Spectral Classification of Stars Noted on Case Objective Prism Plates. II

1957 ◽  
Vol 69 ◽  
pp. 326 ◽  
Author(s):  
William P. Bidelman
Keyword(s):  
Spectral Classification ◽  
Objective Prism

scholarly journals Contributions and Prospects for Spectral Classification of Stars with Objective Prism Techniques

1979 ◽  
Vol 47 ◽  
pp. 127-136
Author(s):  
E. K. Kharadze
Keyword(s):  
Galactic Structure ◽  
Spectral Classification ◽  
Missing Mass ◽  
Mass Problem ◽  
Important Stage ◽  
Objective Prism ◽  
Low Dispersion

The following topics will be discussed: a) A few historical comments; b) MK classification - the most important stage of classification work; c) Recently revealed peculiarity features and the problem of further differentiation of the classification scale; d) Classification work in the USSR; e) The role of classification results with respect to galactic structure studies; f) Low dispersion spectra and faint M-type stars and the missing mass problem; g) Extraterrestrial spectral observations: new promising means for research.

scholarly journals A Test of the Accuracy of low Dispersion Objective Prism: Spectral Classification of Late-Type Stars Using DDO Photometry

1976 ◽  
Vol 72 ◽  
pp. 73-73
Author(s):  
J. J. Clariá ◽  
W. Osborn
Keyword(s):  
Band System ◽  
Class I ◽  
Spectral Features ◽  
Spectral Classification ◽  
Late Type ◽  
Intermediate Band ◽  
Metal Abundance ◽  
Objective Prism ◽  
Low Dispersion

A test has been made of the reliability of the multidimensional classification of late-type stars from low dispersion objective prism plates recently attempted by Stock and Wroblewski. Such classification at low dispersion is difficult due to the problem of separating the effects of luminosity from those of abnormal metal abundance. A sample of the stars classified by Stock and Wroblewski as metal weak (pec) and of those classified as luminous stars (class I) were observed using the DDO intermediate-band system. The photometry shows that the stars classified as pec are indeed population II giants, of low metal abundance ([Fe/H] < −1.0). The stars classified as I, however, were found in general not to be true supergiants but rather a mixture of various types of giants, such as CN strong stars, with spectral features that resemble, in one way or another, those of higher luminosity stars.

scholarly journals Bright Stars in Five LMC Star Clusters

1986 ◽  
Vol 116 ◽  
pp. 417-418
Author(s):  
E. Kontizas ◽  
E. Xiradaki ◽  
M. Kontizas
Keyword(s):  
Star Clusters ◽  
Spectral Classification ◽  
Schmidt Telescope ◽  
Binocular Microscope ◽  
Objective Prism ◽  
Low Dispersion

The bright stars of five LMC clusters were classified for deriving the distribution of various spectral types. The studied clusters are very young (NGC 2093) young (NGC 1818, NGC 2157) intermediate (NGC 1831) and old (NGC 1806) (Van den Bergh 1981). The spectral classification of the stars was carried out using film copies of the 1.2 m Schmidt telescope objective prism plates. Medium dispersion (830 Å at Hγ) unwidened YJ and widened UJ and low dispersion (2440 Å at Hγ) UJ were examined by means of a binocular microscope. Details of the criteria used for the classification are described by Kontizas et al (1985).

scholarly journals Future Objective-Prism Spectral classification at MK Dispersion

1979 ◽  
Vol 47 ◽  
pp. 51-58
Author(s):  
Nancy Houk
Keyword(s):  
Two Dimensional ◽  
University Of Michigan ◽  
Spectral Classification ◽  
The Future ◽  
Objective Prism ◽  
Future Plans

AbstractA brief review and summary of results from Volumes 1 (-90° to -53°) and 2 (-53° to -40°) of the University of Michigan Catalogue of Two-Dimensional Spectral Types for the HP Stars is given. Plans for the classification of the remaining southern HD stars are outlined. Future plans for observation and classification of northern stars are discussed, including the problem of whether to limit such classification to the HD stars. More general remarks about spectral classification in the future, especially for fainter stars, conclude the paper.

scholarly journals Recent Developments in the Work on Automated Spectral Classification by Means of Objective Prism Spectra

1994 ◽  
Vol 161 ◽  
pp. 253-254
Author(s):  
V. Malyuto ◽  
T. Shvelidze
Keyword(s):  
Spectral Classification ◽  
Proper Motions ◽  
Stellar Spectra ◽  
Meridional Section ◽  
Spectrometric Data ◽  
Software Packages ◽  
The Galaxy ◽  
Recent Developments ◽  
Objective Prism

