Luminosity, cause

Equation (6) is used to calibrate the apparatus and determine the detonation temperature Baum et al (Ref 44, p 97) described the spectroscope method developed in Russia in 1945 by Alentsev, Belyaev, Sobolev Stepanov, which was applicable only to transparent liquid expls, such as NG, NGc, etc. In order to elimi-. nate luminosity caused by shock wave in the atmosphere, the authors immersed the test tube with. sample in water. For a more detailed description of the method, see Ref 16 and pp 98-100 of Ref 44. The values obtd by this method are considerably lower than the calcd values. For example, for NG the exptl value was only 3150CK vs 4520°K obtd by calcn and for NGc. 3160 vs 4700... 

The luminosity caused by the action of Tesla currents indicates that the ring of the respective substance exists in Dewar s condition the stronger the luminosity the more pronounced the latter must be. 

In the nineteenth century, Humphry Davy (1778-1829) speculated that the luminosity of flames is caused by fhe production and ignition of solid particles of carbon as a resulf of the decomposition of a part of the gas. Jons Jakob Berzelius (1779-1848) is said to be the first to describe an ordinary candle flame as consisting of four disfincf zones. Davy s protege, Michael Faraday [9] (1791-1867) gave his Christmas lectures and accom-pan3ung demonstrations to a juvenile audience on "The Chemical History of a Candle" in 1848 and 1860. Around the turn of the century, modem combustion science was established based on the increased understanding of chemistry, physics, and thermodynamics. 

Eventually the He burning converts the core to carbon. Core thermonuclear shutdown occurs but fusion continues in the shell around the core, producing He followed by periods of helium flashes, causing wild variations in the luminosity. The Sun will then develop a super wind by convection that will blow off the overshell of the star, leaving a hot core behind. The expelled material forms a shell... 

The emission of light from Cepheid stars has a characteristic light curve seen in Figure 4.14 for a Cepheid in the constellation of Perseus. The sawtooth pattern is characteristic of the class and enables the period of variation to be determined. The observation, however, that the luminosity and period are related has powerful consequences. The Cepheid variables fall into two classes type I classical Cepheids have periods of 5-10 days and type II have periods of 12-20 days. The two types of Cepheids initially caused problems when determining the luminosity-period relation but the relation has now been determined. Type I Cepheids follow the expression... 

The potentially harmful effects of exposure to high concentrations of nitrates in drinking water result from reduction to nitrites, which combine with haemoglobin to form methaemoglobin (blue baby disease). Additionally, nitrosamine formation can cause cancer and hypertension. In nature, high levels of nutrients, such as nitrates, lead to eutrophication of water sources, which in, severe cases, lead to the extermination of the other aquatic life due the decreased levels of oxygen and luminosity. 

In order to determine what effects cause a star to be a blue supergiant instead of a red supergiant we calculated a number of envelopes of stars, varying the hydrogen content and the metallicity. We chose a star of 12 M0 of which the outer 6 M0 are modeled. The luminosity was... 

Another major and as yet unresolved issue centers upon precisely why SK-202-69 was a blue supergiant, and not a red one. This issue has been recently reviewed by Woosley (1987) and will be briefly summarized here. The essential problem is that there exist multiple solutions to the structure equations for the stellar atmosphere (see also Wheeler, this volume). Two stars having the same helium core mass and only slightly different luminosities, for example, can have radically different envelope structures, either a convective red supergiant or one that is radiative and blue (Woosley, Pinto, and Ensman 1987). There are several physical parameters that may break this symmetry and cause the star to chose one solution and not the other. Among them axe metallicity, (extreme) mass loss, and the theory of convection used in calculating the stellar model. 

Like many red dwarfs, Proxima or Alpha Centauri C is a flare star. Flare stars can brighten suddenly to many times their normal luminosity. The cause is thought to be a sudden and intense outburst of radiation on or above the star s surface. An increase in radio emission is often detected simultaneously with the optical outburst. 

Cause of Luminosity.—In 1815 Davy 1 suggested that the luminosity of a candle flame is due to the presence of minute particles of carbon at white heat. These particles were believed to be produced by incomplete combustion of the hydrocarbon vapours in the restricted supplies of air available within the flame, the hydrogen of the vapours being preferentially oxidised (see p. 64), leaving the carbon to shift for itself. This theory was generally accepted for many years, and it was not until 1867 that a rival theory wras projected by Frankland,2 according to which the luminosity of the flame is due to radiations from dense but transparent hydrocarbon vapours. ... 

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