No abstract

Abstract. Elemental abundances analyses of the superfically normal B and A stars α Dra (A0 III), τ Her (B5 IV), γ 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 γ 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.

Two fine analyses of the AO III star a Dra were performed using the same sources of atomic data, the same spectrophotometric data, and the same model-atmospheres code, but with photographic region spectrograms obtained at two different observatories, Kitt Peak National Observatory and Dominion Astrophysical Observatory. The resultant values show differences typically of the order of a factor of two with the higher signal-to-noise data yielding smaller abundances. On the whole, a Dra is a star with abundances typically one-third solar. However, it is definitely scandium and nickel poor. Its abundance pattern shows a strong resemblance to those of Vega and other metal-poor A stars.

Elemental abundances of 28 And (A7 III) and 99 Her (F7 V), which have modest rotational velocities, are derived in a manner consistent with previous studies in this series of papers. The values for 28 And, a δ Scuti variable, show that it is slightly metal‐poor, but not a classical Am star. 99 Her, which is somewhat more metal‐poor, has a rather small microturbulence for its spectral type.