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Spectra of unevolved metal-poor halo stars uniquely reflect the elementalabundances incorporated during the earliest Galactic epoch. Their heavy-elementcontent is well understood as the products of neutron capture on iron-peakelements. However, the lightest elements just past the iron peak, with atomicnumber 30<Z<52, show striking abundance patterns open to severalinterpretations. Understanding their nature may illuminate the diverse halo,thick disk, or extragalactic origins of metal-poor stars. For five metal-poordwarfs, we analyzed high-resolution echelle UV spectra from the Hubble SpaceTelescope Imaging Spectrograph, as well as archival optical echelle spectra.The goal was to derive reliable halo dwarf abundances and uncertainties for sixtrans-iron elements from UV spectra, and optical abundances for four additionaltrans-Fe elements and two well-understood heavier elements. Our two independentanalyses showed that the largest source of discrepancy is UV continuumplacement. Once rectified, the internal results agree to 0.2 dex formoderately-unblended, moderately strong lines. Our results similarly agree withprevious work, except where new data and unidentified Fe I lines are important.We show that these heavily congregate blueward of 2000A and redward of 2600A.Our exclusion of trans-Fe lines blended by such lines proved critical forarsenic. A metallicity-dependent odd-even effect is uncovered among trans-Feelements: an odd-Z element abundance is depressed relative to those of adjacenteven-Z elements, especially at low metallicity. This is supported by previousstudies of Sr-Y-Zr, and also appears in some theoretical calculations. To date,no calculations predict the high Mo/Ge ratio, independent of Mo/Fe, that wefind in all five stars.

Trans-iron Ge, As, Se, and heavier elements in the dwarf metal-poor stars, HD~19445, HD~84937, HD~94028, HD~140283, and HD~160617