scholarly journals Preliminary Investigation of Quantitative Spectral Classification by Means of Objective-Prism Spectra Obtained with the Broerfelde Schmidt Telescope

1973 ◽  
Vol 50 ◽  
pp. 134-137
Author(s):  
J. V. Clausen
Keyword(s):  
Preliminary Investigation ◽  
Spectral Classification ◽  
Schmidt Telescope ◽  
Mean Error ◽  
Objective Prism ◽  
Hydrogen Lines

Different methods, used for measuring the strength of hydrogen lines in objective-prism spectra, are discussed and the parameters are compared with the photoelectric β-index. It is found that for A5V–G1V stars β can be given with a mean error of ±0.m020 (one spectrum).

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 An Extended Scheme of Spectral Classification for Objective Prism Spectra

1994 ◽  
Vol 161 ◽  
pp. 255-257
Author(s):  
P.A. Hantzios ◽  
E. Kontizas ◽  
F. Pasian ◽  
A. Dapergolas ◽  
M. Kontizas ◽  
...  
Keyword(s):  
Spectral Type ◽  
Classification Scheme ◽  
Graphical Form ◽  
Spectral Classification ◽  
Schmidt Telescope ◽  
Luminosity Class ◽  
Objective Prism

A spectral classification scheme has been developed for objective prism spectra of LMC stars, taken with the 1.2 m UK Schmidt Telescope in Australia. Various line ratios, discontinuities, and continuum intensities have been used as criteria. The scheme is a 2-D system (spectral type — luminosity class), and the criteria are given in graphical form. The typical accuracy of our scheme is 2 subdivisions of spectral type. Comparison of our types with those given by other authors for common stars yields a very good correlation with deviations within our accuracy.

scholarly journals A Search for Galactic Carbon Stars

1988 ◽  
Vol 108 ◽  
pp. 48-49
Author(s):  
Hideo Mabhara
Keyword(s):  
Galactic Plane ◽  
Carbon Star ◽  
Spectral Features ◽  
Spectral Classification ◽  
Carbon Stars ◽  
Schmidt Telescope ◽  
Infrared Wavelength ◽  
V Band ◽  
The Galaxy ◽  
Objective Prism

The carbon star is one of the best probes for the galactic study; (1)it is intrinsically bright (Mbol = − 2 to − 6) especially in the red and infrared wavelength regions,(2)it has spectral features readily detectable on objective prism plates due to their strong carbon molecular bands,(3)it is an evolved star distributed abundantly (∼1 star per square degree) along the galactic plane.We can detect it in the Galaxy up to several kpc from the sun on objective prism plates of the Schmidt telescope.We have been making survey observations of faint cool carbon stars using the Kiso 105-cm Schmidt telescope. Kodak IN and 103aF plates are respectively taken behind the 4-degree objective prism (700 Åmm−1 at Hα) for the detection and for the spectral classification. V-band plates are utilized to obtain the position and the brightness of the stars detected.The survey areas are distributed along the northern galactic plane. Seven fields in the Cassiopeia region (l = 115° to 133° and eight fields in the Taurus-Auriga-Gemini region (i = 170° to 188°) have been observed and processed up to now (Maehara and Soyano 1987a,b).

scholarly journals Spectral Classification from Low Dispersion Objective Prism spectra taken with the UK 1.2m Schmidt Telescope

1979 ◽  
Vol 47 ◽  
pp. 259-270
Author(s):  
K. Nandy
Keyword(s):  
Red Shift ◽  
Spectral Classification ◽  
Schmidt Telescope ◽  
Objective Prism ◽  
Measuring Machine ◽  
The Uk ◽  
Low Dispersion

AbstractA thin prism (with a dispersion of 2480 Å/mm at Hγ and Hβ) is now available for the UK 1.2m Schmidt telescope. Å 60-min. unwidened exposure on a Ilia-J (hypersensitized) emulsion reaches fainter than 20 mag. The spectra are measured and digitised with the fast measuring machine COSMOS. A method to determine the red shift of faint galaxies and the spectral classes of faint stars and galaxies from the digitised spectra will be described.

scholarly journals A New Objective Prism Catalogue of OB and Supergiant B, A, F and G Stars in the Magellanic Clouds

1979 ◽  
Vol 47 ◽  
pp. 155-157
Author(s):  
A. G. Davis Philip ◽  
N. Sanduleak
Keyword(s):  
Magellanic Clouds ◽  
Schmidt Telescope ◽  
Ob Stars ◽  
Objective Prism ◽  
Hydrogen Lines

The Michigan Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory has been used with the “thin” prism (Blanco 1974) to survey the Large and Small Magellanic Clouds. Four plates, covering approximately 90 square degrees, and three plates, covering approximately 70 square degrees, were taken of the Large and Small Magellanic Clouds respectively. One hour exposures on nitrogen baked, IIIa-J plates were obtained. The limiting magnitude of the plates is V = 16 mag. At the dispersion of 1360 Å/mm OB stars can be recognized by their long uv extension, in which no sign of a Balmer discontinuity can be seen. The supergiants can be recognized by the appearance of a Balmer discontinuity and classified into temperature types by the strength of the hydrogen lines.

scholarly journals Swedish Programmes Concerning the Z Distribution of Stars

1977 ◽  
Vol 4 (2) ◽  
pp. 69-69
Author(s):  
Tarmo Oja
Keyword(s):  
Classification System ◽  
Narrow Band ◽  
Space Distribution ◽  
Spectral Classification ◽  
Hydrogen Line ◽  
Line Intensities ◽  
Mean Error ◽  
Objective Prism ◽  
The Subject ◽  
Absolute Magnitudes

Swedish investigations on stellar space distribution generally are based on the Uppsala - Stockholm spectral classification system. In this system the properties of the stars are derived from objective prism spectra by means of narrow-band photometry. The main criteria are the hydrogen-line intensities, the intensity of the K line, the intensity of the G band, the break at the G band, and the intensity of the blue cyanogen band (for a description of the system see e.g. Ljunggren and Oja, 1961), when possible supplemented by a measure of the Balmer discontinuity (Rydström, 1976). The method yields absolute magnitudes with a dispersion of about and intrinsic colours (B-V)° with a mean error below for most kinds of stars.Three investigations are relevant to the subject of this Joint Discussion.

An Extended Scheme of Spectral Classification for Objective Prism Spectra

1994 ◽  
pp. 255-257 ◽  
Author(s):  
P. Hantzios ◽  
E. Kontizas ◽  
F. Pasian ◽  
A. Dapergolas ◽  
M. Kontizas ◽  
...  
Keyword(s):  
Spectral Classification ◽  
Objective Prism

scholarly journals Automated Quasar Detection

1983 ◽  
Vol 104 ◽  
pp. 31-31
Author(s):  
Roger G. Clowes ◽  
John A. Cooke ◽  
Steven M. Beard
Keyword(s):  
Selection Effects ◽  
Schmidt Telescope ◽  
Royal Observatory ◽  
Objective Prism ◽  
Measuring Machine ◽  
The Uk

The existing spectral searches for quasars have increased the number of quasars known very substantially but have not contributed proportionately to an understanding of the collective properties because of the selection effects. To fully exploit the spectral searches we have developed the technique of automated quasar detection (AQD) using objective-prism plates from the UK Schmidt Telescope, the COSMOS measuring machine at the Royal Observatory Edinburgh, and the STARLINK nodes at Durham and Edinburgh.

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