M-27 A Study in Narrow Band Imaging

The first image is an overstretched view of the H-alpha shot alone just to show the remarkable amount of faint outer structure which is present in M-27. Longer exposures would really capture this well, and some amateurs and pros have already done this. When you're done reading this page, maybe you would like to see a really deep shot of M-27? Do a web search on the term "M27 Hubble".

The second image is a color combination of the three bands as follows: Ha=RED SII=BLUE OIII=GREEN This image is lovely, though only represents the elements by pseudo color. Red is hydrogen, but the colors of SII and OIII have been swapped.

The third image is the same as the second but with slight color modifications to equalize the color balance.

The forth image is a color combination of the three bands as follows: Ha=RED SII=GREEN OIII=BLUE This one almost represents reality, if your eyes could only see such faint objects with color.

The fifth and last image is a color combination of the three bands in what is commonly called the Hubble color sequence. This is when the colors have been mapped as Ha=GREEN OIII=BLUE SII=RED. Ok - no reality here... but, scientists and illustrators have noted that using this color map with other nebulae has resulted in an interesting three dimensional effect which is pleasing to the eye. The next time you see an image of the "Pillars of Creation" taken by the Hubble team, note that the blue looks like a background glow. Humans are trained to see blue haze as a distance phenomena. Interesting!

Image details: all filtered images were 10 minutes in duration at -15C by the light of a near full Moon. Yuk. The backgrounds are a little on the bright side to show the fainter nebulosity at the edges of M-27. Color combination was done in Adobe Photoshop with FITS Liberator for import. Flats, darks, and bias frames were used to clean up the images prior to combination.

Ok - off to the search engine with you: to search for "M27 Hubble".