How do supernovae happen

A white dwarf is what's left after a star the size of our sun has run out of fuel. If one white dwarf collides with another or pulls too much matter from its nearby star, the white dwarf can explode. In this illustration, a white dwarf pulls matter from a companion star. Eventually, this will cause the white dwarf to explode. Image credit: STScI. These spectacular events can be so bright that they outshine their entire galaxies for a few days or even months.

They can be seen across the universe. Not very. Astronomers believe that about two or three supernovas occur each century in galaxies like our own Milky Way. Because the universe contains so many galaxies, astronomers observe a few hundred supernovas per year outside our galaxy. Space dust blocks our view of most of the supernovas within the Milky Way. Scientists have learned a lot about the universe by studying supernovas. Animals Wild Cities Morocco has 3 million stray dogs. Meet the people trying to help.

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Travel A road trip in Burgundy reveals far more than fine wine. Travel My Hometown In L. Subscriber Exclusive Content. Why are people so dang obsessed with Mars? That bright star isn't actually a star, at least not anymore. The brilliant point of light is the explosion of a star that has reached the end of its life, otherwise known as a supernova.

Supernovae can briefly outshine entire galaxies and radiate more energy than our sun will in its entire lifetime. They're also the primary source of heavy elements in the universe. According to NASA , supernovae are "the largest explosion that takes place in space. Various civilizations recorded supernovae long before the telescope was invented. Their records show that this "guest star" stayed in the sky for eight months, according to NASA.

Before the early 17th century when telescopes became available , there are only seven recorded supernovae , according to Encyclopedia Britannica. What we know today as the Crab Nebula is the most famous of these supernovae. Chinese and Korean astronomers recorded this star explosion in their records in , and southwestern Native Americans may have seen it as well according to rock paintings seen in Arizona and New Mexico.

The supernova that formed the Crab Nebula was so bright that astronomers could see it during the day. Other supernovae that were observed before the telescope was invented occurred in , , , studied by famed astronomer Tycho Brahe and When the pressure drops low enough in a massive star, gravity suddenly takes over and the star collapses in just seconds.

This collapse produces the explosion we call a supernova. Supernovae are so powerful they create new atomic nuclei. These fusion reactions create new atomic nuclei in a process called nucleosynthesis. Supernovae are considered one of the original sources of the elements heavier than iron in the Universe. Even the iron in your blood can be traced back to supernovae or similar cosmic explosions from long before our Sun had formed. Supernovae are thus essential to life.