NGC 4608 - SB(r)0/a

NGC 4608

De Vaucouleurs Atlas Type: SB(r)0/a

Filter: B

Telescope: NOT 2.5-m
North up , East left
Field Dimensions: 5.3 x 3.9 arcminutes

RC3 Type: SB(r)0o
RSA Type: SB03/a
Surface Brightness Range Displayed: 17.5-27.0 mag per square arcsec
Absolute Blue Magnitude: -19.2

De Vaucouleurs Atlas Description:

The bar is very well-defined in this galaxy. Surrounding the bar is an inner ring defined mainly by a sharp inner edge. The outer edge of the ring is barely distinguishable from the surrounding disk light. Weak spiral features are detectable in the outer disk.

Based on two-dimensional photometric decomposition, Gadotti and de Souza (2003) concluded that NGC 4608 is an example of a strongly-barred galaxy without a disk. This is unusual because it was thought that bars can only form in disks (e.g., Kormendy 1982). However, Laurikainen, Salo, and Buta (2005) find independently that NGC 4608 has a small bulge and a disk that is exponential outside the bar, and non-exponential in the bar region.

The B-V color index map shows that the bar has an old stellar population and that there is little or no recent star formation in the outer disk.