THE ASTRONOMICAL JOURNAL    VOLUME 108, NUMBER 3, PAGE 896       SEPTEMBER 1994

ARM STRUCTURE IN NORMAL SPIRAL GALAXIES. I. MULTIVARIATE DATA FOR 492 GALAXIES

                               CHRISTOPHER MAGRI

     Department of Astronomy and National Astronomy and Ionosphere Center,
                  Cornell University, Ithaca, New York 14853


                                   ABSTRACT
    
    Multivariate data have been collected as part of an effort to develop a
    new classification system for spiral galaxies, one which is not
    necessarily based on subjective morphological properties.  A sample of
    492 moderately bright northern Sa and Sc spirals was chosen for future
    statistical analysis.  New observations were made at 20 and 21 cm; the
    latter data are described in detail here.  IRAS fluxes were obtained
    from archival data.  Finally, new estimates of arm pattern randomness
    and of local environmental harshness were compiled for most sample
    objects.