An emission nebula is a cloud of ionized gas (i. A cloud is a visible mass of droplets or frozen crystals floating in the atmosphere above the surface of the Earth or another Planetary body Ionization is the physical process of converting an Atom or Molecule into an Ion by adding or removing charged particles such as Electrons This page is about the physical properties of gas as a state of matter e. a plasma) emitting light of various colors. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound The most common source for ionization are high-energy photons emitted from a nearby hot star. Ionization is the physical process of converting an Atom or Molecule into an Ion by adding or removing charged particles such as Electrons In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth Among the several different types of emission nebula are H II regions, in which star formation is taking place and young, massive stars are the source of the ionising photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them. An H II region (also known as Emission nebula) is a cloud of glowing Gas and plasma, sometimes several hundred Light-years across A planetary nebula is an Emission nebula consisting of a glowing shell of Gas and plasma formed by certain types of Stars when they die
General information
Usually, a young star will ionize part of the same cloud from which it was born. Only big, hot stars can release the amount of energy required to ionize a significant part of a cloud. Often, an entire cluster of young stars is doing the work. Star clusters are groups of Stars which are gravitationally bound
The nebula's color depends on its chemical composition and amount of ionization. Due to the high prevalence of Hydrogen in interstellar gas, and its relative low energy requirement for ionization, many emission nebulae are red. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 If more energy is available, other elements can be ionized and green and blue nebulae are possible. By examining the spectra of nebulae, astronomers deduce their chemical content. The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies Most emission nebulae are about 90% hydrogen, with the remainder helium, oxygen, nitrogen, and other elements. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14
Some of the most prominent emission nebulae visible from the northern hemisphere are the North America Nebula (NGC 7000) and Veil Nebula NGC 6960/6992 in Cygnus, while in the south celestial hemisphere, the Lagoon Nebula M8 / NGC 6523 in Sagittarius and the Orion Nebula M42. Northern Hemisphere is the half of a Planet that is North of the Equator —the word hemisphere literally means 'half ball' The North America Nebula ( NGC 7000 or Caldwell 20) is an Emission nebula in the Constellation Cygnus, close to The Veil Nebula, also known as the Cygnus Loop or the Witch's Broom Nebula, is a large relatively faint Supernova remnant in the constellation Cygnus (ˈsɪgnəs Swan, Κύκνος) is a northern Constellation. The Lagoon Nebula (also known as Messier Object 8 ( M8) and NGC 6523) is a giant interstellar cloud classified as an Emission nebula The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a Diffuse nebula situated south of Orion 's Belt [1] Further in the southern hemisphere is the bright Carina Nebula NGC 3372. The Carina Nebula (also known as the Great Nebula in Carina, the Eta Carinae Nebula, or NGC 3372) is a large bright Nebula that surrounds
Emission nebulae often have dark spots in them which result from clouds of dust which block the light. The combination of emission nebula and dust cloud make for some interesting looking objects, and many of these nebulae bear the name of objects that they resemble, such as the North America Nebula or the Cone Nebula. The North America Nebula ( NGC 7000 or Caldwell 20) is an Emission nebula in the Constellation Cygnus, close to The Cone Nebula (also known as NGC 2264) is an H II region in the constellation of Monoceros.
Some nebulae are made up of both reflection and emission components such as the Trifid Nebula. In Astronomy, reflection nebulae are clouds of dust which are simply reflecting the light of a nearby Star or stars The Trifid Nebula (also known as Messier 20 and NGC 6514) is an H II region located in Sagittarius.
Science fiction
An emission nebula is mentioned in the Star Trek: Deep Space Nine episode "Return to Grace". " Return to Grace " is an episode of the Television series Star Trek Deep Space Nine, the thirteenth episode of the fourth season
References
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic