Rod spiral galaxy M 109

Messier 109 (M 109, also called NGC 3992) is a rod-shaped spiral galaxy located in Ursa Major, about 4 1 100 million light years away. M 109 is the largest galaxy in Ursa major, accompanied by messier 108. M 109 can be measured at 40' distance, azimuth120&; Ordm, where I found it.

Messier 109 was discovered by Pierre Machin in 178 1 and catalogued by Charles Messier in 1783.

Only 103 celestial bodies in messier were officially recognized between 1920 and 1950, and these newly added celestial bodies were widely accepted in the following years. David levy mentioned the modern object 1 10. At that time, Sir Patrick Moore provided the most primitive object 104, and listed M 105-M 109 as an appendix. From the late 1970s to now, messier objects has been widely used by astronomers, with a total of 1 10.

M 109 is the standard sample of rod spiral galaxies. In 2005, our galaxy was proved to be similar to M 109.

M 109 has three companion galaxies (UGC 6923, UGC 6940 and UGC 6969). It is observed that M 109 has obvious hydrogen spectral lines with its companion galaxy, and more spectral lines may appear in more detailed observation. The H I distribution of M 109 is regular, extending out of the astrolabe in the shape of low-order radiation, but it is clear in the rod region. The central H ⅰ presents a cavity distribution, which may be due to the rod-shaped structure conveying a large amount of gas, or it may be due to the failure to gather a large amount of gas in the center in the past gathering events.

1956 In March, the supernova SN 1956 A in the southeast of the inner galaxy in M 109 was discovered. The luminosity at the time of discovery is 12. 8, and so on, the brightest time is 12. Third class. This is a 1a supernova and the only supernova discovered by M 109 so far.

China Science and Technology Network News According to the British "Daily Mail" recently reported, NASA and the European Southern Observatory used the Hubble Space Telescope to take the most "sharp" photos of the rod-shaped spiral galaxy NGC 1073, and our Milky Way is considered to be very similar to this galaxy, so astronomers have a clear sample and can understand the characteristics of the Milky Way from the perspective of onlookers.

As early as 20 10, among the top ten space pictures judged by the southern European observatory, a fledgling work by Ukrainian astronomical photographer-portrait of NGC galaxy 1073 was among them. But at that time, astronomers' understanding of NGC 1073 was limited to: this is a very vague spiral galaxy, located in the constellation Cetacea, about 55 million light years away from us.

Our Milky Way galaxy is also one of many spiral galaxies in the vast universe. But in the early years, it was not very common to find it in the comprehensive structural analysis of the Milky Way. There was once a "stellar rod" composed of a star with a length of 27,000 light years in its center, and all the "similar molecules" with a rod-like structure in the central region were classified as rod-like spiral galaxies.

The attitude of NGC 1073 galaxy photographed by Hubble telescope is no longer ambiguous, but it shows very clearly that it is a standard rod-rotating galaxy, and the central region is dazzling because of the dense stars, which just reveals the distribution of the structure in the central core region.

Astronomers have analyzed that when a large amount of gas transported by gravitational density waves of spiral galaxies enters the core of galaxies, they will form "rods" composed of such stars; At the same time, this is also the nourishment of the "newborn" of the stars; There are also huge black holes lurking in almost every galaxy. You are welcome to "eat" with the "food" brought by gas.

Because there are far more older red stars than younger blue stars in the spiral galaxy, astronomers further predict that a rod-like structure appears in the center, which means that the spiral galaxy has gone through the stage of being a high-yield "star factory", just like people steadily enter middle age from youth, just like our Milky Way. When the whole universe was young, there were only 1/5 spiral galaxies, but now the proportion of spiral galaxies in the universe exceeds 2/3. This observation is undoubtedly consistent with the theoretical prediction made by astronomers.