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MICHIGAN: Two-dimensional spectral types for HD stars(IV)


Table name:     Michigan
Records:        33301                                                          
Spectral Band:  OPT,Photo                                                     
Kind of Object: HD-Star                                                      
Mode:           Spectroscopy,Objective-Prism 
Coordinates:    J2000                                                           



This catalogue is part of a program of systematic reclassification of the Henry Draper stars on the MK system and contains all HD stars between dec = -26.0 and -12.0 degrees. The stars were classified visualy on objective-prism plates taken with the Michigan Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory. The 4 + 6 degrees prisms yield a dispersion at Hgamma of 108 Angstrom/mm, and the resolution is about 2 Angstrom/mm, comparable to that of the original MK system. The spectra were taken on IIaO plates and widened to 0.8 mm, with 20 min, 4min, 1min exposures being obtained. The high quality of the spectra is illustrated in 'An Atlas of Objective-Prism Spectra' by N.Houk, N.J. Irvine and D. Rosenbush and 'A Second Atlas of Objective-Prism Spectra' by Nancy Houk and Michael V. Newberry. In order to mantain a uniform, consistent system, all the spectra classification was done by one person(NH). Over 170 standard stars were used. Of the 33301 stars in the catalogue, 32563 (98%) were classifiable. Internal classification errors were obtained using the stars classified independently on more than one plate. Both internal and external errors are similar to those usually obtained in the classification of slit spectra. 15% of the stars have remarks giving futher information. (See also the R_MICHIGAN catalogue.)


Name           Meaning                                                    

HD             HD number                                                  
pmag           Photographic magnitude                                     
pecul          Flag about peculiarity                                     
sp             Spectral type                                              
others         + means that the sp is taken from another source           
qur            Quality and Remarks code                                   
               Quality: 1 (best) to 4 (worst)                             
               Remarks code: B,L,O,R,D                                    
var            V means that the star is variable                          
remark         Remark from the r_michigan catalogue                       
ra_ori         Right ascension: epoch 1900.0                              
dec_ori        Declination:     epoch 1900.0                              
lii_ori        Galactic longitude (integer 2 bytes)                       
bii_ori        Galactic latitude (integer 2 bytes)                        
ra             Right ascension: epoch 2000.0                              
dec            Declination:     epoch 2000.0                              
lii            Galactic longitude (integer 4 bytes)                       
bii            Galactic latitude (integer 4 bytes)                        
prc_ra         100 years Precession in (alp)                              
prc_dec        100 years Precession in (del)                              
DM             DM number                                                  
SAO            SAO number                                                 
plate          Plate codes                                                


Further information about 5144 stars is given in the 'remark' field (taken from the r_michigan catalogue). The kind of information that one can find in this field is indicated in the 'qur' field: