NGC 2244 CFHT Mapped

Other image sizes:

2400 x 1850 pixels (h-alpha only)

MAPPED COLOR - Ha/OIII/SII LIGHT

NGC 2244 - THE ROSETTE NEBULA in "CFHT" COLORS
Red = Ha, Green = OIII, Blue = SII
2 frame MOSAIC

About this Image:

This is an attempt to take spectral line emission data as the HST mapped shot (see <here>) and rearrange the color channels in a technique made known by the Canada-France-Hawail Telescope, or CFHT. Whereas the Hubble "maps" the same data set with Sulfur as Red, Hydrogen as Green, and Oxygen as Blue, the CFHT mapping simply switches the channels around.

Therefore, in the image above, reddish areas represent Hydrogen gases, greenish areas are Oxygen, and bluish areas are bluish. Of course when you mix gases in the same area, the colors also mix to form a distinct "palette" of colors.

For NGC 2244 mapped to "Hubble" colors, click <here>
For NGC 2244 in regular RGB, click <here>

Location: Ballauer Observatory near Azle, Texas and Date: November, 2005 to January 2006
Seeing: Varied
Transparency: Varied
Scope/Mount: 12.5" RCOS RC and 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 for left side and 150:90:90 minutes for 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: The SII data is 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. Interesting to note that despite similar conditions, the left side is much cleaner than the right side despite having less exposure time in Ha.