Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components.

2002 ◽  
Vol 143 (2) ◽  
pp. 513-537 ◽  
Author(s):  
N. Ginestet ◽  
J. M. Carquillat
Keyword(s):  
Spectral Classification ◽  
Large Sample ◽  
Composite Spectra ◽  
The Absolute ◽  
Absolute Magnitudes

On the absolute magnitudes of late-type giant stars

1966 ◽  
Vol 24 ◽  
pp. 317-321
Author(s):  
B. Ljunggren ◽  
T. Oja
Keyword(s):  
Late Type ◽  
Group V ◽  
Group Iii ◽  
Giant Stars ◽  
The Absolute ◽  
Type Giant ◽  
Photometric Measurements ◽  
Absolute Magnitudes ◽  
Group D

The classification of late-type stars in the Uppsala system is made from photometric measurements of the criteriagandc, gmeasuring the break at the G-band andcthe cyanogen absorption. On the basis of these criteria the stars are divided into luminosity groups. Earlier only two groups, dwarfs and giants, were used. A few years ago a refinement in luminosity classification was introduced (1), the stars being divided into four luminosity groups designated d, dg, g, and c in the order of increasing luminosity. Specially the groups d and g have been defined so as to make them as homogeneous as possible. The group d corresponds to the MK luminosity group V and g approximately to the luminosity group III.

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.

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 Observed Relations Between Physical Properties and MK Classification as Functions of Metal Abundance for F5-K4 Stars

1976 ◽  
Vol 72 ◽  
pp. 75-78
Author(s):  
M. Grenon
Keyword(s):  
Physical Properties ◽  
Spectral Range ◽  
Spectral Type ◽  
Photometric System ◽  
Luminosity Class ◽  
Empirical Relations ◽  
Metal Abundance ◽  
Systematic Effects ◽  
The Absolute ◽  
Absolute Magnitudes

The Geneva photometric system has been calibrated in terms of [M/H], θeff, Mv in the spectral range F5 to K4. As the spectral type is a datum generally available, we derive empirical relations showing the coupling of θeff and [M/H] at given spectral type and luminosity class. Similar relations are offered for the absolute magnitudes and provide a more accurate means for deriving spectroscopic parallaxes. Systematic effects on the estimation of the luminosity class are also shown.

scholarly journals The Absolute Magnitude of the Early-Type MK Standards From Hipparcos Parallaxes

1998 ◽  
Vol 11 (1) ◽  
pp. 566-566
Author(s):  
C. Jaschek ◽  
A.E. Gómez
Keyword(s):  
Main Sequence ◽  
Rotational Velocity ◽  
Wide Band ◽  
Absolute Magnitude ◽  
Interstellar Extinction ◽  
Early Type ◽  
Class V ◽  
Luminosity Class ◽  
The Absolute ◽  
Absolute Magnitudes

We have analysed the standards of the MK system in the B0-F5 spectral region with the help of Hipparcos parallaxes, using only stars for which the error on the absolute magnitude is ≤ 0.3 mag. The sample stars (about one hundred) were scrutinized for companions and for interstellar extinction. We find that the main sequence is a wide band and that, although in general giants and dwarfs have different absolute magnitudes, the separation between luminosity class V and III is not clear. We conclude that there is no strict relation between luminosity class and absolute magnitude. The relation is only a statistical one and has a large intrinsic dispersion. We have analysed similarly the system of standards defined by Garrison and Gray (1994) separating low and high rotational velocity standards. We find similar effects as in the original MK system.

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.

scholarly journals A New Revision of the HDEC (Henry Draper Extension Charts) Catalog

2016 ◽  
Vol 25 (1) ◽  
Author(s):  
N. Ashimbaeva ◽  
V. Sementsov
Keyword(s):  
Binary Systems ◽  
Measurement Model ◽  
Spectral Classification ◽  
Multiple Systems ◽  
Cross Matching

AbstractA new version of the HDEC (Henry Draper Extension Charts) catalog is presented. The catalog includes 88,548 entries, more than 3500 of which (components of binary systems) were earlier corrupted by an algorithmic error (1579 multiple systems were revealed). Spectral classification of these objects has been corrected manually using the CDS data. We also corrected some mistakes of the catalog detected by the measurement model and cross-matching with other CDS catalogs, and, in some cases, by the authors of the catalog and through collaboration of the HDEC users.

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