\documentstyle{preprint}
\begin{document}
\title{HST STUDY OF THE STELLAR POPULATION WITHIN\\
~\\
30 PC OF SN 1987A\/\thanks{Based on observations with the NASA/ESA Hubble Space 
Telescope, obtained at the Space Telescope Science Institute, which is operated 
by AURA, Inc., under NASA contract NAS 5-26555.}}

\author{Nino Panagia,\thanks{Affiliated to the Astrophysics Division, Space 
Science Department of ESA.} Martino Romaniello\/\thanks{Scuola Normal 
Superiore, Pisa, Italy.}\\
\\
Space Telescope Science Institute\\
\\
3700 San Martin Drive\\
\\
Baltimore, MD  21218\\
\\
panagia@stsci.edu, martino@stsci.edu\\
\and
Salvatore Scuderi\\
\\
Catania Astrophysical Observatory\\
\\
Viale A.\ Doria 6\\
\\
I-95125, Catania, Italy\\
\\
scuderi@ct.astro.it}

\pub{{\em the proceedings of the CTIO/ESO/LCO Workshop}\\
~\\
SN 1987A: Ten Years After\\
~\\
{\em held 23--28 February 1997 in La Serena, Chile}}

\maketitle

\begin{abstract}
We present the preliminary results of a study of the stellar population around 
SN~1987A based on an analysis of multi-based {\it HST-WFPC2\/} images.  The 
effective temperature, radius and reddening of each star were determined by 
fitting the measured broad band magnitudes to the ones calculated with model 
atmospheres.  In addition, all stars with H$\alpha$ equivalent widths in 
excess of 8~\AA\ were identified.  An inspection to the HR diagram reveals the 
presence of several generations of stars, with ages between 1 and 150 {\it 
Myrs}, superposed on a much older field population.  The youngest stars in the 
field appear to be {\it T~Tau\/} stars, characterized by strong H$\alpha$ 
excesses.  We conclude that SN~1987A is associated to a region in which star 
formation has been active over a long stretch of time and is still very active 
at present.
\end{abstract}
\end{document}