\begin{center}{\Large\bf 
The formation and evolution of very massive stars}\end{center} 

\centerline{\bf H. Belkus, J. Van Bever and D. Vanbeveren
}{\footnotesize Astrophysical Institute, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
}
 
Core collapse of dense massive star clusters is unavoidable and this leads to the formation of
massive  objects, with a mass up to 1000 Mo  and even larger. When these objects become stars, stellar
wind mass loss determines their evolution and final fate, and decides upon whether they form black holes
(with normal mass or with intermediate mass) or explode as a pair instability supernova. In the present
paper, we discuss the evolution of very massive stars and we present a convenient evolution recipe that
can be implemented in a gravitational N-body code to study the dynamics of dense massive clusters.

{\bf Reference: Letter to the Editor} \\{\it Status:} Manuscript has been submitted
 \\ {\it Comments:} 

{\it On the web at:} {\tt } 

{\it Preprints from:} {\tt  dvbevere@vub.ac.be} 
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