KPL/PCK

Asteroid Ceres P_constants (PcK) SPICE kernel file
===========================================================================
 
     By: Boris Semenov (NAIF)    12-OCT-2004
 
 
Organization
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     The sections of this file are as follows.
 
     Introductory Information:
 
         --   Version description
 
         --   Disclaimer
 
         --   Sources
 
     Pck Data:
 
         --   Orientation constants for asteroid Ceres
 
         --   Radii for asteroid Ceres


Version description
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     This file was created on October 12, 2004.
     
     This is a preliminary PCK containing draft values for the pole
     direction, rotation period and shape (from [1] and [2]) and 
     placeholder value for prime meridian.
     
 
Disclaimer
--------------------------------------------------------
 
     This constants file may not contain the parameter values that you
     prefer. Note that this file may be readily modified by you or
     anyone else. NAIF suggests that you inspect this file visually
     before proceeding with any critical or extended data processing.
 
     NAIF requests that you update the ``by line'' and date if you
     modify the file.
 
 
Sources
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     The sources for the constants listed in this file are:
 
        1) Saint-Pe, O., M. Combes, F. Rigaut (1993). Ceres surface 
           properties by high-resolution imaging from Earth. Icarus 105, 
           271-281.

        2) JPL Solar System Dynamic Group Horizon's System.


Orientation constants for asteroid Ceres
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     The inertial reference frame for these constants is J2000; this is
     the default reference frame for PCK orientation data.
 
     The epoch of the constants is J2000; this is Julian ephemeris date
     (JED) 2451545.0.
 
     The NAIF integer code for Ceres is 2000001. See the NAIF_IDs
     required reading for further information on NAIF integer codes.
 
     The pole direction was derived from the following ecliptic equinox
     B1950.0 latitude and longitude values provided in [1]:

        latitude  =  70 deg
        longitude = 332 deg

     The W1 term is derived from the rotation period of 9.075 hours 
     provided in [2]. The W0 term is arbitrarily set to 0.

 
     \begindata
 
        BODY2000001_POLE_RA    = ( 300.4    0.0              0.0 )
        BODY2000001_POLE_DEC   = (  53.1    0.0              0.0 )
        BODY2000001_PM         = (   0.0  952.06611570       0.0 )
 
     \begintext


Radii for asteroid Ceres
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     The radii provided in the keyword below are from [2]. 

     \begindata
 
        BODY2000001_RADII      = ( 475.0  475.0  475.0  )
 
     \begintext