Stars, like our sun, fill the universe. The core of a star constantly converts hydrogen, its fuel supply, into helium. This process, called “nuclear fusion,” makes stars shine so brightly.

After billions of years of burning, a star will eventually use up its hydrogen fuel supply. When nuclear fusion stops, gravity pulls the star inward on itself.

As the star begins to collapse, its inner shell eventually hits the iron core, which creates a huge shock wave. Kaboom! The star explodes, and a supernova is born!

Supernovae (the plural of supernova) can become billions of times brighter than our sun. A supernova explosion releases billions of tiny particles called “atoms” into space. These atoms form a huge dust cloud called a “nebula.”

Many of the atoms that exist today were originally created inside stars and released into space when the stars became supernovae. In fact, scientists believe much of the carbon, oxygen, nitrogen, silicon and iron on Earth came from supernovae.

The first stars became supernovae about 14 billion years ago. To give you an idea of how long ago that was, a billion seconds ago the year was 1979. Fourteen billion seconds ago the year was 1566. As you can imagine, 14 billion years was a really, really long time ago!

When a supernova ends, the star can become a white dwarf, neutron star or black hole. Smaller stars (those similar in size to our sun) become “white dwarf” stars. Medium-size stars (between two to five times the mass of our sun) become “neutron stars.”

Large stars (more than five times the mass of our sun) become “black holes.” The gravity inside black holes is so strong that not even light can escape!


21 Join the Discussion

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    • That’s a great question, Nick! Here’s the link to an article about the YOUNGEST person to discover one! She is only 10, but has made quite a large impact on the scientific community this year!

    • We think you should have spoken up when you discovered it, Tom! :-) Isn’t it great that someone so young can have such a significant impact on science?

  1. I love Wonderopolis and this was the second wonderopolis my class ever did. It was defentley my favorite!!!!

  2. Thank you for sharing that video! I really enjoyed that clip. The idea of a black hole and the universe just intrigues me. I cannot imagine the idea of it being never ending like the number pi. I love that you go out of your way to answer all these poeple who talk/blog to you! You guys are awesome!

    • We think YOU are awesome for checking out more Wonders in Wonderopolis, Team Wilch #4! We’re also glad to know that you did some WONDERing about black holes and supernovas! Way to go! :-)

    • Hi there, Anthony, great Wonder! We bet you could do some WONDERing of your own about gamma ray bursts! Some have lasted only a few milliseconds, while others have lasted for minutes! We hope you have a SUPER day! :)

    • Great question, Pedesto! We know that the color depends on the wavelength of light, so the color depends on the supernova burst itself! We hope you have a terrific Tuesday, Wonder Friend! :)

    • We’re so happy you learned and saw something new, Mining Kitten! Very cool! We hope you have a SUPERnova kind of weekend! :)

  3. Hi Wonderpolis! I never knew stars created super novae! I know that every galaxy has a black hole in the center but does that mean that a star created it?

  4. Seeing the supernova burst is so awesome! :)

    Some facts :
    Supernovas do not always become black holes, they sometimes become quasars. When supernovas explode, they shoot out billions of atoms in every direction resulting in the creation of colorful nebulae. In order for there to be black holes, the star must be big enough. If a supernova is at least one light year away, you will have one year to prepare for eminent doom.

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Have you ever wondered…

  • What is a supernova?
  • Why does the sun shine so brightly?
  • Where did a lot of the carbon, oxygen, nitrogen, silicon and iron on Earth come from?

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