Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Luminosity


Related Topics
Sun

  
  Luminosity - Wikipedia, the free encyclopedia
The SI unit for luminosity is candela per square metre.
W. Luminosity is an intrinsic constant independent of distance, while in contrast apparent brightness observed is related to distance with an inverse square relationship.
The integrated luminosity is the integral of the luminosity with respect to time.
en.wikipedia.org /wiki/Luminosity   (713 words)

  
 Luminosity   (Site not responding. Last check: 2007-10-21)
In physics, luminosity is the density of luminous intensity in a given direction.
Luminosity is an intrinsic constant independent of distance, while in contrast apparent brightness observed is related to distance with an inverse square relationship.
In measuring star brightnesses, luminosity, apparent magnitude (brightness), and distance are interrelated parameters.
www.serebella.com /encyclopedia/article-Luminosity.html   (386 words)

  
 luminosity   (Site not responding. Last check: 2007-10-21)
In general physics, "luminosity" (more properly called luminance) is the density of luminous intensity in a given direction.
In astronomy, "luminosity" is the amount of energy a body radiates per unit time.
In scattering theory and accelerator physics, "luminosity" is the number of particles per unit area per unit time times the opacity of the target, usually expressed in either the cgs units cm
www.paloweb.com /wikipedia.asp?l=en&pages=luminosity   (717 words)

  
 MSN Encarta - Star (astronomy)
The luminosity of a star is its intrinsic brightness, or the total energy radiated per second.
Luminosity often depends on where a star is in its evolutionary sequence, so it is important to astrophysicists who study the evolution of stars (see Astrophysics).
Although luminosity calculations are made partly by observation and partly from theory, values have been established for many stars.
encarta.msn.com /encyclopedia_761557483_2/Star_(astronomy).html   (1727 words)

  
 Eddington luminosity   (Site not responding. Last check: 2007-10-21)
Eddington luminosity (sometimes also called the Eddington limit) is the largest luminosity that can pass through a layer of gas in hydrostatic equilibrium.
If the luminosity of a star exceeds the Eddington luminosity of a layer on the stellar surface, the gas layer is ejected from the star.
The exact value of Eddington luminosity depends on the mass of the star and chemical composition of the gas layer.
www.serebella.com /encyclopedia/article-Eddington_luminosity.html   (192 words)

  
 Luminosity   (Site not responding. Last check: 2007-10-21)
Luminosity is an intrinsic constant independent of distance, while in contrast apparent brightness observed is related todistance with an inverse square relationship.
In measuring star brightnesses, luminosity, apparentmagnitude (brightness), and distance are interrelated parameters.
Since the sun's luminosity is the standard, comparing these parameters with the sun's apparentmagnitude and distance is the easiest way to remember how to convert between them.
www.therfcc.org /luminosity-2044.html   (336 words)

  
 NationMaster.com - Encyclopedia: Luminosity   (Site not responding. Last check: 2007-10-21)
The solar luminosity is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars.
For stars on the main sequence, luminosity is also related to mass: Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram.
The SI unit for luminosity is candela per square meter.
www.nationmaster.com /encyclopedia/Luminosity   (2115 words)

  
 The Temporal Doorway - An Analysis of UFO Luminosity
Further the Levelland case may indicate some relationship between full body luminosity and vehicle interference effects (the witness observed the intensity of his headlights varied inversely with the brightness of the UFO luminosity, this may have been a brightness effect or may have been an actual response to the cause of the luminosity variations).
Ejected luminosity, as shown in the Robert Campbell photos from August 2, 1965, is sometimes reported.
I also consider it possible that UFO luminosity represents a laser-type phenomenon, in the sense that an energy population inversion might be necessary to allow UFO luminosity to propagate from the base to the edge of the sheath.
www.temporaldoorway.com /ufo/analysis/luminosity   (1600 words)

