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Stars/X-ray classification

Any X-ray classification of stars seems unlikely as the visible portion of the electromagnetic spectrum is expected to accompany the emission of X-radiation (X-rays) and phenomena may be associated.

But, the emission of X-rays is most often associated with a coronal cloud, a corona, or at least a high temperature plasma (about 106 K).

X-rays
X-ray astronomy is a physical subfield of astronomy, more specifically radiation astronomy, that uses a variety of X-ray detectors fashioned into X-ray telescopes to observe natural sources that emit, reflect, transmit, or fluoresce X-rays. X-rays can only penetrate so far into a planetary atmosphere such as that surrounding the crustal and oceanic surface of the Earth. This limitation requires that these detectors and telescopes be lofted above nearly all of the atmosphere to function. Another alternative is to place them on astronomical bodies such as the Moon or in orbit.

X-radiation
X-rays span 3 decades in wavelength, frequency and energy. From 10 to 0.1 nanometers (nm) (about 0.12 to 12 keV) they are classified as soft x-rays, and from 0.1 nm to 0.01 nm (about 12 to 120 keV) as hard X-rays.

Although the more energetic X-rays, photons with an energy greater than 30 keV (4,800 aJ) can penetrate the air at least for distances of a few meters (they would never have been detected and medical X-ray machines would not work if this was not the case) the Earth's atmosphere is thick enough that virtually none are able to penetrate from outer space all the way to the Earth's surface. X-rays in the 0.5 to 5 keV (80 to 800 aJ) range, where most celestial sources give off the bulk of their energy, can be stopped by a few sheets of paper; ninety percent of the photons in a beam of 3 keV (480 aJ) X-rays are absorbed by traveling through just 10 cm of air.

Planetary sciences
"Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus, the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere."

Metallicities
The metallicity (also called Z ) of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. The metallicity of an astronomical object may provide an indication of its age. When the universe first formed, according to the Big Bang theory, it consisted almost entirely of hydrogen which, through primordial nucleosynthesis, created a sizeable proportion of helium and only trace amounts of lithium and beryllium and no heavier elements. Therefore, older stars have lower metallicities than younger stars such as our Sun.

Stellar populations are categorized as I, II, and III, with each group having decreasing metal content and increasing age. The populations were named in the order they were discovered, which is the reverse of the order they were created. Thus, the first stars in the universe (low metal content) were population III, and recent stars (high metallicity) are population I. ... The next generation of stars was born out of those materials left by the death of the first. The oldest observed stars, known as Population II, have very low metallicities;

The metallicity of the Sun is approximately 1.8 percent by mass. For other stars, the metallicity is often expressed as "[Fe/H]", which represents the logarithm of the ratio of a star's iron abundance compared to that of the Sun (iron is not the most abundant heavy element, but it is among the easiest to measure with spectral data in the visible spectrum). The formula for the logarithm is expressed thus:

 * $$ [\mathrm{Fe}/\mathrm{H}] = \log_{10}{\left(\frac{N_{\mathrm{Fe}}}{N_{\mathrm{H}}}\right)_{star}} - \log_{10}{\left(\frac{N_{\mathrm{Fe}}}{N_{\mathrm{H}}}\right)_{sun}} $$

where $$N_{\mathrm{Fe}}$$ and $$N_{\mathrm{H}}$$ are the number of iron and hydrogen atoms per unit of volume respectively. The unit often used for metallicity is the "dex" which is a (now-deprecated) contraction of decimal exponent. By this formulation, stars with a higher metallicity than the Sun have a positive logarithmic value, while those with a lower metallicity than the Sun have a negative value. The logarithm is based on powers of ten; stars with a value of +1 have ten times the metallicity of the Sun (101). Conversely, those with a value of -1 have one tenth (10 −1), while those with -2 have a hundredth (10−2), and so on. Young Population I stars have significantly higher iron-to-hydrogen ratios than older Population II stars. Primordial Population III stars are estimated to have a metallicity of less than −6.0, that is, less than a millionth of the abundance of iron which is found in the Sun.

Theoretical stellar classification
A star is a massive, luminous sphere of plasma held together by gravity. This is a traditional definition of a star. The term "luminous" relates to light, specifically visible light, as it is perceived by the human eye.

From a dictionary:

Def.

 * 1.a: "any natural luminous body visible in the sky [especially] at night",
 * 1.b: "a self-luminous gaseous celestial body of great mass whose shape is [usually] spheroidal and whose size may be as small as the earth or larger than the earth's orbit".

is called a star.

Def. "[t]he natural medium emanating from the sun and other very hot sources (now recognised as electromagnetic radiation with a wavelength of 400-750 nm), within which vision is possible" is called light.

Def. "to shine light on something" is called illuminate.

Def. "emitting light" is called luminous.

From astrophysics:

Def. "any object forming on a dynamical timescale, by gravitational instability", is called a star.

As an objective of original research, an X-ray classification of stars needs to produce evidence that it is possible to classify stars by X-ray astronomy or coronal cloud characteristics. These characteristics need not correspond in any way with the conventional visual classification.

Def. "[a] visible surface layer of a star, and especially that of a sun" is called a photosphere.

Def. "[t]he faint pink extension of a star's atmospheric envelope between the corona and the photosphere" is called the chromosphere.

Def. "[t]he luminous plasma atmosphere of the Sun or other star, extending millions of kilometres into space, most easily seen during a total solar eclipse" is called a corona.

Def. "a low energy discharge caused by ionization of a gas by an electric field [quite common at conductor bends of 12kV or higher]" is called a corona, or an electrical corona.

Def. "[t]he outflow of charged particles from the solar corona into space ... [b]ecause of the high temperature of the particles of the corona, ... are moving at speeds higher than the solar escape velocity" is called a solar wind.

Def. "[t]he equivalent of solar wind associated with a star other than our Sun" is called a stellar wind.

Def. "[t]he region of space where interstellar medium is blown away by solar wind" is called the heliosphere.

It may be the case that coronal clouds around a star are independent of the stellar type based upon photospheric characteristics. But, if heat is being radiated or transferred to the photosphere to heat it to the temperature observed (Teff), then the photospheric temperature may reflect the coronal cloud conditions. Ions characteristic of the chromosphere should not be used to classify stars.

Testing the coronal cloud independence of stellar classification may be statistically possible once a proper separation of chromospheric and above phenomena is performed. The same coronal cloud at different locations may produce different star types depending solely upon what is the star itself (photosphere and beneath).

Continua
X-ray continuum emission "can arise both from a jet and from the hot corona of the accretion disc via a scattering process: in both cases it shows a power-law spectrum. In some radio-quiet active galactic nuclei (AGN) there is an excess of soft X-ray emission in addition to the power-law component.

X-ray line emission is a result of illumination of cold heavy elements by the X-ray continuum that causes fluorescence of X-ray emission lines.

Using X-rays to determine a crystal structure results in diffraction intensities that are represented in reciprocal space as peaks. These have a finite width due to a variety of defects away from a perfectly periodic lattice. There may be significant diffuse scattering, a continuum of scattered X-rays that fall between the Bragg peaks.

The X-ray continuum can arise from bremsstrahlung, black-body radiation, synchrotron radiation, or what is called inverse Compton scattering of lower-energy photons by relativistic electrons, knock-on collisions of fast protons with atomic electrons, and atomic recombination, with or without additional electron transitions.

Meteors
"[A] medium-strength flare erupted from the sun on July 19, 2012. The blast also generated the enormous, shimmering plasma loops, which are an example of a phenomenon known as "coronal rain," agency officials said."

"Hot plasma in the corona cooled and condensed along strong magnetic fields in the region" slowly falling back to the solar surface as plasma "rain".

"Many CMEs have also been observed to be unassociated with any obvious solar surface activity".

In the images at right, a CME, or "arcs rise above an active region on the surface of the Sun in this series of images taken by the STEREO (Behind) spacecraft on January 27, 2010. The arcs are plasma, superheated matter made up of moving charged particles (electrons and ions). Just as iron filings arc from one end of a magnet to another, the plasma is sliding in an arc along magnetic field lines. In a movie of STEREO observations made between January 26 and January 29, the dynamic streams were initially just over the Sun’s edge and readily spotted as the Sun rotated them more into view."

"About mid-way through the movie clip, a small coronal mass ejection (a stream of charged particles from the Sun) shoots out and into space at about a million miles per hour, carrying some magnetic field with it. The [first] image shows the beginning of the coronal mass ejection, while the [second] image shows the solar matter leaving the Sun’s corona. Most coronal mass ejections are more bulbous and wide: this one is quite narrow and contained. Nonetheless, NASA solar scientists agree that its speed and characteristics suggest that it was indeed a non-typical coronal mass ejection."

The February 10, 1956, event "was observed at Sacramento Peak. A bright ball appears above the [Sun's] surface, grows in size and Hα brightness, and explodes upward and outward."

Magnetic clouds represent about one third of ejecta observed by satellites at Earth. Other types of ejecta are multiple-magnetic cloud events (a single structure with multiple subclouds distinguishable) and complex ejecta, which can be the result of the interaction of multiple CMEs.

Cosmic rays
"[T]he relative abundances of solar cosmic rays reflect those of the solar photosphere for multicharged nuclei with approximately the same nuclear charge-to-mass ratio."

Protons
The Sun and the solar wind, at least that portion that originates through the polar coronal holes apparently from the photosphere, may be major sources of protons within the solar system.

At right is a temporal distribution of solar proton flux in units of particles cm-2 s-1 sr-1 as measured by GOES 11 over the four days from November 2, 2003, to November 4, 2003, in three windows of energy: ≥ 100 MeV (green), ≥ 50 MeV (blue), and ≥ 10 MeV (red). The percentage originating from the surface of the Sun either directly or through the contribution to the solar wind is not indicated.

