A SYSTEMATIC SURVEY OF CHEMICAL ABUNDANCES AMONG A-TYPE STARS BASED ON HIGH DISPERSION SPECTROSCOPIC DATA

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This research project is based on a large body of high dispersion digital spectroscopic data of early type stars obtained at the Dominion Astrophysical Observatory in 1990. The initial motivation has been to carry out a systematic analyzes of many stars using a homogeneous technique. The first stage of the project was devoted to develop a system of data analysis using a Work Station and the IRAF software. After the completion of the data analysis system, several interesting objects have been discovered among the sample stars and detailed studies of these objects were carried out.The first object was a peculiar star HR 1094 exhibiting amomalously strong lines of chroline (Cl) and cobalt (Co). It also shows lines of mercury (Hg) and platinum (Pt) and does not belong to any previously known group of CP stars. The second object was a strong magnetic star HR 7575. As an initial step of analyzing the complex spectrum of this star, an identification list of observed lines has been prepared.The spectrum of a 'normal' A3V star 95 Leo has been analyzed in detail and the star turned out to be a metal deficient star. 95 Leo is the coolest star among previously detected metal deficient stars. The result of chemical abundances of this star will give a constraint on the theoretical interpretation of metal deficient stars.Analysis of other stars are now in progress and the final results will be published in the near future.