  
 May 14, 2003 - KEKB Records 1034/cm^2s Luminosity
Luminosity is a measure of the rate at which the collisions occur.
The higher the luminosity, the greater the rate at which B-meson and anti-B-meson pairs are produced.
In order to increase the luminosity, the intensity of both the electron and positron beams must be increased, and each must be squeezed to the smallest possible size.
www.interactions.org /cms/?pid=1002036&printable=1   (848 words)

  
 Eddington Luminosity   (Site not responding. Last check: 2007-10-21)
The classical Eddington luminosity is the theoretical maximum luminosity for a star of a given mass.
At this luminosity, the outward force due to radiation pressure exactly equals the inward pull due to gravity; particles in the outer layers are no longer bound.
For the classical Eddington luminosity, the opacity is taken to be entirely due to free electron scattering in a fully ionized gas.
www.pha.jhu.edu /~ericpeng/seminar/node4.html   (274 words)

  
 Tevatron Luminosity
Luminosity is a measure of particle interaction, specifically the chance that a proton will collide with an antiproton.
To achieve high luminosity you place as many particles as possible into as small a space as possible.
(The luminosity drops as the particles continue to collide with each other during the life of the store.) The red triangle displays a point representing the last 20 peak values averaged together.
www.fnal.gov /pub/now/tevlumemp.html   (472 words)

  
 Luminosity functions
Luminosity functions are typically tabulated in energy units, but we provide both energy and quantal versions.
Unlike cone spectral sensitivities, the shape of the luminosity function changes with chromatic adaptation (e.g., De Vries, 1948; Eisner and MacLeod, 1981), and is highly dependent on the observing conditions (e.g., size, retinal eccentricity, duration and intensity of the viewing field) and the measurement criterion.
De Vries, H. The luminosity curve of the eye as determined by measurements with the flicker photometer.
www-cvrl.ucsd.edu /database/text/intros/introvl.htm   (913 words)

  
 luminosity class
A classification of stellar spectra according to luminosity for a given spectral type; it was introduced as part of the Morgan-Keenan classification.
The luminosity class broadly indicates whether a star is a dwarf (that is, a main sequence star), a giant, or a supergiant, since luminosity is directly related to surface area.
Luminosity class is expressed as a Roman numeral, from I to V, and appears after the spectral type; for example, Tau Ceti, with spectral type G8, is listed as a G8V object.
www.daviddarling.info /encyclopedia/L/luminosity_class.html   (164 words)

  
 The Temporal Doorway - UFO Surface Luminosity
This cross section reveals that the luminosity is red close to the object and passes through yellow to green and possibly blue as distance from the surface of the object increases.
This is the luminosity on the side of the object closest to the observer.
It is clear from this image that the luminosity does have a thickness and that the red layer is lower than the yellow and green layers.
www.temporaldoorway.com /ufo/analysis/luminosity/surface.htm   (513 words)

  
 ScienceDaily: Luminosity   (Site not responding. Last check: 2007-10-21)
In scattering theory and accelerator physics, luminosity is the number of particles per unit area per unit time times the opacity of the target, usally expressed in either the cgs units cm
Luminosity -- In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given...
Astrophysics -- Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature and chemical composition) of astronomical...
www.sciencedaily.com /encyclopedia/luminosity   (1925 words)

  
 Probing the shape of the Globular Cluster Luminosity Function
Local calibration of the luminosity function continues to be the main weakness of this distance indicator.
Additionally, consistent and useful models of globular cluster formation indicate that the shape of the globular cluster luminosity function (GCLF) is in fact a residual of dynamic processes which destroy low mass clusters, thus resulting in a peak in the luminosity function (for example Murali and Weinberg, 1997).
If the picture of cluster evolution shaping the luminosity function (as first proposed in Fall and Ress 1977) is correct then there should be some variation in the shape of the GCLF when examined at different distances form the center of the host galaxy.
www.cfht.hawaii.edu /Reference/Proceedings/kavelaars/index.html   (844 words)

