For the Press:

Release Date January 10 at 9:20 AM:

The Abundances and Age of the Galactic Halo Star BD +17 3248, Poster #137.06. J. Cowan (Univ. of Oklahoma), C. Sneden, I. Ivans (Univ. of Texas), S. Burles (MIT), T. Beers (MSU), J. Truran (Univ. of Chicago), J. Lawler (Univ. of Wisconsin), F. Primas (ESO), G. Fuller (UCSD), K.-L. Kratz, B. Pfeiffer (Univ. of Mainz)

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BD +17 3248 :

We show in the following images our recent observations and analyses of the elements in the star BD +17 3248. This star

STAR IMAGE IN JPEG FORMAT

is located in the Galactic halo approximately 2500 light years from earth and was formed very early in the history of our Galaxy. The observations were made using the Hubble Space Telescope (HST) and both the Keck and H. J. Smith ground-based telescopes. The 10 meter Keck telescope is one of the largest telescopes in the world.

1. In the first image (in .pdf format) we show our detection of gold in this star, the first detection in any such halo stars. This can be thought of as the ``first gold in the Galaxy.'' Since the dominant wavelengths for the atomic transitions for this element are in the ultraviolet, mostly blocked by our atmosphere, space observations using the Hubble Space Telescope were necessary for this discovery.

HST SPECTRUM SHOWING GOLD IN BD +17 3248

2. In the second image we show silver lines in this same star. This element can be observed at the ground-level. The observations were made using the Keck telescope.

SILVER LINES IN BD + 17 3248 TAKEN WITH THE KECK TELESCOPE --caption for the silver lines (pdf format)

3.  Platinum lines detected using HST.    

HST OBSERVATIONS OF PLATINUM LINES IN BD + 17 3248 --caption for the platinum lines (pdf format)

4. Abundance observations of all of the elements in this star including Gold (Au), Platinum (Pt), Silver (Ag), and the radioactive elements Thorium (Th) and Uranium (U). Employing the abundance of the radioactive elements, observed in BD + 17 3248, in comparison with each other and other stable elements, we have determined the ``radioactive-decay age'' of this star.    
   

ALL ELEMENTS OBSERVED IN BD +17 3248 --caption for the abundance plot (pdf format)

Our analyses and calculations indicate an approximate age for this star of 14 +/- 4 Billion years old, making this one of the oldest stars in our Galaxy.

This research was supported by the NSF, NASA-STScI grant no. GO-08432, the DOE and the German BMBF.

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Last Updated 1/4/02

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