ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The Life Cycle of a Star

Updated on October 20, 2014

The life cycle of a star is a facinating process, taught in all junior science classrooms. In this brief hub I've compressed several billion years into a few paragraphs in order to demonstrate the life cycle of a star.

  1. Clouds of dust and gas (nebula) begin to collapse and spin. When the density reaches 100 atoms/cm3 gravity takes effect, and the temperature rises to form a protostar.
  2. The protostar joins the main sequence stars, where is position is dependant upon its mass (Refer to the Hertzsprung - Russel Diagram). Hydrogen is fused to helium in the core of the stars via proton-proton chain reactions and the CNO cycle (both occur in all stars, but one process is more dominant).
  3. When all the core hydrogen has fused, the shell of hydrogen ignites and expands to 200 to 300 times its original size, cools, and forms a red giant. The core contracts and heats, and helium begins to fuse to carbon and oxygen through the triple alpha reaction process.
  4. The star becomes increasingly unstable and begins to pulsate as a variable star. These pulsatations are often at regular intervals, and so serve as markers for scientist when measuring interstellar distances.
  5. Pulsations become more rapid, which eventually leads to the self-destruction of the star. Outer layers are violently thrown into space, and the core flares brightly for 2 to 3 weeks, called a nova.
  6. The nova graudually fades to become a white dwarf, surrounded by a layer of hot gas known as 'planetary nebula.' Note that the energy in white dwarfs is not due to electron degeneracy pressure, but the conversion of gravitational potential to kinetic energy to heat.
  7. The white dwarf eventually cools to form a black dwarf, and in time, the planetary nebula disappears.

The Life Cycle of a Star


    0 of 8192 characters used
    Post Comment
    • The Pink Panther profile imageAUTHOR

      The Pink Panther 

      8 years ago from Sydney, Australia

      Excellent question attempted humour. I guess it't not so much facinating as useful in trivia, or for making small talk on an elevator ;)


    • attemptedhumour profile image


      8 years ago from Australia

      Who the hell works this stuff out and why do we need to know? Are two questions that spring to mind. Because it's handy at trivia nights being one obvious answer and fascinating being another. Will i remember this info in three minutes time? Is another question too? Cheers PP.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)