Electrons
By using estimates of the interstellar electron influx that may have been measured by Voyager 1, a back-of-the-envelope calculation shows that the electron influx may be sufficient to heat the solar corona to MK and the photosphere to 5777 K. These estimates put the coronal heating problem in perspective of the overall external heating of the outer Sun including the photosphere.

The news report of Voyager 1 reaching some 120 AU from the Sun contain interesting discoveries. The most significant may be a flux of electrons diffusing into our solar system from elsewhere in the galaxy. The solar wind has ceased earlier and has even been turned backward. These results suggest a net influx of electrons perhaps toward the Sun that may be involved in heating the solar corona. The possibility is explored using some "back-of-the-envelope" calculations in the learning resource electron beam heating/Laboratory.

The lecture electron beam heating describes at least one example of the use of this technology to heat objects.

Def. the "rate of transfer of energy (or another physical quantity) through a given surface, specifically electric flux, magnetic flux" is called a flux.

"Mass flux of species α [is in units of] g/cm2 s" or, in dimensions [quantity of species α]·[area]−1·[time]−1, where an area may be cm2.

Electron winds
As of December 5, 2011, "Voyager 1 is about ... 18 billion kilometers ... from the [S]un [but] the direction of the magnetic field lines has not changed, indicating Voyager is still within the heliosphere ... the outward speed of the solar wind had diminished to zero in April 2010 ... inward pressure from interstellar space is compacting [the magnetic field] ... Voyager has detected a 100-fold increase in the intensity of high-energy electrons from elsewhere in the galaxy diffusing into our solar system from outside ... [while] the [solar] wind even blows back at us."

Surface area
From the image at the above right it appears that the coronal clouds about the Sun cover a partial shell from say 80° N to about 80° S that follows the curvature of the photosphere. There does seem to be a physical separation of the shell of coronal clouds from the concentric shell of the photosphere. The coronal holes perhaps being void of incoming electron flux.

Photosphere volumes
R⊙eq ≈ 6.955 x 105 km. The thickness of the photosphere is about 400 km. R⊙p ≈ 6.951 x 105 km.

 * $$V_{\odot p} = \frac{4\pi}{3} [R_{\odot eq}^3 - R_{\odot p}^3] km^3,$$

 * $$V_{\odot p} = \frac{4\pi}{3} [6.955^3 - 6.951^3] \times 10^{15} km^3,$$

 * $$V_{\odot p} = \frac{4\pi}{3} (0.580) \times 10^{15} km^3,$$

 * $$V_{\odot p} = 7.288 \times 10^{15} km^3.$$

Photosphere hydrogens
The density of the Sun is about 2 x 10-4 kg m-3. Or,

 * $$\rho_{\odot p} = 2 \times 10^{-4} kg \cdot m^{-3},$$

 * $$\rho_{\odot p} = 2 \times 10^{-4} kg \cdot [10^{-3} km]^{-3},$$

 * $$\rho_{\odot p} = 2 \times 10^5 kg \cdot km^{-3}.$$

One mole of H2 (gas) has a mass of 2.016 x 10-3 kg. The molar density of the photosphere may be

 * $$\rho_{\odot p} = \frac{2 \times 10^5 kg}{2.016 \times 10^{-3} kg/mole} km^{-3},$$

 * $$\rho_{\odot p} = \frac{2}{2.016} \frac{10^5}{10^{-3}} \frac{kg}{kg/mole} km^{-3},$$

 * $$\rho_{\odot p} = 0.992 \times 10^8 moles \cdot km^{-3},$$

 * $$\rho_{\odot p} = 10^8 moles \cdot km^{-3}.$$

 * $$V_{\odot p} = 7.288 \times 10^{15} km^3.$$

 * $$H_{2 \odot p} = (10^8 moles \cdot km^{-3}) \cdot (7.288 \times 10^{15} km^3),$$

 * $$H_{2 \odot p} = 7.288 \times 10^{23} moles.$$

Constant volume specific heat capacity
For H2 (gas) the molar constant-volume heat capacity at 298 K is 20.18 J/(mol · K). At 2000 K it is about 25 J/(mol · K). Using a linear extrapolation,

 * $$C_{V,m} = (2.83 \times 10^{-3})T J/(mol \cdot K^2) + 19.3 J/(mol \cdot K),$$

for 5777 K, yields

 * $$C_{V,m} = (2.83 \times 10^{-3}) (5777) J/(mol \cdot K) + 19.3 J/(mol \cdot K),$$

 * $$C_{V,m} = 35.6 J/(mol \cdot K).$$

Before calculating the amount of energy or power necessary to heat the coronal clouds around the Sun, let's see if the influx of electrons from outside the heliosphere may be able to heat the surface of the photosphere (p) to 5777 K from 100 K.

 * $$\Delta Q = [35.6 J/(mol \cdot K)] \cdot (5777 - 100) K,$$

 * $$\Delta Q = (35.6) \cdot (5677) \frac{J}{mole \cdot K}{K},$$

 * $$\Delta Q = 2.02 \times 10^5 J/mole.$$

 * $$1 J = 6.24 \times 10^{18} eV.$$

 * $$\Delta Q = (2.02 \times 10^5 J/mole) \cdot (6.24 \times 10^{18} eV/J),$$

 * $$\Delta Q = (2.02) \cdot (6.24) \times 10^5 \times 10^{18} eV/mole,$$

 * $$\Delta Q = 12.6 \times 10^{23} eV/mole,$$

 * $$\Delta Q = 1.26 \times 10^{24} eV/mole.$$

Photosphere heating

 * $$\Delta Q = 1.26 \times 10^{24} eV/mole.$$

 * $$H_{2 \odot p} = 7.288 \times 10^{23} moles.$$

Voyager 1 is 17,932,000,000 km (119.9 AU) from the Sun at RA 17.163h Dec +12.44°, ecliptic latitude of 34.9°.

For this laboratory example, let the electron flux be 2 e- cm-2 s-1 diffusing into our solar system from elsewhere in the galaxy. Each of these electrons has an energy of 10 MeV.

 * $$\Phi_{e^-} = 2 e^- \cdot cm^{-2} \cdot s^{-1} \cdot \frac{(10^{-2} \cdot m \times 10^{-3} \cdot km/m)^{-2}}{cm^{-2}},$$

 * $$\Phi_{e^-} = 2 e^- \cdot cm^{-2} \cdot s^{-1} \cdot \frac{10^{10} \cdot km^{-2}}{cm^{-2}},$$

 * $$\Phi_{e^-} = 2 \times 10^{10} e^- \cdot km^{-2} \cdot s^{-1}.$$

If the electron flux measured by Voyager 1 is close to 2 e- cm-2 s-1 where each electron averages 10 MeV and these electrons are heading for the Sun, then each electron may strike the photosphere from anywhere in a sphere around the Sun.

To heat the photosphere to 5777 K takes

 * $$\Delta Q = (1.26 \times 10^{24} eV/mole) \cdot (7.288 \times 10^{23} moles),$$

 * $$\Delta Q = (1.26) \cdot (7.288) \times (10^{24} \times 10^{23}) \cdot eV,$$

 * $$\Delta Q = 9.18 \times 10^{47} eV.$$

The power (P) that may be deposited on the photospheric surface of the Sun is

 * $$P_{e^-} = 4 \pi R_{Voyager 1}^2 \cdot \Phi_{e^-} \cdot (10 MeV/e^-),$$

 * $$P_{e^-} = 4 \pi (1.7932 \times 10^{10} km)^2 \cdot (2 \times 10^{10} e^- \cdot km^{-2} \cdot s^{-1}) \cdot (10 MeV/e^-),$$

 * $$P_{e^-} = (4 \pi) \cdot (1.7932)^2 \cdot 2 \times (10^{20} \times 10^{10} \times 10^7) \cdot (km^2 \cdot e^- \cdot km^{-2} \cdot s^{-1} \cdot eV/e^-),$$

 * $$P_{e^-} = 80.8 \times 10^{37} \cdot eV \cdot s^{-1},$$

 * $$P_{e^-} = 8.08 \times 10^{38} eV \cdot s^{-1}.$$

The luminosity (in Watts, W) of the Sun is 3.846 x 1026 W. In eV/s this is

 * $$L_{\odot} = 3.846 \times 10^{26} W \cdot (10^7 erg/(s \cdot W)) \cdot 6.24 \times 10^{11} eV/erg,$$

 * $$L_{\odot} = (3.846) \cdot (6.24) \times (10^{26} \times 10^7 \times 10^{11}) \cdot (W \cdot erg/(s \cdot W)) \cdot eV/erg),$$

 * $$L_{\odot} = 24.0 \times 10^{44} \cdot eV \cdot s^{-1},$$

 * $$L_{\odot} = 2.40 \times 10^{45} \cdot eV \cdot s^{-1}.$$

If the energy of the incoming electrons is 700 MeV and the flux is 8.48 x 104 e- cm-2 s-1, then the power from the incoming electrons would be

 * $$P_{e^-} = (8.08 \times 10^{38} eV \cdot s^{-1}) \cdot (70) \cdot (8.48/2 \times 10^4),$$

 * $$P_{e^-} = (8.08) \cdot (70) \cdot (4.24) \times (10^4 \times 10^{38}) eV \cdot s^{-1},$$

 * $$P_{e^-} = 2400 \times 10^{42} eV \cdot s^{-1},$$

 * $$P_{e^-} = 2.40 \times 10^{45} eV \cdot s^{-1}.$$

The power calculated for the electron influx is compared with the first experiment and with the known luminosity of the Sun.

