scholarly journals The Integrated Photometry of Globular Clusters in the Vilnius Photometric System

1980 ◽  
Vol 85 ◽  
pp. 483-484
Author(s):  
K. Zdanavičius ◽  
V. Straižys
Keyword(s):  
Globular Clusters ◽  
Color Index ◽  
Photometric System ◽  
Intrinsic Values ◽  
Average Color ◽  
Color Excess ◽  
Free Parameters ◽  
Range Of Variation

Thirty-three globular clusters of our Galaxy were observed with the filters of the Vilnius photometric system UPXYZVS with 3450, 3740, 4050, 4660, 5160, 5440, 6550 å filters (Straižys 1977). For the classification of clusters in metallicities the reddening-free parameters QUYV QPYV and QXYV can be used. In Figure 1 these Q parameters, having a range of variation of the order of 0.4, are plotted against metallicity values from Kukarkin (1974). The parameter QPYZ has an even larger range of variation (of the order of 0.6). For determination of color excesses of clusters every color index can be used if its intrinsic values for a given metallicity defined by quantities Q are known (Figure 2). Average color excesses determined from the diagrams QUYV, (Y-V)o; QPYV, (Y-V)o and QXYV (Y-V)o and transformed to EB-V in Figure 3 are compared with color excesses from Kukarkin (1974). To summarize, the Vilnius system presents a number of metallicity sensitive, reddening-free parameters which can be used for [Fe/H] and color-excess determinations of globular clusters.

scholarly journals Globular Clusters in the Vilnius Photometric System

1988 ◽  
Vol 126 ◽  
pp. 515-516
Author(s):  
K. Zdanavičius
Keyword(s):  
Globular Clusters ◽  
Photometric System ◽  
Two Dimensional ◽  
Halo Stars ◽  
Dimensional Classification

The Vilnius photometric system was developed for photometric two-dimensional classification of stars and for the determination of interstellar reddening. The system consists of seven magnitudes U, P, X, Y, Z, V and S with mean wavelengths of 345, 375, 405, 466, 516, 544 and 655 nm and half-widths of the order 20 – 30 nm (Straižys 1977). Later on the system was successfully used for the determination of temperatures and the metallicities of halo stars (Bartkevičius and Sperauskas 1983).

scholarly journals Ultraviolet Photometry from the S2/68 Observations in the TD1 Satellite

1977 ◽  
Vol 35 ◽  
pp. 85-91
Author(s):  
K. Nandy
Keyword(s):  
Spectral Type ◽  
Photometric System ◽  
Sky Survey ◽  
Free Parameters

SummaryAn ultraviolet photometric system based on observations obtained from the ultraviolet Sky Survey Telescope in the TD1 satellite is described. The system considered here consists of ultraviolet magnitudes at λ1 = 2740A, λ2 = 2190A and λ3 = 1490A. The extinction free parameters derived from the observed ultraviolet colours enable determination of interstellar reddening, spectral type and luminosity. This photometric system has been evaluated by comparing these parameters with other classification parameters.

scholarly journals Results from Three Dimensional Spectral Classification of Population II Stars Using the DDO Photometric System

1973 ◽  
Vol 50 ◽  
pp. 176-182
Author(s):  
W. Osborn
Keyword(s):  
Globular Clusters ◽  
Three Dimensional ◽  
Photometric System ◽  
Horizontal Branch ◽  
Intermediate Band ◽  
Theoretical Predictions ◽  
The Mean ◽  
Red Giant ◽  
The Masses

The David Dunlap Observatory (DDO) intermediate-band photometric system described in the previous paper has been used to observe a number of red giant branch, horizontal branch, and asymptotic branch members in each of the five globular clusters M3, M5, M10, M13, and M92. A calibration of the DDO system is described by which it was possible to determine the effective temperatures, surface gravities, [Fe/H] values, and masses of the observed stars. The mean [Fe/H] values for the clusters were found to be −1.01 for M3, −0.68 for M5, −1.44 for M10, −1.69 for M13, and −1.96 for M92. Evidence was found that the masses of the horizontal branch and asymptotic branch stars are systematically smaller than those of red giant branch members. Two stars were discovered to have CN bands that are anomalously strong for Population II objects. The observational results have been compared with the theoretical predictions of two detailed Population II evolutionary tracks and in general the agreement is good.

scholarly journals Photometric Classification of Carbon-Rich Stars

1989 ◽  
Vol 106 ◽  
pp. 62-62
Author(s):  
V. Straizys
Keyword(s):  
Photometric Determination ◽  
Abundance Ratio ◽  
Photometric System ◽  
The Mean ◽  
Absolute Magnitudes

