I. A method of measurement and reduction of spectrograms for the determination of radial velocities. II. Application to a study of the variable star W Sagittarii.

1904 ◽  
Vol 20 ◽  
pp. 149
Author(s):  
R. H. Curtiss
Keyword(s):  
Variable Star ◽  
Radial Velocities ◽  
Method Of Measurement

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

A Proposed Method for the Determination of Radial Velocities of Stars

1906 ◽  
Vol 23 ◽  
pp. 148 ◽  
Author(s):  
George C. Comstock
Keyword(s):  
Radial Velocities

Method of Measurement of Mean Concentration for an Element Segregated in Layers by X-Ray Analysis

1977 ◽  
Vol 21 ◽  
pp. 143-147
Author(s):  
I. Vander
Keyword(s):  
Fluorescence Analysis ◽  
Primary Radiation ◽  
Angle Of Incidence ◽  
Simple Method ◽  
X Ray ◽  
Elemental Compositions ◽  
Detection Angle ◽  
Method Of Measurement ◽  
Mean Concentration

Traditionally, in X-ray fluorescence analysis for the determination of elemental compositions, the fluorescence is measured from the irradiated side of the sample. The composition measurements obtained by this method are sensitive to a gradient in composition as a function of depth of the element being measured. This report presents a simple method for measuring a mean composition for an element segregated in layers applicable to thin samples so that the fluorescence can be measured on the side opposite to that being irradiated. It is shown that for a particular relation between the angle of incidence of the primary radiation and of the detection angle on the opposite side of the sample that a mean concentration can be measured for an element which is independent of the composition in the separate layers.

Note on the Determination of Radial Velocities of Nebulae

1913 ◽  
Vol 25 ◽  
pp. 288
Author(s):  
W. W. Campbell
Keyword(s):  
Radial Velocities

scholarly journals Formation Depths of Spectral Lines in Cepheids

1995 ◽  
Vol 155 ◽  
pp. 373-374
Author(s):  
Michael D. Albrow ◽  
P. L. Cottrell
Keyword(s):  
Spectral Line ◽  
Velocity Fields ◽  
Radial Velocities ◽  
Spectral Lines ◽  
Line Formation ◽  
Ionisation Potential ◽  
Velocity Gradients ◽  
Different Levels ◽  
Line Depth

There has been a number of observational programmes that have endeavoured to investigate the atmospheric velocity fields in Cepheids (e.g., Sanford 1956, Wallerstein et al. 1992, Butler 1993). These studies measured the radial velocities of lines of different strength, excitation and ionisation potential as these provide an indication of line formation at different levels in the atmosphere. From these measurements, the presence of velocity gradients can be inferred, but determination of the magnitude of such gradients requires knowledge of the spectral line depth of formation. Through dynamical modelling we are endeavouring to ascertain what is actually being measured in the above observational programmes.

scholarly journals A Determination of Secular Parallaxes of Reference Stars from Relative Proper Motions of Open Clusters

1970 ◽  
Vol 7 ◽  
pp. 74-76
Author(s):  
A. N. Deutsch
Keyword(s):  
Systematic Errors ◽  
Open Clusters ◽  
Radial Velocities ◽  
Proper Motions ◽  
The Mean

The determination of secular parallaxes of stars is usually based on meridian observations of proper motions of bright stars, this introducing known systematic errors. The mean parallaxes of stars can be obtained by means of radial velocities which are known for the bright stars. The more perspective method, the reference of stars to galaxies, is not applicable at low galactic latitudes.

Measurement for Warm-Up Decrement: A Review

1982 ◽  
Vol 55 (1) ◽  
pp. 253-254 ◽  
Author(s):  
Joseph F. Murray
Keyword(s):  
Orthogonal Polynomial ◽  
Polynomial Regression ◽  
Warm Up ◽  
Method Of Measurement ◽  
Standardized Method

Research dealing with warm-up decrement shows there is diversity in measurement of this phenomenon. It would be advantageous to have a standardized method of measurement that is objective and does not require the determination of a peak trial. One such technique is orthogonal polynomial regression.

A determination of the apex and velocity of the solar motion from radial velocities of stars of spectral type B

1924 ◽  
Vol 222 (8) ◽  
pp. 113-122
Author(s):  
B. Fessenkoff ◽  
C. Ogrodnikoff
Keyword(s):  
Spectral Type ◽  
Radial Velocities ◽  
Type B ◽  
Solar Motion
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