Coronal heating
The power to heat the solar corona is on the order of 1039 eV s-1. While this is within range of the estimated electron influx beam heating, X-rays are usually generated between 0.1 and 120 keV. 10 to 700 MeV electrons would likely produce gamma rays rather than X-rays.

The initial guess put the power at about six orders of magnitude too low to match the Sun's current luminosity. However, increasing the electron energy by 70 times and the influx by about 4 x 104 brings the estimate into agreement. It is likely that either increase may be too much.

Other concerns focus on whether any of these electrons can reach the Sun. The Sun has a net surface negative charge. The solar wind contains electrons, protons and heavier nuclei that may alter the energy or influx significantly.

While likely factors exist that may decrease the estimated electron energy or influx, it appears that such an influx may not only heat the solar corona but also the photosphere. Actual numbers from Voyager 1 may shed more light on this conclusion.

Unless the influx is significantly higher at lower energies it seems that 10 to 700 MeV is way too high. The corona of the Sun would be producing gamma-rays not X-rays. No justification is given for the 104th increase in the influx estimate. Actual data on interstellar electrons does suggest MeV levels.

Positrons
The solar flare at Active Region 10039 on July 23, 2002, exhibits many exceptional high-energy phenomena including the 2.223 MeV neutron capture line and the 511 keV electron-positron (antimatter) annihilation line. In the image at right, the RHESSI low-energy channels (12-25 keV) are represented in red and appear predominantly in coronal loops. The high-energy flux appears as blue at the footpoints of the coronal loops. Violet is used to indicate the location and relative intensity of the 2.2 MeV emission.

During solar flares “[s]everal radioactive nuclei that emit positrons are also produced; [which] slow down and annihilate in flight with the emission of two 511 keV photons or form positronium with the emission of either a three gamma continuum (each photon < 511 keV) or two 511 keV photons." The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) made the first high-resolution observation of the solar positron-electron annihilation line during the July 23, 2003 solar flare. The observations are somewhat consistent with electron-positron annihilation in a quiet solar atmosphere via positronium as well as during flares. Line-broadening is due to "the velocity of the positronium." "The width of the annihilation line is also consistent ... with thermal broadening (Gaussian width of 8.1 ± 1.1 keV) in a plasma at 4-7 x 105 K. ... The RHESSI and all but two of the SMM measurements are consistent with densities ≤ 1012 H cm-3 [but] <10% of the p and α interactions producing positrons occur at these low densities. ... positrons produced by 3He interactions form higher in the solar atmosphere ... all observations are consistent with densities > 1012 H cm-3. But such densities require formation of a substantial mass of atmosphere at transition region temperatures."

Neutrinos
Neutrinos are hard to detect. The Super-Kamiokande, or "Super-K" is a large-scale experiment constructed in an unused mine in Japan to detect and study neutrinos. The image at right required 500 days worth of data to produce the "neutrino image" of the Sun. The image is centered on the Sun's calculated position. It covers a 90° x 90° octant of the sky (in right ascension and declination). The higher the brightness of the color, the larger is the neutrino flux.

The surface of the Sun is not a known source of neutrinos. Those detected may be from nucleosynthesis within the coronal cloud in the near vicinity of the Sun or perhaps from nucleosynthesis occurring interior to the Sun.

Gamma rays
The Earth's atmosphere is a relatively bright source of gamma rays produced in interactions of ordinary cosmic ray protons with air atoms. In gamma-ray and X-ray astronomy, Earth is a dwarf gaseous object.

X-rays
"X-ray photons can be effectively backscattered by photosphere atoms and electrons (Tomblin 1972; Bai & Ramaty 1978). ... [A]t energies not dominated by absorption the backscattered albedo flux must be seen virtually in every solar flare spectrum, the degree of the albedo contribution depending on the directivity of the primary X-ray flux (Kontar et al. 2006). The solar flare photons backscattered by the solar photosphere can contribute significantly (the reflected flux is 50-90 % of the primary in the 30 - 50 keV range for isotropic sources) to the total observed photon spectrum. for the simple case of a power-law-like primary solar flare spectrum (without albedo), the photons reflected by the photosphere produce a broad 'hump' component. Photospheric albedo makes the observed spectrum flatter below ~ 35 keV and slightly steeper above, in comparison with the primary spectrum."

Opticals
The color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. To measure the index, one observes the magnitude of an object successively through two different filters, such as U and B, or B and V, where U is sensitive to ultraviolet rays, B is sensitive to blue light, and V is sensitive to visible (green-yellow) light (see also: UBV system). The set of passbands or filters is called a photometric system. The difference in magnitudes found with these filters is called the U-B or B–V color index, respectively. The smaller the color index, the more blue (or hotter) the object is. Conversely, the larger the color index, the more red (or cooler) the object is. This is a consequence of the logarithmic magnitude scale, in which brighter objects have smaller (more negative) magnitudes than dimmer ones. The passbands most optical astronomers use are the UBVRI filters, where the U, B, and V filters are as mentioned above, the R filter passes red light, and the I filter passes infrared light. These filters were specified as particular combinations of glass filters and photomultiplier tubes.

Visuals
The visual color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. To measure the [visual] index, one observes the magnitude of an object successively through two different filters, such as B and V, where B is sensitive to blue light, and V is sensitive to visible (green-yellow) light. The difference in magnitudes found with these filters is called the B–V color index. The smaller the color index, the more blue (or hotter) the object is. Conversely, the larger the color index, the more red (or cooler) the object is. For comparison, the yellowish Sun has a B–V index of 0.656 ± 0.005, while the bluish Rigel has a B–V of –0.03 (its B magnitude is 0.09 and its V magnitude is 0.12, B–V = –0.03).

Greens
The Na I green lines at 568.2 and 568.8 nm arise "in the photospheric layers between log τ5000 ≈ -1 and -2."

Yellows
"[H]igh-resolution spectral measurements of Mercury show emission in sodium D lines (Potter and Morgan 1985a). This suggests a substantial sodium population in Mercury's atmosphere ... possibly due to photo-sputtering of the planetary surface". At least in emission yellow astronomy, Mercury is a dwarf gaseous object.

"Stars of spectral classes F and G, such as our sun Sol, have color temperatures that make them look "yellowish".

Plasma objects
Plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions.

For plasma to exist, ionization is necessary. The term "plasma density" by itself usually refers to the "electron density", that is, the number of free electrons per unit volume. The degree of ionization of a plasma is the proportion of atoms that have lost or gained electrons, and is controlled mostly by the temperature. Even a partially ionized gas in which as little as 1% of the particles are ionized can have the characteristics of a plasma (i.e., response to magnetic fields and high electrical conductivity). The degree of ionization, α is defined as α = ni/(ni + na) where ni is the number density of ions and na is the number density of neutral atoms. The electron density is related to this by the average charge state  of the ions through ne =  ni where ne is the number density of electrons.

"Plasma is the fourth state of matter, consisting of electrons, ions and neutral atoms, usually at temperatures above 104 degrees Kelvin." "The sun and stars are plasmas; the earth's ionosphere, Van Allen belts, magnetosphere, etc., are all plasmas. Indeed, plasma makes up much of the known matter in the universe."

Magnetohydrodynamics
Def. "the study of the interaction of electrically conducting fluids with magnetic fields", after magnetohydrodynamics, is called magnetohydrodynamics (MHD).

In a coronal cloud are magnetohydrodynamic plasma flux tubes along magnetic field lines.

"[M]otions resulting from [a linear magnetohydrodynamic] instability act as a dynamo to sustain the magnetic field." "Supersonic flows are initially generated by the Balbus-Hawley magnetic shear instability." From radiative dynamo: "A plasma with local magnetohydrodynamic instabilities creates mechanical turbulence, motion, or shear (a dynamo) which in turn generates or sustains the local magnetic field."

Hydrogens
Depending primarily upon gas temperature, the presence of gas may be used to determine the composition of the gas object observed, at least the outer layer. Early spectroscopy of the Sun using estimates of "the line intensities of several lines by eye [to derive] the abundances of ... elements ... [concluded] that the Sun [is] largely made of hydrogen."

Heliums
Helium was first detected as an unknown yellow spectral line signature in sunlight during a solar eclipse in 1868 by French astronomer Jules Janssen. Janssen is jointly credited with detecting the element along with Norman Lockyer during the solar eclipse of 1868, and Lockyer was the first to propose that the line was due to a new element, which he named.

Lithiums
"[S]ome observed properties of the Sun still defy explanation, such as the degree of Li depletion" [the "solar Li abundance is roughly a factor of 200 below the meteoritic abundance"].

Atmospheres
The graph at right shows the temperature and density of the Sun's atmosphere from Skylab observations. Above and in contact with the outer surface of the photosphere is considered to be the solar atmosphere.

"The Sun's photosphere has a temperature between 4500 and 6000 K (with an effective temperature of 5777 K) and a density of about [2 x 10-4kg/m3; other stars may have hotter or cooler photospheres.

Sun
The GOES 14 spacecraft carries a Solar X-ray Imager that took this image at right of the Sun during the most recent quiet period. The Sun appears dark because the wavelength band of observation is of higher energy than any X-rays being produced.

Except for X-ray emission that suggests a circular disc with some isolated X-ray sources at specific locations, the Sun is almost invisible. X-rays are primarily emitted from plasmas near 106 K.

Photospheres
Def. "[a] visible surface layer of a star, and especially that of a sun" is called a photosphere.

"When we speak of the surface of the Sun, we normally mean the photosphere." "[T]he photosphere may be thought of as the imaginary surface from which the solar light that we see appears to be emitted. The diameter quoted for the Sun usually refers to the diameter of the photosphere." The photosphere emits visual, or visible, radiation.

The solar photosphere is a "weakly ionized [ni/(ni + na)] ~ 10-4, relatively cold and dense plasma".

