Meathook Galaxy (NGC 2442)
The Meathook Galaxy, or NGC 2442, is an easily recognizable
spiral galaxy with its bright northern arm and starkly contrasting dust lane. In typical spiral galaxy coloration, it has a warm yellow core with blue outer arms speckled with pink clouds of ionized, glowing hydrogen gas associated with star formation. A small, but conspicuous background galaxy is also peeking through just left of the nucleus.
This was an unlikely mosaic. Since late 2006, Hubble has been looking at this galaxy with its Advanced Camera for Surveys and Widefield Camera 3 in bits and pieces, usually involving supernovas and their progenitors. So the telescope looked here and there, but never at the whole galaxy in one sitting. Last year, enough observations had been made to nearly cover the galaxy in 3 channels. I've gathered them up into what I think is a decent result.
If you zoom in, you may notice some areas that have some odd or no coloration near the edges and dark parts. These are places where fewer observations were taken, and I couldn't generate proper or perfectly matching color. I'm glad most of the galaxy was covered, though, because it's really not noticeable. There is a place in the northeast arm right under that dark, dark dust lane where data were completely absent, and I filled it with a brightness-matching blank patch and some fake noise. Two other less obtrusive blank places are in the lower left and lower right corners. There is also a small spot where only older WFPC2 data were available, so it looks a little blurry. Other than that, nice data!
Special thanks to Bill Keel, who freely offered up his data to try and help fill the gaps. I ended up using his H-alpha data in places where there was none available from HST. Mostly the upper half, and a little on the right side. I also removed the stars and galactic nucleus from his data, leaving (hopefully) just the star-forming regions.
Data from the following proposals were used to create this image:
Red: ACS/WFC F814W + ACS/WFC F658N + SARA H-alpha + WFPC2 F814W
Green: WFC3/UVIS F555W + WFPC2 F606W
Blue: WFC3/UVIS F438W + ACS/WFC F435W
North is 18.10° counter-clockwise from up.