Galaxy Central Constellation _ Galaxy Central Constellation

In which constellation is the central direction of the Milky Way located?

The center of the Milky Way is in the direction of Sagittarius. The coordinates of 1950 calendar elements are: right ascension17 42' 29 ",declination-28 59'18".

Radio telescopes found a strong radio source in the center of the Milky Way galaxy, named Sagittarius A*. The center of this radio source is extremely small, and the maximum is not greater than Jupiter's orbit around the sun.

Some people think that if the radius of the central nucleus of the Milky Way does not exceed 0.326 16 light-years, that is, it does not exceed 0.3 light-years, which means that it is likely to be the center of a massive and dense celestial body, or even a black hole.

If the radius of the central core is 1.95696 light-years, which is about 2 light-years, then if it is not a black hole, it should be a mass mass, which contains the mass equivalent to 2 million suns.

According to the observation results of 1987 ~ 1988 astronomical satellite, Japanese scientists believe that there was a massive celestial body or a large number of supernovae in Yin Xin.

Extended data

Besides being a geometric point, the galactic center also means the central region of the Milky Way. The sun is about10,000 parsec from Yin Xin, which lies about 8 parsec to the north of galactic plane. There is a lot of interstellar dust between the galactic center and the solar system, so it is difficult to see the galactic center in visible light band with optical telescopes in the northern hemisphere.

After the rise of radio astronomy and infrared observation technology, people can detect the information of the silver center in the band of 2 microns to 73 cm through interstellar dust. The observation of neutral hydrogen 2 1 cm spectral line reveals that there is a hydrogen flow expansion arm at a distance of 4000 parsec from Yin Xin, which is the so-called "3000 parsec arm" (the distance was mistakenly set at 3000 parsec at first, and then revised to 4000 parsec, but the old name is still used).

About 1 10 million neutral hydrogens with solar mass rushed to the solar system at a speed of 53km/ s, and on the other side of the silver core, there was a neutral hydrogen expansion arm with roughly the same mass, leaving the silver core at a speed of135 km/s.

They should have been driven out of the silver heart in an asymmetric way from100000 to150000 years ago. In the sky area 300 parsec away from Yin Xin, there is a hydrogen disk rotating rapidly around Yin Xin, expanding outward at a speed of 70 ~ 140 km/s, and there is a hydrogen molecular cloud with an average diameter of 30 parsec in the disk.

70 parsec away from Yin Xin, there is a violently disturbed ionized hydrogen region, which expands outward at a high speed. It has been known that not only a large amount of gas gushes from the center of the Milky Way, but also there is a strong radio source in the center of the Milky Way-Sagittarius A, which emits strong synchronous radiation. The detection of very long baseline interferometer shows that the central area of the central radio source of the Milky Way is very small, even less than ten astronomical units, that is, it does not exceed Jupiter's orbit around the sun.

According to the infrared observation data of 12.8 micron, the mass of the silver core with the diameter of 1 parsec is equivalent to millions of solar masses, of which about 1 10,000 solar masses exist in the form of stars. There is a huge dense nucleus in the center of the Milky Way, which may be a black hole. Relativistic electrons flowing into the compact core accretion disk are accelerated in a strong magnetic field, resulting in synchrotron radiation.

The latest observation of the center of the Milky Way shows that the core of the Milky Way is basically composed of white dwarfs, the number of which is at least 654.38+ million. The core of harmony consists of about 70 large white dwarfs.

As for how to observe more contents, scientists say that this needs to be done by the next generation of observation equipment, such as the james webb Telescope being built by NASA.

Reference source: Baidu Encyclopedia-Galaxy