Coronal clouds
The high temperature of the coronal cloud indicates a plasma's temperature in excess of 106 Kelvin (MK).

Although a coronal cloud (as part or all of a stellar or galactic corona) is usually "filled with high-temperature plasma at temperatures of T ≈ 1–2 (MK), ... [h]ot active regions and postflare loops have plasma temperatures of T ≈ 2–40 MK."

An X-ray classification of stars may actually need to focus on the coronal clouds surrounding the stars rather than the stars themselves. A star always has a photosphere that does not emit X-rays, although not all photospheres are as spherical as the Sun.

Solar nanoflares
A nanoflare is a very small solar flare which happens in the corona, the external atmosphere of the Sun. Observations show that the solar magnetic field, which is frozen into the motion of the plasma opens into semicirculal structures in the corona. These coronal loops, which can be seen in the EUV and X-ray images (see the figure on the left), confine very hot plasma, emitting as it were at a temperature of a few million degrees. Many flux tubes are stable for several days on the solar corona in the X-ray images, emitting at steady rate. However flickerings, brightenings, small explosions, bright points, flares and mass eruptions are observed very frequently, especially in active regions. These macroscopic signs of solar activity are considered by astrophysicists as the phenomenology related to events of relaxation of stressed magnetic fields, during which part of the coronal heating is released by current dissipation or Joule effect. These nanoflares might be very tiny flares, so close one to each other, both in time and in space, to heat the corona and to cause all the phenomena due to solar activity.

The distribution of the number of flares observed in the hard X-rays is a function of the energy, following a power law with negative spectral index 1.8. If this distribution would have the same spectral index also at lower energies, flares, micro-flares and nanoflares might provide a considerable part of coronal heating. Actually a negative spectral index of the order of 2 is required in order to maintain the solar corona.

"[T]he importance of the magnetic field is recognized by all the scientists: there is a strict correspondence between the active regions, where the irradiated flux is higher (especially in the X-rays), and the regions of intense magnetic field.

More energy is released in turbulent regimes when nanoflares happen at much smaller scale-lengths, where non-linear effects are not negligible.

Surface fusions
Surface fusion is produced by reactions during or preceding a stellar flare and at much lower levels elsewhere above the photosphere of a star. Nuclear fusion usually occurs within a star as a part of stellar nucleosynthesis. But, a variety of subatomic particle and γ-ray reactions have been observed during solar flares indicating nuclear fusion reactions occur above the photosphere, most likely in the chromosphere.

Based on the 3He-flare flux from the Sun's surface and Surveyor 3 samples (implanted 15N and 14C in lunar material) from the surface of the Moon, the level of nuclear fusion occurring in the solar atmosphere is approximately at least two to three orders of magnitude greater than that estimated from solar flares such as those of August 1972.

For a moderately sized star originating very early in the age of the universe and undergoing surface fusion due to the presence of a coronal cloud, its metallicity should increase from this fusion and any going on internally plus metal pickup as it travels through supernovae produced dust.

Sunspot cycles
The image at right is a montage of ten years' worth of Yohkoh SXT images, demonstrating the variation in solar activity during a sunspot cycle, from after August 30, 1991, to September 6, 2001.

Venus
The lower right image is the first X-ray image ever made of Venus. It "shows a half crescent due to the relative orientation of the Sun, Earth and Venus. The X-rays from Venus are produced by fluorescent radiation from oxygen and other atoms in the atmosphere between 120 and 140 kilometers above the surface of the planet." The fluorescent source of the X-rays places Venus in the gas dwarf category even though a rocky object lies some 120 km beneath this layer.

Earth
Bright X-ray arcs of low energy (0.1 - 10 keV) are generated during auroral activity above the Earth. The images at right are superimposed on a simulated image of the Earth. The color code represents brightness, maximum in red. Distance from the North pole to the black circle is 3,340 km.

"Auroras are produced by solar storms that eject clouds of energetic charged particles. These particles are deflected when they encounter the Earth’s magnetic field, but in the process large electric voltages are created. Electrons trapped in the Earth’s magnetic field are accelerated by these voltages and spiral along the magnetic field into the polar regions. There they collide with atoms high in the atmosphere and emit X-rays".

Moon
The Chandra X-ray Observatory, right image, detects X-rays from the Moon. These X-rays are produced by fluorescence when solar X-rays bombard the Moon's surface. Close inspection of the Chandra X-ray image shows a region of X-rays in the dark region trending toward the lower left corner of the X-ray image. These X-rays only appear to come from the Moon. Instead, they originate from radiation of the Earth's geocorona (an extended outer atmosphere) through which orbiting spacecraft such as the Chandra satellite move.

Mars
The upper image at right is an X-ray image of Mars. X-radiation from the Sun excites oxygen atoms in the Martian upper atmosphere, about 120 km above its surface, to emit X-ray fluorescence. A faint X-ray halo that extends out to 7,000 km above the surface of Mars has also been found. The Chandra X-ray Observatory image on the right is the first look at X-rays from Mars. If X-ray astronomy was the first astronomy to view Mars, the conclusion that the X-rays are fluorescence rather than emission is important. The first class of X-ray sources may be fluorescence sources rather than emission sources.

Jupiter
The "image of Jupiter [at right] shows concentrations of auroral X-rays near the north and south magnetic poles." The Chandra X-ray Observatory accumulated X-ray counts from Jupiter for its entire 10-hour rotation on December 18, 2000. Note that X-rays from the entire globe of Jupiter are detected.

The X-rays from the poles of Jupiter are not fluorescent X-rays but emission X-rays. Those from the main portion of Jupiter may be fluorescence with some reflectance.

Saturn
X-rays from Saturn have a spectrum similar to that of the Sun indicating that Saturn's X-radiation is due to reflection of solar X-rays by Saturn's atmosphere.

Sirius

An example of the differences between visual stellar classification and a possible X-ray classification is the disparity between the image of Sirius A [at above centre in the overexposed Hubble image] with the dim Sirius B [tiny dot at lower left]. [The cross-shaped diffraction spikes and concentric rings around Sirius A, and the small ring around Sirius B, are artifacts produced within the telescope's imaging system.] And, the lower image of the same two stars in X-rays.

This image shows two sources and a spike-like pattern due to the support structure for the transmission grating. The bright source is Sirius B, a white dwarf star that has a surface temperature of about 25,000 degrees Celsius which produces very low energy X-rays. The dim source at the position of Sirius A – a normal star more than twice as massive as the Sun – may be due to ultraviolet radiation from Sirius A leaking through the filter on the detector. In contrast, Sirius A is the brightest star in the northern sky when viewed with an optical telescope, while Sirius B is 10,000 times dimmer.

In the bottom image, Sirius B clearly outshines Sirius A. However, in the visual range the reverse is the case as shown in the top image. The surface effective temperature of Sirius A (spectral type A1V) is only 9,940±210 K, while that of Sirius B (a white dwarf, DA2) is 25,200 K. On the surface temperature of the photosphere alone, Sirius B would be a Class B star.

Stellar sciences
In stellar science, a division of astronomical objects between rocky bodies and gas bodies (including gas giants and stars) may be natural and informative. This division allows moons like Io to be viewed as rocky objects like Earth, a part of planetary science or rocky object science rather than as a satellite around a gas giant like Jupiter. A further benefit is the view of gaseous objects as potential stars, failed stars, or stars radiant over peak radiation bands, especially those that emit X-rays. Gaseous objects need not be considered alone but in binaries and multiple gaseous object systems including clusters, galaxies, and galaxy clusters.

Stellar classifications
Stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure of the temperature in this chromosphere.

The luminosity class [is] expressed by the Roman numbers I, II, III, IV and V, expressing the width of certain absorption lines in the star's spectrum.

The color of a star, as determined by the peak frequency of the visible light, depends on the temperature of the star's outer layers, including its photosphere. The effective temperature of the surface of the Sun's photosphere is 5,778 K.

"When we speak of the surface of the Sun, we normally mean the photosphere." "[T]he photosphere may be thought of as the imaginary surface from which the solar light that we see appears to be emitted. The diameter quoted for the Sun usually refers to the diameter of the photosphere."

All of these stellar classes and the ones below are too low in temperature to emit X-rays from their photospheres.

There are extended spectral types:
 * 1) Class W: surface effective temperature up to 70,000 K,
 * 2) Class L: 1,300–2,000 K,
 * 3) Class T: ~700-1,300 K, and
 * 4) Class Y: < 600 K.

Others are based on spectral lines.

Brown dwarfs
Some brown dwarfs emit X-rays. Here are some X-ray milestones from the same article:

 * 1998: First X-ray-emitting brown dwarf found. Cha Halpha 1, an M8 object in the Chamaeleon I dark cloud, is determined to be an X-ray source, similar to convective late-type stars.
 * December 15, 1999: First X-ray flare detected from a brown dwarf. A team at the University of California monitoring LP 944-20 (60 Jupiter masses, 16 ly away) via the Chandra X-ray Observatory, catches a 2-hour flare.

X-ray flares detected from brown dwarfs since late 1999 suggest changing magnetic fields similar to those in very low-mass stars. When combined with the rapid rotation that most brown dwarfs exhibit, conditions [may exist] for the development of a strong, tangled magnetic field near the surface. The flare observed by Chandra from LP 944-20 could have its origin in the turbulent magnetized hot material that may conduct heat to the atmosphere, allowing electric currents to flow and produce an X-ray flare, like a stroke of lightning. The absence of X-rays from LP 944-20 during the non flaring period is also a significant result. It sets the lowest observational limit on steady X-ray power produced by a brown dwarf star, and shows that coronas cease to exist as the surface temperature of a brown dwarf cools below about 2500°C and becomes electrically neutral.

