Two-color CCD mapping of the luminous type I irregular galaxy NGC 4449.

The author presents two color (B-R) difference maps of NGC 4449. The dispersion in (B-R) is indicative of a mixture of stellar populations of differing ages. Moreover, examination of the structure of NGC 4449 as a function of (B-R) color reveals that the locus of present-day star formation is occurring in a highly flattened and connected configuration. Embedded within the main body of NGC 4449 are 150 - 200 blue, resolved images, which the author identifies as OB associations. Distributed outside of the main body is a small population of globular clusters. Assuming a cluster luminosity function similar to our galaxy's yields a distance modulus of 27.3±0.1 to NGC 4449.