. The site is obviously written for a younger audience, as it is appropriately called "ESA for Kids". The website also has interactive labs for children and printable pages for workbooks and so-forth.

__ Stars Like the Sun Die in a Glorious Display __
@http://hubblesite.org/hubble_discoveries/hstexhibit/stars/stardeath_twin.shtml

Reviewed by Dylan Jensen: 11/19/12 Author: STScI - operated by the Association of Universities for research in Astronomy - prepared for NASA under contract NAS5-26555 This is an excellent website that provides pictures of various star deaths. The information on this site is extremely accurate, as the research for the website is funded by NASA. The website has four different well-known star deaths that have accompanying pictures and descriptions. These dying stars are Cat's Eye Nebula, Twin-Jet Nebula, Ring Nebula, and Hourglass Nebula. The website gives detailed descriptions for the average astronomy enthusiast as to why stars may die in these different shapes. Some reasons include small companion stars preventing the death to form a ring (as in the Twin-Jet Nebula), and how stars like the Sun puff off their outer layers when they die, as in the Cat's Eye Nebula.

//<span style="color: #800080; font-family: &#39;Comic Sans MS&#39;,cursive; font-size: 240%;"> **Daisy Gallegos: Spring 2011** // <span style="color: #800080; font-family: &#39;Comic Sans MS&#39;,cursive; font-size: 240%;">

=**<span style="color: #004175; font-family: Arial,sans-serif; font-size: 22px;">__ Double explosion signals star-death __ **=
 * // Edit by Daisy //**


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 * //Viewed on May 20, 2011//**
 * This website is very useful because it has a lot of different articles and includes the latest news about Stardeath.**

=**__ From Star birth to Stardeath __**=
 * //Edit by Daisy//**


 * [|http://thespacewriter.com/wp/2011/04/13/from-starbirth-to-stardeath]**


 * //Viewed on May 20, 2011//**
 * This website gives key facts about star birth and star death. It's straightforward and easy to understand. The website is written by "spacewriters" who write about many astronomy topics.**

=** __A Star's Death Comes to Light__ **=
 * //Edit by Daisy//**


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 * View//ed on May 20, 2011//**
 * This an image that is on the website. It shows the youngest supernova, which was caused by a star death. It has many facts about supernovas in the galaxy.**

=** The Cataclysmic Death of Stars **= [] Edit By Huy le

This link was written by Ron Cowen from National Geographic. This article gives you detailed information about the study that Ron did for NG on the Cataclysmic of star death.

=The Life and Death of Stars= [] Edit by Huy Le This link is very useful to get any information on the life of star death. It has some pictures for you to see how stars are formed and gives you an overview of star death. The pictures really help so you can have some visuals of how stars die. This page was last updated on 4/16/2010, so this information is pretty up to date.

__**The Death of Stars**__ [|**www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/stardeath.shtml**]

This site is a good starting point. It is well laid out with clear links to what you need. The text is clear and to the point, but at times can seem a little vague in some areas. This is where all the different links become very helpful. The site lays out the cycle of star death and how the sizes of a star determine the way it dies. When you click on the link to "Sun-like stars" it gives an easy to follow diagram on the stages of death for those sized stars as well as a description below. The site gives two other links for star sizes, "Huge Stars" and "Giant Stars." The site describes these sizes; huge stars as 1.5 to 3 times the mass of the sun and 3 or more times the mass of the sun for giant stars. One of the drawbacks of this site is that both of these links lead to the same page and only give a slight difference between the two. Overall the site has good, easily readable and well laid out information but is very brief. Couldn't find when it was last updated but copyright is through 2007. Again this site doesn't have everything you need but is a great starting place for your research or for anyone who is just curious and doesn't know much about astronomy. The author is not named. I feel like this site explains all about the death of stars in very easy to understand language.

__**Star Death**__ []

I really wouldn't recommend this site to anyone looking for general information on star death. Its very short and has very little information. Really the only thing this website would be good for is if you are writing an incredibly in-depth report and want to include stellar winds and how they are used to find information on dying stars. Even in that case, this is only one example of using this technique. If that is what you need then this site does use a specific star along with images and explanations of what instruments are used and what you are looking at. They have three video files of a professor talking about the subject, but again there isn't much information. Anyone using this site may also want to look for more up to date information as well to see if the information on the site is still valid because it hasn't been updated since 11/11/95. No specific author is named but the site is copyrighted by the Univ. of Illinois. The link to the site works but the videos on the site do not.

[]
 * __Chronicle Of A Star's Death Foretold__**

While this site is not about star death, in general, it is a really good website for research on specific star deaths. This webpage is an article on one specific star in the process of dying and is a good source of up to date information and has links to other articles on the study of dying stars. There is an abundance of information and is intended for those who are somewhat educated on the subject. It may take some extra research to understand everything that the article has to say, but the webpage does have some links to help with that and it would be well worth the effort if you are looking to write a really good in-depth paper on star death. The site also has links to other similar articles that are about different and even newly discovered types of star death. Since this is a science news website there will always be new material on it. I did not see any specific author for the article. There is a lot of good information on this site but it is geared towards someone who knows a little about astronomy or has taken a class.


 * The following has been added by Irene Craig.**

[|http://books.google.com/books?id=rMQFStCuzC8C&dq=white+dwarf&printsec=frontcover&source=bl&ots=37sRjupsjI&sig=485m4IyZ84D5ik4MSIocywt-AKo&hl=en&ei=rzf2SqK_IJHSsQPG-NEH&sa=X&oi=book_result&ct=result&resnum=11&ved=0CC4Q6AEwCg#v=onepage&q=white%20dwarf&f=false] //**__White Dwarf__**// //Viewed: 11-7-09// This may be a long website link, but it is a Google search. It is a full book on everything about white dwarfs. It has things from the discovery of a white dwarf to a model of its atmosphere. I would recommend looking at this site for information about white dwarfs because it’s a place where everything about white dwarfs is covered.

[] //**__Black Dwarfs__**// //Viewed: 11-7-09// This site has links to other articles about black dwarfs. There are many articles and most of them are a pretty short, quick overview about black dwarfs. Also, some of these articles have some other information about other things in the universe.

[] //**__Brown Dwarfs__**// //Viewed: 11-7-09// Most articles about brown dwarfs are short. This website had more information than most. It has information on what a brown dwarf is, detecting a brown dwarf, distinguishing them from other stars and planets, the different types of brown dwarfs, and where they can be found. It's probably the best site to find information on brown dwarfs.

[] //**__Red Giants__**// //Viewed: 11-7-09// There is little information on Red Giants. This site gives general information such as what it is and the temperature and mass. There may be other sites with better and more information, but they are probably connected to other links of a stars death. [] (this site has information on what is a star and different ways a star will die depending on its size)

[] //**__How Our Sun Will Die__**// //Viewed: 11-7-09// This site is quick information about how our sun will die. It has detail about how, when and why the sun will die.

[] //**__Supernova__**// //Viewed: 11-7-09// Briefly explains what a supernova is and gives the names of the different types. There are also supernova story links to give more information in supernovas. It has many different pictures and other information about things in the universe.