Using NASA's Chandra X-ray Observatory, scientists have detected X-rays from a low-mass brown dwarf in a multiple star system. This is the first time that a brown dwarf this close to its parent star(s) (Sun-like stars TWA 5A) has been resolved in X-rays. "Our Chandra data show that the X-rays originate from the brown dwarf's coronal plasma which is some 3 million degrees Celsius", said Yohko Tsuboi of Chuo University in Tokyo. "This brown dwarf is as bright as the Sun today in X-ray light, while it is fifty times less massive than the Sun", said Tsuboi. "This observation, thus, raises the possibility that even massive planets might emit X-rays by themselves during their youth!"

O stars
"Both the Einstein and ROSAT all-sky surveys have shown that nearly all O stars are X-ray emitters", with luminosities given by the relation:

Lx ≈ 10-7 Lbol,

where wind attenuation of X-rays may be significant.

Interpretation of the Einstein X-ray spectra indicate emission from a hot gas at temperatures of typically 3 x 106 to 9 x 106 K.[27] Most of the X-ray emission from OB supergiants comes from regions well above a base coronal zone, since there is too little absorption of the coronal emission by the material in the intervening wind.[24][26]

Red dwarfs
Red dwarfs are by far the most common type of star in the Galaxy, at least in the neighborhood of the Sun.

Proxima Centauri
Proxima Centauri, the nearest star to the Sun, is a red dwarf (Type M5, apparent magnitude 11.05), as are twenty of the next thirty nearest. One mystery which has not been solved as of 2009 is the absence of red dwarf stars with no metals. (In astronomy, a metal is any element heavier than hydrogen or helium.)

Both the Einstein X-ray Observatory and ROSAT have detected X-rays from Proxima Centauri. It is X-ray sources (1E 1425.9-6228, 2E 1426.0-6227, 2E 3278, and 1ES 1426-62.4) per Einstein and (RE J1429-624, RE J142950-624056, RX J1429.7-6240, 1RXS J142947.9-624058, and [FS2003] 0708) per ROSAT. Proxima Centauri is a known flare star.

Lalande 21185
Lalande 21185 is still a primary standard for M2 V. Robert Garrison does not list any "anchor" standards among the M dwarf stars, but Lalande 21185 has survived as a M2 V standard through many compendia.

Lalande 21185 (a known flare-star) is X-ray source XBS J110320.1+355803, detected by the X-ray astronomy observatory XMM-Newton.

Standard red dwarfs
A group at Steward Observatory (Kirkpatrick, Henry, & McCarthy 1991) filled in the spectral sequence from K5 V to M9 V. It is these M type dwarf standard stars which have largely survived intact as the main standards to the modern day. There have been negligible changes in the M dwarf spectral sequence since 1991. Additional M dwarf standards were compiled by Henry et al. (2002), and D. Kirkpatrick has recently reviewed the classification of M dwarf stars and standard stars in Gray & Corbally's 2009 monograph. The M-dwarf primary spectral standards are: GJ 270 (M0 V), GJ 229A (M1 V), Lalande 21185 (M2 V), GJ 752A (M3 V), GJ 402 (M4 V), GJ 51 (M5 V), Wolf 359 (M6 V), Van Biesbroeck 8 (M7 V), VB 10 (M8 V), LHS 2924 (M9 V).

Per SIMBAD:

GJ 229A is an X-ray source detected by Einstein and ROSAT,

GJ 752A is an X-ray source detected by Einstein,

GJ 51 is an X-ray source detected by ROSAT,

Wolf 359 is an X-ray source detected by ASCA, Einstein, and ROSAT,

Van Biesbroeck 8 (HD 152751) is an X-ray source detected by Einstein and ROSAT,

not yet detected as X-ray sources are GJ 270, GJ 402, VB 10, and LHS 2924.

White dwarfs
[S]pectroscopy typically shows that white dwarf emitted light comes from an atmosphere which is observed to be either hydrogen-dominated or helium-dominated. The dominant element is usually at least 1,000 times more abundant than all other elements.

The system currently in use classifies a spectrum by a symbol which consists of an initial D, a letter describing the primary feature of the spectrum followed by an optional sequence of letters describing secondary features of the spectrum, and a temperature index number, computed by dividing 50,400 K by the effective temperature. The visible radiation emitted by white dwarfs varies over a wide color range, from the blue-white color of an O-type main sequence star to the red of a M-type red dwarf. White dwarf effective surface temperatures extend from over 150,000 K to barely under 4,000 K. One of the coolest so far observed, WD 0346+246, has a surface temperature of approximately 3,900 K.

Examples: The symbols ? and : may also be used if the correct classification is uncertain.
 * 1) A white dwarf with only He I lines in its spectrum and an effective temperature of 15,000 K could be given the classification of DB3, or, if warranted by the precision of the temperature measurement, DB3.5.
 * 2) A white dwarf with a polarized magnetic field, an effective temperature of 17,000 K, and a spectrum dominated by He I lines which also had hydrogen features could be given the classification of DBAP3.

Hot white dwarfs, with surface temperatures in excess of 30,000 K, have been observed to be sources of soft (i.e., lower-energy) X-rays. This enables the composition and structure of their atmospheres to be studied by soft X-ray and extreme ultraviolet observations.

The first magnetic white dwarf to be observed was GJ 742, which was detected to have a magnetic field in 1970 by its emission of circularly polarized light. Magnetic fields have been discovered in well over 100 white dwarfs, ranging from 2 x 103 to 109 gauss (0.2 T to 100 kT). The magnetic fields in a white dwarf star may allow for the existence of a new type of chemical bond, perpendicular paramagnetic bonding, in addition to ionic and covalent bonds, resulting in what has been initially described as "magnetized matter"

The first variable white dwarf found was HL Tau 76; in 1965 and 1966, it varied with a period of approximately 12.5 minutes.

Known types of pulsating white dwarf include the DAV, or ZZ Ceti, stars, including HL Tau 76, with hydrogen-dominated atmospheres and the spectral type DA;, pp. 891, 895 DBV, or V777 Her, stars, with helium-dominated atmospheres and the spectral type DB; , p. 3525 and GW Vir stars (sometimes subdivided into DOV and PNNV stars), with atmospheres dominated by helium, carbon, and oxygen. ,§1.1, 1.2; ,§1. GW Vir stars are not, strictly speaking, white dwarfs, but are stars which are in a position on the Hertzsprung-Russell diagram between the asymptotic giant branch and the white dwarf region. They may be called pre-white dwarfs. , § 1.1; These variables all exhibit small (1%–30%) variations in light output, arising from a superposition of vibrational modes with periods of hundreds to thousands of seconds. Observation of these variations gives asteroseismological evidence about the interiors of white dwarfs.

The first white dwarf discovered was in the triple star system of 40 Eridani, which contains the relatively bright main sequence star 40 Eridani A, orbited at a distance by the closer binary system of the white dwarf 40 Eridani B and the main sequence red dwarf 40 Eridani C.

40 Eridani B
The pair 40 Eridani B/C was discovered by William Herschel on 31 January 1783;, p. 73 it was again observed by Friedrich Georg Wilhelm Struve in 1825 and by Otto Wilhelm von Struve in 1851. In 1910, Henry Norris Russell, Edward Charles Pickering and Williamina Fleming discovered that, despite being a dim star, 40 Eridani B was of spectral type A, or white. The spectral type of 40 Eridani B was officially described in 1914 by Walter Adams.

Per SIMBAD, 40 Eridani B is an X-ray source detected by the Einstein X-ray Observatory.

Sirius B
It was not until 31 January 1862 that Alvan Graham Clark observed a previously unseen star close to Sirius, later identified as the predicted companion. Walter Adams announced in 1915 that he had found the spectrum of Sirius B to be similar to that of Sirius.

Per SIMBAD, Sirius B is an X-ray source detected by the Einstein X-ray Observatory, HEAO 1, and ROSAT.

Van Maanen's Star
In 1917, Adriaan Van Maanen discovered Van Maanen's Star, an isolated white dwarf.

Van Maanen's Star is not a known X-ray source per SIMBAD.

Hypotheses

 * 1) The temperature of the photosphere results from a balance between the charge on the surface of the photosphere and the energy of the incoming electron flux.

title: Stars/X-ray classification


text: TESOL/Introducing yourself

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: TESOL/Introducing yourself


text:
Financial management

Define financial management Involves the planning, directing, monitoring, organizing, and controlling of the monetary resources of an organization.

Discuss the functions and scope of financial management 1st. Scope of financial management

1.Estimating the financial requirement: on the basis of their forecast of the volume of business operations of the company, the finance executives have to estimate the amount of fixed capital and working capital required in a given period of time

2. Determining the structure of capitalization: after estimating the requirement of capital, the finance executives have to decide about the composition of capital. They have to determine the relative proportion of owner’s risk, capital and borrowed capital. These decisions have to be taken in the light of cost of raising form different resources, period for which funds are needed and several others factors.

3. Investment decision: the funds raised from different resources are to be intelligently invested in various assets so as to optimize their return of investment. While making investment decision, management should be guided by three important principles-safety, liquidity and profitability.

4. Management of cash flows: - Cash is needed to pay off creditors, for purchase of materials, pay labor and to meet everyday expenses. These should not be shortage of cash at any time as it will damage credit- worthiness of the company. These should not be access cash them required because money has time value.

5. Management of earnings: - The finance executive has to decide about the allocation of earnings among several competitive needs. A certain amount of total earnings may be kept as reserve or a portion of earnings may be distributed among and ordinary and preference share holders, yet another portion may be ploughed back or re-invested. The finance executives must consider the merits and de-merits of alternative schemes of utilizing the funds generating from the companies own earnings.

