scholarly journals Determination of accurate stellar radial-velocity measures

2002 ◽  
Vol 390 (1) ◽  
pp. 383-395 ◽  
Author(s):  
D. Gullberg ◽  
L. Lindegren
Keyword(s):  
Radial Velocity

Determination of the Radial Velocity of a Relativistic Star

Nature ◽  
1970 ◽  
Vol 226 (5247) ◽  
pp. 737-738 ◽  
Author(s):  
A. C. LE FLOCH
Keyword(s):  
Radial Velocity ◽  
Relativistic Star

scholarly journals Radial Velocity Profiles for Anisotropic Spherically Symmetric Clusters: An Example

1988 ◽  
Vol 126 ◽  
pp. 691-692
Author(s):  
Herwig Dejonghe
Keyword(s):  
Distribution Function ◽  
Radial Velocity ◽  
Velocity Dispersion ◽  
Mass Density ◽  
Distribution Functions ◽  
Spherically Symmetric ◽  
Line Profiles ◽  
Anisotropic Models ◽  
The Family

A 1-parameter family of anisotropic models is presented. They all satisfy the Plummer law in the mass density, but have different velocity dispersions. Moreover, the stars are not confined to a particular subset of the total accessible phase space. This family is mathematically simple enough to be explored analytically in detail. The family is rich enough though to allow for a 3-parameter generalization which illustrates that even when both the mass density and the velocity dispersion profiles are required to be the same, a degeneracy in the possible distribution functions persists. The observational consequences of the degeneracy can be studied by calculating the observable radial velocity line profiles obtained with different distribution functions. It turns out that line profiles are relatively sensitive to changes in the distribution function. They therefore can be considered to be more natural observables when a determination of the distribution function is desired.

Coravel Radial-Velocity Curves for Cepheids in the Large Magellanic Cloud

1984 ◽  
Vol 88 ◽  
pp. 375-380
Author(s):  
M. Imbert ◽  
J. Andersen ◽  
A. Ardeberg ◽  
C. Bardin ◽  
W. Benz ◽  
...  
Keyword(s):  
Comparative Study ◽  
Radial Velocity ◽  
Stellar Evolution ◽  
Large Magellanic Cloud ◽  
Magellanic Clouds ◽  
Independent Determination ◽  
Fundamental Information ◽  
The Galaxy ◽  
Cepheid Variables

Radii and luminosities for Cepheid variables provide fundamental information on stellar evolution. Such data, obtained by the Baade-Wesselink method, are available and have been used for a number of galactic Cepheids. It is of particular interest to obtain corresponding data for Cepheids in the Magellanic Clouds. Firstly, this allows a comparative study of stellar evolution between the Galaxy and the Magellanic Clouds. Secondly, it provides data for an independent determination of the distance to the Magellanic Clouds.Radial-velocity observations have been made for a total of around 20 Cepheid variables in both the LMC and the SMC. All measurements were made with the photoelectric scanner CORAVEL attached to the Cassegrain focus of the Danish 1.54-m telescope at European Southern Observatory, La Silla, Chile. Observations were made from January 1981 through October 1983. The accuracy of individual radial-velocity observations is of the order of 1 km s−1. The B magnitudes of the six Cepheids presented range from 13.0 to 15.5.

scholarly journals Studies of Large-Amplitude δ Scuti Variables

1993 ◽  
Vol 139 ◽  
pp. 104-104
Author(s):  
W. J. F. Wilson ◽  
E. F. Milone ◽  
D. J. I. Fry
Keyword(s):  
Radial Velocity ◽  
Large Amplitude ◽  
Light Curves ◽  
Pulsating Stars ◽  
Modest Contribution ◽  
The Mean ◽  
Absolute Magnitudes ◽  
Scuti Stars ◽  
Radial Velocity Data

