Questions about constellations _ What are the questions about constellations?

1. Astronomy calls the track of the sun's apparent motion on the celestial sphere every year "ecliptic", which is the projection of the earth's orbit on the celestial sphere. The sun rotates once a year on the celestial sphere along the ecliptic. In order to determine the position, people divide the ecliptic into twelve equal parts (each part is equivalent to 30 parts), and each part is named after an adjacent constellation. These constellations are called the zodiac or the zodiac. This is equivalent to dividing a year into twelve segments, in which the sun enters a constellation. In the west, when a person is born, which constellation the sun is going to, he is said to belong to this constellation.

2. Altair: Eagle; Lyra

3. Altair is slightly larger than the sun, with a radius of 1.7 times that of the sun and a distance of 16 light years from the earth (one light year is about 10 trillion kilometers). Vega is 26.4 light years away. Astronomers use triangulation to calculate the distance between Altair and Vega as 16 light years.

Sirius is Alpha Canis, the brightest star in the whole day. Sirius is a visual binary star consisting of A and B. Star A is the first bright star in the whole day and belongs to the main sequence blue dwarf. Star B, commonly known as Sirius companion, is a white dwarf star with a slightly larger mass than the sun and a smaller radius than the earth. Its substance is mainly in degenerate state, and its average density is about 3.8× 106/ cubic centimeter. The orbital period of satellites A and B is 50.090 0.056 years and the orbital eccentricity is 0.5923 0.0019. Sirius is 8.65 0.09 light years away. Whether Sirius is a near binary is related to the evolution of Sirius binary. It was recorded in ancient times that Sirius was red, which provided us with research clues. X-rays of Sirius were discovered in 1975. Some people think that it may be the thermal radiation in the deep atmosphere of almost pure hydrogen of Star B, while others think that it may be caused by the high temperature corona of Star A or Star B, which is still under study. According to the data of 1980, the X-rays of A and B in the band of 0. 15 ~ 3.0 kV were measured by the High Energy Observatory-2 satellite, and it was found that the X-rays of B were much stronger than that of A..

5. Jiangchengzi

Hunting in Michigan (1)

Song sushi

I am a teenager.

Pull yellow left,

Right green. ②

Golden hat, mink,

A thousand riding rolls Hiraoka.

For the whole city and the satrap, ③

Kiss the tiger,

Look at Sun Lang. ④

The wine is full and the box is still open. ⑤

There is a slight frost on the temple,

What are the disadvantages?

In the festive clouds,

When will it be sent to Feng Tang? ⑥

Will bow like a full moon, 7

Looking to the northwest,

Shoot Sirius. ⑧

① Mizhou: Zhucheng in Shandong Province today. ② Yellow: yellow dog. Cang: Goshawk. Used to hunt prey when hunting. (3) Han Yulin army wearing a brocade hat, wearing a mink coat. Here and the next sentence "Qian Qi" refers to Su Shi's entourage. 4 newspapers: reports, languages. Allure: refers to the soldiers who watch the hunting in the whole city. ⑤ Sun Quan used to shoot tigers in Lingting to refer to himself. Section 6: Jeff. During the Han Dynasty, Feng Tang was ordered by Emperor Wen to observe the festival and reuse Shang Wei as the cloud satrap. Compared with Feng Tang, there is a sense of two rooms that refuse to accept old age and go to the frontier. ⑦ Yes: When? Such as the full moon: drawing a bow shows strength. Sirius invaded and plundered in ancient times. Sirius is used here to describe Xixia.

6. Among all kinds of meteor phenomena, the most beautiful and spectacular is the meteor shower. When it appears, millions of meteors are like shining ribbons. Meteor shower is a special phenomenon, in which groups of meteors seem to come from a point in the sky and fall with them. This point or a small sky area is called the radiation point of meteor shower. The radiation point is a perspective effect. The fundamental reason for the formation of meteor shower is the fragmentation of comets. Comets are mainly composed of ice and dust. When the comet approaches the sun, the ice will evaporate, so that dust particles will be ejected from the mother body and enter the orbit of the comet like water in a fountain. However, large particles still remain around the mother comet, forming a dust comet head; Small particles are blown away by the radiation pressure of the sun, forming tails. The rest of the material stays near the comet's orbit. However, even a small eruption speed will cause a great difference in particle period of revolution. Therefore, in the next comet return, small particles will lag behind the mother, while large particles will lead the mother. When the earth passes through the dust tail orbit, we have a chance to see the meteor shower. Meteor shower activity cycle: Five dust particles located in the orbit of comets are called "meteor swarms". When meteoroid particles are just ejected from comets, their distribution is relatively planned. Due to the gravity of the planet, these particles gradually spread all over the orbit of the comet. At present, this process is not very clear. When the earth passes through the meteoroid group, there may be various forms of meteor showers. Every year, the earth passes through the orbits of many comets. If there are meteoroid particles in orbit, periodic meteor showers will appear at the edge. A meteor shower that only happens when the mother comet runs to the perihelion is called a near-comet meteor shower. This shows that the meteoroid group is still near the comet. Most meteor showers formed by comets with a period of less than several hundred years are of this type. Due to the gravitational perturbation of the planet, the meteoroid group of the long-period comet may be far away from the parent comet. Meteor showers may also occur when the parent comet is not at perihelion, which is the far comet meteor shower. In order to distinguish meteor showers in different directions, meteor showers are usually named after the constellations in the sky where the meteors radiate. For example, every year165438+1October 17 or so, the radiant point of the meteor shower is in Leo, so it is named Leonid meteor shower. Other meteor showers include Aquarius meteor shower, Orion meteor shower and Perseid meteor shower. Some meteors are single, the direction and time are random, and there are no radiation points at all. This kind of meteor is called accidental meteor. Meteor shower and accidental meteor are essentially different. Sometimes only a few meteors appear in an hour, but they all seem to "flow out" from the same radiation point, so they also belong to the category of meteor showers; Sometimes, in a very short time, thousands of meteors can be seen at the same radiation point, just like people setting off fireworks in festivals. When the number of meteors per hour exceeds 1000, we call it "star cluster".

7. Perseus, Andromeda, Cepheus, Cassiopeia, Pegasus and Cepheid Variable Stars.

The story is too long. Look it up yourself.