Encyclopedia of astronomical knowledge

Encyclopedia of astronomical knowledge

An encyclopedia of astronomical knowledge. Nowadays, many people are interested in astronomy. The universe is boundless, and the universe refers to a space-time continuous system in which we exist. The following is an encyclopedia of astronomical knowledge I compiled for you, hoping to help you.

Encyclopedia of astronomical knowledge 1 1, what is the universe?

The universe is everything in the world, and it is the general name of all kinds of celestial bodies and dispersed substances existing in the vast space. Dialectical materialist philosophy holds that the essence of the world is matter, which can be transformed into different forms of existence, but it is eternal and immortal in essence. The universe is a universal and eternal material world, which is infinite in space and time. Seen from space, the universe is boundless. It has no boundaries, no shape and no center. If we admit that there is something outside the universe, we deny the material nature of the world. From the perspective of time, the universe has no beginning and no end. It has no origin, no age and no end. If we admit the origin of the universe, it will lead to creationism and actually deny the material nature of the world.

But we can't deny the finiteness of specific things. There is no contradiction between the infinity of the universe and the finiteness of concrete things, because only countless concrete finiteness can constitute all infinity. The universe observed by human beings is dynamic, and with the progress of science and technology, the known universe is also expanding. /kloc-before the 0/8th century, human knowledge of the universe was limited to the solar system, and later it was realized that there were hundreds of billions of stars outside the solar system, which formed the Milky Way. /kloc-in the 0/9th century, humans once again discovered extragalactic galaxies and found that the Milky Way is only a tiny member of the cosmic family. The optical telescope in the 1950s and the radio telescope in the 1960s greatly increased the detection distance of human beings to the universe, and human beings could extend their observation horizons to the material world forever, instead of staying at a fixed boundary, which strongly proved that the universe was infinite.

Astronomy usually refers to the whole space-time range of astronomical observation as "Hubble volume", and sometimes it is also called "our universe" or simply "the universe". A basic concept of modern science is that Hubble volume, like other things, has a history of its birth and development. According to modern cosmology, the age of the universe is extremely long, about 65.438+0.5 billion years old; The total observable space is extremely huge, and the farthest galaxy that has been observed is about 65.438+0.5 billion light years away. The universe has both unity and diversity. The unity of the universe lies in its materiality, and the diversity of the universe lies in the diversity of material expressions. The substances that make up the universe are very different in their existence, quality and nature.

The universe is made up of all kinds of celestial bodies and dispersed matter. There are all kinds of celestial bodies in the universe. Stars, nebulae, planets, satellites, comets, meteors and other celestial bodies are all forms of cosmic matter.

2. What are stars and nebulae?

The most important celestial bodies in the universe are stars and nebulae, because they are massive. Stars are spherical or nearly spherical objects composed of hot gas substances, which can spontaneously heat and emit light. Stars are planets that can shine like the sun. Most of the sparkling stars seen by naked eyes on a clear night are stars. Nebula is composed of extremely thin gas and dust, and its shape is very irregular, like a cloud-like celestial body.

3. What is a galaxy?

A huge collection of countless stars and interstellar matter is called a galaxy. Their scales range from thousands of light-years to hundreds of thousands of light-years. Galaxy or star system is an important part of the universe system. There are many galaxies. So far, people have observed about 654.38+000 billion galaxies in the universe. The earth is in the Milky Way, which is composed of10 billion stars and the Milky Way Nebula. Some galaxies are close to the Milky Way, and their structures can be clearly observed. The nearest galaxies to the Milky Way, large magellanic cloud and small magellanic cloud, are hundreds of light years away. Some galaxies are very far away, and the farthest known galaxy is nearly 65.438+0.5 billion light years. People call the currently known part of the universe, including all the observed galaxies, the total galaxy.

