Why does stars explode

And we don't know of anything that can do that. So there's no light that's actually being reflected out of a black hole. That's why we call them black. ERIC: So even though their gravity is incredibly strong, they're not actually sucking things up. It's a really beautiful deep sky object and Mahiro wanted to know why does it look like an explosion?

During that time it was recorded that it looked like a new star in the sky, but when we look now with telescopes we see all of this material that is left over from an exploded star. We often get asked if any of those could explode any time soon.

And if they did, what would it look like from Earth and would it destroy us? And I get this one a lot, especially in the planetarium. But yeah, I mean there are a few stars that we can see with our eyes that are nearing the end of their lives and that are massive enough to go supernova.

A couple that come to mind our Betelgeuse in the constellation of Orion, or Antares in the constellation of Scorpius. And both of these stars are red super giants that are nearing the end of their lives, but it's hard to tell exactly when they are going to go supernova. When astronomers say soon they generally mean within , years or so. And so it's hard to predict exactly when that will happen, but they're at a distance where it won't really cause any alarm.

It'll just look like a really bright star for maybe a couple of weeks. You'll be able to see it during the day, too. So it'll be very bright and then eventually it will fade out. ERIC: Well, if it's just a great show without vaporizing the earth, then hopefully we get to see a good supernova within our lifetime.

ERIC: For more on things in the night sky that could blow up at any time, tune in to our virtual planetarium shows at mos. About us. Sign Up for Email. We're Open! Why Giving Matters. Podcast Why Do Stars Explode? ERIC: Stars burn brightly for millions or billions of years. And then sometimes they blow up. Thanks, Eric. Iron can only absorb nuclear energy, not produce it. Since it can no longer produce energy, the star loses its source of internal pressure and collapses. When the collapse reaches a critical density it stops.

At this point, the matter in the star's core is packed so tightly that a block of its material the size of a sugarcube would weigh millions of tons. The core has become a neutron star -- an object more massive than the Sun, but only a few miles in diameter.

The process of collapse releases enough energy to rip the star's outer layers to bits and blast them into space at several percent of the speed of light. These fragments carry helium, calcium, oxygen, carbon, and other elements into space, where they may someday be incorporated into new stars and planets.

Artist's concept of a nova "Nova" is a Latin word that means "new. Novae occur in multiple star systems in which a white dwarf, neutron star, or even black hole draws gases from the outer atmosphere of a companion star into an envelope of matter around itself.

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The era of greyhound racing in the U. 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. They use the second type of supernova the kind involving white dwarfs like a ruler, to measure distances in space.

Stars generate the chemical elements needed to make everything in our universe. At their cores, stars convert simple elements like hydrogen into heavier elements. These heavier elements, such as carbon and nitrogen, are the elements needed for life.