%0 Generic %1 howes2015extremely %A Howes, L. M. %A Casey, A. R. %A Asplund, M. %A Keller, S. C. %A Yong, D. %A Nataf, D. M. %A Poleski, R. %A Lind, K. %A Kobayashi, C. %A Owen, C. I. %A Ness, M. %A Bessell, M. S. %A Da Costa, G. S. %A Schmidt, B. P. %A Tisserand, P. %A Udalski, A. %A Szymański, M. K. %A Soszyński, I. %A Pietrzyński, G. %A Ulaczyk, K. %A Wyrzykowski, Ł. %A Pietrukowicz, P. %A Skowron, J. %A Kozłowski, S. %A Mróz, P. %D 2015 %K carbon iron metal poor stars %R 10.1038/nature15747 %T Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way %U http://arxiv.org/abs/1511.03930 %X The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that the most metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through the bulge, as expected for stars formed at redshifts greater than 15. Their chemical compositions are in general similar to typical halo stars of the same metallicity although intriguing differences exist, including lower abundances of carbon.

@misc{howes2015extremely, abstract = {The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that the most metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through the bulge, as expected for stars formed at redshifts greater than 15. Their chemical compositions are in general similar to typical halo stars of the same metallicity although intriguing differences exist, including lower abundances of carbon.}, added-at = {2015-11-13T09:38:58.000+0100}, author = {Howes, L. M. and Casey, A. R. and Asplund, M. and Keller, S. C. and Yong, D. and Nataf, D. M. and Poleski, R. and Lind, K. and Kobayashi, C. and Owen, C. I. and Ness, M. and Bessell, M. S. and Da Costa, G. S. and Schmidt, B. P. and Tisserand, P. and Udalski, A. and Szymański, M. K. and Soszyński, I. and Pietrzyński, G. and Ulaczyk, K. and Wyrzykowski, Ł. and Pietrukowicz, P. and Skowron, J. and Kozłowski, S. and Mróz, P.}, biburl = {https://www.bibsonomy.org/bibtex/24b305eccc446c6e281729f4525c3cdae/miki}, description = {[1511.03930] Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way}, doi = {10.1038/nature15747}, interhash = {7bba9ee07e64496e7bc32d4a34653f31}, intrahash = {4b305eccc446c6e281729f4525c3cdae}, keywords = {carbon iron metal poor stars}, note = {cite arxiv:1511.03930Comment: Published in Nature on 11/11/15, see http://dx.doi.org/10.1038/nature15747}, timestamp = {2015-11-13T09:38:58.000+0100}, title = {Extremely metal-poor stars from the cosmic dawn in the bulge of the Milky Way}, url = {http://arxiv.org/abs/1511.03930}, year = 2015 }