\documentstyle{preprint}

\input pub.sty
\begin{document}

\title{WOBBLING ACCRETION DISKS, JETS, AND\\
~\\
POINT-SYMMETRIC NEBULAE}
\author{Mario~Livio and J.~E.~Pringle\/\thanks{Permanent address: Institute of Astronomy, 
Madingley Road, Cambridge CB3 0HA, United Kingdom}\\
\\
Space Telescope Science Institute\\
\\
3700 San Martin Drive\\
\\
Baltimore, MD  21218}

\pub{The Astrophysical Journal}

\maketitle
\end{document}

\abstract{
We present numerical calculations of the evolution of an accretion disk which
is irradiated by a central source.  The parameters chosen represent those of
the central star of a planetary nebula.  We show that an irradiation induced
warping can occur in the disk, and that it is accompanied by a wobbling motion
in both the inclination and azimuthal directions.  Since jets are assumed to
be perpendicular to the inner disk, this motion is capable of producing the
`point-symmetric' morphology observed in some nebulae.}