which are the special regions it has?
Orion Nebula, the Eta Carinae Nebula, and the Berkeley 59 / Cepheus OB4 Complex
H II region
Notable Galactic H II regions include the Orion Nebula, the Eta Carinae Nebula, and the Berkeley 59 / Cepheus OB4 Complex
where could be found hii emission nebula regions Sometimes several hundred light-years across, are often associated with giant molecular clouds what does this region mean? It is a region of interstellar atomic hydrogen that is ionized how did it get the name? The term H II is pronounced "H two" by astronomers. "H" is the chemical symbol for hydrogen, and "II" is the Roman numeral for 2. what are it's features? It vary greatly in their physical properties, their size is also known as the Stromgren radius and essentially depends on the intensity of the source of ionising photons and the density of the region, their densities range from over a million particles per cm³ in the ultra-compact H II regions to only a few particles per cm³ in the largest and most extended regions how is it distributed? The reason H II regions rarely appear in elliptical galaxies is that ellipticals are believed to form through galaxy mergers. In galaxy clusters, such mergers are frequent. does it face any problems? UNANSWERABLE
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H II region [SEP] Notable regions
The supernova SN 1987A occurred in the outskirts of the Tarantula Nebula. Another giant H II region—NGC 604 is located in M33 spiral galaxy, which is at 817 kpc (2.66 million light years). Measuring at approximately () across, NGC 604 is the second-most-massive H II region in the Local Group after the Tarantula Nebula, although it is slightly larger in size than the latter. It contains around 200 hot OB and Wolf-Rayet stars, which heat the gas inside it to millions of degrees, producing bright X-ray emissions. The total mass of the hot gas in NGC 604 is about 6,000 Solar masses.