What is a white dwarf?

White dwarf (also known as degenerate dwarf) is a star with low luminosity, high density and high temperature.

White dwarfs are white in color and small in size, so they are named white dwarfs. White dwarfs are stars that have evolved to the final stage. They are mainly composed of carbon and are covered with hydrogen and helium. White dwarfs gradually cooled and darkened over hundreds of millions of years. They are small in size and low in brightness, but high in density and mass.

The catalogue of white dwarfs published by 1982 shows that there are 488 white dwarfs found in the Milky Way, all of which are near celestial bodies not far from the sun. According to the statistics of observation data, about 3% of stars are white dwarfs, but theoretical analysis and calculation suggest that white dwarfs should account for about 10% of all stars.

Extended data:

German researchers have discovered the oldest white dwarf so far:

At 20 19 Beijing time, 2 1 Beijing time and 19 local time, NASA announced that the German volunteer scientist Melinda Zervinott had discovered the oldest and lowest temperature white dwarf.

This star, named J0207, is located in Capricorn, which is 145 light-years away from the Earth. Its temperature is 5800 degrees Celsius, and NASA believes that this planet has existed for 3 billion years.

In a statement released on June 5438+09, NASA wrote that Tsevinot's discovery "forced researchers to rethink the planetary system again, and it will also help us understand the distant future of the solar system." Cevinott is an amateur scientist. Her research focuses on brown dwarfs, which are bigger than planets and smaller than stars. During the ESA study in the European Space Agency, she discovered very bright and distant substances.

At first, Cevinott thought the data obtained from NASA was inaccurate, but he gave his findings to astronaut Debes and astrophysicist Kuhner. So the two of them got in touch with Burgass of the University of California, San Diego, got the opportunity to observe the white dwarf with the Keck Observatory telescope in Hawaii, and successfully confirmed the existence of this star.

Baidu encyclopedia-white dwarf

China. com-NASA: German researchers have discovered the oldest white dwarf so far.