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absorption spectrum

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the spectrum formed by electromagnetic radiation that has passed through a medium in which radiation of certain frequencies is absorbed.

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aurora

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Meteorology. a radiant emission from the upper atmosphere that occurs sporadically over the middle and high latitudes of both hemispheres in the form of luminous bands, streamers, or the like, caused by the bombardment of the atmosphere with charged solar particles that are being guided along the earth's magnetic lines of force.

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baryon

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an elementary particle that comprises three quarks. PROTONS AND NEUTRONS ARE THIS

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black body spectrum

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the spectrum of an ideal thermal source of radiation (i.e. a black body). This is a (General Physics) physics a hypothetical body that would be capable of absorbing all the electromagnetic radiation falling on it. Also called: full radiator

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bow shock

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the shock front along which the solar wind encounters a planet's magnetic field.

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chromosphere

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a reddish gaseous layer immediately above the photosphere of the sun or another star. Together with the corona, it constitutes the star's outer atmosphere.

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conduction

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the process by which heat or electricity is directly transmitted through a substance when there is a difference of temperature or of electrical potential between adjoining regions, without movement of the material.

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continuous spectrum

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a spectrum that contains or appears to contain all wavelengths but not spectrum lines over a wide portion of its range. The emission spectrum of incandescent solids is continuous; bremsstrahlung spectra consisting of a large number of lines may appear continuous

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convection

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Heat transfer in a gas or liquid by the circulation of currents from one region to another.

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core

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The core is the innermost layer of the sun and it is a source for all the Sun's energy. The material in the core is firmly attached and has very high temperature, which is about 15 million degrees Kelvin. In the core the intense heat destroys the internal structure of an atom and therefore all atoms are broken down into their constituent parts. An atom is composed of protons, electrons and neutrons. Neutrons have no electric charge and so they do not interact a lot with the surrounding medium. Thus neutrons go away the core fairly and quickly. The protons, which have positive electric charge, and the electrons, which have negative electric charge, remain in the core and force the reactions which fuel the Sun. The charge neutral material of protons and electrons that makes up the core is called plasma. The high temperature provides the protons and electrons with a great amount of thermal energy and therefore they moved pretty quickly and they combine with the high density of the plasma, causes the particles to continuously slam into one another creating nuclear reactions. It is the fusion, or slamming together, of particular combinations of particles that provides the energy source of the Sun.

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corona

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he corona is the outer atmosphere of the Sun, which is much larger in volume than the Sun itself. The corona merges slickly with the solar wind so as to fill the solar system and heliosphere. The low corona, which is very close to the surface of the Sun, has a particle density of 1011/m3 (Earth's atmosphere near sea level has a particle density of about 2x1025/m3). The temperature of the corona is several million degrees K.

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coronal loop

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Coronal loops form the basic structure of the lower corona and transition region of the Sun. These highly structured loops are a direct consequence of the twisted solar magnetic flux within the solar body.

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coronal mass ejection

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A coronal mass ejection (CME) is a massive burst of gas and magnetic field arising from the solar corona and being released into the solar wind, as observed in a coronagraph.

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electromagnetic spectrum

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The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object has a different meaning, and is instead the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

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emission spectrum

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The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.

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energy-level diagram

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Chemists sometimes use an energy level diagram to represent electrons when they're looking at chemical reactions and bonding. An energy level diagram is more useful and easier to work with than quantum numbers in the quantum mechanical model. Chemists use the energy level diagram as well as electron configuration notation to represent which energy level, subshell, and orbital are occupied by electrons in any particular atom. Chemists use this information in these ways: To predict what type of bonding will occur with a particular element and show exactly which electrons are being used To show why certain elements behave in similar ways

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faculae

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a bright region on the surface of the sun, linked to the subsequent appearance of sunspots in the same area.

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filament

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A strand of cool gas suspended over the photosphere by magnetic fields, which appears dark as seen against the disk of the Sun; a filament on the limb of the Sun seen in emission against the dark sky is called a prominence.

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frequency

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the rate at which a vibration occurs that constitutes a wave, either in a material (as in sound waves), or in an electromagnetic field (as in radio waves and light), usually measured per second.

