Astrophysics Astrophysics The galaxy rotation problem is the discrepancy between the observed rotation speeds of matter in the disk portions of spiral galaxies and the predictions of Newtonian dynamics considering the luminous mass. The presence of this discrepancy is explained by astronomers as pointing to the existence of dark matter in the halo of the galaxy. ...more on Wikipedia about "Galaxy rotation problem"
Gamma-ray bursts (GRBs) are the most luminous physical phenomena in the universe known to the field of astronomy. They consist of flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. These flashes occur at apparently random positions in the sky about once per day. ...more on Wikipedia about "Gamma ray burst"
A gravitational lens is formed when the light from a very distant, bright source (such as a quasar) is "bent" around a massive object (such as a massive galaxy) between the source object and the observer. ...more on Wikipedia about "Gravitational lens"
Helioseismology is the study of the propagation of pressure waves in the Sun. These waves are generated by the turbulence in the convection zone, near the surface of the sun, and certain frequencies are amplified by constructive interference. In other words, the turbulence "rings" the sun like a bell. The acoustic waves are transmitted to the outer photosphere of the sun, which is where the light emitted by the sun is generated. The acoustic oscillations are detectable on almost any time series of solar images, but are best observed by measuring the doppler shift of photospheric emission lines. Changes in the propagation of pressure waves through the Sun reveal inner structures and allows astrophysicists to develop extremely detailed profiles of the interior conditions of the Sun. ...more on Wikipedia about "Helioseismology"
The Heliospheric current sheet (HCS) is the surface within the Solar System where the polarity of the Sun's magnetic field changes from plus (north) to minus (south). This field extends from the Sun's equatorial plane throughout the entire Solar System, and can be considered its largest structure ** . The shape of the current sheet results from the influence of the Sun's rotating magnetic field on the plasma in the interplanetary medium ( Solar Wind) ** . A small electrical current flows within the sheet, about 10-10 amps/m2. The thickness of the current sheet is about 10,000km. ...more on Wikipedia about "Heliospheric current sheet"
The history of the Big Bang theory begins with the Big Bang's development from observations and theoretical considerations. Much of the theoretical work in cosmology now involves extensions and refinements to the basic Big Bang theory. ...more on Wikipedia about "History of the Big Bang"
A hypernova is a theoretical type of supernova produced when an exceptionally large star collapses at the end of its lifespan. In a hypernova, the core of the star collapses directly into a black hole and two extremely energetic jets of plasma are emitted from its rotational poles at nearly the speed of light. These jets emit intense gamma rays, and are a candidate explanation for gamma ray bursts. In recent years a flurry of observational data on gamma ray bursts significantly increased our understanding of these events. ...more on Wikipedia about "Hypernova" It must be www.shortopedia.com. Astrophysics
The initial mass function, also known as the Salpeter function, is a relationship that specifies the mass distribution of a newly formed stellar population. It was derived by Edwin Salpeter in the second half of the 20th century. The equation is written as ...more on Wikipedia about "Initial mass function"
The Instituto de Astrofísica de Canarias is an astrophysical research institute based on Tenerife in the Canary Islands, Spain. It was formed in 1975 at the University of La Laguna. ...more on Wikipedia about "Instituto de Astrofísica de Canarias"
An Interacting binary star is a type of double star in which one or both of the component stars has filled or exceeded its Roche lobe. When this happens, material from one star will flow towards the other, forming an accretion disk. The physical conditions in such a system can be complex and highly variable, and they are common sources of cataclysmic outbursts. ...more on Wikipedia about "Interacting binary stars"
In radio astronomy, the flux unit or jansky (abbreviation Jy) is a non- SI unit of electromagnetic flux equivalent to 10−26 watts per square metre per hertz. The unit "jansky" is named after the pioneering radio astronomer Karl Jansky. ...more on Wikipedia about "Jansky"
In astrophysics, the Lane-Emden equation is Poisson's equation for the gravitational potential of a self-gravitating, spherically symmetric polytropic fluid. Its solution provides the run of pressure and density with radius: ...more on Wikipedia about "Lane-Emden equation"
