THE CIRCUMSTANCES OF MINOR PLANET DISCOVERY                   
                                                                                
                              Frederick Pilcher                                 
                               Illinois College                                 
                         Jacksonville, IL 62650 USA                             
                                                                                
     This tabulation of minor planet discovery data for the first 3774 numbered 
minor planets was originally prepared in machine-readable form for NSSDC.  This 
version has been updated by the author to include subsequently numbered         
planets.                                                                        
                                                                                
     The first column contains the permanent number; the second, the official   
name; the third, for planets 330 and forward, the provisional designation       
attached to the discovery apparition; the fourth, the year, month, and day of   
discovery according to criteria explained below; the fifth, the name of the     
discoverer, discoverers, or institution of discovery; the sixth, the discovery  
place.  The seventh column is used when needed for notes referencing two or     
more discoverers with names of combined length too great to fit in the          
discoverer column, to give a more complete description of programs involving    
several persons, and to reference cases in which two numbered planets were      
subsequently discovered to be identical and the number and name of one of       
these was re-assigned to a newly discovered planet.  Notes in the last column   
(see end of table) have also been used to reference conflicting discovery       
claims and list important independent discoveries which are no longer regarded  
as official.                                                                    
                                                                                
     The discovery date is in local mean time prior to 1 January 1925, and in   
UT thereafter, and refers to the time of mid-exposure for planets discovered    
by photographic means.  In many cases, the permanent number was assigned only   
when several unnumbered planets observed in different years were found to be    
identical, often many years after the discovery photographs were made.  In      
these cases, the discovery date is the first of that series of photograhic      
observations from which the preliminary orbit was computed, and the provisional 
designation is that associated with this particular set of observations. Often  
earlier observations exist, but they are considered prediscoveries.  In some    
cases the discovery and subsequent observations permitted images to be found    
on photographs obtained at the same observatory earlier in the discovery        
apparition; these earlier observations are considered prediscoveries.           
     The following literature has been examined comprehensively to              
determine the discovery data.                                                   
                                                                                
STRACKE, G., Identifizierungsnachweis der Kleinen Planeten (Berlin, 1938);      
HERGET, P., Names of Minor Planets (University of Cincinnati Observatory,       
  1957, 1967);                                                                  
Astronomische Nachrichten;                                                      
Astronomische Nachrichten Indices;                                              
Monthly Notices of the Royal Astronomical Society;                              
Rechen-Institute Circulars;                                                     
Beobachtungs Zircular;                                                          
Minor Planet Circulars;                                                         
Lick Research Surveys on Minor Planets;                                         
Turku Informo.                                                                  
                                                                                
     Acknowledgments.  The author wishes to thank the following people for      
valuable contributions to this work.  B. G. Marsden has arduously searched the  
literature, resolved various errors and discrepancies; and has passed judgment  
on conflicting discovery claims.  J. Meeus and M. Combes have prepared an       
earlier list of discovery data from which the present list was adapted and      
expanded, and K. Kelly has proofread the material and provided continuing       
advice and counsel.