An oversized supernova image is exploding

Scientists at the Weizmann Institute of Science and the University of San Diego have for the first time observed what happens when a star is 50 times larger than the sun explodes. As they continued to observe this spectacular event, they discovered that the majority of the star's mass crumbled to form a large black hole.

Although the exploding stars - also known as supernovae - can be observed with the naked eye or by high-tech satellites used in research, no one has been honored to witness it. the moment a big star explodes. Dr. Avishay Gal-Yam of the Weizmann Institute's Department of Physics and Professor Douglas Leonard of San Diego University recently located and calculated the mass of a giant star about to explode. Their findings, published in the journal Nature, also support the contemporary hypothesis that stars 10 to 100 times the mass of the sun will eventually end up as black holes.

The moment of the end of a star has been predetermined since it was formed by its size as well as the energy source that helps it shine throughout life. Stars, including our sun, are mixed with helium by hydrogen nuclei in extreme heat and pressure inside the energy supply core. A helium nucleus is slightly lighter than the total mass of four hydrogen nuclei. According to Einstein's theory of relativity (E = mc2), we know that the lost mass is released into energy.

When stars like the sun use up all their hydrogen energy, they will die quite calmly through the stream of steam. But the star that is 8 times bigger than the sun has a much more spectacular death. Nuclear fusion will continue after the hydrogen source is depleted, to produce heavier elements distributed in different classes of stars. When this process reaches a level where the star's core turns into iron, another phenomenon occurs: under extreme pressure and temperature in the central region of the star, the iron nucleus divides into protons and neutrons. To some extent, this causes the core and layers above it to sink, burning the remaining part of the star quickly in a flash of a supernova.

Scientists have recently observed an oversized supernova explosion from the beginning to the end, resulting in a black hole forming. (Photo: Image courtesy of Weizmann Institute of Science)

In just a few days supernovae release more energy than the total energy that our sun releases during the life cycle, the supernova explosion is so bright that even if it happens in our way hundreds light years, we can still observe even during the day. While the outer layers of the supernova light the universe like fireworks, its core subsides deeper and deeper inside. Gravity generated in this phenomenon is so large that protons and electrons are twisted together to form neutrons, the core of the star is reduced in size: from a 10,000 km circumference sphere to just 10 km. Now the matter of the star is only equal to our Earth. But when an exploding star is about 20 times more massive than the sun or more, its gravity is so strong that the wavelengths of light are also held in place. Such stars are essentially black holes, almost impossible to observe.

Until now, no supernova stars that scientists have identified are 20 times more massive than the sun's weight. Gal-Yam and Leonard searched in a specific area of ​​space using the Keck telescope located at Mauna Kea in Hawaii and the Hubble space telescope. Supernova SN 2005gl was originally observed in the striped stripe galaxy NGC 266 on October 5, 2005. Photographs before the explosion occurred by Hubble telescope in 1997 The photos show the star glowing brightly. Recognizing that a star is about to explode, scientists have calculated its weight, about 50 to 100 times the weight of the sun. Subsequent observations revealed only a small fraction of its mass was removed in the explosion. Most of the material, according to Gal-Yam, is pulled into the core zone due to increased gravity. Indeed, in photographs taken by telescopes then the star seems to have disappeared. In other words, it has become a black hole - it has such a strong attraction that even light cannot escape.

Research by Dr. Avishai Gal-Yam received support from the Astrophysical Center of Nella and Leon Benoziyo, the awards of Peter and Patricia Gruber, the Heritage Foundation, and the William Z. and Eda Young Scientists Fund Bess Novick.

Refer
A. Gal-Yam, DC Leonard.Một lớn hypergiant sao như là progenitor of the supernova SN 2005gl.Nature, 2009;DOI: 10.1038 / nature07934