Information about Orion (bonus: 5 points! )

Orion is the most magnificent constellation in the whole day, which is located at the equator of the celestial sphere and can be seen in most parts of the earth. The constellation represents the hunter, and there are two dogs (Canis major and Canis minor) at its feet. In Greek mythology, Orion is the son of Poseidon. It is said that he was stung to death by a scorpion, so the scorpion (Scorpio) rose and Orion fell to the horizon. Another legend is that Orion is infatuated with the goddess Seven Sisters (the seven daughters of Atlas, the Pleiades cluster in Taurus). As the earth rotates, Orion chases the Pleiades in the sky. There are many bright stars in Orion, but the most famous feature is the giant nebula M42 on Orion's sword, which is located in the south of Orion's belt and is lined with three stars.

Alpha star Orion (Betelgeuse) is a red Supergiant star with brightness ranging from 0 to 1.3, with a period of about 6 years, and the average brightness is 10 bright star in the whole day. 430 light years from the earth. The western name Betelgeuse comes from Arabia, meaning the position of the hand. In fact, Betelgeuse is located on the shoulder of Orion. Orion β (Betelgeuse) is a blue Supergiant star, 0.2, etc. It is the brightest star in Orion and the seventh brightest star in the whole day, about 770 light years away from the earth. The western name Betelgeuse comes from Arabia, which means foot, because its position represents the foot of Orion. Orion θ 1 is a multi-star, called Orion quadruplet, located in the center of Orion nebula. Four stars can be seen with a small telescope, arranged in an equilateral quadrangle, with brightness of 5. 1, 6.7, 6.7 and 8.0 respectively. If you use a large-aperture telescope, you can see that there are two stars in this cluster, such as 1 1.

M42 is a very famous Orion Nebula and one of the most magnificent celestial bodies in the sky. It is a nebula composed of luminous gas, which is about twice the diameter of the full moon and can be seen by the naked eye. The larger the telescope, the more complex the structure, about 1500 light-years away from the earth. This nebula is illuminated by the Orion quadrangle in the middle. A small nebula named M43 (Orion Nebula) extends in the north.

The Horsehead Nebula is a dark nebula that looks like a horsehead. This outline is set off by a bright nebula extending southward from Orion zeta. However, it is very dim, so you have to use a large telescope to see it, and the shape needs a long exposure to shoot.