KPL/PCK

Asteroid Bennu P_constants (PcK) SPICE kernel file
===========================================================================
 
   By: Boris Semenov (NAIF)    04-NOV-2014
 
 
Version and Date
--------------------------------------------------------
 
   This file was created on November 4, 2014.
 
   This is the first Bennu PCK released for official use by OSIRIS-Rex
   project. It contains values for the pole direction, rotation period
   and shape from [1].
     
 
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
--------------------------------------------------------
 
   The sources for the constants listed in this version of this file
   are:
 
     1) (101955) Bennu Design Reference Asteroid, 
        Document Number: OREX-XLSX-04.00-00001, Rev_10,
        Version: 2014 October 10
        (OREX-XLSX-04.00-00001_Rev_10_Bennu_DRA_Final.xlsx)


Orientation constants for asteroid Bennu
--------------------------------------------------------
 
   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 Bennu is 2101955. See the NAIF_IDs
   required reading for further information on NAIF integer codes.
 
   The pole direction, prime meridian location, rotation period and
   radii in this version are set to the following values from [1]:

       "
        2.1.2  Polar Dimension               508                   meters

        2.1.3  Equatorial Dimensions         565 x 535             meters

        3.1.1  Rotation Period               4.297461              hours

        3.1.6  Pole Position (J200 RA/DEC)   (+86.6388, -65.1086)  deg

        3.1.7  Location of Prime Meridian    89.6456               deg
               (epoch J2000)
       "

   These Bennu orientation and size constants are provided in the
   keywords below. The rotation rate (W1) was derived from the period
   and is provided in degrees/day. The radii are 1/2s of the polar and
   equatorial dimensions provided in kilometers.

   The LONG_AXIS keyword providing the offset between the longest axis
   of the triaxial ellipsoid used to model Bennu and the Bennu prime
   meridian is not used by SPICE geometry software. It is considered 
   deprecated and provided solely for backwards compatibility.

      \begindata
 
         BODY2101955_POLE_RA    = (  86.6388       0.              0. )
         BODY2101955_POLE_DEC   = ( -65.1086       0.              0. )
         BODY2101955_PM         = (  89.6456    2010.4894494679531 0. )
         BODY2101955_LONG_AXIS  = (   0.                              )

         BODY2101955_RADII      = (   0.2825       0.2675       0.254 )
 
      \begintext

End of PCK file.