ELFT HÍRADÓ

[ilka AT konkoly.hu (Kalman Belane)]

                            Meghivo
     
      az MTA Konkoly Thege Miklos Csillagaszati Kutatointezete 
                         szeminariumara 
                       

Eloado: Prof Michael S. Bessell
        Research School of Astronomy and Astrophysics
        Mount Stromlo
        Australia

cim:"A newly discovered star with [Fe/H] of -5.2"

Abstract:
During the last 30 years researchers have tried to find stars that
still carry vestiges of the very origin of the Milky Way Galaxy, when
it formed from a gigantic collection of gas soon after the Big
Bang. The gas of our galaxy, which was presumably composed of hydrogen
and helium at the beginning, is continuously polluted by exploding
stars that enrich it with heavier chemical elements. Consequently, the
oldest stars should contain very little of such elements.
In 1978 Mike Bessell discovered CD -38 245, a giant star with 1/10,000 
the solar metallicity and in the 24 years since then extensive surveys have
failed to find any stars with lower metallicity leading many to suggest
that such stars do not exist in the Galaxy. Now, from a list of stars
provided by Norbert Christlieb of the University of Hamburg, using the
2.3m telescope at Siding Spring Observatory, Bessell has found another 
giant star with less than 1/100,000 of the solar content of heavy
elements, which is about 20 times more metal-poor than CD -38 245. It
gives astronomers a unique possibility to study stellar gas with a
composition close to the state it had directly after the Big Bang.
Christlieb, currently at Uppsala, together with Bengt Gustafsson is
leading a team of researchers from Germany, Sweden, Australia and the 
USA in analysing this intriguing star.  The discovery paper will be 
published soon in Nature followed by a more detailed paper in ApJ. Some 
of these results will be discussed in the talk.
      

Idopont: 2002. oktober 3. csutortok 14 ora 

Helyszin: MTA Konkoly Thege Miklos Csillagaszati Kutatointezete eloadoterme
          Budapest, XII. Konkoly Thege u. 13/17.
                             
                                       Patkos Laszlo s.k.