DG.1.02 — The first stars - Recent results and prospectives

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Aug 7th at 10:40 AM until 11:10 AM

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Author(s): Anna Frebel1

Institution(s): 1. Massachusetts Institute of Technology

The new Australian SkyMapper 1.3m telescope is carrying out a photometric survey of the entire Southern Sky. From using ugriz filter plus an additional narrow filter placed at the Ca K line at 3933A, metallicites can be obtained for all stars observed. This allows for an efficient selection of a variety of stellar types, in particular metal-poor stars. Recent results include a new record holder for the most iron-poor star (no iron lines were detected in the high-resolution follow-up Magellan spectrum) for which only an upper limit of [Fe/H]<-7.1 could be determined. Contrary to its iron deficiency, the star contains significant amounts of carbon and oxygen, but not nitrogen. This abundance pattern can be explained with the star being a second generation star in the universe which formed from a gas cloud enriched by only one PopIII first star. Along with this star, a large sample of ~120 metal-poor stars were also found. It showcases the potential of SkyMapper for finding more of the most metal-poor stars.