From: Jon.D.Giorgini@jpl.nasa.gov
   Date: February 5, 2019 at 11:11:58 AM HST
     To: griep@hawaii.edu
Subject: Re: Rec # for Comet 46P/Wirtanen [2018]

David,

The Horizons database record numbers were rescaled yesterday in 
preparation for the catalog count of objects exceeding 1,000,000.

Six-digit record numbers won't be enough once that
occurs, thus the move to 8 digits.

Note that database record numbers are arbitrary and not 
guaranteed to stay the same (except for IAU-numbered asteroids,
where the record number always equals the IAU number, i.e., 
1 Ceres, will always be "record number" 1).

To select the current apparition for a comet, you are "safest" 
to look up with "DES= 46P; CAP;"

... where the CAP; modifier means "closest apparition solution".

This will always work, even as record numbers change as objects 
need to get relocated in the database.

Apologies for any confusion!
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Jon Giorgini                       |  Navigation & Mission Design Section
Senior Analyst                     |  Solar System Dynamics Group
Jon.D.Giorgini@jpl.nasa.gov        |  Jet Propulsion Laboratory
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