Download Solar Lithium Mystery Solved

Solar Lithium Mystery Solved
Our sun contains far less lithium than
similar stars––because it has planets
Elizabeth K. Wilson
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 November 16, 2009, Volume 87, Number 45, p.
39
ISSN 0009-2347
Copyright © 2009 American Chemical Society