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granulation

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Granules on the photosphere of the Sun are caused by convection currents (thermal columns, Bénard cells) of plasma within the Sun's convective zone. The grainy appearance of the solar photosphere is produced by the tops of these convective cells and is called granulation.

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helioseismology

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The study of conditions far below the Sun's surface through the analysis of internal "sound" waves that repeatedly cross the solar interior.

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limb darkening

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is an optical effect seen in stars (including the Sun), where the center part of the disk appears brighter than the edge or limb of the image.

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magnetic reconnection

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Magnetic reconnection (henceforth called "reconnection") refers to the breaking and reconnecting of oppositely directed magnetic field lines in a plasma. In the process, magnetic field energy is converted to plasma kinetic and thermal energy.

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magnetosphere

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the region surrounding the earth or another astronomical body in which its magnetic field is the predominant effective magnetic field.

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metallicity

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the metallicity or Z, is the proportion of its matter making up the chemical elements in stars or other kinds of astronomical objects, excluding their hydrogen (X) and helium (Y).

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neutrinos

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Any of three electrically neutral leptons (the electron neutrino, muon neutrino and tau neutrino—one in each of the three generations of elementary fermions) that have small or very small masses.

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neutrons

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The electrically neutral nucleon, a baryon composed of two down quarks and one up quark, which has a mass 1,839 times that of an electron, is stable when bound in an atomic nucleus, but has a mean lifetime of 886 seconds as a free particle. It is a basic component of all atomic nuclei except the protium isotope of hydrogen.

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photons

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The smallest unit of light or other electromagnetic energy, having no mass and no electric charge. Photons behave both as particles and waves.

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photosphere

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The directly visible outer layer or atmosphere of a star, especially of the sun.

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plages

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A bright and intensely hot area in the sun's chromosphere, usually associated with a sunspot.

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plasma

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An electrically neutral, highly ionized phase of matter composed of ions, electrons, and neutral particles. It is distinct from solids, liquids, and gases.

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polarities

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the condition of a body or system in which it has opposing physical properties at different points, esp magnetic poles or electric charge

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positrons

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An elementary particle having the same mass and magnitude of charge as an electron but exhibiting a positive charge; the antiparticle of the electron. Also called antielectron.

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ppI chain

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The proton-proton chain reaction is one of several fusion reactions by which stars convert hydrogen to helium, the primary alternative being the CNO cycle. The proton-proton chain dominates in stars the size of the Sun or smaller.

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prominences

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A prominence is a large, bright, gaseous feature extending outward from the Sun's surface, often in a loop shape. Prominences are anchored to the Sun's surface in the photosphere, and extend outwards into the Sun's corona.

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protons

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a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign.

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radiation

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the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization. Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.

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rest energy

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the energy equivalent to the mass of a particle at rest in an inertial frame of reference, equal to the rest mass times the square of the speed of light.

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solar flares

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a brief powerful eruption of particles and intense electromagnetic radiation from the sun's surface, associated with sunspots and causing disturbances to radio communication on earth

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solar neutrino problem

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The solar neutrino problem was a major discrepancy between measurements of the numbers of neutrinos flowing through the Earth and theoretical models of the solar interior, lasting from the mid-1960s to about 2002. The discrepancy has since been resolved by new understanding of neutrino physics, requiring a modification of the Standard Model of particle physics - specifically, neutrino oscillation. Essentially, as neutrinos have mass, they can change from the type that had been expected to be produced in the Sun's interior into two types that would not be caught by the detectors in use at the time.

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solar wind

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the continuous flow of charged particles from the sun that permeates the solar system.

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spectroscopy

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the branch of science concerned with the investigation and measurement of spectra produced when matter interacts with or emits electromagnetic radiation.

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sunspots

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one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena.

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supergranulation

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is a particular pattern of convection cells on the Sun's surface called supergranules. It was discovered in the 1950s by A.B.Hart using Doppler velocity measurements showing horizontal flows on the photosphere (flow speed about 300 to 500 m/s, a tenth of that in the smaller granules).

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termination shock

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is the boundary marking one of the outer limits of the Sun's influence, and is one boundary of the Solar System.

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thermalization

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to undergo or cause to undergo a process in which neutrons lose energy in a moderator and become thermal neutrons

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