Some years ago a complex programme of studying the main meridional section of the Galaxy was started by astronomers of Kiev, Tartu, Abastumani and Vilnius Observatories with the aim of improving our knowledge of spatial and kinematic characteristics of stellar populations. Characteristic to the programme is the use of absolute proper motions of stars together with automated quantitative spectral classification for large stellar-statistical samples. The data are gathered in areas lying within 30° of the main meridional section of the Galaxy. To classify stars, objective prism stellar spectra of intermediate dispersion (166 å/mm at Hγ), obtained with the 70 cm meniscus telescope at the Abastumani Astrophysical Observatory, are used. The field diameter is 4° 50′, and the limiting photographical stellar magnitude is about 12 m . Our system of automated quantitative spectral classification of F-K stars applies criteria evaluation and is mainly based on two software packages: the SDR package for spectrometric data reduction and the CTATEC-2 package determining the linear regression model used for classification (Malyuto &amp; Shvelidze 1989; Malyuto, Pelt &amp; Shvelidze 1993).

scholarly journals The Spectral Classification of Southern Carbon Stars

1973 ◽  
Vol 50 ◽  
pp. 96-108
Author(s):  
P. M. Rybski
Keyword(s):  
South Africa ◽  
Research Center ◽  
Spectral Classification ◽  
Carbon Stars ◽  
The Third ◽  
Objective Prism ◽  
Astronomical Research ◽  
The One

Well-widened objective prism spectra of carbon stars south of −25° declination have been examined to determine their suitability for classification. These spectra, taken by Henize in the early 1950's from South Africa as part of the Michigan-Mt. Wilson Hα survey of the southern sky, have a reciprocal dispersion at Na I 5890 Å of 300 Å mm−1 and are in good focus in the range between 5100 and 6600 Å.Compared with spectra of northern carbon stars taken by the writer at the Lindheimer Astronomical Research Center with the one meter reflecting telescope and Cassegrain spectrograph at a grating reciprocal dispersion of 263 Å mm-1, and compared with spectra taken by Sanford of carbon stars overlapping the Henize sample, the objective prism spectra have been found of sufficient quality to support their classification into five groups following the scheme as proposed by Keenan and Morgan in 1941 and as refined by Gordon in 1967.The first group exhibit weak C2 and CN features and Hα in absorption; the second, features attributable to a low C12/C13 ratio; the third, strong C2 and CN features and only moderately strong Na i in absorption; the fourth, very strong Na i in absorption; and the fifth, Hα in emission. Examples are given of each group, stars not fitting well into any of these groups are discussed, and the significance of each group is mentioned in light of work by Bouigue, Gordon, Peery, and Richer.

scholarly journals Accurate spectral classification by objective-prism techniques

1966 ◽  
Vol 24 ◽  
pp. 53-54
Author(s):  
W. P. Bidelman
Keyword(s):  
Radial Velocity ◽  
Large Scale ◽  
Naval Research ◽  
Spectral Classification ◽  
High Quality ◽  
Office Of Naval Research ◽  
Metallic Line ◽  
Objective Prism ◽  
The U.S

The performance of moderate dispersion objective-prism equipment, and in particular that of the 10°-prism combination of the Michigan Curtis Schmidt, has been evaluated through a direct comparison of objective prism and slit spectrograms of a number of standard stars. The results suggest that one should seriously consider using objective-prism equipment rather than slit spectrographs for large scale programs of accurate classification of fairly bright stars.A survey of 171 high-quality Curtis Schmidt plates covering 105 different fields has resulted in the discovery of 46 new peculiar A stars and 66 new metallic-line stars. In addition, 17 stars of later type have been classified as “weak-metal” objects. The most interesting stars detected were HD 3473, which is greatly overabundant in both silicon and magnesium, and the G-type star HD 2665 (mv= 7 · 6), which has subsequently been found to have a radial velocity of approximately – 390 km/sec. This is the brightest star known to have such a large radial velocity.(The above paper appears in full in the volume entitledBasic Data Pertaining to the Hertzsprung-Russell Diagram, a symposium dedicated to Ejnar Hertzsprung and sponsored by the U.S. Office of Naval Research, to be published by Pergamon Press asVistas in Astronomy, vol. 8).

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