6. Choice of sources of finance: - The management can raise finance from various sources like share holders, banks and others financial distributors finance executives has to evaluate each source over method of finance and choose the best source. Financial management is the new branch of accounting that deals with the acquisition of financial resources & management of them.

2nd. Functions of financial management

First. Investment Decisions: To survive and grow, all organizations must be innovative. Innovation demands managerial proactive actions. Proactive organization’s continuously search for innovative ways of performing the activities of the organization. Innovation is wider in nature. It could be expansion through entering into new markets, adding new products to its product mix, performing value added activities to enhance the customer satisfaction, or adopting new technology that would drastically reduce the cost of production or rendering services or mass production at low cost or restructuring the organization to improve productivity. All these will change the profile of an organization. These decisions are strategic because, they are risky but if executed successfully with a clear plan of action, they generate super normal growth to the organization. If the management errs in any phase of taking these decisions and executing them, the firm may become bankrupt. Therefore, such decisions will have to be taken after taking into account all facts affecting the decisions and their execution. Two critical issues to be considered in these decisions are: 1.Evaluation of expected profitability of the new investments. 2. Rate of return required on the project. The rate of return required by investor is normally known by hurdle rate or cutoff rate or opportunity cost of capital. After a firm takes a decision to enter into any business or expand it’s existing business, plans to invest in buildings, machineries etc. are conceived and executed. The process involved is called Capital Budgeting. Capital Budgeting decisions demand considerable time, attention and energy of the management. They are strategic in nature as the success or failure of an organization is directly attributable to the execution of capital budgeting decisions taken. Investment decisions are also known as Capital Budgeting Decisions. Capital Budgeting decisions lead to investment in real assets Dividends are payouts to shareholders. Dividends are paid to keep the shareholders happy. Dividend policy formulation requires the decision of the management as to how much of the profits earned will be paid as dividend. A growing firm may retain a large portion of profits as retained earnings to meet its needs of financing capital projects. Here, the finance manager has to strike a balance between the expectation of shareholders on dividend payment and the need to provide for funds out of the profits to meet the organization’s growth. Second. Financing Decisions: Financing decisions relate to the acquisition of funds at the least cost. Here cost has two dimensions viz explicit cost and implicit cost. Explicit cost refers to the cost in the form of coupon rate, cost of floating and issuing the securities etc. Implicit cost is not a visible cost but it may seriously affect the company’s operations especially when it is exposed to business and financial risk. For example, implicit cost is the failure of theorganization to pay to its lenders or debenture holders loan installments on due date on account of fluctuations in cash flow attributable to the firms business risk. A company which employs debt as a means of financing normally faces this risk especially when its operations are exposed to high degree of business risk. In all financing decisions a firm has to determine the proportion of equity and debt. The composition of debt and equity is called the capital structure of the firm. Debt is cheap because interest payable on loan is allowed as deductions in computing taxable income on which the company is liable to pay income tax Another thing notable in this connection is that the firm cannot avoid its obligation to pay interest and loan installments to its lenders and debentures. On the other hand, a company does not have any obligation to pay dividend to its shareholders. A company enjoys absolute freedom not to declare dividend even if its profitability and cash positions are comfortable. However, shareholders are one of the stakeholders of the company. They are in reality the owners of the company. Therefore well managed companies cannot ignore the claim of shareholders for dividend. Dividend yield is an important determinant for stock prices. Dividend yield refers to dividend paid with reference to the market price of the shares of the company. An investor in company’s shares has two objectives for investing: 1. Income from Capital appreciation (i.e. Capital gains on sale of shares at market price) 2. Income from dividends. It is the ability of the company to give both these incomes to its shareholders that determines the market price of the company’s shares. The most important goal of financial management is maximisation of net wealth of the shareholders. Therefore, management of every company should strive hard to ensure that its shareholders enjoy both dividend income and capital gains as per the expectation of the market. Third. . Dividend Decisions Dividend yield is an important determinant of an investor’s attitude towards the security (stock) in his portfolio management decisions. But dividend yield is the result of dividend decision. Dividend decision is a major decision made by a finance manager. It is the decision on formulation of dividend policy. Since the goal of financial management is maximisation of wealth of shareholders, dividend policy formulation demands the managerial attention on the impact of its policy on dividend on the market value of the shares. Optimum dividend policy requires decision on dividend payment rates so as to maximize the market value of shares. The payout ratio means what portion of earnings per share is given to the shareholders in the form of cash dividend. In the formulation of dividend policy, management of a company must consider the relevance of its policy on bonus shares. Dividend policy influences the dividend yield on shares. Since company’s ratings in the Capital market have a major impact on its ability to procure funds by issuing securities in the capital markets, dividend policy, a determinant of dividend yield has to be formulated having regard to all the crucial elements in building up the corporate image. The following need adequate consideration in deciding on dividend policy: 1. Preferences of share holders Do they want cash dividend or Capital gains? 2. Current financial requirements of the company 3. Legal constraints on paying dividends. 4. Striking an optimum balance between desires of share holders and the company’s funds requirements. Fourth. Liquidity Decision Liquidity decisions are concerned with Working Capital Management. It is concerned with the day to day financial operations that involve current assets and current liabilities. The important element of liquidity decisions are: 1) Formulation of inventory policy 2) Policies on receivable management. 3) Formulation of cash management strategies 4) Policies on utilization of spontaneous finance effectively. Fifth. Organization Of Finance Function Financial decisions are strategic in character and therefore, an efficient organizational structure is required to administer the same In all organizations CFOs play an important role in ensuring proper reporting based on substance to the stake holders of the company. Because of the crucial role these functions play, finance functions are organized directly under the control of Board of Directors. For the survival of the firm, there is a need to ensure both long term and short term financial solvency. Failure to achieve this will have its impact on all other activities of the firm. Weak functional performance by financial department will weaken production, marketing and HR activities of the company. The result would be the organization becoming anemic. Once anemic, unless crucial and effective remedial measures are taken up it will pave way for corporate bankruptcy..

title: Financial management


text:
User talk:Jaakaappi1

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title: User talk:Jaakaappi1


text:
User:OpenScientist/Open grant writing/Wissenswert 2011/Documentation

''This page hosts information about the project in its initial stages. We have since moved the codebase to GitHub entirely, while the bot now runs on Wikimedia Commons.''

Architecture
Translated from the German project proposal.

The Open Access Media Importer for Wikimedia Commons is designed in a modular fashion. This shall facilitate the addition of new media types, resources or output formats. In general, every component takes an item out of a queue, processes it and puts the data into the queue of the next component. We envisage all components to run on the same server.
 * The Crawler/ Scraper scans a list of Open Access resources for new articles with multimedia files (particularly video but also audio). This can be achieved via a search API (if available, e.g. at PLoS), a local search (PLoS example) or Google (example: PLoS ONE). For each matching article, the URLs and metadata (creator, description, licensing, original article etc.) of the media files are extracted and stored locally.
 * The Downloader downloads these media files and saves them locally.
 * The Transcoder converts the media files into Commons-compatible open formats (mainly Ogg Theora, Ogg Vorbis) and includes the metadata into the resulting files.
 * The Categorizer analyses the files and their metadata and suggests Commons categories that may be suitable.
 * The Review Tool allows the user to check image and sound quality, licensing, metadata and categories and to fix any errors before the upload is approved.
 * The Uploader uploads the files along with metadata and categories.
 * The configuration of the component shall be performed via a protected wiki page, so as to allow also non-programmers to add new resources for the tool to work on.
 * Before processing a file, all components check whether it has already been processed or even uploaded to Wikimedia Commons. In such cases, work on the file is skipped by default.

To Do
''This list is to be updated as we move forward. Before making changes here, please check the most recent uploads whether the proposed change has indeed been implemented.''

Wiki

 * update documentation,

 * add milestones

 * PMCID does not display in commons:Cite journal. ✅

 * Cite doi template formatting from enwp does not work on Commons

Code

 * Bug tracking moved to https://github.com/erlehmann/open-access-media-importer/issues

Discuss

 * RW: Should we add the license and source to each video's metadata? ✅
 * I'd say yes. --Daniel Mietchen 21:55, 20 February 2012 (UTC)

 * RW: Should we inform the corresponding author about the import to WM Commons?
 * I don't think so, though I have informed authors in the past about actual use of "their" files. --Daniel Mietchen 21:55, 20 February 2012 (UTC)
 * A single e-mail, with an opt-in for further notifications, and a link to an author's listed Commons contributions, seems minimally intrusive. It might also be useful, under "community outreach" or "broader impact" in a grant or tenure application. We'd rely on the corresponding author to forward the e-mail to interested co-authors, but we could also offer opt-in notifications (#icanhazwikicommonsnotifications?). We'd have to code each author with their e-mail address, has-been-notified-once and opted-in, so this would take some work, and may not be worth it. But I doubt anyone will object to one e-mail per e-mail address, ever, except on request. HLHJ (discuss • contribs) 16:11, 15 June 2019 (UTC)

 * I don't understand the purpose of having three different commands (oa-get, oa-put, and oa-cache), each of which takes as its first argument a longish subcommand (download-metadata, etc.). I would vote either to combine all of these into one command (maybe, "oami"), or to abbreviate the subcommands, or maybe even both. Klortho (talk) 23:14, 3 June 2012 (UTC)
 * We do not vote here. If you are willing to submit a patch to overhaul the option parsing system (maybe using python-opster?), feel free to do so.

