De Vaucouleurs Atlas Type: SA(r)ab
Telescope: UH 2.2-m
North up , East left
Field Dimensions: 0.94 x 0.87 arcminutes
RC3 Type: SA(s)b?
RSA Type: -----
Surface Brightness Range Displayed: 16.5-23.5 mag per square arcsec
Absolute Blue Magnitude: -18.1
De Vaucouleurs Atlas Description:
This small object is a rare low luminosity spiral galaxy with a disk only 1-2 kpc in diameter (van den Bergh 1980). It has a very bright inner ring of nonuniform surface brightness, and faint, tightly-wrapped spiral arms. The light patchiness and the tightness of the arms are the basis for the Sab classification.
Using RC3 data and a distance from Tully et al. (1996), the absolute magnitude of NGC 3928 is MB=-18. Taniguchi and Watanabe (1987) show that NGC 3928 has a bulge-to-disk luminosity ratio of ~3, implying a very bulge-dominated system. Thus, the spiral is very low luminosity . These authors argue that NGC 3928 has experienced an accretion event that supplied the gas for star formation in the miniature disk.