% useful definitions to simplify the typing%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\def\bu{$\bullet$ \hskip 7pt}
\def\listitem{\par \hangindent=50pt\hangafter=1
     $\ $\hbox to 20pt{\hfil $\bullet$ \hfil}}
\def\refitem{\par\noindent\hangindent 20pt}
\def\ref2{\par\noindent\hangindent 40pt}
\def\mb{$m_{B(0)}$}
\def\MB{$M_{B(0)}$}
\def\puncspace{\ifmmode\,\else{\ifcat.\C{\if.\C\else\if,\C\else\if?\C\else%
\if:\C\else\if;\C\else\if-\C\else\if)\C\else\if/\C\else\if]\C\else\if'\C%
\else\space\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi}%
\else\if\empty\C\else\if\space\C\else\space\fi\fi\fi}\fi}
\def\SP{\let\\=\empty\futurelet\C\puncspace}
\def\dec{$\delta$\SP}
\def\ra{$\alpha$\SP}
\def\menor {$\leq$\SP}
\def\maior {$\geq$\SP}
\def\kms{km~s$^{-1}$\SP}
\def\BT{B$_{T}$\SP}
\def\degree{$^\circ$\SP}
\def\h1{h${^{-1}}$\SP}
\def\hour{$^h$\SP}
\def\arcm{'\SP}
\def\ap{$\approx$\SP}
\def\minutes{$^m$\SP}
\def\etal{{\it et al.\/}\ }
\def\ie{\it i.e.\/\rm,\ }
\def\eg{\it e.g.\/\rm,\ }
\def\apj{Ap. J.}
\def\apjlet{Ap. J. (Letters)}
\def\apjsup{Ap. J. (Suppl. Ser.)}
\def\aa{Astr. Ap.}
\def\mnras{M.N.R.A.S.}
\def\araa{Ann. Rev. Astr. Ap.}
\def\aj{A. J.}

%\hsize=16 true cm
%\vsize=24 true cm
\baselineskip=13pt
\parskip=\baselineskip
\parindent=2.5em