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We present the abundance analyses of three isolated A-type supergiant starsin the dwarf irregular galaxy Sextans A from high-resolution spectra the UVESspectrograph at the VLT. Detailed model atmosphere analyses have been used todetermine the stellar atmospheric parameters and the elemental abundances ofthe stars. The mean iron group abundance was determined from these three starsto be [(FeII,CrII)/H]=-0.99+/-0.04+/-0.06. This is the first determination ofthe present-day iron group abundances in Sextans A. These three stars nowrepresent the most metal-poor massive stars for which detailed abundanceanalyses have been carried out. The mean stellar alpha element abundance wasdetermined from the alpha element magnesium as[alpha(MgI)/H]=-1.09+/-0.02+/-0.19. This is in excellent agreement with thenebular alpha element abundances as determined from oxygen in the H II regions.These results are consistent from star-to-star with no significant spatialvariations over a length of 0.8 kpc in Sextans A. This supports the nebularabundance studies of dwarf irregular galaxies, where homogeneous oxygenabundances are found throughout, and argues against in situ enrichment. Thealpha/Fe abundance ratio is [alpha(MgI)/FeII,CrII]=-0.11+/-0.02+/-0.10, whichis consistent with the solar ratio. This is consistent with the results fromA-supergiant analyses in other Local Group dwarf irregular galaxies but instark contrast with the high [alpha/Fe] results from metal-poor stars in theGalaxy, and is most clearly seen from these three stars in Sextans A because oftheir lower metallicities. The low [alpha/Fe] ratios are consistent with theslow chemical evolution expected for dwarf galaxies from analyses of theirstellar populations.Comment: 40 pages, 8 figures, accepted for publication in A

First Stellar Abundances in the Dwarf Irregular Galaxy Sextans A