The Peculiar Stars and Spectral Classification

1973 ◽  
pp. 91-94 ◽  
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya
Keyword(s):  
Spectral Classification ◽  
Peculiar Stars

Ultraviolet Spectrometry of Peculiar Stars

1979 ◽  
Vol 47 ◽  
pp. 461-464
Author(s):  
G. B. Baratta ◽  
A. Cassatella ◽  
R. Viotti
Keyword(s):  
Emission Line ◽  
Spectral Region ◽  
Physical Characteristics ◽  
Classification Criteria ◽  
Spectral Classification ◽  
Complementary Information ◽  
Peculiar Stars ◽  
Standard Classification

The standard classification criteria, when applied to peculiar objects, such as emission line and shell stars, cannot easily be interpreted in terms of their intrinsic physical characteristics. Observations outside the optical spectral region may provide complementary information on their nature leading to a better spectral classification.

Spectral classification and three-colour photometry of A-type peculiar stars

1966 ◽  
Vol 24 ◽  
pp. 15-18
Author(s):  
K. Osawa
Keyword(s):  
Homogeneous System ◽  
Spectral Classification ◽  
Peculiar Stars ◽  
The Difference ◽  
Ap Stars ◽  
The Way

1. Since the pioneering works by Morgan (1) and later by Deutsch (2) for classifying A-type peculiar stars, many observers have discovered stars of this kind. A catalogue of Ap stars was compiled in 1959 by Bertaud (3). This catalogue is obviously very useful for astronomers in this field, but the type of peculiarity described in it is not homogeneous. The way of describing the spectral peculiarity differs somewhat with different observers, mainly due to the difference of dispersion of the spectrograph. The purpose of the observing programme of Ap stars reported in the present paper is to classify these Ap stars by an homogeneous system, and also to see relations between the spectra and the colours (B–V) and (U–B).

scholarly journals The Peculiar Stars and Spectral Classification

1973 ◽  
Vol 50 ◽  
pp. 91-94
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya
Keyword(s):  
Slight Modification ◽  
High Accuracy ◽  
Two Dimensional ◽  
Spectral Classification ◽  
High Quality ◽  
Peculiar Stars ◽  
Objective Prism ◽  
Telescope Optics ◽  
Existing Data

The spectral classification experiments with the 70-cm meniscus telescope and 8° objective prism of Abastumani Observatory (dispersion 166 Å mm-1) have shown that if we apply the Kodak IIa-O plates at the 0.4 mm widening of spectra and the 20 minutes exposure time, we can successfully classify with relatively high accuracy in two dimensional MK system the stars down to the 11th magnitude, with simultaneous discrimination of peculiars.We have undertaken such determinations first of all in Kapteyn Selected Areas aiming to fill the gaps in existing data for these standard areas.Finally we could mention the high quality of the meniscus telescope optics together with good seeing in Abastumani as favourable factors making the Abastumani spectra of 10–11th magn. stars comparable with the slit spectra of the same dispersion.The Abastumani spectra allow to apply the Morgan and Kitt-Peak criteria of MK classification only with a slight modification.We have two-dimensionally classified in MK system about ten thousand stars down to the 11th magnitude in KA Nos. 2–43 (4.°5 × 4°5 each). Among them 137 peculiar stars have been revealed. They are mainly Ap, Am and BaII (7 stars) and the stars with composed spectra (5). 97 stars have been first identified as peculiars.

scholarly journals Spectral Morphology in Southern open Clusters and Associations at La Plata Observatory

1979 ◽  
Vol 47 ◽  
pp. 99-100
Author(s):  
H. Levato ◽  
S. Malaroda
Keyword(s):  
Open Clusters ◽  
Spectral Classification ◽  
Open Clusters And Associations ◽  
La Plata ◽  
Peculiar Stars

AbstractOur purpose is to describe the program on spectral classification of members of open clusters and associations started in January 1977 at La Plata Observatory. The program is essentially a continuation of the Abt and Levato studies made from Kitt Peak so, many details of it have been already described in Dr. Abt’s paper in this volume. We have a list of 40 clusters and associations included in the program which consists in obtaining two sets of spectra in two dispersions, 39 Å/mm and 125 Vmm, both sets 1.2 wide. These spectra, as has already been mentioned, are very useful for deriving accurate MK types and for discovering peculiar stars.

Note on the spectral classification of carbon stars in the photographic infrared region

1966 ◽  
Vol 24 ◽  
pp. 21-23
Author(s):  
Y. Fujita
Keyword(s):  
Infrared Region ◽  
Spectral Classification ◽  
Carbon Stars

We have investigated the spectrograms (dispersion: 8Å/mm) in the photographic infrared region fromλ7500 toλ9000 of some carbon stars obtained by the coudé spectrograph of the 74-inch reflector attached to the Okayama Astrophysical Observatory. The names of the stars investigated are listed in Table 1.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

Ultraviolet Spectral Classification of O and B Stars in the Large Magellanic Cloud

1999 ◽  
Vol 117 (6) ◽  
pp. 2856-2867 ◽  
Author(s):  
Margaret M. Smith Neubig ◽  
Frederick C. Bruhweiler
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Spectral Classification ◽  
B Stars

scholarly journals UV Spectral Classification of B Stars

1985 ◽  
Vol 111 ◽  
pp. 411-413
Author(s):  
Janet Rountree ◽  
George Sonneborn ◽  
Robert J. Panek
Keyword(s):  
Classification System ◽  
Classification Criteria ◽  
High Dispersion ◽  
Spectral Classification ◽  
Early Type ◽  
B Stars ◽  
Dimensional Classification ◽  
Early Type Stars ◽  
Comprehensive Classification

Previous studies of ultraviolet spectral classification have been insufficient to establish a comprehensive classification system for ultraviolet spectra of early-type stars because of inadequate spectral resolution. We have initiated a new study of ultraviolet spectral classification of B stars using high-dispersion IUE archival data. High-dispersion SWP spectra of MK standards and other B stars are retrieved from the IUE archives and numerically degraded to a uniform resolution of 0.25 or 0.50 Å. The spectra (in the form of plots or photowrites) are then visually examined with the aim of setting up a two-dimensional classification matrix. We follow the method used to create the MK classification system for visual spectra. The purpose of this work is to examine the applicability of the MK system (and in particular, the set of standard stars) in the ultraviolet, and to establish classification criteria in this spectral region.

Sign in / Sign up

Export Citation Format

Share Document