What did people learn from the end of the dead star? For stars with huge volumes and energies, their formation and evolution mechanisms show relative simplicity, and only by understanding the mass of stars and the proportion of elements heavier than hydrogen, people predict their life cycle from cradle to grave, but the evolution of stars is not as simple as imagined, and there is often a rather strange phenomenon, and the forces of nature seem to remind people that there is always a truth that people do not know in the evolution of stars. One of the missions of scientists is to reveal the truth of nature, and the purpose of understanding the laws of nature is to make the laws of nature serve human beings, as if sociologists and journalists are eager to reveal the truth about social events, and the principles of fairness and justice can better serve human beings.
A recent paper published in the journal Science describes the bizarre spectacle of the stellar world, in which scientists discovered bizarre properties through a search of more than 30,000 white dwarfs. A white dwarf is a remnant of a dead star, as if the Sun had died billions of years later and eventually became a white dwarf. A strange white dwarf is almost composed of oxygen, how does an oxygen white dwarf form? Why do white dwarfs have "oxygen" all over their bodies? Scientists are puzzled by this.
Each star is a "giant bomb" of nuclear fusion, by burning light elemental materials such as hydrogen and helium, forming heavier elements such as carbon and oxygen through nuclear fusion reactions within the star. The greater the mass of the star, the brighter it emits, and the faster the fuel consumption. Stars with more than 10 times the mass of the Sun will throw nuclear dust composed of heavy elements into space, and the heavy elemental material thrown into space will form a beautiful landscape of planetary nebulae, which will accumulate and eventually collapse into the next generation of stars and rocky, gaseous planets through their own gravity. Rocky planets in habitable zones may have created conditions for life activity.
Humans are intelligent life on earth planets, and humans are advanced forms of life on earth, and advanced life forms breathe oxygen and eat carbohydrate foods, as the famous astronomer Carl Sagan said, "Our bodies are made of stellar matter." What will the death of a star ultimately leave behind? A large part of the "ash slag" of the sun's mass is compressed into the scale of the Earth, and the incredible density of matter relies on the forces of nature, a teaspoon of object mass equivalent to the mass of about a large truck, astronomers call such high-density objects white dwarfs, and in about 5 billion years, the sun will be on the path of white dwarf destiny.
Scientists' latest discovery of the white dwarf is equivalent to half the mass of the sun, the volume is smaller than our Earth, which means that the gravitational force on its surface will be 100,000 times that of the Earth, if you walk on this planet, then people feel as if they are holding 40 huge weight blue whales on their backs, people try to walk forward, not walking hard, but simply can't walk, there is a feeling of "heavy" in the heart. In order to carry out the thought experiment of "walking on a white dwarf", one had to assume that the "experimenter" did not burn into crispy "potato chips", and the surface temperature of the hot and glowing white dwarf reached 20,000 K. It seems that the ash that burned out at the campfire party, through the examination of the remaining ash residue, people can understand what fuel was burned, and people may leave ashes of wood or burned plastic packaging items at the campfire party. After the combustion of a huge amount of stellar nuclei, different elemental materials are left, and the larger the mass and volume of the star, the higher the temperature of the nuclear combustion, and the more heavy elemental material is left.
Astronomers have only seen oxygen on the peculiar white dwarf, all the carbon has been condensed into heavier elements, and scientists are puzzled that the existing physical models indicate that the conditions under which white dwarfs cannot form aggregate carbon elements, there must be some kind of star death mechanism that people do not understand, and the existing physical model has loopholes. There is an idea that the star pulsates at the end of its life cycle, and under the action of strong radiation pressure, the outer layer of the star is lifted, and the carbon material is smashed again on the surface of the nucleus of the ball, temporarily creating a strong reaction condition, and all the carbon elements are fused into oxygen. Any remaining lighter elemental material, such as hydrogen and helium, may have been "stolen" by the gravitational pull of a nearby companion star, whose presence has not yet been discovered, leaving behind a white dwarf composed only of oxygen.
This white dwarf is extremely unique among thousands of screened white dwarfs, the fact of existence itself proves the value of its scientific discoveries, supernovae occurring in the universe are amazing celestial destruction events, how do supernovae form white dwarfs composed of a single element of oxygen? How does it form? Astrophysicists have worked to correctly describe its formation on the basis of observations. In some supernovae, the explosion of a white dwarf is like a time bomb, this supernova has the same brightness, astronomers see them as "standard candlelight", used to measure the distance of the universe, "candlelight" is brighter, indicating closer distance, and conversely, "candlelight" is darker, indicating a longer distance.
Based on the brightness of standard candlelight, astronomers measured the rate at which the universe expanded, and Professor Brian Schmidt, vice-chancellor of the Australian National University, shared the 2011 Nobel Prize in Physics for the discovery of the accelerated expansion of the universe. White dwarfs are one of the end points of the star's life path, and strange white dwarfs have many confusing mysteries, and scientists are still trying to tell the "astronomical story" of white dwarfs. There are still many unsolved mysteries about extreme celestial bodies, and there is no proud end point on the road to learning from nature.
(Compiled: 2016-4-6)
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