The determination of Baade-Wesselink radii and luminosities for pulsating stars are long-standing and highly desired goals since they provide the promise of being standard candles. In a modest contribution towards these goals, we have undertaken a programme to determine the radii and luminosities of the large-amplitude δ Scuti stars DY Herculis, EH Librae and DY Pegasi from optical and infrared photometry and cross-correlated radial velocity data. We use Fourier representations for V, I and J light curves and for the radial velocity curves in Baade-Wesselink analyses to derive minimum radii over the pulsation cycles. These radii and their errors and the mean bolometric luminosities and absolute magnitudes will be discussed here and in papers to follow. As a check, we also apply our method to the data and results of other groups.

scholarly journals Absolute Parameter Determination in Low-Mass Eclipsing Binaries. Radiative Parameters for BH VIR, ZZ UMa and CR Cas

1993 ◽  
Vol 137 ◽  
pp. 386-391
Author(s):  
R. Clement ◽  
V. Reglero ◽  
M. Garcia ◽  
J. Fabregat ◽  
A. Bravo ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Monitoring Program ◽  
Mass Range ◽  
Eclipsing Binaries ◽  
Radiative Properties ◽  
Parameter Determination ◽  
Low Mass ◽  
Observational Program

AbstractA new uvby and Hβ monitoring program of low mass eclipsing binaries is currently being carried out in the framework of a 5 year observational program which also involves radial velocity determinations. The scope of this work is to provide very accurate absolute astrophysical parameters: mass, radius and effective temperatures, for main sequence late-type stars. One of the main goals is to improve the mass-luminosity relation in the low and intermediate mass range. A second objective is to perform accurate tests of the most recent grids of evolutionary models. This program is complementary to that currently being in progresss by the Copenhagen group.In this contribution we present the photometric preliminary results obtained for three of the systems included in our long term survey: BH Vir, ZZ UMa and CR Cas for which, primary eclipses have been observed. Particular attention is paid to the determination of reddening, distances and radiative properties. A more detailed study will be carried out when the light curves and radial velocity measurements are completed

A precise radial-velocity determination of the orbit of Chi(1) Orionis

1992 ◽  
Vol 104 ◽  
pp. 101 ◽  
Author(s):  
Alan W. Irwin ◽  
Stephenson Yang ◽  
G. A. H. Walker
Keyword(s):  
Radial Velocity

scholarly journals Planetary Nebulae in the Andromeda Galaxy and its Companions

1978 ◽  
Vol 76 ◽  
pp. 19-34 ◽  
Author(s):  
Holland C. Ford
Keyword(s):  
Radial Velocity ◽  
Globular Clusters ◽  
Direct Determination ◽  
Planetary Nebulae ◽  
Emission Lines ◽  
Direct Measure ◽  
Chemical Abundances ◽  
Andromeda Galaxy ◽  
Powerful Means

The identification and observation of planetary nebulae in the Andromeda galaxy (M31) and its companions provide a powerful means of studying their old stellar populations. The direct determination of chemical abundances and radial velocities for even the brightest individual old stars is impossible at the distance of M31. The strongest emission lines of planetary nebulae are as bright as the entire visual continuum of the most luminous giants. Consequently, spectrophotometry of planetary nebulae presently provides the only direct measure of chemical abundances, and, with the exception of globular clusters, the only radial velocity determinations for the old populations.

scholarly journals The Planet Orbiting ρ Coronae Borealis

1999 ◽  
Vol 170 ◽  
pp. 162-165 ◽  
Author(s):  
R. W. Noyes ◽  
A. R. Contos ◽  
S. G. Korzennik ◽  
P. Nisenson ◽  
T. M. Brown ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Giant Planets ◽  
Orbital Parameters ◽  
Upper Limits ◽  
And Migration ◽  
The Times

AbstractContinuing precise radial velocity observations of ρ Coronae Borealis have allowed the determination of updated parameters of the 40-day orbit of its Jupiter-mass companion. This confirms the previously reported period and amplitude, and shows a small but marginally significant non-zero eccentricity. It also provides improved predictions for the times of possible transit of the companion in front of the star. The new data provide upper limits to the mass of a possible second companion to the system. The orbital parameters are discussed in the light of scenarios for the origin and migration of extra-solar giant planets.

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