Their Formation Remains Mysterious
Pete Spotts of the Christian Science Monitor has summarized an article for upcoming publication in the journal Astronomy and Astrophysics on the oldest planets that have been found. The star, a red giant near the end of its life cycle, is 12.8 billion years and 376 light years from earth. There are two planets, one 2.9 times the sized of Jupiter and another with .78 of Jupiter’s mass.
How did such planets form?
Astronomers have long held that stars likely to host planets have hydrogen but also some heavier elements such as carbon, nitrogen, oxygen, calcium and silicon. The sun is an example of this kind of star. These heavier elements may form the core of a planet. But these elements weren’t around in the aftermath of the big bang. The red giant 376 light years away from earth is "metal poor" with respect to the elements usually found in starts that host planets.
Johny Setiawan, lead scientist of the research team, hopes to discover more planets orbiting metal-poor stars to help researchers with this question of the likely mechanism that built such early planets.
Summarized from:
http://www.csmonitor.com/Science/2012/0330/Planets-found-at-dawn-of-universe-but-their-existence-is-a-mystery
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