The Preliminary Results for Atmospheric Parameters of the Candidate Ap Stars HD 90763 and HD 92728

Abstract

Chemical peculiar Ap stars show overabundances of some metals, such as strontium, chromium, europium, praseodymium, and neodymium. The rotations of these stars are much slower than those of normal A-type stars. Another characteristic of Ap stars is that they have stronger magnetic fields compared to classical A-type stars. We have selected the A-type stars HD 90763 and HD 92728 to derive their atmospheric parameters. Both stars' high-resolution spectra were obtained using the Coude Echelle Spectrograph mounted on the 1.5 m Russian-Turkish Telescope at the TÜBİTAK National Observatory, on the 23^rd of February, 2017. The wavelength range of the spectra is from 3900 to 7900 Å. We followed the standard reduction procedures for both stars and normalised the order covering the hydrogen beta profile. We used ATLAS9 model atmospheres. The strontium 4215.519 Å line seen in the spectra of HD 90763 and the neodymium 5102.428 Å line of HD 92728 were compared to the same lines of the normal A-type star HD 187983. Sr line in HD 90763 and Nd line in HD 92728 are much stronger than those of the normal A-type star. Thus, we suggest that HD 90763 and HD 92728 may be chemically peculiar Ap star candidates.

Keywords

• Ap stars,HD 90763,HD 92728

References

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