两项新的研究对某些恒星的不寻常的大小和组成提出了见解。 在这些气态发光球体形成之前，宇宙中只有氢、氦和锂元素。
最早出现的恒星通过发出最早的光线及产生最早的金属而根本性地转变了早期的宇宙。
Michele Fumagalli及其同事现在根据在夏威夷的凯克望远镜所做的观测发现了2颗没有可辨识出的金属的恒星。 这两颗恒星是在宇宙大爆炸后约2百万年时形成的。
在宇宙大爆炸时期产生了大量的恒星和星系，天文学家预计这些恒星和星系中的大多数富含金属。
然而，该研究小组的结果意味着恒星和星系间的金属的运输并没有像以前所认为的那样有效率或普遍。
过去的研究还提示，最早的恒星要比太阳大数百倍。
然而，Takashi Hosokawa及其同事在另外一则研究中所做的数值模拟揭示，早期的恒星可能要小得多。
他们的计算显示了最早的恒星要成长至太阳的几十倍之大的困难。 这两项研究的结果给早期恒星的形成所描绘的画面略有不同，这提示，恒星仍然还有值得探索的秘密。(生物谷 Bioon.com)
doi:10.1126/science.1213581
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Detection of Pristine Gas Two Billion Years After the Big Bang
Michele Fumagalli, John M. O'Meara, J. Xavier Prochaska
In the current cosmological model, only the three lightest elements were created in the first few minutes after the Big Bang; all other elements were produced later in stars. To date, however, heavy elements have been observed in all astrophysical environments. We report the detection of two gas clouds with no discernible elements heavier than hydrogen. These systems exhibit the lowest heavy-element abundance in the early universe and thus are potential fuel for the most metal poor halo stars. The detection of deuterium in one system at the level predicted by primordial nucleosynthesis provides a direct confirmation of the standard cosmological model. The composition of these clouds further implies that the transport of heavy elements from galaxies to their surroundings is highly inhomogeneous.
