Very high abundances of the heavy element lead have been discovered in three distant stars in the Milky Way galaxy. All the lead contained in each of the three stars weighs about as much as our Moon. This finding strongly supports the long-held view that roughly half of the stable elements heavier than iron are produced in common stars during a phase toward the end of their life when they burn their helium -- the other half results from supernova explosions.
The observations show that these "lead stars" -- all members of binary stellar systems -- have been more enriched with lead than with any other chemical element heavier than iron. This new result is in excellent agreement with predictions by current stellar models about the buildup of heavy elements in stellar interiors.
The new observations are reported by a team of Belgian and French astronomers who used the Coude Echelle Spectrometer on the ESO 3.6-m telescope at the La Silla Observatory (Chile).
(Reference: "Discovery of three Lead stars" by S. Van Eck, S. Goriely, A. Jorissen and B. Plez Nature August 23, 2001)
Related images:
The Lead Star HD196944
Lead Line in the Spectrum of HD196944
[Contact: Sophie Van Eck, Bertrand Plez]
23-Aug-2001
