This image was created from HST data from proposal 11807: M. Livio, Z. Levay, M. Mutchler, L. Frattare, and D. Taylor (STScI). Additional image processing by A. Bowers and B. Ferguson (STScI).
F502N ([O III]), F656N (H-alpha), F673N ([S II]), and F606W (V)
The image is a composite of separate exposures made by the WFPC2 instrument on the Hubble Space Telescope. Three filters were used to sample narrow wavelength ranges matching the emission of specific chemical elements. One filter was used to sample a broad wavelength randge in the visible. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
Blue: F502N ([O III])
Green: F656N (H-alpha)
Maroon: F673N ([S II])
White: F606W (V)