Source Code

 * Source code is hosted on GitHub.
 * All source code is licensed under the terms of the GPL v3

About

 * Initial announcement; First progress report
 * Project proposal (in German)

OA Repositories

 * Directory of Open Access Journals
 * PubMedCentral: Open Access Subset documentation
 * PubMedCentral: Search results for supplementary videos in OA articles
 * Example of an article with multiple videos

Tools

 * BeautifulSoup (HTML/XML parsing) documentation

Blog posts
Blog posts are on the Wikimedian in Residence blog. Here is a list of posts by this category. Some specific posts are:

 * December 15, 2011: Announcement and overview
 * January 18, 2012: Roadmap and crawler
 * March 10, 2012: Frontend
 * March 29, 2012: Plugging in your own data source
 * April 30, 2012: Encoding
 * September 30, 2012: Open Access Media Importer: Presentation at WMDE, Collaborative Coding


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User:Kaihsu/IMlawA4

European internal market.

Section A: The scope of the four freedoms.

Chapter 4: Wholly internal situations.

Notes by Kaihsu Tai, 2012-01-25.

Goods
Reclassification of a customs duty within the EU is contrary to Article 30 TFEU (abolition of customs duties and charges with equivalent effect): Case 26/62 Van Gend en Loos.

“Any pecuniary charge, however small and whatever its designation and mode of application, which is imposed unilaterally on domestic or foreign goods by reason of the fact that they cross a frontier, and which is not a customs duty in the strict sense, constitutes a charge having equivalent effect [...] even if it is not imposed for the benefit of the State, is not discriminatory or protective in effect or if the product on which the charge is imposed is not in competition with any domestic product”: Joined Cases 2/69 and 3/69 Sociaal Fonds voor de Diamantarbeiders .

Regional levies based on transit across an frontier internal to a Member State are incompatible with Article 28 TFEU (customs union): Case C-163/90 Legros; developed in Joined Cases C-303/93 and C-407/93 Lancry; confirmed in Joined Cases C-485/93 and C-486/93 Simitzi and Case C-293/02 Jersey Produce Marketing Organisation.

National rules refusing to permit a name to be used for a product, legally so named in other Member States, is incompatible with Article 34 TFEU (quantitative import restrictions and measures having equivalent effect): Case 298/87 Smanor. Even the mere potential for a measure having equivalent effect to affect intra-Union trade is enough for the Treaties to apply: Case 8/74 Dassonville, confirmed in Case C-321/94 Pistre and Case C-184/96 Commission v France (foie gras).

“When a national measure has limited territorial scope because it applies only to a part of the national territory, it cannot escape being characterized as discriminatory or protective for the purposes of the rules on the free movement of goods on the ground that it affects both the sale of products from other parts of the national territory and the sale of products imported from other Member States. For such a measure to be characterized as discriminatory or protective, it is not necessary for it to have the effect of favouring national products as a whole or of placing only imported products at a disadvantage and not national products”; but such a measure, if proportionate, can be justified on public-health grounds under Article 36 TFEU: Joined Cases C-1/90 and C-176/90 Aragonesa de Publicidad Exterior and Publivía. These provisions of the Treaties do not apply on national measures that are less favourable for domestic goods (“reverse discrimination”): Joined Cases 80/85 and 159/85 Edah.

Persons: workers
Typically a transfrontier element needs to be present for the Treaties to apply. Hypothetical prospect of employment in another Member State do not establish Treaty applicability in wholly-internal cases: Case 180/83 Moser.

Third-country nationals cannot claim Treaty rights for family reunion when their EU-citizen children have never moved to another Member State: Joined Cases 35/82 and 36/82 Morson and Jhanjan. The Treaties (in particular Article 21 TFEU, citizenship of the Union) do not provide a remedy for wholly-internal reverse discrimination against citizens residing in one region in a Member State: Case C-212/06 Government of the French Community and Walloon Government. Article 21 TFEU does not apply to a dual-national not having exercised free-movement rights: Case C-434/09 McCarthy. But children with another EU nationality than that of the host Member State can raise EU law without having moved: Case C-148/02 Garcia Avello, Case C-353/06 Grunkin and Paul, Case C-200/02 Zhu and Chen. The distinguishing point is whether “genuine enjoyment of the substance of the rights” conferred by the Treaty is deprived by the national measure at issue: see also Case C‑34/09 Ruiz Zambrano, Case C‑256/11 Dereci.

Article 45 TFEU “precludes an employer from requiring persons applying to take part in a recruitment competition to provide evidence of their linguistic knowledge exclusively by means of one particular diploma issued only in one particular province of a Member State” even though both parties in the case referred were from the same Member State, because persons “not resident in that province therefore have little chance of acquiring the Certificate and it will be difficult, or even impossible, for them to gain access to the employment in question”: Case C-281/98 Angonese.

Any EU citizen “who, irrespective of his place of residence and his nationality, has exercised the right to freedom of movement for workers and who has been employed in a Member State other than that of residence” falls within the scope of Article 45 TFEU; returning nationals can raise Article 45 TFEU against his home State: Case C-18/95 Terhoeve. (See also Case C-385/00 De Groot, Case C-152/03 Ritter-Coulais, Case C-212/05 Hartmann, Case C-527/06 Renneberg.)

But “national of a Member State who has exercised the right to freedom of movement for workers guaranteed by [Article 45 TFEU] and has ceased to exercise his occupational activity in the host Member State and returned to his Member State of origin [...] cannot rely on [that article] to obtain from the [host] Member State a right” unconnected to his former employment: Case C-33/99 Fahmi and Esmoris, confirmed in Case C-43/99 Leclere and Deaconescu.

The Treaties do not affect a residence requirement for candidacy in a regional election: Case C-535/08 Pignataro.

Services and establishment
Article 49 TFEU (establishment) does not apply to situations which are purely internal to a Member State: Case C-17/94 Gervais. Article 56 TFEU (service provision) cannot be applied to activities which are confined within a single Member State: Case C-41/90 Höfner v Macrotron. Confirmed in Case C-134/95 USSL nº 47 di Biella: these Treaty provisions “do not apply to a situation, such as that in the main proceedings, which is confined in all respects within a single Member State”.

The freedom to provide services could not be fully effective if a provider “were to be deterred from exercising it by obstacles raised in his country of origin to the entry and residence of his spouse”: Case C-60/00 Carpenter.

A national having a qualification from another Member State can have such recognized and thus establish themselves within their own Member State: Case 115/78 Knoors, strengthened by Directive 2005/36. But a Member State has a legitimate interest in preventing the evasion of national requirements using Treaty provisions: Case C-61/89 Bouchoucha.

A national residing both in his own Member State and another can raise Article 49 TFEU against his own Member State’s discriminatory tax treatment: Case C-107/94 Asscher; this does not apply where the establishment is in the home Member State, though the residence is in another: Case C-112/91 Werner.

Capital
Once a cross-border element is in place, the Treaty (in particular Article 63 TFEU) can be invoked: Case C-364/01 Barbier.

Even though the facts in a case referred are confined to a single Member State, ECJ may consider the potential “application of national legislation such as that in issue in the main proceedings to the extent that it is applied to persons resident in other Member States”: Joined Cases C-515/99 etc. Reisch. ECJ will consider a case where national rules require equal treatment of own nationals and other EU nationals: Case C-300/01 Doris Salzmann II.

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Dominant group/Attribution and copyright

Attribution or credit means to let everyone know where a piece of knowledge, even as small as a least publishable unit, is from.

Dominant group has been shown to be a two-word term that originated at or before 1826. It is highly likely that any copyright on the term has long since expired. But, is dominant group still or has it ever been intellectual property?

Perhaps the term is the intellectual property of Kirby whose apparent earliest use in 1826 to describe the regional extent of insects put the two-word term into the entomology literature.

The ownership of the term may have passed from Kirby's efforts into the genre of scientists and notable social commentators separate from the common-language users whose vocabulary is contained in language dictionaries.

As a potential indicator of original research, plagiarism, copyright violations, properly cited uses, or simply mistakes in usage by editors and contributors, dominant group has great potential to help further the acceptance of web-based endeavors with scientists and notable social commentators.

Attributions
Def. "an explicit or formal acknowledgment of ownership or authorship" is called attribution.

Copyrights
Def. "the right by law to be the entity which determines who may publish, copy and distribute a piece of writing, music, picture or other work of authorship" is called copyright.

Copyright and policy
Def. a "principle of behaviour, conduct etc. thought to be desirable or necessary, especially as formally expressed by a government or other authoritative body" is called a policy.

"True copyright violation is a matter of policy".

"The licensing policy is designed to ensure as well as possible that if content complies with the policy’s requirements it will also comply with the legal requirements."

Copyright violations
Def. "[t]he unauthorized use of copyrighted material in a manner that violates one of the copyright owner's exclusive rights, such as the right to reproduce or perform the copyrighted work, or to make derivative works that build upon it" is called copyright infringement.

“One of the least understood laws that affects or potentially affects perhaps 90% of the school teachers in the country is the Copyright Act.” “The primary violations are of two types: illegal copying and illegal display or performance.” “Illegal copying occurs when public educators copy music, poetry, literature, current news articles, and computer software without permission of the copyright holder.”

Often a copyright notice will say "whole or in part", so how much is that? Whole is the easy one. So don't copy the whole thing without permission, unless it's been proven to be in the PUBLIC DOMAIN. Even when it is I still like to give credit with a Credit: line, as for images or files. There are arguments pro and con about copyright and payment. Usually there's an initial lump sum, salary, or wage, sometimes followed by a royalty, say 5% for each individual reuse of the whole thing, or for a neat part design the assembly line manufacture of which is being used on automobiles. But payment if not forever with every penny you have.

