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Dust Lane
A dust lane consists of relatively dense, obscuring clouds of interstellar dust, observed as a dark swath against the background of brighter object(s), especially a galaxy. These dust lanes can usually be seen in spiral galaxies, such as the Milky Way, when viewed from the edge. Due to the dense and relatively thick nature of this dust, observed light from a galaxy can be reduced by dust lanes by up to several magnitudes. In the Milky Way, this attenuation of visible light makes it impossible to see the stars behind the Great Rift through the bulge around the Galactic Center from Earth. This dust, as well as the gasses also found within these lanes, mixes and combines to form stars and planets. The gas in the dust lanes is funneled toward the Central Molecular Zone. Approximately one third of the gas will combine with the CMZ. The rest will overshoot and accrete at a later time. The presence of a dust lane is most apparent in disc galaxies that are viewed edge on. Altho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M104 Ngc4594 Sombrero Galaxy Hi-res
M1, M01 or M-1 may refer to: Arts, entertainment & media * M-1 (rapper), one half of hip hop duo Dead Prez * Korg M1, a keyboard synthesizer * Leica M1, a 1959 35 mm camera model * Olympus OM-1, a 1972 manually operated 35mm single-lens reflex camera * M1 (TV channel), news channel of the Hungarian MTVA * M-1 (Lithuanian radio station) * M1 (Ukraine), a television channel * M1 (Russian TV channel) Economics and finance * M1 (money supply measure), in economics, a measure of the money supply * M1 Finance, an online financial services company Military equipment Vehicles US Armed Forces * M1 Abrams, a main battle tank * M1 armored car * M1 combat car, an early tank * M1 light tractor * M1 medium tractor * M1 heavy tractor Other * Bristol M.1, a 1916 British fighter aircraft * (M1), a WWI Royal Navy monitor * (1919), an early British submarine * , a List of mine warfare vessels of the Swedish Navy, Swedish Navy mine sweeper * , a Swedish Royal Navy mine layer Weapon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge
Cambridge ( ) is a List of cities in the United Kingdom, city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, north of London. As of the 2021 United Kingdom census, the population of the City of Cambridge was 145,700; the population of the wider built-up area (which extends outside the city council area) was 181,137. (2021 census) There is archaeological evidence of settlement in the area as early as the Bronze Age, and Cambridge became an important trading centre during the Roman Britain, Roman and Viking eras. The first Town charter#Municipal charters, town charters were granted in the 12th century, although modern city status was not officially conferred until 1951. The city is well known as the home of the University of Cambridge, which was founded in 1209 and consistently ranks among the best universities in the world. The buildings of the university include King's College Chap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Dust Cloud
The interplanetary dust cloud, or zodiacal cloud (as the source of the zodiacal light), consists of cosmic dust (small particles floating in outer space) that pervades the space between planets within planetary systems, such as the Solar System. This system of particles has been studied for many years in order to understand its nature, origin, and relationship to larger bodies. There are several methods to obtain space dust measurement. In the Solar System, interplanetary dust particles have a role in scattering sunlight and in emitting thermal radiation, which is the most prominent feature of the night sky's radiation, with wavelengths ranging 5–50 μm. The particle sizes of grains characterizing the infrared emission near Earth's orbit typically range 10–100 μm. Microscopic impact craters on lunar rocks returned by the Apollo Program revealed the size distribution of cosmic dust particles bombarding the lunar surface. The ’’Grün’’ distribution of interplan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intergalactic Dust
Intergalactic dust is cosmic dust in between galaxies in intergalactic space. Evidence for intergalactic dust has been suggested as early as 1949, and study of it grew throughout the late 20th century. There are large variations in the distribution of intergalactic dust. Dust may affect intergalactic distance measurements, such as supernovae and quasars in other galaxies. Partially due to the dust's absorption and re-emission of visible light, observations of more distant astronomical objects have greater apparent magnitude when conducted in infrared. Intergalactic dust can form intergalactic dust clouds, known since the 1960s to exist around some galaxies. By the 1980s, at least four intergalactic dust clouds had been discovered within several megaparsecs of the Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interplanetary Medium
The interplanetary medium (IPM) or interplanetary space consists of the mass and energy which fills the Solar System, and through which all the larger Solar System bodies, such as planets, dwarf planet A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the ...s, asteroids, and comets, move. The IPM stops at the Heliopause (astronomy), heliopause, outside of which the interstellar medium begins. Before 1950, interplanetary space was widely considered to either be an empty vacuum, or consisting of "Aether theories, aether". Composition and physical characteristics The interplanetary medium includes Interplanetary dust cloud, interplanetary dust, cosmic rays, and hot Plasma (physics), plasma from the solar wind. The density of the interplanetary medium is very low, decreasing in inverse pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction (astronomy)
In astronomy, extinction is the absorption (electromagnetic radiation), absorption and light scattering, scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observation, observer. Interstellar extinction was first documented as such in 1930 by Robert Julius Trumpler. However, its effects had been noted in 1847 by Friedrich Georg Wilhelm von Struve, and its effect on the colors of stars had been observed by a number of individuals who did not connect it with the general presence of Cosmic dust, galactic dust. For stars lying near the plane of the Milky Way which are within a few thousand parsecs of the Earth, extinction in the visual band of frequencies (photometric system) is roughly 1.8 Magnitude (astronomy), magnitudes per kiloparsec. For Observatory#Ground-based_observatories, Earth-bound observers, extinction arises both from the interstellar medium and the Atmosphere of Earth, Earth's atmosphere; it may also arise fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeans Instability
