NGC 891 - Sb sp

NGC 891

De Vaucouleurs Atlas Type: Sb sp

Filter: B

Telescope: WIYN 3.5-m
North up , East left
Field Dimensions: 6.5 x 6.2 arcminutes

RC3 Type: SA:(s?)b sp
RSA Type: Sb on edge
Surface Brightness Range Displayed: 21.0-26.0 mag per square arcsec
Absolute Blue Magnitude: -20.5

De Vaucouleurs Atlas Description:

Only the inner part of this famous edge-on spiral is shown in our Atlas images. The planar dust lane shows a great deal of detail in the form of what appear to be hundreds of fine dust filaments emanating above and below the main dust disk. As discussed by Howk and Savage (1997), these extraplanar dust filaments can be followed to as far as 2kpc away from the midplane of the dust layer. The B-V color index map shows that virtually all of these filaments are red, but the main dust layer is blue as in NGC 4013 . Some of this blue color is due to direct starlight from young associations in low extinction areas, while the rest is likely to be scattered blue starlight. The bulge of NGC 891 is visible as a boxy feature, and may signify the presence of a bar.