Elemental abundances of the supergiant stars sigma Cygnus and eta Leonis
Küçük Resim Yok
Tarih
2013
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
ELSEVIER SCIENCE BV
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
This study aims to analyse the elemental abundances for the late B type supergiant star sigma Cyg and the early A-type supergiant eta Leo using ATLAS9 (Kurucz, 1995; Sbordone et al., 2004), assuming local thermodynamic equilibrium (LTE). The spectra used in this study are obtained from Dominion Astrophysical Observatory and have high resolution and signal-to-noise ratios. The effective temperature and the surface gravity of a Cyg are determined from the ionisation equilibria of Al I/II Mg I/II, Fe I/II, Fe and by fitting to the wings of Hy and Hp profiles as T-eff = 10388 K and log g = 1.80. The elemental abundances of eta Leo are determined using T-eff = 9600 K and log g = 2.00, as reported by Przybilla et al. (2006). The ionisation equilibria of C I/II, N I/II, Mg I/II, Ca I/II, Cr I/II and Fe I/II/III are also satisfied in the atmosphere of eta Leo. The radial velocities of sigma Cyg and eta Leo are -7.25 +/- 7.57 km s(-1) and 10.40 +/- 13.37 km s(-1), respectively, The derived projected rotational velocities vsini from synthetic spectra are 27 and 2 km s(-1) for both stars, respectively. The macroturbulent velocities (zeta) are 24 2 km s(-1) and 14.5 +/- 1.5 km s(-1). Also, the microturbulent velocities (xi) have been determined for both of stars as 3.5 km s(-1). The CNO abundance results of sigma Cyg and eta Leo show C deficiency, N overabundance and O in excess. (C) 2013 Elsevier B.V. All rights reserved.
Açıklama
Anahtar Kelimeler
Supergiants-stars, Individuals: (sigma Cyg, eta Leo) stars, Abundances-technique: spectroscopic
Kaynak
NEW ASTRONOMY
WoS Q Değeri
Q3
Scopus Q Değeri
Q3
Cilt
25
