we can see the brightest stars in the night sky is Sirius, especially in the winter, Sirius and betelgeuse, south river three three stars in the night sky form a bright on the south side of the equilateral triangle, is known as the "triangle" in winter, very conspicuous, so Sirius is a what kind of star?If change the sun to Sirius, we will be able to see?What the earth will be like?
is a young star, Sirius was born only in 1 billion, 8.7 light years away from solar system, it with blue and white light, illustrate its internal activity is very intense, but it is a binary system, we can see Sirius is in the main sequence star stage star, also known as the great dog a star, it is about 2.3 times the mass of the sun, the quality of the diameter is 1.8 times the mass of the sun, up to 2.5 million kilometers, the brightness is 25 times the mass of the sun, the surface temperature as high as eleven thousand degrees Celsius.Obviously, if you put such a planet to the sun's position, we are not directly with the naked eye to see its bright lights, but can be in the evening or morning light is not strong and see the appearance of it, will find that the planet several times larger than the sun.
but creatures on the earth were certainly can't stand the bright light of Sirius, the luminosity is 25 times the mass of the sun, you can imagine more than 20 what would it be like the sun shining on the earth?So its luminosity will only kill the vast majority of life on earth, and its strong light can make the earth very hot, the high temperature of the surface will have a few baidu, all the trees of the die, the animals will also be basked in death, polar ice melts, the ocean water evaporates, hot air on the earth, over time, the earth will become a hot desert planet.
moreover, due to the quality of Sirius is almost equivalent to two and a half of the sun, so it's gravity is much larger than the sun, if the earth is still in the original orbit, absorption in the past, so will soon be Sirius finally hit upon Sirius, become a part of it.
however, Sirius is not lonely traveler, it also has a companion star, this companion star earth volume is not large, but quality is more than the sun, because it is a White Dwarf, and it is the first White Dwarf star was discovered.Since it absorbs the Sirius star continuously blow out stellar wind, so its quality is slowly growing.
this White Dwarf and Sirius star distance of about 20 astronomical unit, is equivalent to 20 times the earth-sun distance, both in a considerably eccentricity orbit each other around, turn around period is 49.9 years, if the earth revolves around Sirius star spread, so must be between Sirius and the White Dwarf star, so that the earth's orbit becomes unstable, because will be affected by the double gravity of Sirius and a White Dwarf star, after a long time the earth will be out of their own orbit, or hit the Sirius star, or by both gravity throw, drifting in the universe.