5.5. Systems With Peculiar or Complex Nuclei (Plates XXV-XXVII)
A phenomenon has been observed that appears to be fairly common in S and B galaxies in categories "f" and "fg." The nuclear region can consist of an extremely brilliant, small nucleus superposed on a considerably fainter background (NGC 4051), or it may be made up of multiple "hot spots" (NGC 5248, 1808, 4321, and 3351). Of somewhat similar nature, but in population category "gk," is NGC 4151 (Plate XXVII).
A catalogue of the new galactic types is given for 608 systems in Table I. An asterisk in the first column refers to a note at the end of the table. The last column lists the types determined by Hubble as given by Humason, Mayall, and Sandage; (2) the types for NGC 134, 3990, and 4256 were determined by Sandage on the system as defined by Hubble.