This image was created from HST data from proposal 10424:
H. Richer (University of British Columbia), P. Guhathakurta (University of California, Santa Cruz), R.M. Rich (University of California, Los Angeles), J. Anderson (STScI), G. Fahlman (NRC Herzberg Institute of Astrophysics/National Research Council Canada, Saanich, British Columbia), B. Gibson (Swineburne University of Technology, Australia), B. Hansen (University of California, Los Angeles), J. Hurley (Swinburne University of Technology, Australia), J. Kalirai (University of California, Santa Cruz), I. King (University of Washington, Seattle), M. Shara (American Museum of Natural History), and P. Stetson (National Research Council/Herzberg Institute of Astrophysics, Canada).
The science team comprises: H. Richer (University of British Columbia), I. King (University of Washington, Seattle), J. Anderson (STScI), J. Coffey (University of British Columbia, Vancouver), G. Fahlman (Herzberg Institute of Astrophysics/National Research Institute of Canada, British Columbia), J. Hurley (Swinburne University of Technology, Australia), and J. Kalirai (University of California, Santa Cruz).
These HST images are composites of many separate exposures made by the ACS instrument on the Hubble Space Telescope using several different filters. Three filters sample broad wavelength ranges, one isolates the light of hydrogen. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
