scholarly journals 30. Commission des Vitesses Radiales Stellaires

1939 ◽  
Vol 6 ◽  
pp. 254-266 ◽  
Author(s):  
M. W. S. Adams ◽  
MM. Bok ◽  
Guthnick ◽  
Harper ◽  
Joy ◽  
...  
Keyword(s):  
Radial Velocities ◽  
Early Type ◽  
The Past ◽  
Special Groups ◽  
Mount Wilson Observatory ◽  
Galactic Clusters ◽  
Cepheid Variables ◽  
Early Type Stars ◽  
Large Telescopes ◽  
Selection Of

During the past three years the measurement of stellar radial velocities has formed an important part of the spectroscopic programme of most observatories possessing large telescopes. As observations are carried to fainter and fainter stars and the number of observable objects increases rapidly, a natural development has been the selection of special groups and types of stars, the radial velocities of which will aid in the solution of certain specific problems. Illustrations are the studies of the O, B and A type stars made at the Dominion Astrophysical, the Lick, and the Simeis Observatories, of the members of the galactic clusters at the Lick Observatory, and of the fainter Cepheid variables and early-type stars with strong interstellar lines at the Mount Wilson Observatory.

scholarly journals The properties of early-type stars in the Magellanic Clouds

2008 ◽  
Vol 4 (S256) ◽  
pp. 325-336
Author(s):  
Christopher J. Evans
Keyword(s):  
Physical Properties ◽  
Mass Loss ◽  
Temperature Scale ◽  
Massive Stars ◽  
Magellanic Clouds ◽  
Early Type ◽  
The Past ◽  
The Galaxy ◽  
Stellar Temperature ◽  
Early Type Stars

AbstractThe past decade has witnessed impressive progress in our understanding of the physical properties of massive stars in the Magellanic Clouds, and how they compare to their cousins in the Galaxy. I summarise new results in this field, including evidence for reduced mass-loss rates and faster stellar rotational velocities in the Clouds, and their present-day compositions. I also discuss the stellar temperature scale, emphasizing its dependence on metallicity across the entire upper-part of the Hertzsprung-Russell diagram.

scholarly journals Long-Term Spectroscopic Monitoring and Surveys of Early-Type Stars with and without Circumstellar Envelopes

2017 ◽  
Vol 26 (1) ◽  
Author(s):  
Anatoly S. Miroshnichenko ◽  
Steven Danford ◽  
Sergei V. Zharikov ◽  
Nadine Manset ◽  
Hugo Levato ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Binary Systems ◽  
Theoretical Explanation ◽  
Evolutionary Status ◽  
Early Type ◽  
Fundamental Parameters ◽  
Spectroscopic Monitoring ◽  
Early Type Stars ◽  
Large Telescopes

AbstractOngoing studies of different groups of stars result in improving our knowledge of their fundamental parameters and evolutionary status. Also, they result in finding new phases of stellar evolution, which require theoretical explanation. At the same time, availability of large telescopes and sensitivity improvement of detectors shift the focus of many observational programs toward fainter and more distant objects. However, there are still many problems in our understanding of details of stellar evolution which can now be solved with small telescopes and observations of bright stars. Approaching these problems implies conducting surveys of large groups of stars and long-term monitoring of individual objects. In this talk, we present the results of recent international programs of photometric and spectral monitoring of several groups of early-type stars. In particular, we discuss the role of binarity in creation of the Be phenomenon and show examples of recently discovered binary systems as well as the problem of refining fundamental parameters of B and A type supergiants. Special attention will be paid to collaboration with the amateur community and use of échelle spectrographs mounted on small telescopes.

scholarly journals Radial velocities of early-type stars in the Perseus OB2 association

2003 ◽  
Vol 402 (2) ◽  
pp. 587-605 ◽  
Author(s):  
K. C. Steenbrugge ◽  
J. H. J. de Bruijne ◽  
R. Hoogerwerf ◽  
P. T. de Zeeuw
Keyword(s):  
Radial Velocities ◽  
Early Type ◽  
Early Type Stars

Radial Velocities of Some Early-Type Stars

1938 ◽  
Vol 87 ◽  
pp. 517 ◽  
Author(s):  
Roscoe F. Sanford ◽  
Paul W. Merrill
Keyword(s):  
Radial Velocities ◽  
Early Type ◽  
Early Type Stars

scholarly journals Radial velocities of early-type stars

1970 ◽  
Vol 38 ◽  
pp. 290-290
Author(s):  
J. P. Kaufmann
Keyword(s):  
Velocity Gradient ◽  
Milky Way ◽  
Radial Velocities ◽  
Circular Motion ◽  
The Sun ◽  
Spectral Classification ◽  
Early Type ◽  
Objective Prism ◽  
Minimum Distances ◽  
Early Type Stars

With the Fehrenbach objective prism radial velocities of about 700 stars of type B0 to A0 were determined in two fields of the Southern Milky Way (lII = 295° bII = −0.6°; lII = 320° bII = −2.5°), with a mean error of ±20 km s−1. An additional photographic UBV-photometry with plates of the ADH-telescope at Boyden Observatory was accomplished. Minimum distances for the stars resulted from absorption-corrected magnitudes and a MK-spectral classification. About 200 stars lay at distances greater than 1.5 kpc from the sun. The largest distances determined were 5 kpc. From the radial velocities and distances circular velocities were derived and plotted against galactocentric distances R. Even within the possible error limits a positive velocity gradient showed up in the range 8 kpc < R < 9.5 kpc, which French authors had already found for the region 10.5 kpc < R < 12.5 kpc. If there do not exist significant deviations from circular motion for these stars, a conformity with Schmidt's 1965 model cannot be obtained.

The measurement of precise radial velocities of early type stars

1991 ◽  
Vol 101 ◽  
pp. 1495 ◽  
Author(s):  
Jon A. Morse ◽  
Robert D. Mathieu ◽  
Stephen E. Levine
Keyword(s):  
Radial Velocities ◽  
Early Type ◽  
Early Type Stars
Sign in / Sign up

Export Citation Format

Share Document