A pair-instability supernova, located in a galaxy in the Pegasus constellation 240 million light-years away, is believed to be the brightest supernova ever since the early days of the universe.
Ordinary supernovas fall into one of two types. All supernovas occur during the dying days of a star, after the hydrogen fuel has been turned to helium, and the helium to higher-order elements such as carbon and all the way up to iron; without supernovas such higher-order elements could not exist. The first type, found in white dwarf stars around one and a half times as massive as our sun, are uniform explosions of the stars matter. The larger, second type is found in more massive stars, which instead of exploding implode, creating a neutron star or black hole and exploding the outer bits of the star outward. Both types of supernova typically reach peak brightness within a week, and fade away within a couple of months.
A supermassive star such as the one being observed, which weighs in at 100-200 times the mass of our sun, is far, far greater and rarer. Indeed, such explosions were thought to have existed only with first-generation stars that should have all died out billions of years ago. In such a star, the inner heat becomes so great that matter-antimatter pairs are created in large amounts, which eventually leads to an explosion that scatters the remains of the star into the intergalactic medium. These explosions are far more efficient at dispersing the higher-order elements needed for life. This supernova has also lasted a long, long time; it began in September 2006, reached peak brightness in 70 days, and even now nine months later is still one of the brightest objects in the night sky.
Ordinary supernovas fall into one of two types. All supernovas occur during the dying days of a star, after the hydrogen fuel has been turned to helium, and the helium to higher-order elements such as carbon and all the way up to iron; without supernovas such higher-order elements could not exist. The first type, found in white dwarf stars around one and a half times as massive as our sun, are uniform explosions of the stars matter. The larger, second type is found in more massive stars, which instead of exploding implode, creating a neutron star or black hole and exploding the outer bits of the star outward. Both types of supernova typically reach peak brightness within a week, and fade away within a couple of months.
A supermassive star such as the one being observed, which weighs in at 100-200 times the mass of our sun, is far, far greater and rarer. Indeed, such explosions were thought to have existed only with first-generation stars that should have all died out billions of years ago. In such a star, the inner heat becomes so great that matter-antimatter pairs are created in large amounts, which eventually leads to an explosion that scatters the remains of the star into the intergalactic medium. These explosions are far more efficient at dispersing the higher-order elements needed for life. This supernova has also lasted a long, long time; it began in September 2006, reached peak brightness in 70 days, and even now nine months later is still one of the brightest objects in the night sky.
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