Which constellation does Sirius belong to?

The brightest star in the winter night sky has a visual magnitude of-1.45, etc. It is a binary star in the constellation Canis. Liangzi, a binary star, is a blue and white star. Its brightness is 23 times that of the sun, slightly larger than the sun, its diameter is 1.7 times that of the sun, and its surface temperature is 10000℃ twice that of the sun. It is about 8.6 light-years away from the solar system, only twice as far as the nearest star except the sun. The ancient Egyptians realized that the star pool rose with the sun, that is, the Nile Delta began to flood every year before the sun rose. Moreover, they found that the time interval between Sirius's two rises was 365.25 days, not 365 days in Egypt. (Photo: Sirius is the brightest star in the sky. )

In ancient China, it was regarded as an evil star, symbolizing intrusion. So scholars also wrote something like "I can bow like a full moon, look northwest and shoot Sirius". Ancient Egypt worshipped Sirius, because once he rose, it meant that the Nile would flood.

The word "Sirius" is associated with loneliness, indifference and remoteness. Although this is not the case, he is a hot star with a companion. Compared with other stars in the night sky, he is very close to the earth. Perhaps it is due to historical and cultural reasons, or personal mood. Sirius is destined to be a star that cannot be associated with romance and enthusiasm. It can watch the moon, meteor shower, Venus or Mars with lovers and friends. However, Sirius, pale and blue, can't make people feel happy. Perhaps it is because of this unique personality that he has attracted countless lonely hearts.

The ancient Egyptians realized that the star pool rose with the sun, that is, the Nile Delta began to flood every year before the sun rose. Moreover, they found that the time interval between Sirius's two rises was 365.25 days, not 365 days in Egypt. German astronomers reported in 1844 that Sirius is a binary star, because it moves along a wavy trajectory in the nearby space, thus inferring that it has a companion star with an orbital period of about 50 years. This companion star was first seen by American astronomers in 1862. Sirius and its companion star revolve around each other in orbits with large eccentricity, and the average distance is about 20 times that of the sun and the earth. Although the bright star shines brightly, it is not difficult to see the companion star with a large telescope. The companion star is similar in mass to the sun, but much denser than the sun. This is the first white dwarf discovered.

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 a degenerate state, with an average density of about 3.8 ×. 106/ cm3。 The orbital period of satellites A and B is 50.090; 0.056 years, the track eccentricity is 0.5923; 0.00 19。 The distance between Sirius and us is 8.65; 0.09 light years. 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..

In the winter sky, from Orion to the southeast, one of the brightest stars in the whole day shines there. It is Alpha Canis, also known as Sirius in ancient China. Sirius's apparent magnitude is-1.45 m, which is only 8.6 light years away from us.

In ancient Egypt, whenever Sirius rose from the eastern horizon at dawn (this phenomenon is called "rising together" in astronomy), it was the annual flood of the Nile, which irrigated large areas of fertile land on both sides of the river, so the Egyptians began farming again. Because the appearance of Sirius was closely related to the agricultural production in ancient Egypt, people at that time regarded it as a god, and determined the day when Sirius rose in the east before dawn as the beginning of the year. It can be said that the Gregorian calendar we use now was first born in ancient Egypt.