De Vaucouleurs Atlas Type: SB(rs)bc
Telescope: UH 2.2-m
North up , East left
Field Dimensions: 7.5 x 6.8 arcminutes
RC3 Type: SB(rs)bc
RSA Type: SBb(rs)I
Surface Brightness Range Displayed: 18.5-26.0 mag per square arcsec
Absolute Blue Magnitude: -21.1
Elmegreen Spiral Arm Class: AC 9
De Vaucouleurs Atlas Description:
This is a very fine example of the type. The bar is well-defined and appears to have a symmetric pattern of dust patches, rather than leading dust lanes . Two of the main arms begin slightly offset from the bar axis, and these define only a partial inner pseudoring . We use the underline to emphasize its weakness. In the deprojected image, the inner ring has a relatively circular shape, and although it is weak, it is still worth recognizing. There are four major outer spiral arms, but the pattern is not as regular as that seen in ESO 566-24 . At least two more secondary spiral arcs are also present among the main arms.
The color index map reveals the complete lack of star formation in the bar region of NGC 3992 . Instead, a complex dust pattern is seen that could represent disorganized leading dust lanes as well as asymmetry caused by tilt.
NGC 3992 has been the subject of a dynamical study by the Florida group (Hunter et al. 1988; Hunter and Gottesman 1996).