NGC 4449 - IB(s)m

NGC 4449

De Vaucouleurs Atlas Type: IB(s)m

Filter: B

Telescope: KPNO 4-m
North up , East left
Field Dimensions: 8.8 x 6.7 arcminutes

RC3 Type: IBm
RSA Type: SmIV
Surface Brightness Range Displayed: 17.5-26.0 mag per square arcsec
Absolute Blue Magnitude: -18.3

De Vaucouleurs Atlas Description:

NGC 4449 is an excellent example of its type. The Im classification is justified from the appearance at high surface brightness levels; the bright inner parts were all that were seen in old photographs. In the Atlas image here, a bright, boxy-shaped outer disk is also seen. There is a clear bar in the inner regions with a bright nucleus. The bar shows scattered dust patches, and is surrounded by highly resolved regions of star formation. The B-V color index map shows that the resolved stellar sources include a mix of red and blue supergiants. The nucleus was bright enough to be saturated in the V-band image, and its color in the map is not reliable. The (s) classification recognizes weak spiral features breaking from near the ends of the bar.