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An overview of the exploding star supernova in astronomy

A blindingly bright star bursts into view in a corner of the night sky — it wasn't there just a few hours ago, but now it burns like a beacon.

  • Spectroscopically, they show blue-shifted emission lines, which imply that hot gases are blown outward;
  • One suggestion has been that the shock of an exploding star may compress raw material in its cosmic neighborhood and give it the extra little "kick'' it needs to collapse into new stars;
  • Stars develop when gravity compacts clouds of gas;
  • As they burn through the thin air, usually 60 to 100 kilometers above the ground, they create luminous streaks that we call meteor;
  • Also, in recent years, we have found intriguing evidence that the formation of our own solar system may well have been triggered by a nearby supernova more than five billion years ago.

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.

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They're also the primary source of heavy elements in the universe. According to NASAsupernovae are "the largest explosion that takes place in space. 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 availablethere are only seven recorded supernovaeaccording to Encyclopedia Britannica.

  • While peering at her computer screen, astronomer Alicia Soderberg expected to see the small glowing smudge of a month-old supernova;
  • So when electrons and positrons collide, they annihilate each other, releasing energy;
  • The Best Meteor Showers This table gives some characteristics of the four meteor showers that usually produce the year's richest crops of meteors;
  • Type Ia supernovae that exploded when the universe was only two-thirds of its present size were fainter and thus farther away than they would be in a universe without dark energy.

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 1054, and southwestern Native Americans may have seen it as well according to rock paintings seen in Arizona and New Mexico.

  • Because of the enormous violence of the supernova explosion, the material it produces — in the form of individual atomic nuclei — can be propelled into space at speeds approaching the speed of light;
  • The total distance they now span would equal one light-year.

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 393, 1006, 1181, 1572 studied by famed astronomer Tycho Brahe and 1604.

Brahe wrote about his observations of the "new star" in his book, "De nova stella," which gave rise to the name "nova. Both are sudden outbursts of brightness as hot gases are blown outward, but for a supernova, the explosion is cataclysmic and signifies the end of the star's life, according to Encyclopedia Britannica. The term "supernova" was not used until the 1930s.

It was located in the Andromeda Galaxy. They also suggested that supernovas happen when ordinary stars collapse into neutron stars. In the modern era, one of the more famous supernovas was SN 1987A from 1987, which is still being studied by astronomers because they can see how a supernova evolves in the first few decades after the explosion.

Weird star explodes over and over, cheating death

Star death On average, a supernova will occur about once every 50 years in a galaxy the size of the Milky Way. Put another way, a star explodes every second or so somewhere in the universe, and some of those aren't too far from Earth. Exactly how a star dies depends in part on its mass.

Our sun, for example, doesn't have enough mass to explode as a supernova though the news for Earth still isn't good, because once the sun runs out of its nuclear fuel, perhaps in a couple billion years, it will swell into a red giant that will likely vaporize our world, before gradually cooling into a white dwarf. But with the right amount of mass, a star can burn out in a fiery explosion.

A star can go supernova in one of two ways: For a star to explode as a Type II supernovait must be at several times more massive than the sun estimates run from eight to 15 solar masses. Like the sun, it will eventually run out of hydrogen and then helium fuel at its core.

Astronomers Find Star That Has Exploded Six Times

However, it will have enough mass and pressure to fuse carbon. Here's what happens next: Once the star's core surpasses a certain mass the Chandrasekhar limitthe star begins to implode for this reason, these supernovae are also known as core-collapse supernovas. The core heats up and becomes denser. Eventually the implosion bounces back off the core, expelling the stellar material into space, forming the supernova.

What's left is an ultra-dense object called a neutron stara city-sized object that can pack the mass of the sun in a small space.

There are sub-categories of Type II supernovas, classified based on their light curves. Both types have the signature of hydrogen in their spectra. Stars much more massive than the sun around 20 to 30 solar masses might not explode as a supernova, astronomers think. Instead they collapse to form black holes. Type I supernovae Type I supernovae lack a hydrogen signature in their light spectra.

Type Ia supernovae are generally thought to originate from white dwarf stars in a close binary system. As the gas of the companion star accumulates onto the white dwarf, the white dwarf is progressively compressed, and eventually sets off a runaway nuclear reaction inside that eventually leads to a cataclysmic supernova outburst.

Astronomers use Type Ia supernovas as " standard candles " to measure cosmic distances because all are thought to blaze with equal brightness at their peaks.

Type Ib and Ic supernovas also undergo core-collapse just as Type II supernovas do, but they have lost most of their outer hydrogen envelopes. In 2014, scientists detected the faint, hard-to-locate companion star to a Type Ib supernova. The search consumed two decadesas the companion star shone much fainter than the bright supernova.

Caught in the act Recent studies have found that supernovas vibrate like giant speakers and emit an audible hum before exploding. In 2008, scientists caught a supernova in the act of exploding for the first time.

While peering at her computer screen, astronomer Alicia Soderberg expected to see the small glowing smudge of a month-old supernova. But what she and her colleague saw instead was a strange, extremely bright, five-minute burst of X-rays.

With that observation, they became the first astronomers to catch a star in the act of exploding. The new supernova was dubbed SN 2008D. Further study has shown that the supernova had some unusual properties.