ПИСЬМА В АСТРОНОМИЧЕСКИЙ ЖУРНАЛ, 2019, том 45, № 8, с. 585

HIGH RESOLUTION OPTICAL SPECTROSCOPY OF A B-TYPE

ABUNDANCE STANDARD CANDIDATE IN Ori OB1 — HD 35039¹

S ahin¹, Ahmet Dervi ¸so ˘glu^2,3

¹Space Sciences and Technologies Dept., Faculty of Science, Akdeniz University, 07058, Antalya, Turkey

²Department of Astronomy and Space Sciences, Erciyes University, Kayseri, Turkey

³Department of Physics, Faculty of Science, University of Zagreb, Bijenika cesta 32, 10000 Zagreb, Croatia

Received 29.11.2018 г.; in final form, 28.05.2019 г.; accepted 28.05.2019 г.

We present LTE analysis of high resolution optical spectra for the B-type abundance standard candidate

HD 35039 (HR 1765, 22 Ori) with an ambigous binary nature. The spectra were obtained with the

3.9-m Anglo-Australian Telescope (AAT) and the UCLES spectrograph. The standard 1D LTE analysis

with line-blanketed LTE model atmospheres and spectral synthesis provided fundamental atmospheric

parameters of T_eff = 22.000 ± 1300 K, log g = 3.5 ± 0.3, ξ = 6.0 ± 3.0 km s-1, v sin i = 5.0 ± 1.0 km s-1,

[Fe/H] = -0.3 dex, and the photospheric abundances of eleven elements. The FEROS spectrum of the

star from the public spectra archive were also obtained and used to test the model parameters of the star:

Hydrogen Paschen lines (P₁₂, P₁₃, and P₁₄ ) provided a good fit for the reported model parameters. We

have also acquired high resolution HIDES and HERMES spectra of the star. The error margins in the

reported model parameters as well as their degeneracies were tested by the Bayesian inference method. We

detect for the first time the P III 4059, 4222, and 4246

A lines and determine the phosphorus abundance,

log ϵ(P ) = 4.95 ± 0.3 dex (i.e. [P/H] = -0.15 dex), from line synthesis. The obtained argon abundance,

log ϵ(Ar) = 6.55 ± 0.19 dex, agrees well with the literature measurements. For the remaining elements,

abundances determined in this study for HD 35039 are lower than the average abundances of B dwarfs

of well studied OB associations as well as the mean abundances of a sample of early B-type stars in the

solar neighbourhood, by up to 0.3 dex. In the FEROS, HIDES, and HERMES spectra, we observe the

emission in the high-excitation lines of Si II and Al II. We find a variable radial velocity, with a peak-to-peak

amplitude of about 10 km s-1.

DOI: 10.1134/S0320010819080102

¹ Полный текст статьи публикуется только в ангдийской версии журнала (Astronomy Letters 45, 2019).

*E-mail: timursahin@akdeniz.edu.tr

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