EDP Sciences
Free access
Issue
A&A
Volume 371, Number 3, June I 2001
Page(s) 1078 - 1083
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20010408


A&A 371, 1078-1083 (2001)
DOI: 10.1051/0004-6361:20010408

Elemental abundance analyses with DAO spectrograms

XXV. The superficially normal B and A stars $\alpha$ Draconis, $\tau$ Herculis, $\gamma$ Lyrae, and HR 7926
Saul J. Adelman1, 2, H. Caliskan3, D. Kocer3, H. Kablan3, K. Yüce4 and S. Engin4

1  Department of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409, USA
2  Guest Investigator, Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 W. Saanich Road, Victoria V8X 4M6 Canada
3  Department of Astronomy and Space Sciences, Istanbul University, 34452 University, Istanbul, Turkey
4  Department of Astronomy and Space Sciences, Science Faculty, Ankara University, 06100, Tandogan, Ankara, Turkey

(Received 26 January 2001 / Accepted 15 March 2001 )

Abstract
Elemental abundances analyses of the superfically normal B and A stars $\alpha$ Dra (A0 III), $\tau$ Her (B5 IV), $\gamma$ Lyr (B9 III), and HR 7926 (B8 II-III) are performed consistent with previous studies of this series using spectrograms obtained with Reticon and CCD detectors. Comparisons of the first two analyses with those of the same stars performed earlier in this series which used mostly coadded photographic plates show the general consistency of the derived elemental abundances. A slight increase in the adopted effective temperature produces a corresponding increase in the derived abundances. In these stars the He/H ratios are found to be close to solar. Except for $\gamma$ Lyr the metals show for the most part marginally subsolar abundance values. But this star has Al, Ca, Sc, and Sr abundances that are substantially underabundant as well as other underabundant values.


Key words: stars: abundances -- stars: individual: $\alpha$ Dra -- stars: individual: $\tau$ Her -- stars: individual: $\gamma$ Lyr -- stars: individual: HR 7926

Offprint request: Saul J. Adelman, adelmans@citadel.edu

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