Unicorn is one of the twelve constellations. Located in the south of Gemini and the north of Canis Canis, in the Milky Way between Canis Canis and Orion. However, this part of the Milky Way is located at the edge of the Milky Way, so it is far less bright than the Milky Way in summer. The most beautiful celestial body in Kirin constellation is the Rose Nebula (also known as the Rose Nebula, NGC2237, with a visual magnitude of about 6). In the center of this dim rose-red nebula, there is an open cluster (NGC2244), which consists of more than a dozen turquoise and golden stars. This kind of rose in the sky can't be seen directly by astronomical telescope, and its color can only be seen by photos taken by astronomical telescope for a long time. It is generally believed that the unicorn constellation was discovered by the Dutch astronomer Planck in 16 13.
The beautiful Rose Nebula NGC 2237 is a large emission nebula 3000 light years away from us. There is an open cluster numbered NGC 2244 in the center of the nebula, and the star wind from the star cluster has blown a big hole in the center of the nebula. These stars were formed by the clouds around them about 4 million years ago, and there is an isolation layer of dust and hot clouds on the edge of the hole. The ultraviolet radiation emitted by this hot star breaks down the surrounding clouds and makes them glow. The rich hydrogen in the nebula is excited by young and bright stars, which makes NGC 2237 appear red in most photos. The most special thing about this picture is that its color is different from the common rose nebula photo. Through the filters of red light emitted by hydrogen, green light emitted by oxygen and blue light emitted by sulfur, astronomers took photos of the Rose Nebula, and then combined them to synthesize the beautiful image above. In the image, we can also clearly see the dark filamentous dust bands scattered in the clouds. Recently, astronomers have discovered some fast-moving molecular clusters in the Rose Nebula, but their origins are still unknown. The Rose Nebula is located in the unicorn constellation in the southern sky. Its size is about 100 light years, and it is about 5000 light years away from us. You can see it with a small telescope.
The Rose Nebula (NGC 2237) is a huge hydrogen II region, located at the end of a huge molecular cloud in the constellation Unicorn. This molecular cloud includes five NGC objects: NGC 2237, NGC 2238, NGC 2239, NGC 2244 and NGC 2246. The open cluster NGC 2244 is closely related to the Rose Nebula, and the stars in NGC 2244 are formed by the matter of the Rose Nebula. The cluster and nebula are about 5,200 light-years away from the Earth and about 130 light-years in diameter. The mass of this nebula is estimated to be about 10000 times that of the sun. When the rose nebula is not red, of course, not all roses are red, but they are still beautiful. However, in the sky map, the beautiful rose nebula and other star-forming areas are always dominated by red-partly because the main emission in the nebula is produced by hydrogen atoms. The strong visible light of hydrogen atom -H-alpha is a red band in the spectrum, but a beautiful emission nebula needs more than red light. Other atoms in the nebula are also excited by high-energy starlight, and also form narrow-wave emission light. In this gorgeous image of the central region of the Rose Nebula, the narrow-wave image consists of red light emitted by sulfur atoms, blue light emitted by hydrogen atoms and green light emitted by oxygen atoms. In fact, the method of using these narrow-wave atoms to express colors has also been used in Hubble images of many star nurseries. This image spans about 50 light-years in the constellation Unicorn and is located in the Rose Nebula, with an estimated distance of 3,000 light-years.
Unicorn is located in the east of Orion, just cut by the Milky Way. There are few bright stars among them. Every year on the night of 65438+10.5, the unicorn constellation reaches the zenith, and10 and February are the best months to observe it. Unicorn is Monoceros in Latin, which means unicorn or rhinoceros. Astronomers in China translated it into Kirin. Kirin is a mysterious animal in legend. The unicorn depicted in ancient legends in China is bijuu, a one-horned deer. The whole body is covered with scales, which was used by the ancients to symbolize auspiciousness, so Kirin is called an auspicious constellation.