What about the 'part' part? Usually, that refers to one page of many. Of course, if the entire thing is one page, then copying it is a violation without consent, when it's copyrighted. But, sentences that are cited with or without quotes are a part. Here again I use the "beyond reasonable doubt" principle. Let's say an article has 10,000 words and I quote 150 in ten sentences either all together or scattered about. And, I cite them. The part used is less than 2%. Is it a copyright violation? I say no. It's Fair Use. Even more than that is something most don't think about. I'm citing the source. The usual argument is that by taking any small part I've lowered the value of the creator's work. No, what I've done is increase the value of the creator's work. Because anyone who reads what I've written knows where it came from and can check it out. Every time that happens, the original and its creator have their value increased. From an author's perspective, the worst that can happen is no one reads what you've written any more. Now that's zero value or even negative value. It's just a journal on a shelf, now in microfiche, or in a memory chip somewhere, maybe.

It has been written that “any work can be reduced to plagiarism if enough research is done.” Paraphrasing this regarding copyright, 'any work can be reduced to copyright violation if enough research is done.' This is where the nebulous concepts of 'fair' and 'reasonable'; hence, Fair use, come in. Also, within fair use is the idea of "likely to be replaceable by public domain material." This is better providing the PUBLIC DOMAIN text serves the exact same purposes. If it does not, then the referenced source should remain.

"Dominant group" is in the PUBLIC DOMAIN in many countries.

Dominant group
"The original inquiry simply started out as curiosity about a phrase that appeared in a number of wikipedia articles yet stood unwritten about."

"Dominant group" is a term that has several definitions in the scholarly literature and a number of relative synonyms. Its origin dates to at least 1826 and perhaps earlier. It appears to be an entity designated by authors to indicate an observation of importance that needs to be addressed by relevant theory.

"A study of usage, which is what the subject research involves, requires exact quotation, paraphrase would not be showing primary evidence, and a link to an article, in lieu of exact quotation, would simply not work, it would be too cumbersome. The citations are necessary for the research, they are the very core of it."

Intellectual property
Intellectual property (IP) is a term referring to a number of distinct types of creations of the mind for which a set of exclusive rights are recognized under the corresponding fields of law. Under intellectual property law, owners are granted certain exclusive rights to a variety of intangible assets, such as musical, literary, and artistic works; discoveries and inventions; and words, phrases, symbols, and designs. Common types of intellectual property rights include copyrights, trademarks, patents, industrial design rights and trade secrets in some jurisdictions.

"The history of patents does not begin with inventions, but rather with royal grants by Queen Elizabeth I (1558-1603) for monopoly privileges ... Approximately 200 years after the end of Elizabeth's reign, however, a patent represents a legal [right] obtained by an inventor providing for exclusive control over the production and sale of his mechanical or scientific invention ... [demonstrating] the evolution of patents from royal prerogative to common-law doctrine."

Thomas Jefferson wrote to Isaac McPherson on August 13, 1813:

"If nature has made any one thing less susceptible than all others of exclusive property, it is the action of the thinking power called an idea, which an individual may exclusively possess as long as he keeps it to himself; but the moment it is divulged, it forces itself into the possession of every one, and the receiver cannot dispossess himself of it. Its peculiar character, too, is that no one possesses the less, because every other possesses the whole of it. He who receives an idea from me, receives instruction himself without lessening mine; as he who lights his taper at mine, receives light without darkening me."

Least publishable units
A "least publishable unit" (LPU) is an older expression for the smallest possible fact that has been determined to be a fact that just might be publishable, and has not as yet been published.

LPUs seem to be everywhere yet each one probably has an originator who may have included it in a published context somewhere. When one occurs in a text without attribution to an earlier source, the author including it usually gets the credit, and the honor, of introducing that little fact to everyone.

Some LPUs require extensive research and exploration to determine what they are and prove that they are. The phrase "dominant group" initially appears to be an LPU. Its earliest origin on Wikipedia is not known.

Plagiarisms
Def. "[t]he act of plagiarizing: the copying of another person's ideas, text or other creative work, and presenting it as one's own, especially without permission", from Wiktionary plagiarism, is called plagiarism.

Here's a simple example: from Edmond Halley, "In 1718 he discovered the proper motion of the "fixed" stars by comparing his astrometric measurements with those given in Ptolemy's Almagest." A least publishable unit is that Halley had a copy of the Almagest available to him that he compared his efforts to. While it makes sense considering his position at the University of Oxford, he'd have access, but how did anyone know that he made this comparison? This apparent little tiny fact has no attribution or citation. Okay, maybe the fact is in the PUBLIC DOMAIN. But, I want to know who found that out or where that little fact came from. While it may not be plagiarism that no citation for this little fact is given (I think it may be), I may have to search high and low to find out. Worse, let's say someone just found this out by reviewing an old handwritten note left in the University of Oxford archives that Halley really did this. Who ever found this out has had a part of his/her soul stolen and appropriated by whomever put this in the article without a citation. Not a big deal - Yes it is!

"If you have referred material from the writings of earlier scholars, please be bold enough to give the reference. Not doing so is plagiarism - an academic sin which must be avoided at all costs." "The act of stealing from the writings of another person and passing the material off as one’s own is a form of intellectual property theft. In other words, plagiarism is an act of fraud. It involves both stealing someone else’s work and pretending that this is to be one’s own and, lying about it afterward."

“Plagiarism is the act of using the words of another without giving the originator credit.” Yes, but more importantly is the phrase "put it into your own words". Briefly this means some kind of factual synonymy. Beautiful! But, the 'synonymizer' didn't determine the fact, the apparent originator who put it in the literature did. "Within these quotes is a short sentence that may contain a fact, even a little tiny inconspicuous fact."[1] Let's say the quotes were left off, who cares why, but the citation [1] is still there. Credit has been given! No plagiarism. It's better with the quotes there but in the past and in some disciplines quotes are forbidden, but the citation is not. What about the synonymy "put it in your own words". Not an excuse to uncite anything. I don't care whether the synonymizer understands the fact or not. I want to know where the synonymizer got it from. And, the person who determined that fact is going to want to know why the cite was left off.

Some authors, editors, writers, article creators "think that changing the words is sufficient to avoid plagiarism." So they leave off the citation. Wrong!

"Plagiarism also can be an unintentional or accidental [act] when there is careless omission of citations and failure in using quotation marks".

Everyone makes mistakes too! But, here's the important part. Let's say someone writes 100 sentences that should have an attribution or citation after them or within them somewhere and misses one. Is that plagiarism? Well, for that one sentence, yes. But, the other 99 are cited. The rule of thumb is "beyond reasonable doubt", that's better than 98% certainty. So is it beyond reasonable doubt that the author who wrote those 100 sentences is not plagiarizing. Yes! Should we shoot the author for that one - no! But, if you find it let the author know so it can be cited. If you don't, you could be considered an accessory after the fact. In addition, give the author the benefit of the doubt (assume good faith, AGF). It's not only the good thing to do, in many countries it's the law - to do anything else may be a serious crime! When the author is no longer with Wikipedia, Wikiversity, or other Wikimedia resources, then it's up to you. You found it, please have the courage to fix it (be bold). At the other extreme is to put the whole page up for deletion (AfD) on Wikipedia, (RfD) on Wikiversity, each Wikimedia resource may have its own version.

Public domain
Works in the public domain are those whose intellectual property rights have expired, have been forfeited, or are inapplicable.

Short quotation
Here the word 'short' means something less than quoting the full written work. "[T]he right of quotation and criticism ... is a basic prerequisite of any journalist's or scientist's works." "This right should also be effectively protected under the conditions of DRM [Digital Rights Management] and access to the relevant information should not be prevented by technical measures."

"According to Copyright Law of the United States: ... Short quotations of a copyrighted publication may be reproduced without permission in books, articles, and other publications. This is often interpreted as fewer than 250 words (in total) from a book-length work or less than 5% of a journal article." Just to illustrate: all of the quotes from More total 160 words of a total of 5704; i.e., 2.81%. While this is above my preferred less than 2% rule, it is below the 285 words of the 5% rule indicated.

"[T]he French copyright act recognise[s] a right of short quotation". But, "the complete representation of a protected work [is] not covered by the right to make short quotations."

An older ruling by the Landgericht Berlin (District Court) in 1960 indicated that there are "statutory exceptions for quotation" with respect to copyright law. But, "the German Copyright Act [does] not allow quoting protected works in their integrity in the press." "[A]n integral reproduction of caricatures must be allowed under special circumstances, such as political debates, where the possibility to quote the political adversary is necessary."

From the German Constitutional Court back in 1978, of the legislator, "He shall bring into just equation and balance the constitutionally guaranteed requirement of a reasonable use of the creative accomplishment and the interests of the general public worthy of protection". This statement is to provide guidance for resolving conflicts "between the individual proprietary interests and the general cultural, social and political interests arising in the digital environment."

"Considering that DRM systems will most probably affect the general conditions of intellectual freedom in democratic societies this issue is too important to be left to the industry to determine." The Supreme Court of Austria "the (OGH) on 3 October 2000" noted "the exception for the use of copyright protected works in quotations." in the Austrian Copyright Act.

Over on Wikiquote are several quotation guidelines (unreferenced):
 * 1) Length of quotes - "a maximum of 250 words per quote", that's about 20-25 lines from a journal article,
 * 2) Books - "[a] recommended maximum of five lines of prose or eight lines of poetry for every ten pages of a book not in the public domain. This is equal to about 1.25% of the total content of a book."
 * 3) "Adding unsourced quotes to articles will be reverted." - plagiarism!

On Harper & Row v. Nation Enterprises/Dissent Brennan are many excellent points regarding use of quotations (Fair Use) by Supreme Court Justice Brennan. Also, Harper & Row v. Nation Enterprises/Opinion of the Court contains a few additional, albeit limited points. The case was actually focused on using quotes prior to original publication as a violation of copyright, but the justices took the opportunity to clarify the fair use issue to some extent.

Hypotheses

 * 1) Dominant group probably originated at least a century earlier than Kirby's use in 1826.