Peering deep into a neighboring galaxy is routine fare for dedicated astrophotographers these days. It's quite common to see a colorful image of M31 or M101 with cumulative exposures totaling a few dozen hours, revealing extensive spiral arms, star-forming regions, and even individual stars. But sometimes an image stands out from the crowd. Such is the case with this exceedingly deep, high-resolution mosaic of the Large Magellanic Cloud.
The image, compiled by a team of French amateur astronomers calling themselves Ciel Austral, represents the culmination of more than a half-year's work using their remotely operated Telescope Engineering Company TEC 160 and Morovian G4-16000 CCD camera at the El Sauce Observatory hosted by Obstech in the Rio Hurtado Valley in Chile.
The Ciel Austral team (Jean Claude Canonne, Philippe Bernhard, Didier Chaplain, Nicolas Outters, and Laurent Bourgon) targeted the Large Magellanic Cloud over the course of seven months between July 2017 and January, 2019, accumulating a 16-panel mosaic through color and narrowband filters. In the end, the image incorporates 1,060 hours of exposure, revealing the faintest wisps of nebulosity in the galaxy at 1.66 arcseconds per pixel. The image shows that starbirth and stardeath are rife in our neighboring galaxy, revealing dozens of supernova remnants, planetary nebulae, and star-forming regions in unprecedented detail. Visit the group's website to see the image presented in both narrowband (using the descending-wavelength Hubble palette) and enhanced-color versions assembled with red, green, and blue-filtered images as well as hydrogen-alpha data.
Processing a large color mosaic is quite a challenge that requires some heavy computing power. Including calibration frames, the data amounts to 620 gigabytes, larger than most hard drives on a typical laptop computer. Image calibration, mosaic assembly, and final processing took another three months of work, but I'm sure you'll agree that the final, jaw-dropping result was worth all the effort.