An ancient planetary system from 13 billion years ago has been discovered in the constellation Cetus, 375 lightyears from Earth, that could determine when stars first started to form.
The star HIP 11952 is orbited by two planets, HIP 11952b and HIP 11952c. The planets bring to 750 the total number of planets observed orbiting suns other than our own.
Johny Setiawan of the Max Planck Institute for Astronomy, who led the study of HIP 11952 said in a statement: "This is an archaeological find in our own backyard. These planets probably formed when our Galaxy itself was still a baby."
Planets like Earth usually form within clouds that include heavier chemical elements swirling around young stars.
But HIP 11952 contains very little other than hydrogen and helium, in stark contrast to the planets in our solar system. It's a metal-poor star.
Veronica Roccatagliata from the University Observatory Munich, and the principal investigator of the planet survey around metal-poor stars that led to the discovery, said: "In 2010 we found the first example of such a metal-poor system, HIP 13044. Back then, we thought it might be a unique case; now, it seems as if there might be more planets around metal-poor stars than expected."
The HIP 11952 discovery suggests that originally the universe contained almost no chemical elements other than hydrogen and helium.
Almost all heavier elements have been produced, over time inside stars, and then flung into space as massive stars end their lives in giant supernova explosions.
Anna Pasquali from the Center for Astronomy at Heidelberg University (ZAH), a co-author of the paper, said: "We would like to discover and study more planetary systems of this kind. That would allow us to refine our theories of planet formation. The discovery of the planets of HIP 11952 shows that planets have been forming throughout the life of our Universe."
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