In special relativity, a light cone is the pattern describing the temporal evolution of a flash of light in Minkowski spacetime. This can be visualized in 3-space if the two horizontal axes are chosen to be spatial dimensions, while the vertical axis is time. ...more on Wikipedia about "Light cone"
This page aims to list articles on Wikipedia that are related to astronomy, astrophysics and cosmology. This is so that those interested in the subject can monitor changes to the pages by clicking on Related changes in the sidebar. ...more on Wikipedia about "List of astronomical topics"
This is a list of molecules that have been detected in the interstellar medium, as of 2003. These molecules were detected using radio telescopes to examine the spectra of interstellar clouds. ...more on Wikipedia about "List of molecules in interstellar space"
Description: The Philosophiae Naturalis Principia Mathematica ( Latin: "mathematical principles of natural philosophy", often Principia or Principia Mathematica for short) is a three-volume work by Isaac Newton published on July 5, 1687. Probably the most influential scientific book ever published, it contains the statement of Newton's laws of motion forming the foundation of classical mechanics as well as his law of universal gravitation. He derives Kepler's laws for the motion of the planets (which were first obtained empirically). ...more on Wikipedia about "List of publications in physics"
Luminosity has different meanings in several different fields of science. ...more on Wikipedia about "Luminosity"
A Magnetogravity wave is a type of plasma wave. A magnetogravity wave is an acoustic gravity wave which is associated with fluctuations in the background magnetic field. In this context, gravity wave refers to a classical fluid wave, and is completely unrelated to the relativistic gravitational wave. ...more on Wikipedia about "Magnetogravity wave"
In astronomy, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. All heavier elements are described in astronomy as " metals". ...more on Wikipedia about "Metallicity"
In physics, the modified Newtonian dynamics (MOND) is a burgeoning theory that attempts to explain the galaxy rotation problem by modifying Newton's second law of motion. (The most widely accepted approach to explaining this problem postulates the existence of dark matter.) MOND was proposed in 1983 by Mordehai Milgrom. The central pillar of MOND is the assumption that Newton's Second Law () is a high-acceleration approximation of a more accurate law that describes all accelerations. The proposed modification would only become relevant when the total acceleration of a body falls significantly below the constant . Consequently, observations of this behavior could never be made on Earth. ...more on Wikipedia about "Modified Newtonian dynamics"
Neutronium is a term used in science fiction and popular literature to refer to an extremely dense phase of matter composed primarily of neutrons. The word had been coined by Andreas von Antropoff in 1926 (scil., before the discovery of the neutron itself) for the 'element of atomic number zero' that he placed at the head of the periodic table. The meaning of the term changed over time, and from the last half of the 20th century onwards it was used to refer to extremely dense phases of matter resembling the neutron-degenerate matter postulated to exist in the cores of neutron stars. ...more on Wikipedia about "Neutronium"
In theoretical astrophysics, the Nordtvedt effect refers to the relative motion between the Earth and the Moon which would be observed if the gravitational self-energy of a body contributed to its gravitational mass but not its inertial mass. If observed, the Nordtvedt effect would violate the strong equivalence principle, which shows that an object's movement in a gravitational field does not depend on its mass or composition. ...more on Wikipedia about "Nordtvedt effect"
In astrophysics, normal stars are usually defined as these having standard amounts of each atomic element. Yet another definition is that the star has a metal composition similar to the standard cosmic abundances. ...more on Wikipedia about "Normal star"
A nova (pl. novae) is a cataclysmic nuclear explosion caused by the accretion of hydrogen onto the surface of a white dwarf star. ...more on Wikipedia about "Nova"
Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). The primordial preexisting nucleons were formed from the quark-gluon plasma of the Big Bang as it cooled below ten million degrees. This first process may be called nucleogenesis, the genesis of nucleons in the universe. The subsequent nucleosynthesis of the elements occurs primarily either by nuclear fusion or nuclear fission. ...more on Wikipedia about "Nucleosynthesis"
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