About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 69. Chapters: H II regions, Orion Nebula, Coronal cloud, Astronomical X-ray sources, Lockheed X-ray source, Visibly dark X-ray source, Astronomical gamma-ray source, Serpens XR-2, Sagittarius XR-3, Sagittarius XR-1, First X-ray source in Cancer, Scorpius XR-6, Ara XR-1, Centaurus XR-2, Cygnus X-ray ring, Lyra XR-1, Centaurus XR-4, Cygnus X-7, Centaurus X-1, X-ray halo, First X-ray source in Volans, Lupus XR-1, Cygnus X-4, Cepheus XR-1, Centaurus XR-3, Carina Nebula, Fossil stellar magnetic field, Norma X-1, Centaurus X-2, NGC 3603, Cygnus X-6, Omega Nebula, Scorpius X-5, 3U 0430+37, Eagle Nebula, Tarantula Nebula, Scorpius XR-2, Ophiuchus XR-1, Lupus X-1, Sagittarius XR-4, Centaurus XR-1, Lagoon Nebula, Ophiuchus XR-2, Ophiuchus X-2, Scorpius XR-3, Trifid Nebula, RCW Catalogue, Rosette Nebula, North America Nebula, Scorpius X-3, Norma XR-2, NGC 7635, Scorpius XR-5, Gum catalog, Scorpius XR-4, Barnard's Loop, Bubble Nebula, NGC 281, Cone Nebula, NGC 604, Elephant's Trunk nebula, IC 2177, Lynx Arc, NGC 6820 and NGC 6823, Gomez's Hamburger, NGC 346, Fox Fur Nebula, Pelican Nebula, NGC 2174, RCW 120, NGC 7538, Messier 43, Westerhout 49, IRAS 12063-6259, Ring Nebula, Sadr Region, NGC 595, Pistol Nebula. Excerpt: An H II region is a large cloud of gas and ionized gas of glowing low density in which star formation has recently taken place. Young, hot, blue stars-which have formed from the gas-emit copious amounts of ultraviolet light, ionizing and heating the gas surrounding them. H II regions-sometimes several hundred light-years across-are often associated with giant molecular clouds in which star formation takes place, and from which the stars that produce the H II region were born. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc. H II regions are named for the large a...