The Jeans instability is a concept in astrophysics that describes an instability that leads to the gravitational collapse of a cloud of gas or dust. It causes the collapse of interstellar gas clouds and subsequent star formation. It occurs when the internal gas pressure is not strong enough to prevent the gravitational collapse of a region filled with matter. It is named after James Jeans. For stability, the cloud must be in hydrostatic equilibrium, which in case of a spherical cloud translates to \frac=-\frac, where M_\text(r) is the enclosed mass, ''p'' is the pressure, \rho(r) is the density of the gas (at radius ''r''), ''G'' is the gravitational constant, and ''r'' is the radius. The equilibrium is stable if small perturbations are damped and unstable if they are amplified. In general, the cloud is unstable if it is either very massive at a given temperature or very cool at a given mass; under these circumstances, the gas pressure gradient cannot overcome gravitational fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatic Equilibrium
In fluid mechanics, hydrostatic equilibrium, also called hydrostatic balance and hydrostasy, is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. In the planetary physics of Earth, the pressure-gradient force prevents gravity from collapsing the atmosphere of Earth into a thin, dense shell, whereas gravity prevents the pressure-gradient force from diffusing the atmosphere into outer space. In general, it is what causes objects in space to be spherical. Hydrostatic equilibrium is the distinguishing criterion between dwarf planets and small solar system bodies, and features in astrophysics and planetary geology. Said qualification of equilibrium indicates that the shape of the object is symmetrically rounded, mostly due to rotation, into an ellipsoid, where any irregular surface features are consequent to a relatively thin solid crust. In addition to the Sun, there are a dozen or s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Cloud
A molecular cloud—sometimes called a stellar nursery if star formation is occurring within—is a type of interstellar cloud of which the density and size permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, H2), and the formation of H II regions. This is in contrast to other areas of the interstellar medium that contain predominantly ionized gas. Molecular hydrogen is difficult to detect by infrared and radio observations, so the molecule most often used to determine the presence of H2 is carbon monoxide (CO). The ratio between CO luminosity and H2 mass is thought to be constant, although there are reasons to doubt this assumption in observations of some other galaxies. Within molecular clouds are regions with higher density, where much dust and many gas cores reside, called clumps. These clumps are the beginning of star formation if gravitational forces are sufficient to cause the dust and gas to collapse. Research and discovery The histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Binding Energy
The gravitational binding energy of a system is the minimum energy which must be added to it in order for the system to cease being in a gravitationally bound state. A gravitationally bound system has a lower (''i.e.'', more negative) gravitational potential energy than the sum of the energies of its parts when these are completely separated—this is what keeps the system aggregated in accordance with the minimum total potential energy principle. The gravitational binding energy can be conceptually different within the theories of Newtonian gravity and Albert Einstein's theory of gravity called General Relativity. In Newtonian gravity, the binding energy can be considered to be the linear sum of the interactions between all pairs of microscopic components of the system, while in General Relativity, this is only approximately true if the gravitational fields are all weak. When stronger fields are present within a system, the binding energy is a nonlinear property of the sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barred Spiral Galaxy
A barred spiral galaxy is a spiral galaxy with a central bar-shaped structure composed of stars. Bars are found in about two thirds of all spiral galaxies in the local universe, and generally affect both the motions of stars and interstellar gas within spiral galaxies and can affect spiral arms as well. The Milky Way Galaxy, where the Solar System is located, is classified as a barred spiral galaxy. Edwin Hubble classified spiral galaxies of this type as "SB" (spiral, barred) in his Hubble sequence and arranged them into sub-categories based on how open the arms of the spiral are. SBa types feature tightly bound arms, while SBc types are at the other extreme and have loosely bound arms. SBb-type galaxies lie in between the two. SB0 is a barred lenticular galaxy. A new type, SBm, was subsequently created to describe somewhat Barred irregular galaxy, irregular barred spirals, such as the Magellanic Clouds, which were once classified as irregular galaxies, but have since been found t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Sequence
The Hubble sequence is a morphological classification scheme for galaxies published by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a tuning fork. It was invented by John Henry Reynolds and Sir James Jeans. The tuning fork scheme divided regular galaxies into three broad classes – ellipticals, lenticulars and spirals – based on their visual appearance (originally on photographic plates). A fourth class contains galaxies with an irregular appearance. The Hubble sequence is the most commonly used system for classifying galaxies, both in professional astronomical research and in amateur astronomy. Classes of galaxies Ellipticals On the left (in the sense that the sequence is usually drawn) lie the ellipticals. Elliptical galaxies have relatively smooth, featureless light distributions and appear as ellipses in photographic images. They are denoted by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