The Vilnius seven-color photometric system with the mean wavelengths of bandpasses at 345, 374, 405, 466, 516, 544, and 656 nm is intended for photometric determination of spectral classes, absolute magnitudes, and metallicities of stars and the amount of interstellar reddening. At the same time, different reddening-free diagrams of the system make it possible to recognize stars with different peculiarities. Carbon-rich stars are among these types of objects. For separation of carbon, barium, and CH stars from normal stars, the diagram Q (345, 374, 466, 544), Q (405, 516, 656) is the best. Its merit is based on sensitivity of the 405 magnitude to the violet depression and of the 374 magnitude to the absorption of the C3, SiC, and CN bands, This diagram can be used to estimate the C/0 abundance ratio with corresponding calibration at hand.

scholarly journals The David Dunlap Observatory (DDO) Photometric System for Classification of Late-Type Stars

1973 ◽  
Vol 50 ◽  
pp. 162-175
Author(s):  
R. D. McClure
Keyword(s):  
Heavy Element ◽  
Bandpass Filter ◽  
Open Cluster ◽  
Surface Gravity ◽  
Element Abundance ◽  
Photometric System ◽  
Band Absorption ◽  
The Continuum

An intermediate bandpass filter system is described that is useful for classification of G and K stars in terms of effective temperature (spectral type), surface gravity (luminosity class), heavy element abundance, and interstellar reddening. The system measures the strength of the cyanogen band in the region shortward of λ4216, the break in the continuum at the G band, and a colour index in the λ4500–λ4900 region of the spectrum. The surface gravity parameter is independent of the cyanogen index, and the cyanogen band strength, after a surface gravity correction, is used as a measure of heavy element abundance.Application of the system to the determination of the atmospheric parameters of open cluster giants, as well as of field stars, is discussed. The system has been used to isolate stellar populations among field stars without any prior knowledge of their distances. From observations on this system, the only open cluster found so far to have giants with stronger cyanogen band absorption than the Hyades giants is the intermediate age southern cluster NGC 2477.

The decomposition of crystal families

1980 ◽  
Vol 88 (2) ◽  
pp. 245-263 ◽  
Author(s):  
J. D. Jarratt
Keyword(s):  
Dimensional Space ◽  
Canonical Decomposition ◽  
Space Groups ◽  
Higher Dimensional ◽  
Result Theorem ◽  
Free Parameters

In the course of their enumeration of all 4-dimensional space groups, Brown, Bülow, Neubüser, Wondratschek and Zassenhaus have introduced concepts appropriate to the study of n-dimensional crystallography for n ≥ 4 (see (2), (3)). One such concept is that of a crystal family. Families seem to be particularly useful as a framework within which to study higher dimensional crystallography, primarily because they determine a classification of all the standard crystallographic objects and overcome the traditional confusion over crystal systems (see (2); pp. 16–17, (9)). In this paper, techniques are developed for the determination of all rationally decomposable families in a given dimension from the indecomposable families of lower dimensions. These techniques place emphasis on three geometric invariants of families: the decomposition pattern; the canonical decomposition pattern; and the number of free parameters. This, it is felt, further reinforces their position as fundamental objects. The key result (Theorem 5.4) is:a family uniquely determines, and is uniquely determined by, the constituent families in the canonical decomposition.

THE ESSENCE, THE NEED FOR EVALUATION AND TYPES OF ECONOMIC POTENTIAL OF ENTERPRISES

2017 ◽  
Author(s):  
Olexandr Yemelyanov ◽  
Keyword(s):  
Economic Activity ◽  
Business Strategies ◽  
Enterprise Management ◽  
Value Assessment ◽  
Economic Potential ◽  
Enterprise Value ◽  
Development Assessment ◽  
State Of The Environment

The formation of business strategies of enterprises should be based on a preliminary assessment of their current and future economic opportunities. Such an assessment is to establish the value of the total economic potential of enterprises and its individual varieties. The purpose of this study was to clarify the essence of the economic potential of enterprises, justify the need for its evaluation and selection of its types. The main approaches to interpreting the terms "potential" and "enterprise potential" are identified. These include resource, result, resource-result, resource-target, and result-target concepts. It is established that the potential of any object, including the enterprise, can be interpreted as a set of its external functional properties, which this object shows or can show in a certain state of the environment in which it is located. Accordingly, the assessment of the potential of an object should be based on the identification and determination of its external properties, taking into account the environment in which the object is located. The main situations in which there is a need for information about certain components of the economic potential of the enterprise are identified, and the types of this potential and the consumers of the information about their level, corresponding to these situations, are determined. In particular, such situations include management of production and sales, management of financial and economic results of the enterprise, management of enterprise development, assessment of the company's need for various types of resources, assessment of enterprise value, assessment of current and future impact of the enterprise on the economy of the country (region), etc. The features of classification of types of enterprise potential existing in the scientific literature are supplemented by the following ones: by the main types of economic activity, by the dynamics of changes in the economic and production system of the enterprise, by consequences for the subject of enterprise potential assessment, by the stages of economic activity, enterprise potential, etc. The obtained results make it possible to improve the understanding of the complex patterns that underlie the formation of the economic potential of enterprises.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

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