Astronomical knowledge encyclopedia 2-day solar eclipse forecast

The most noteworthy astronomical phenomena next year are solar eclipse and meteor shower. You can see two solar eclipses and one lunar eclipse in China. These two eclipses occurred on June 6, 65438+ and February 26, 65438+ respectively, both of which were partial eclipses. However, the partial solar eclipse on June 6, 65438 can only be seen in the north of central Taiwan Province Province, and the partial solar eclipse is too small to be detected.

The partial solar eclipse on 65438+February 26th can be seen everywhere, and nearly half of the sun is covered by the moon, which is a wonderful astronomical phenomenon with five stars! /kloc-The partial lunar eclipse in July of 0/7 is a rare astronomical phenomenon from 4 a.m. to the setting of the moon.

Next year, 65438+1October 4th will be a huge quadrant meteor shower. It is estimated that the hourly meteor occurrence rate at zenith will reach 120! On May 6th, Aquarius also had more than 40 η meteor showers, all of which were not disturbed by moonlight. The observation conditions are the best in recent years and should not be missed.

Classification of lunar eclipses

Eclipses can be divided into three types: partial eclipse, total eclipse and penumbral eclipse. When only a part of the moon enters the umbra of the earth, there will be a partial lunar eclipse; When the whole moon enters the umbra of the earth, a total lunar eclipse will occur. As for the penumbral eclipse, it means that the moon only passes through the penumbral region of the earth, resulting in a slight decrease in the brightness of the moon, which is difficult for the naked eye to see the difference.

There is no eclipse. Because the umbra of the earth is much larger than the umbra of the moon, it also means that in the event of a total lunar eclipse, the moon will completely enter the umbra of the earth, so there will be no annular eclipse.

The solar eclipse must happen in Wangwang (that is, around the fifteenth day of the lunar calendar). When the moon enters the penumbra of the earth, it should be a penumbral eclipse, but it is not called an eclipse because the brightness drops very little and is not easy to detect. Some people think that there are only two kinds of eclipses: total solar eclipse and partial solar eclipse.

Encyclopedia of astronomical knowledge 3 spiral galaxy knowledge

Spiral galaxies are the most numerous and beautiful galaxies observed. It is shaped like a whirlpool in a river, hence its name. This kind of galaxy contains a lot of diffuse matter near its symmetry plane, which looks like a vortex from the front; Viewed from the side, it looks like a space shuttle. Andromeda Nebula and Triangle Nebula are both extragalactic galaxies of this type.

Spiral galaxies are code-named S-type, and rod-shaped spiral galaxies are named SB-type. Whether it is a spiral galaxy or a bar spiral galaxy, English letters such as A, B and C are usually added after S or SB to indicate the tightness of the spiral arm, with A indicating the tightest and C indicating the loosest.

The shape is a spiral structure with obvious core. The core is a convex lens. Outside the core sphere, there is a thin disk with several spiral arms on it. In spiral galaxies, the core is not spherical, but rod-shaped, and the spiral arms extend from both ends of the rod, which is called rod-shaped spiral galaxies.

Spiral galaxies are very different from elliptical galaxies in terms of morphological structure and star composition. Of course, the core of a spiral galaxy is much like an elliptical galaxy, but that's all. The spiral arms of spiral galaxies contain a large number of blue giant, open clusters and gas nebulae. The Andromeda galaxy M3 1 is a typical spiral galaxy, which is very close to our Milky Way galaxy (2.2 million light-years away from the sun) and can be faintly seen by the naked eye, just like a thin cloud floating in the sky. In the picture on the right, the details of Andromeda galaxy are very clear. In the middle is a core composed of a second group of stars.

Each spiral arm is a band of emission nebulae, dim gas, galaxy clusters and blue giant, all of which are stars in group I. Although the spiral arms are bright, the light outside the core mainly comes from the buffer layer composed of stars with luminosity equal to or slightly less than that of giant stars. The spiral arms are superimposed on this almost transparent stellar cushion, so more distant galaxies can still be seen through the cushion between the spiral arms. The observation results show that the shape of the pad is similar to an ellipsoid, distributed above and below the central plane of the galaxy, rich in globular clusters, and slightly redder than the spiral arms, so it may belong to the star family.