<h3><center> NGC 2237/2238<br>The Rosette Nebula</center></h3>

NGC 2237/2238
The Rosette Nebula

Combination of 30, 2 minute exposures.
SBIG ST-8E CCD and wide-band H-alpha filter. 50mm f/2 nikkormat lens.

The Rosette Nebula is a very well known example of an emission nebula surrounding an open cluster. Its photograph has adorned many a book or slide show on astronomy. Situated in Monoceros, it can be an ellusive object unless the skies are very dark. Then it can be observed with as small as a 6" telescope. Low magnification provides the best view as the nebula is quite large.

The nebula has 2 NGC designations, 2237 and 2238. These designate 2 of the brighter regions. The cluster in the middle has its own designation, NGC 2244. In the telescope the cluster appears as 2 parallel lines of stars, shown in the image below. The above image was made in bright moonlight using a wide-band H-alpha filter.

Combination of 24, 5 minute images using an H-alpha filter.
SBIG ST-8E CCD. 5" f/5 refractor at prime focus.

Combination of 6, 3 minute images using an h-alpha filter.
SBIG ST-9E CCD. 16" f/10 schmidt-cassegrain telescope with an f/6.3 focal reducer.

Combination of 5, 3 minute images using an h-alpha filter.
SBIG STL-1001E CCD. 20" f/6.8 Dall-Kirkham cassegrain telescope at prime focus.

Combination of 10 5-minute images with an H-alpha filter, 10, 5 minute images with an SII filter and 17, 5 minute images with an OIII filter.
SBIG STL-1001E CCD. 5" f/5 refractor at prime focus.

The above image was processed using the H-alpha images as the red channel. This is the preferred palette of the European Southern Observatory. The HST observers prefer to use the SII images as the red channel since the SII line is at a slightly longer wavelength than the H-alpha line. This results in a more green-dominated image as shown below.

Same image as above but processed using the HST palette.

1 Combination of 15 1 minute exposures. Modified Canon Digital Rebel DSLR camera.
5" f/5 refractor at prime focus.