Content 
                     asteroid: 2005 PR_21
                   satellites: companion 
                 total number: 1  
                         type: position
                        dates: 2007-2007 
                  observatory: 250 - Hubble Space Telescope
                   
Reference.
Noll, K. S.; Grundy, W. M.; Kern, S. D.; Levison, H. F.; Stephens, D. C.
2001 QQ_322 and 2005 PR_21
IAUC 8925, 2008
2008IAUC.8925....2N

Informations.
                  relative to: the primary
              reference frame: astrometric ICRF 
              centre of frame: topocentric 
             epoch of equinox: J2000 
                   time scale: UTC 
                    reduction: no information
                  coordinates: relatives Delta(RA), Delta(Decl) 
             diff. refraction: no information 
                     receptor: 
                    telescope: Wide Field Planetary Camera 2

Comments. The observations were made during 2007 May 10.5156-10.6019 UT 
          We used the average time from this interval   

Format.                                       
 1. Year of the moment of observation 
 2. Month of the moment of observation  
 3. Day of the moment of observation 
 4. Delta(RA) - relative right ascension, arcsec
 5. SigX - the error of Delta(RA) , arcsec
 6. Delta(Decl) - relative declination, arcsec 
 7. SigY - the error of Delta(Decl), arcsec
                          
-------------------------------------------------------------
Year       Day      Delta(RA) Sig X    Delta(Decl)   Sig Y    
     Month          arcsec    arcsec     arcsec      arcsec  
-------------------------------------------------------------