کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1778737 | 1523736 | 2016 | 4 صفحه PDF | دانلود رایگان |
• Detailed spectral analysis is performed on two chemically normal A-type stars.
• The spectra were obtained at Tubitak National Observatory.
• The atmospheric parameters are determined using spectroscopic methods based on LTE model atmospheres.
• The evolutionary status of the stars are estimated.
• The abundances of both stars were compared with members in open clusters.
The atmospheric parameters and chemical abundances of two neglected A-type stars, 28 Peg and HD 202240, were derived using high resolution spectra obtained at the TÜBİTAK National Observatory. We determined the photospheric abundances of 11 elements for 28 Peg and 20 for HD 202240, using equivalent-width measurement and spectral synthesis methods. Their abundance patterns are in good agreement with those of chemically normal A-type stars having similar atmospheric parameters. We pinpoint the position of these stars on the H-R diagram and estimate their masses and ages as; 2.60 ± 0.10 M⊙ and 650 ± 50 Myr for 28 Peg and 4.50 ± 0.09 M⊙ and 150 ± 10 Myr for HD 202240. To compare our abundance determinations with those of stars having similar ages and atmospheric parameters, we select members of open clusters. We notice that our target stars exhibit similar abundance patterns with these members.
Journal: New Astronomy - Volume 42, January 2016, Pages 38–41