All stars are different; each possesses its own unique \u00a0character\u00a0 and \u00a0personality\u00a0. However, the underlying mechanism that brings forth the birth of most of the stars we observe remains constant, allowing us to consider that \u00a0all are related\u00a0. Stars are born from clouds of dust and gas scattered throughout the \u00a0universe\u00a0, a process that initiated shortly after the \u00a0Big Bang\u00a0, which occurred approximately \u00a014 billion years ago\u00a0 according to scientific estimates.<\/p>\n
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Recent analyses conducted by various research groups suggest that the first stars emerged shortly after the formation of the universe. In fact, it is believed that the oldest known star, a complex cluster of letters and numbers, was born about \u00a013.6 billion years ago\u00a0, making it nearly as old as the universe itself. A team of astronomers from the \u00a0National University of Australia\u00a0\u2014the scientists responsible for this discovery\u2014asserts that this star is \u00a0sixty times larger than our Sun\u00a0 and is situated in our own galaxy, the \u00a0Milky Way\u00a0, 6,000 light-years away from Earth.<\/p>\n
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Interestingly, despite its advanced age, astronomers believe that there are even older stars still yet to be discovered. This assumption stems from the fact that our 13.6 billion-year-old giant is composed not just of hydrogen, but also of \u00a0carbon\u00a0, \u00a0magnesium\u00a0, and \u00a0calcium\u00a0. These chemical elements must have been originally formed in one or more even older stars, which possessed a markedly low presence of \u00a0metals\u00a0; here understood as all elements heavier than helium, regardless of their position on the periodic table.<\/p>\n
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However, the knowledge astrophysicists possess about these primordial stars is limited. This situation appears poised to change, as a research team at the \u00a0Max Planck Institute of Nuclear Physics\u00a0 in Heidelberg, Germany, recently identified unexpected behaviors of \u00a0helium hydride (HeH\u207a)\u00a0, which is recognized as the \u00a0oldest molecule known in the cosmos\u00a0. Composed of a helium atom (He) and a proton (H\u207a), astrophysicists believe this molecule formed shortly after the \u00a0Big Bang\u00a0, when temperatures dropped sufficiently for helium and hydrogen atoms to unite.<\/p>\n
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Astrophysicists at the Max Planck Institute of Nuclear Physics have managed to reproduce the conditions of the original universe using a cryogenic storage ring.<\/p>\n<\/p><\/div>\n<\/div>\n
One key reason helium hydride bears such significance is its formation signifies the triggering of \u00a0chemical bonds\u00a0 within the universe, laying the foundation for the creation of \u00a0molecular hydrogen (H\u2082)\u00a0, the essential fuel that powers stars. The strategy employed by scientists at the Max Planck Institute to recreate the dynamics of this molecule shortly after the Big Bang is remarkable. They successfully reproduced conditions reminiscent of the original universe through the use of a \u00a0cryogenic storage ring\u00a0.<\/p>\n
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This innovative experimental setup allows for the \u00a0storage of ion beams\u00a0 over extended periods at extremely low temperatures and under ultra-high vacuum conditions. In turn, this framework enables scientists to investigate the properties of molecules as unstable as helium hydride \u00a0without them disintegrating\u00a0 rapidly upon collision. As explained in an intriguing article published by these astrophysicists in \u00a0Astronomy & Astrophysics\u00a0, their experiments revealed that instead of decelerating as the temperature declined, the reaction between helium hydride and deuterium remained constant.<\/p>\n
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This finding is pivotal; in the primal universe, helium hydride played a crucial role in the gas cooling process. This cooling was essential for the dust and gas clouds to collapse under the force of \u00a0gravity\u00a0, leading to the formation of stars. Thus, the revelations presented by these scientists suggest that helium hydride had a far more active role in the primary chemistry of the universe than previously thought. Building on this new understanding, astrophysicists can now refine the theoretical models that delineate the processes involved in the formation of the oldest stars.<\/p>\n
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Image | POT<\/a><\/p>\n