Issue Date: November 16, 2009
Solar Lithium Mystery Solved
Our sun contains far less lithium than other similar stars—a conundrum that’s dogged astronomers for decades—because it has planets. Not only does that finding solve a mystery, it gives astronomers a potential routine scanning method to apply in the search for extrasolar planets. Using the European Southwest Observatory’s High Accuracy Radial Velocity Planet Searcher, or HARPS, astronomer Garik Israelian of the Institute of Astrophysics of the Canary Islands, in Tenerife, Spain, and colleagues conducted a survey of 500 stars, nearly 25% of which are like our own sun (Nature 2009, 462, 189). Seventy of the sunlike stars are known to have planetary systems. Most of the stars that host planets have on average one-tenth the amount of lithium of sunlike stars without planets. The researchers suppose that lithium is somehow distributed differently on the surface of the stars or consumed to make other elements. Scientists already know that sunlike stars rich in metals are likely to be part of a planetary system. “Those solar analogs with low lithium content, which is extremely easy to detect with simple spectroscopy, have an even higher probability of hosting exoplanets,” the researchers write.
- Chemical & Engineering News
- ISSN 0009-2347
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