  
 New Machine Record for Heavy Ion Luminosity at RHIC
Luminosity is an extremely important measure of a colliding-beam accelerator’s performance.
Given the record-setting luminosity and its contribution to the run’s success, “RHIC’s experiments may nail it this time,” says accelerator physicist Thomas Roser, who is responsible for RHIC operations within C-AD.
Instantaneous luminosity is a measure of the number of particle collisions per second.
www.bnl.gov /bnlweb/pubaf/pr/PR_display.asp?prID=04-46   (980 words)

  
 Universe theory : Light, spectrum and luminosity
The luminosity, or intrinsic intensity, is an indication of the energy radiated by a star.
Also the luminosity of larger stars is higher than that of smaller ones (like blue giants compared to white dwarfs).
When the temperature of stars is plotted on a graph against their luminosity, you will find that the majority of the stars lie on a narrow diagonal band, which is called the main sequence.
library.thinkquest.org /18188/english/universe/theory/spectrum.htm   (1015 words)

  
 Topics : KEKBluminosity
Integrated luminosity is a measure of the capability of producing the particle collisions in a collider experiments.
The integrated luminosity improves as the stability of the accelerator operation and the data collection capability of the detector etc, increases.
During the operation of the former TRISTAN accelerator from 1987 to 1995 by KEK, the total integrated luminosity by the VENUS detector was 400/pb.
www.kek.jp /intra-e/topics/2005/KEKBluminosity.html   (320 words)

  
 Solar luminosity - Wikipedia, the free encyclopedia
, is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars.
It is equal to the luminosity of the Sun, which is 3.827 × 10
You can calculate how much solar power hits the Earth by comparing a cross sectional area of the Earth and the total surface area of a sphere with a radius equal to the distance of the earth from the sun.
en.wikipedia.org /wiki/Solar_luminosity   (224 words)

  
 Lives and Deaths of Stars
In fact, all of the other aspects of a star such as its luminosity, temperature, size, density, etc., can be explained using the fundamental property of a star: its mass.
There is also a slight dependence of the luminosity, temperature, size, etc. on the composition of the star, but because stars are all mostly hydrogen and helium, the star's mass is the important quantity.
In the previous chapter, the relationship between the luminosity and mass was explained using basic principles of how compressed gases behave.
www.astronomynotes.com /evolutn/s2.htm   (533 words)

  
 Luminosity - By Frank & Gillian
The prose is elegant in its simplicity, the characters firmly shaped, and the story a mesh of human aspiration, spiritual questing and a touch of the incredible.
Luminosity begins with the introduction of two young men, Breetz and Richard, who have been friends since childhood.
It’s not often that you pick up a book, read it to the end, enjoy it immensely, and then only truly realize on the final page what the whole work was about.
www.unb.ca /web/bruns/9900/issue15/entertainment/book4.html   (573 words)

  
 mass-luminosity relation on Encyclopedia.com
MASS-LUMINOSITY RELATION [mass-luminosity relation] in astronomy, law stating that the luminosity of a star is proportional to some power of the mass of the star.
For stars on the main sequence of the Hertzsprung-Russell diagram, it is found empirically that the luminosity varies as the 3.5 power of the mass.
One important use of the mass-luminosity relation is in estimating the mass of a star of known luminosity that is not in a binary system.
www.encyclopedia.com /html/m1/masslumi.asp   (192 words)

  
 [No title]
The Luminosity is a function of time (which may be falling even more rapidly during run II than it was during run I).
The luminosity 'L_ST(n)' that a particular Specific Trigger 'n' is exposed to is derived the same way as the beam luminosity, but the calculation needs to be restricted to the beam crossings 'ST_exposed_Rate(n,i)' that the Specific Trigger was exposed to.
Another view is that the ST_exposed state is dependent on the luminosity in the previous bunches (and even maybe on the PREVIOUS crossings of this particular bunch) but not on the current crossing of this particular bunch.
www.pa.msu.edu /hep/d0/ftp/l1/framework/exposure_groups/measuring_luminosity_online.txt   (2934 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.