
\centerline{\bf From Telescope to MPC: Organizing the Minor Planets}
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\centerline{BRIAN G. MARSDEN}
\centerline{\it Harvard-Smithsonian Center for Astrophysics}
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The IAU Minor Planet Center in Cambridge, Massachusetts, continues to
receive astrometric observations at an ever-increasing rate.  Much of
the current increase arises from the convenience of CCD imaging, even by
many advanced amateur astronomers.  The majority of the observations 
reported are of minor planets that are not yet among the 6500 or so
that have been numbered and have good orbital solutions.  Observers
are encouraged to communicate (in the same e-mail message) positions of
any given object on two neighboring nights.  It can also improve
efficiency if they don't try to identify the objects they observe.
Such identification, even of numbered minor planets, is automatically
included in the MPC processing, and an erroneous
identification can stall this operation.  The other principal source of
gross error is in the time (or date!) of observation.  Objects that
cannot be identified with numbered minor planets, other multiple-opposition
minor planets, long-arc single-opposition minor planets or same-opposition
minor planets already under observation are given MPC provisional designations,
and representative two-night V\"ais\"al\"a orbits are filed for comparison
with observations reported subsequently.  If appropriate, general
orbit solutions and orbit improvements are made, and automatic
searches are then made for less obvious identifications, which---if
successful---lead to further orbit improvements and new numberings of
minor planets.  New observations and orbits
are published monthly in the {\it Minor Planet Circulars}, which are
available in printed and electronic (with modification) form.
Unusual objects, including those observed near the earth or beyond Neptune, 
are isolated for special treatment, which includes the immediate
publication of results on the {\it Minor Planet Electronic Circulars}.
Although it has long been possible for subscribers to the MPC Computer
Service to extract published orbits from the MPC files and to compute
ephemerides, this feature has recently been extended to allow the
computation of ephemerides from orbits on file that have not yet been
published.  Some low-precision data on unusual objects are also made
available free-of-charge in the MPC's WWW homepage.  Although the monthly
activity of the MPC is now higher than ever before, improved computer
hardware and software have allowed this to be accomplished with more time
to spare than ever before, and this efficiency nurtures itself.  The MPC's
most important product is its massive collection of astrometric observations,
which now number very nearly one million.  This includes many observations
of comets, and there are ongoing efforts to re-reduce and incorporate into the
collection many of the previously-excluded micrometric observations from the
nineteenth and early-twentieth centuries.
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