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Abstract. Traditional and statistical line-identification methods indicate the presence of Pm I and II, Tc I, and perhaps Tc II in the spectrum of the roAp star HD 101065. These methods also lead to the presence of Pm II and probably also Pm I in a related cool Ap star, HD 965. The spectroscopic evidence is strong enough that we would declare promethium to be present without hesitation, if any of its isotopes were stable. The longest-lived promethium isotope has a half-life of only 17.7 years. The presence of this element would mean that unrecognized processes -perhaps flare activities -are taking place in the atmospheres of these stars. The significance of such processes for galactic chemical evolution cannot be ruled out. We discuss the possibility that the highly improbable wavelength coincidences are due to chance, or due to contamination of the laboratory sources.

HD 65949 is a late B star with exceptionally strong Hg ii λ3984, but it is not a typical HgMn star. The Re ii spectrum is of extraordinary strength. Abundances or upper limits are derived here for 58 elements based on a model with Teff= 13 100 K and log  (g) = 4.0. Even‐Z elements through nickel show minor deviations from solar abundances. Anomalies among the odd‐Z elements through copper are mostly small. Beyond the iron peak, a huge scatter is found. Enormous enhancements are found for the elements rhenium through mercury (Z= 75–80). We note the presence of Th iii in the spectrum. The abundance pattern of the heaviest elements resembles the N= 126 r‐process peak of solar material, though not in detail. An odd‐Z anomaly appears at the triplet (Zr Nb Mo), and there is a large abundance jump between Xe (Z= 54) and Ba (Z= 56). These are signatures of chemical fractionation. We find a significant correlation of the abundance excesses with second ionization potentials for elements with Z > 30. If this is not a red herring (false lead), it indicates the relevance of photospheric or near‐photospheric processes. Large excesses (4–6 dex) require diffusion from deeper layers with the elements passing through a number of ionization stages. That would make the correlation with second ionization potential puzzling. We explore a model with mass accretion of exotic material followed by the more commonly accepted differentiation by diffusion. That model leads to a number of predictions which challenge future work. New observations confirm the orbital elements of Gieseking and Karimie, apart from the systemic velocity, which has increased. Likely primary and secondary masses are near 3.3 and 1.6 M⊙, with a separation of ca. 0.25 au. New atomic structure calculations are presented in two appendices. These include partition functions for the first through third spectra of Ru, Re and Os, as well as oscillator strengths in the Re ii spectrum.

The completion of the observation and reclassification of the A stars in the Bright Star Catalogue (see Cowley 1968) has lead to the recognition of additional new peculiar and metallic-line A stars. These stars are listed in Table I with their new classifications.

Gas accreting onto a galaxy will be of low metallicity while halo gas due to a galactic fountain will be of near-solar metallicity. We test these predictions by measuring the metal absorption line properties of halo gas 5 kpc above the plane of the edge-on galaxy NGC 891, using observations taken with HST/STIS toward a bright background quasar. Metal absorption lines of Fe II, Mg II and Mg I in the halo of NGC 891 are clearly seen, and when combined with recent deep H I observations, we are able to place constraints on the metallicity of the halo gas for the first time. The H I line width defines the line broadening, from which we model opacity effects in these metal lines, assuming the absorbing gas is continuously distributed in the halo. The gas-phase metallicities are [Fe/H] = −1.18 ± 0.07 and [Mg/H] = −0.23 + 0.36/ − 0.27 (statistical errors) and thisdifference is probably due to differential depletion onto grains. When corrected for such depletion using Galactic gas as a guide, both elements have approximately solar or even supersolar abundances. This suggests that the gas is from the galaxy disk, probably expelled into the halo by a galactic fountain, rather than from accretion of intergalactic gas, which would have a low metallicity. The abundances would be raised by significant amounts if the absorbing gas lies in a few clouds with thermal widths smaller than the rotational velocity of the halo.If this is the case, both the abundances and [Mg/Fe] would be supersolar.