NGC 2244 - The Rosette Nebula (CFHT Colors)

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NGC 2244, the Rosette Nebula, mapped Ha/OIII/SII to Red/Green/Blue — a reprocess of the same data set as the Hubble-palette version, using the “CFHT” (Canada-France-Hawaii Telescope) color mapping instead.

Location: Ballauer Observatory near Azle, Texas

Date: November 2005 to January 2006

Equipment: 12.5" RCOS RC on a Software Bisque Paramount ME

Camera: SBIG STL-6303e astro CCD camera

Filters: Custom Scientific 4.5nm Ha, OIII, and SII spectral line filters

Exposure Info: Mapped color mosaic, Ha/OIII/SII, 210:60:90 minutes (left side) and 150:90:90 minutes (right side), 20 and 30 minute subexposures unbinned

Processing Information: Calibration, registration, and DDP in CCDStack. Color mapping, cropping, color balance, levels/curves, sharpening, and noise removal (Astronomy Tools/Pro Digital Software) in Photoshop CS.

Exposure Notes: SII data mapped to the red channel, Ha to green, and OIII to blue. Seeing was exceptional for the left side of the mosaic but poor for the right; interestingly, the left side came out much cleaner than the right despite having less exposure time in Ha.

About this Image

This is the same spectral-line data set as the Hubble-mapped shot, rearranged into the color scheme made known by the Canada-France-Hawaii Telescope, or CFHT. Whereas the Hubble mapping assigns Sulfur to red, Hydrogen to green, and Oxygen to blue, the CFHT mapping simply shifts the channels around: here, reddish areas represent hydrogen gases, greenish areas are oxygen, and bluish areas are sulfur. Mixing gases in the same region blends these into a distinct palette of intermediate colors.

🤖 AI-drafted · unverified

What it is: NGC 2244, the Rosette Nebula, is a large emission nebula surrounding a young open star cluster at its center, shown here reprocessed from the same narrowband data using the "CFHT" SII/Ha/OIII → R/G/B color mapping.
Constellation: Monoceros
Distance: ~5,200 light-years
Apparent magnitude: ~9.0 (cluster); nebula surface brightness is much fainter
Angular size: ~80 × 60 arcminutes
Coordinates: RA 06h 32m, Dec +04° 52′

This summary was generated by an AI assistant from general astronomical references, not from Jay's own notes on this specific image. Treat every detail above as a starting point for research, not settled fact.