NGC 2237: Rosette Nebula (Broadband and Narrowband combination)

18 January 2023

I always wanted to enhance the image of the Rosette Nebula from December '22 with dedicated oxygen-3 and h-alpha data. But it took more than a month to get another usable clear night.

To compose the final image, I did not reprocess the broadband data but instead took the starless and stars partial results as a starting point. Then I combined the starless broadband image and the red and green channels of the starless narrowband image into a starless version with enhanced colors using pixelmath. After some (masked) curve adjustments, I reinserted the broadband stars to get the final result.

Here are some 100% cutouts for better comparison: