Sirius, formal name Canis Major α star, it is the brightest star in night sky, but dark Yu Jinxing and Jupiter, most moment is light at spark. Sirius is double star system, general the Sirius that we say is Sirius A, it is double star system in big that; Small that calls Sirius B, it is the accompanion of Sirius A, the diameter of Sirius B is diameter of 1 times earth about. Diameter of primary Sirius A is 2512560km. Sirius calls Sirius in ancient west, come from Greek, have deeply anxious meaning, the summer is when ancient Hesperian thinks Sirius and sun rise at the same time, the light of the light of Sirius and sun closes together, just be the reason with summertime torrid weather, just call day wolf accordingly Sirius. Summer of ancient Greek person is " canine day " , because only the dog just is met,cranky runs out in so torrid weather, accordingly this star also is called " canine star " . Gu Ai and person Sirius are Sothis, meaning the star that goes up for water.
System of Sirius double star
Sirius is discovered to be double star system first, be 1844, the wave graph that by the basis of Er of a place of strategic importance of German astronomer shellfish at that time its mobile method appears concludes come out, and reached of accompanion circle turn cycle is about 50 years; 1862, gram of American astronomer carat refracts astronomy binoculars with self-restrained 4.7m caliber most discover Sirius accompanion B first, and discover Sirius and its accompanion to be circled each other on eccentricity biggish orbit turn, circle turn cycle is 49.9 years, be apart from 20 times what be apart from for day ground on average. Although the brightness of primary is big, but if use the word of big binoculars,still can see this 7 accompanion that wait.
Of scale great disparity advocate accompanion
Sirius A, namely Sirius primary, its quality is the sun quality of 2.1 times, its surface temperature is 11000 ℃ about, the exterior temperature of outclass sun. Its sidereal rotation rate is relatively slow, for every second 16 kilometers, this makes Sirius more approximate sphere, the basis is forecasted, sirius A will be extinct inside 1 billion years after its are formed store the hydrogen of existence core, to moment it can experience supernova level, come down blandly again later, become a white dwarf, the spectrum of Sirius A is having very dark metal line, compare at our sun, there are more irons in the aerosphere of Sirius A, its content is equivalent to 3.16 times of the sun, but appear unlikelily the case that makes a star contain a lot oftantalum, so these tantalum may be suspension go up at a of the surface thin troposphere.
The contrast of Sirius and sun
Sirius B, namely the accompanion of Sirius, the quality of Sirius B is equal to the quality of the sun almost, and be foregone one of white dwarf of the greatest quality, also be most the white dwarf that is discovered first. It has almost average 0.5 double to 0.6 suns quality. However so much material is compressed however the size that is the earth about. Its current surface temperature is 14000 ℃ about, taller than primary nearly 3000 ℃ . But, had done not have energy as a result of interiorly generate, the rest quantity of heat can radiate with radiant configuration the aerospace outside going out, sirius B can cool gradually after all, when needing 200 million years over.
As general as the earth big Sirius B
A star should be passed advocate foreword star and phase of red giant star just can become white dwarf. The age when Sirius B becomes white dwarf compares its present age small in part many a little bit, before be 100 million 2 thousand all ages about. Or advocate its estimation has 5 suns quality when foreword star big. Sirius B is red giant star when, the likelihood increased the metallic amount of A of its accompanion Sirius.
In light of current observation, did not discover system of Sirius double star has a planet to exist, perhaps do not have originally, perhaps have, and the mankind returns have not to discover just, everything is sealed still. What can affirm basically nevertheless is, in Sirius around, the possibility that has life close to Yu Ling, the interstellar space of the sweeping periphery that lasts because of the high temperature of Sirius B and freeboard radiate, prevented the formation of life.
