URL: https://arxiv.org/abs/1812.04885

DOI: https://doi.org/10.52526/25792776-2018.2.2-223

Նկարագրություն: This talk is devoted to the statistical analysis of the new catalogue of Chemically Peculiar stars compiled from papers, where chemical abundances of those stars were given. The catalogue contains chemical abundances and physical parameters of 428 stars based on high-resolution spectroscopy data. Spearman's rank correlation test was applied for 416 CP (108 HgMn, 188 ApBp and 120 AmFm) stars and the correlation between chemical abundances and different physical parameters (effective temperature, surface gravity and rotational velocity) was checked. From dozens interesting cases we secluded four cases: the Mn peculiarities in HgMn stars, the Ca correlation with respect to effective temperature in AmFm stars, the case of helium and iron in ApBp stars. We applied also Anderson-Darling (AD) test on ApBp stars to check if multiplicity is a determinant parameter for abundance peculiarities.

URL: https://arxiv.org/abs/1807.06902

DOI: https://doi.org/10.1093/mnras/sty1912

Նկարագրություն: In this paper, we present a new catalogue of chemically peculiar (CP) stars obtained by compiling publications in which abundances of metals are provided. Our catalogue includes 428 stars for which the data were obtained through spectroscopic observations. Most of them (416) are AmFm, HgMn, and ApBp stars. We have used this compilation to proceed to a statistical overview of the abundance anomalies versus the physical parameters of the stars. Spearman's rank correlation test has been applied, and a significant number of correlations of abundance peculiarities with respect to effective temperature, surface gravity, and rotation velocity have been found. Four interesting cases are discussed in details: the Mn peculiarities in HgMn stars, the Ca correlation with respect to effective temperature in AmFm stars, the case of helium and iron in ApBp stars. Furthermore, we checked for ApBp stars using Anderson-Darling test whether the belonging to a multiple system is a determinant parameter or not for abundance peculiarities.

URL: https://arxiv.org/abs/1906.06984

DOI: https://doi.org/10.1093/mnras/stz1678

Նկարագրություն: To enlarge our data base of chemically peculiar stars, we compiled published data concerning the He-weak and He-rich stars observed by high-resolution spectroscopy techniques during last decades. Twenty He-weak and 28 He-rich stars have been added to the data base. We have also distinguished roAp stars from stars previously identified as Ap stars. To deepen our knowledge on statistical overview of the abundance anomalies versus the physical parameters of stars, we compared our data with previous compilations. We applied statistical tests on our data and found interesting correlations for effective temperature and surface gravity for all type of stars and a few correlations for projected rotation velocity only for He-rich stars. Because of the lack of the data, we could not check whether being a member of binary system is affecting on chemical peculiarities of those stars.

DOI: https://doi.org/10.52526/25792776-2021.68.2-517

Նկարագրություն: To enlarge our database of Chemically Peculiar stars, we compiled published data concerning the Lambda Boötis stars observed by high-resolution spectroscopy techniques during last decades. In total, 62 Lambda Boötis stars have been added to the database. To deepen our knowledge on statistical overview of the abundance anomalies versus the physical parameters of stars, our data were compared with previous compilations, as well as with Gaia DR2 data. Different statistical tests were applied on our data for 20 chemical elements for the search of interesting correlations for different physical parameters in the atmospheres of those stars. We confirmed all previous results and obtained correlations between different physical parameters, but because of the lack of the data, we could not find new correlations. We hope, that Gaia EDR3 data, on which we are working now, will help us to improve our database and to understand the nature of all Chemically Peculiar stars.