Merging Group Arp 194
These galaxies were imaged with Hubble's old WFPC2 instrument with three filters, and 8 exposures for each filter. The goal was to reach a quality approaching that of the newer Advanced Camera for Surveys (ACS). According to the proposal abstract they were running out of good images to share while waiting for some astronauts to get up there and service the telescope. Tense times at the office of public outreach, eh?
These observations were subsequently used for Hubble's 19th Anniversary image. Hubble's 28th anniversary is coming up next month. What wonders await? It seems like just a short while ago last year's anniversary came. Oh, how the years creep by, almost unnoticed...
As is usual with spiral galaxies, the blue areas represent areas of either younger stars, active star formation, or both. Whiter and yellowish areas are where older stars reside. In this case, H-alpha emission, which is closely associated with star formation, has taken on a blue-green color, and some of the larger emission nebulas stand out in slightly greener hues. These clouds are typically presented in pink colors with traditional astrophotography, but because a near-infrared filter was used, the colors were shifted a bit, making them appear turquoise in this image.
Data from the following proposal were used to create this image:
During processing, I scaled the image by 200%. The color saturation is greatly enhanced.
Red: WFPC2 / WF F814W
Green: WFPC2 / WF F606W
Blue: WFPC2 / WF F450W
North is NOT up. It is 35.18° counter-clockwise from up.